drivers/tty/serial/fsl_lpuart.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  Freescale lpuart serial port driver
   4  *
   5  *  Copyright 2012-2014 Freescale Semiconductor, Inc.
   6  */
   7
   8 #if defined(CONFIG_SERIAL_FSL_LPUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
   9 #define SUPPORT_SYSRQ
  10 #endif
  11
  12 #include <linux/clk.h>
  13 #include <linux/console.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/dmapool.h>
  17 #include <linux/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/of_dma.h>
  23 #include <linux/serial_core.h>
  24 #include <linux/slab.h>
  25 #include <linux/tty_flip.h>
  26
  27 /* All registers are 8-bit width */
  28 #define UARTBDH                 0x00
  29 #define UARTBDL                 0x01
  30 #define UARTCR1                 0x02
  31 #define UARTCR2                 0x03
  32 #define UARTSR1                 0x04
  33 #define UARTCR3                 0x06
  34 #define UARTDR                  0x07
  35 #define UARTCR4                 0x0a
  36 #define UARTCR5                 0x0b
  37 #define UARTMODEM               0x0d
  38 #define UARTPFIFO               0x10
  39 #define UARTCFIFO               0x11
  40 #define UARTSFIFO               0x12
  41 #define UARTTWFIFO              0x13
  42 #define UARTTCFIFO              0x14
  43 #define UARTRWFIFO              0x15
  44
  45 #define UARTBDH_LBKDIE          0x80
  46 #define UARTBDH_RXEDGIE         0x40
  47 #define UARTBDH_SBR_MASK        0x1f
  48
  49 #define UARTCR1_LOOPS           0x80
  50 #define UARTCR1_RSRC            0x20
  51 #define UARTCR1_M               0x10
  52 #define UARTCR1_WAKE            0x08
  53 #define UARTCR1_ILT             0x04
  54 #define UARTCR1_PE              0x02
  55 #define UARTCR1_PT              0x01
  56
  57 #define UARTCR2_TIE             0x80
  58 #define UARTCR2_TCIE            0x40
  59 #define UARTCR2_RIE             0x20
  60 #define UARTCR2_ILIE            0x10
  61 #define UARTCR2_TE              0x08
  62 #define UARTCR2_RE              0x04
  63 #define UARTCR2_RWU             0x02
  64 #define UARTCR2_SBK             0x01
  65
  66 #define UARTSR1_TDRE            0x80
  67 #define UARTSR1_TC              0x40
  68 #define UARTSR1_RDRF            0x20
  69 #define UARTSR1_IDLE            0x10
  70 #define UARTSR1_OR              0x08
  71 #define UARTSR1_NF              0x04
  72 #define UARTSR1_FE              0x02
  73 #define UARTSR1_PE              0x01
  74
  75 #define UARTCR3_R8              0x80
  76 #define UARTCR3_T8              0x40
  77 #define UARTCR3_TXDIR           0x20
  78 #define UARTCR3_TXINV           0x10
  79 #define UARTCR3_ORIE            0x08
  80 #define UARTCR3_NEIE            0x04
  81 #define UARTCR3_FEIE            0x02
  82 #define UARTCR3_PEIE            0x01
  83
  84 #define UARTCR4_MAEN1           0x80
  85 #define UARTCR4_MAEN2           0x40
  86 #define UARTCR4_M10             0x20
  87 #define UARTCR4_BRFA_MASK       0x1f
  88 #define UARTCR4_BRFA_OFF        0
  89
  90 #define UARTCR5_TDMAS           0x80
  91 #define UARTCR5_RDMAS           0x20
  92
  93 #define UARTMODEM_RXRTSE        0x08
  94 #define UARTMODEM_TXRTSPOL      0x04
  95 #define UARTMODEM_TXRTSE        0x02
  96 #define UARTMODEM_TXCTSE        0x01
  97
  98 #define UARTPFIFO_TXFE          0x80
  99 #define UARTPFIFO_FIFOSIZE_MASK 0x7
 100 #define UARTPFIFO_TXSIZE_OFF    4
 101 #define UARTPFIFO_RXFE          0x08
 102 #define UARTPFIFO_RXSIZE_OFF    0
 103
 104 #define UARTCFIFO_TXFLUSH       0x80
 105 #define UARTCFIFO_RXFLUSH       0x40
 106 #define UARTCFIFO_RXOFE         0x04
 107 #define UARTCFIFO_TXOFE         0x02
 108 #define UARTCFIFO_RXUFE         0x01
 109
 110 #define UARTSFIFO_TXEMPT        0x80
 111 #define UARTSFIFO_RXEMPT        0x40
 112 #define UARTSFIFO_RXOF          0x04
 113 #define UARTSFIFO_TXOF          0x02
 114 #define UARTSFIFO_RXUF          0x01
 115
 116 /* 32-bit register definition */
 117 #define UARTBAUD                0x00
 118 #define UARTSTAT                0x04
 119 #define UARTCTRL                0x08
 120 #define UARTDATA                0x0C
 121 #define UARTMATCH               0x10
 122 #define UARTMODIR               0x14
 123 #define UARTFIFO                0x18
 124 #define UARTWATER               0x1c
 125
 126 #define UARTBAUD_MAEN1          0x80000000
 127 #define UARTBAUD_MAEN2          0x40000000
 128 #define UARTBAUD_M10            0x20000000
 129 #define UARTBAUD_TDMAE          0x00800000
 130 #define UARTBAUD_RDMAE          0x00200000
 131 #define UARTBAUD_MATCFG         0x00400000
 132 #define UARTBAUD_BOTHEDGE       0x00020000
 133 #define UARTBAUD_RESYNCDIS      0x00010000
 134 #define UARTBAUD_LBKDIE         0x00008000
 135 #define UARTBAUD_RXEDGIE        0x00004000
 136 #define UARTBAUD_SBNS           0x00002000
 137 #define UARTBAUD_SBR            0x00000000
 138 #define UARTBAUD_SBR_MASK       0x1fff
 139 #define UARTBAUD_OSR_MASK       0x1f
 140 #define UARTBAUD_OSR_SHIFT      24
 141
 142 #define UARTSTAT_LBKDIF         0x80000000
 143 #define UARTSTAT_RXEDGIF        0x40000000
 144 #define UARTSTAT_MSBF           0x20000000
 145 #define UARTSTAT_RXINV          0x10000000
 146 #define UARTSTAT_RWUID          0x08000000
 147 #define UARTSTAT_BRK13          0x04000000
 148 #define UARTSTAT_LBKDE          0x02000000
 149 #define UARTSTAT_RAF            0x01000000
 150 #define UARTSTAT_TDRE           0x00800000
 151 #define UARTSTAT_TC             0x00400000
 152 #define UARTSTAT_RDRF           0x00200000
 153 #define UARTSTAT_IDLE           0x00100000
 154 #define UARTSTAT_OR             0x00080000
 155 #define UARTSTAT_NF             0x00040000
 156 #define UARTSTAT_FE             0x00020000
 157 #define UARTSTAT_PE             0x00010000
 158 #define UARTSTAT_MA1F           0x00008000
 159 #define UARTSTAT_M21F           0x00004000
 160
 161 #define UARTCTRL_R8T9           0x80000000
 162 #define UARTCTRL_R9T8           0x40000000
 163 #define UARTCTRL_TXDIR          0x20000000
 164 #define UARTCTRL_TXINV          0x10000000
 165 #define UARTCTRL_ORIE           0x08000000
 166 #define UARTCTRL_NEIE           0x04000000
 167 #define UARTCTRL_FEIE           0x02000000
 168 #define UARTCTRL_PEIE           0x01000000
 169 #define UARTCTRL_TIE            0x00800000
 170 #define UARTCTRL_TCIE           0x00400000
 171 #define UARTCTRL_RIE            0x00200000
 172 #define UARTCTRL_ILIE           0x00100000
 173 #define UARTCTRL_TE             0x00080000
 174 #define UARTCTRL_RE             0x00040000
 175 #define UARTCTRL_RWU            0x00020000
 176 #define UARTCTRL_SBK            0x00010000
 177 #define UARTCTRL_MA1IE          0x00008000
 178 #define UARTCTRL_MA2IE          0x00004000
 179 #define UARTCTRL_IDLECFG        0x00000100
 180 #define UARTCTRL_LOOPS          0x00000080
 181 #define UARTCTRL_DOZEEN         0x00000040
 182 #define UARTCTRL_RSRC           0x00000020
 183 #define UARTCTRL_M              0x00000010
 184 #define UARTCTRL_WAKE           0x00000008
 185 #define UARTCTRL_ILT            0x00000004
 186 #define UARTCTRL_PE             0x00000002
 187 #define UARTCTRL_PT             0x00000001
 188
 189 #define UARTDATA_NOISY          0x00008000
 190 #define UARTDATA_PARITYE        0x00004000
 191 #define UARTDATA_FRETSC         0x00002000
 192 #define UARTDATA_RXEMPT         0x00001000
 193 #define UARTDATA_IDLINE         0x00000800
 194 #define UARTDATA_MASK           0x3ff
 195
 196 #define UARTMODIR_IREN          0x00020000
 197 #define UARTMODIR_TXCTSSRC      0x00000020
 198 #define UARTMODIR_TXCTSC        0x00000010
 199 #define UARTMODIR_RXRTSE        0x00000008
 200 #define UARTMODIR_TXRTSPOL      0x00000004
 201 #define UARTMODIR_TXRTSE        0x00000002
 202 #define UARTMODIR_TXCTSE        0x00000001
 203
 204 #define UARTFIFO_TXEMPT         0x00800000
 205 #define UARTFIFO_RXEMPT         0x00400000
 206 #define UARTFIFO_TXOF           0x00020000
 207 #define UARTFIFO_RXUF           0x00010000
 208 #define UARTFIFO_TXFLUSH        0x00008000
 209 #define UARTFIFO_RXFLUSH        0x00004000
 210 #define UARTFIFO_TXOFE          0x00000200
 211 #define UARTFIFO_RXUFE          0x00000100
 212 #define UARTFIFO_TXFE           0x00000080
 213 #define UARTFIFO_FIFOSIZE_MASK  0x7
 214 #define UARTFIFO_TXSIZE_OFF     4
 215 #define UARTFIFO_RXFE           0x00000008
 216 #define UARTFIFO_RXSIZE_OFF     0
 217
 218 #define UARTWATER_COUNT_MASK    0xff
 219 #define UARTWATER_TXCNT_OFF     8
 220 #define UARTWATER_RXCNT_OFF     24
 221 #define UARTWATER_WATER_MASK    0xff
 222 #define UARTWATER_TXWATER_OFF   0
 223 #define UARTWATER_RXWATER_OFF   16
 224
 225 /* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
 226 #define DMA_RX_TIMEOUT          (10)
 227
 228 #define DRIVER_NAME     "fsl-lpuart"
 229 #define DEV_NAME        "ttyLP"
 230 #define UART_NR         6
 231
 232 /* IMX lpuart has four extra unused regs located at the beginning */
 233 #define IMX_REG_OFF     0x10
 234
 235 struct lpuart_port {
 236         struct uart_port        port;
 237         struct clk              *clk;
 238         unsigned int            txfifo_size;
 239         unsigned int            rxfifo_size;
 240
 241         bool                    lpuart_dma_tx_use;
 242         bool                    lpuart_dma_rx_use;
 243         struct dma_chan         *dma_tx_chan;
 244         struct dma_chan         *dma_rx_chan;
 245         struct dma_async_tx_descriptor  *dma_tx_desc;
 246         struct dma_async_tx_descriptor  *dma_rx_desc;
 247         dma_cookie_t            dma_tx_cookie;
 248         dma_cookie_t            dma_rx_cookie;
 249         unsigned int            dma_tx_bytes;
 250         unsigned int            dma_rx_bytes;
 251         bool                    dma_tx_in_progress;
 252         unsigned int            dma_rx_timeout;
 253         struct timer_list       lpuart_timer;
 254         struct scatterlist      rx_sgl, tx_sgl[2];
 255         struct circ_buf         rx_ring;
 256         int                     rx_dma_rng_buf_len;
 257         unsigned int            dma_tx_nents;
 258         wait_queue_head_t       dma_wait;
 259 };
 260
 261 struct lpuart_soc_data {
 262         char    iotype;
 263         u8      reg_off;
 264 };
 265
 266 static const struct lpuart_soc_data vf_data = {
 267         .iotype = UPIO_MEM,
 268 };
 269
 270 static const struct lpuart_soc_data ls_data = {
 271         .iotype = UPIO_MEM32BE,
 272 };
 273
 274 static struct lpuart_soc_data imx_data = {
 275         .iotype = UPIO_MEM32,
 276         .reg_off = IMX_REG_OFF,
 277 };
 278
 279 static const struct of_device_id lpuart_dt_ids[] = {
 280         { .compatible = "fsl,vf610-lpuart",     .data = &vf_data, },
 281         { .compatible = "fsl,ls1021a-lpuart",   .data = &ls_data, },
 282         { .compatible = "fsl,imx7ulp-lpuart",   .data = &imx_data, },
 283         { /* sentinel */ }
 284 };
 285 MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
 286
 287 /* Forward declare this for the dma callbacks*/
 288 static void lpuart_dma_tx_complete(void *arg);
 289
 290 static inline u32 lpuart32_read(struct uart_port *port, u32 off)
 291 {
 292         switch (port->iotype) {
 293         case UPIO_MEM32:
 294                 return readl(port->membase + off);
 295         case UPIO_MEM32BE:
 296                 return ioread32be(port->membase + off);
 297         default:
 298                 return 0;
 299         }
 300 }
 301
 302 static inline void lpuart32_write(struct uart_port *port, u32 val,
 303                                   u32 off)
 304 {
 305         switch (port->iotype) {
 306         case UPIO_MEM32:
 307                 writel(val, port->membase + off);
 308                 break;
 309         case UPIO_MEM32BE:
 310                 iowrite32be(val, port->membase + off);
 311                 break;
 312         }
 313 }
 314
 315 static void lpuart_stop_tx(struct uart_port *port)
 316 {
 317         unsigned char temp;
 318
 319         temp = readb(port->membase + UARTCR2);
 320         temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
 321         writeb(temp, port->membase + UARTCR2);
 322 }
 323
 324 static void lpuart32_stop_tx(struct uart_port *port)
 325 {
 326         unsigned long temp;
 327
 328         temp = lpuart32_read(port, UARTCTRL);
 329         temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE);
 330         lpuart32_write(port, temp, UARTCTRL);
 331 }
 332
 333 static void lpuart_stop_rx(struct uart_port *port)
 334 {
 335         unsigned char temp;
 336
 337         temp = readb(port->membase + UARTCR2);
 338         writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
 339 }
 340
 341 static void lpuart32_stop_rx(struct uart_port *port)
 342 {
 343         unsigned long temp;
 344
 345         temp = lpuart32_read(port, UARTCTRL);
 346         lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL);
 347 }
 348
 349 static void lpuart_dma_tx(struct lpuart_port *sport)
 350 {
 351         struct circ_buf *xmit = &sport->port.state->xmit;
 352         struct scatterlist *sgl = sport->tx_sgl;
 353         struct device *dev = sport->port.dev;
 354         int ret;
 355
 356         if (sport->dma_tx_in_progress)
 357                 return;
 358
 359         sport->dma_tx_bytes = uart_circ_chars_pending(xmit);
 360
 361         if (xmit->tail < xmit->head || xmit->head == 0) {
 362                 sport->dma_tx_nents = 1;
 363                 sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
 364         } else {
 365                 sport->dma_tx_nents = 2;
 366                 sg_init_table(sgl, 2);
 367                 sg_set_buf(sgl, xmit->buf + xmit->tail,
 368                                 UART_XMIT_SIZE - xmit->tail);
 369                 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
 370         }
 371
 372         ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 373         if (!ret) {
 374                 dev_err(dev, "DMA mapping error for TX.\n");
 375                 return;
 376         }
 377
 378         sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl,
 379                                         ret, DMA_MEM_TO_DEV,
 380                                         DMA_PREP_INTERRUPT);
 381         if (!sport->dma_tx_desc) {
 382                 dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 383                 dev_err(dev, "Cannot prepare TX slave DMA!\n");
 384                 return;
 385         }
 386
 387         sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
 388         sport->dma_tx_desc->callback_param = sport;
 389         sport->dma_tx_in_progress = true;
 390         sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
 391         dma_async_issue_pending(sport->dma_tx_chan);
 392 }
 393
 394 static void lpuart_dma_tx_complete(void *arg)
 395 {
 396         struct lpuart_port *sport = arg;
 397         struct scatterlist *sgl = &sport->tx_sgl[0];
 398         struct circ_buf *xmit = &sport->port.state->xmit;
 399         unsigned long flags;
 400
 401         spin_lock_irqsave(&sport->port.lock, flags);
 402
 403         dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 404
 405         xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
 406
 407         sport->port.icount.tx += sport->dma_tx_bytes;
 408         sport->dma_tx_in_progress = false;
 409         spin_unlock_irqrestore(&sport->port.lock, flags);
 410
 411         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 412                 uart_write_wakeup(&sport->port);
 413
 414         if (waitqueue_active(&sport->dma_wait)) {
 415                 wake_up(&sport->dma_wait);
 416                 return;
 417         }
 418
 419         spin_lock_irqsave(&sport->port.lock, flags);
 420
 421         if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
 422                 lpuart_dma_tx(sport);
 423
 424         spin_unlock_irqrestore(&sport->port.lock, flags);
 425 }
 426
 427 static int lpuart_dma_tx_request(struct uart_port *port)
 428 {
 429         struct lpuart_port *sport = container_of(port,
 430                                         struct lpuart_port, port);
 431         struct dma_slave_config dma_tx_sconfig = {};
 432         int ret;
 433
 434         dma_tx_sconfig.dst_addr = sport->port.mapbase + UARTDR;
 435         dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 436         dma_tx_sconfig.dst_maxburst = 1;
 437         dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
 438         ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
 439
 440         if (ret) {
 441                 dev_err(sport->port.dev,
 442                                 "DMA slave config failed, err = %d\n", ret);
 443                 return ret;
 444         }
 445
 446         return 0;
 447 }
 448
 449 static void lpuart_flush_buffer(struct uart_port *port)
 450 {
 451         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 452
 453         if (sport->lpuart_dma_tx_use) {
 454                 if (sport->dma_tx_in_progress) {
 455                         dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
 456                                 sport->dma_tx_nents, DMA_TO_DEVICE);
 457                         sport->dma_tx_in_progress = false;
 458                 }
 459                 dmaengine_terminate_all(sport->dma_tx_chan);
 460         }
 461 }
 462
 463 #if defined(CONFIG_CONSOLE_POLL)
 464
 465 static int lpuart_poll_init(struct uart_port *port)
 466 {
 467         struct lpuart_port *sport = container_of(port,
 468                                         struct lpuart_port, port);
 469         unsigned long flags;
 470         unsigned char temp;
 471
 472         sport->port.fifosize = 0;
 473
 474         spin_lock_irqsave(&sport->port.lock, flags);
 475         /* Disable Rx & Tx */
 476         writeb(0, sport->port.membase + UARTCR2);
 477
 478         temp = readb(sport->port.membase + UARTPFIFO);
 479         /* Enable Rx and Tx FIFO */
 480         writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
 481                         sport->port.membase + UARTPFIFO);
 482
 483         /* flush Tx and Rx FIFO */
 484         writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
 485                         sport->port.membase + UARTCFIFO);
 486
 487         /* explicitly clear RDRF */
 488         if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
 489                 readb(sport->port.membase + UARTDR);
 490                 writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
 491         }
 492
 493         writeb(0, sport->port.membase + UARTTWFIFO);
 494         writeb(1, sport->port.membase + UARTRWFIFO);
 495
 496         /* Enable Rx and Tx */
 497         writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
 498         spin_unlock_irqrestore(&sport->port.lock, flags);
 499
 500         return 0;
 501 }
 502
 503 static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
 504 {
 505         /* drain */
 506         while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
 507                 barrier();
 508
 509         writeb(c, port->membase + UARTDR);
 510 }
 511
 512 static int lpuart_poll_get_char(struct uart_port *port)
 513 {
 514         if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
 515                 return NO_POLL_CHAR;
 516
 517         return readb(port->membase + UARTDR);
 518 }
 519
 520 static int lpuart32_poll_init(struct uart_port *port)
 521 {
 522         unsigned long flags;
 523         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 524         u32 temp;
 525
 526         sport->port.fifosize = 0;
 527
 528         spin_lock_irqsave(&sport->port.lock, flags);
 529
 530         /* Disable Rx & Tx */
 531         lpuart32_write(&sport->port, UARTCTRL, 0);
 532
 533         temp = lpuart32_read(&sport->port, UARTFIFO);
 534
 535         /* Enable Rx and Tx FIFO */
 536         lpuart32_write(&sport->port, UARTFIFO,
 537                        temp | UARTFIFO_RXFE | UARTFIFO_TXFE);
 538
 539         /* flush Tx and Rx FIFO */
 540         lpuart32_write(&sport->port, UARTFIFO,
 541                        UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH);
 542
 543         /* explicitly clear RDRF */
 544         if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) {
 545                 lpuart32_read(&sport->port, UARTDATA);
 546                 lpuart32_write(&sport->port, UARTFIFO, UARTFIFO_RXUF);
 547         }
 548
 549         /* Enable Rx and Tx */
 550         lpuart32_write(&sport->port, UARTCTRL, UARTCTRL_RE | UARTCTRL_TE);
 551         spin_unlock_irqrestore(&sport->port.lock, flags);
 552
 553         return 0;
 554 }
 555
 556 static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
 557 {
 558         while (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE))
 559                 barrier();
 560
 561         lpuart32_write(port, UARTDATA, c);
 562 }
 563
 564 static int lpuart32_poll_get_char(struct uart_port *port)
 565 {
 566         if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF))
 567                 return NO_POLL_CHAR;
 568
 569         return lpuart32_read(port, UARTDATA);
 570 }
 571 #endif
 572
 573 static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
 574 {
 575         struct circ_buf *xmit = &sport->port.state->xmit;
 576
 577         while (!uart_circ_empty(xmit) &&
 578                 (readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
 579                 writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
 580                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 581                 sport->port.icount.tx++;
 582         }
 583
 584         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 585                 uart_write_wakeup(&sport->port);
 586
 587         if (uart_circ_empty(xmit))
 588                 lpuart_stop_tx(&sport->port);
 589 }
 590
 591 static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
 592 {
 593         struct circ_buf *xmit = &sport->port.state->xmit;
 594         unsigned long txcnt;
 595
 596         txcnt = lpuart32_read(&sport->port, UARTWATER);
 597         txcnt = txcnt >> UARTWATER_TXCNT_OFF;
 598         txcnt &= UARTWATER_COUNT_MASK;
 599         while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) {
 600                 lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
 601                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 602                 sport->port.icount.tx++;
 603                 txcnt = lpuart32_read(&sport->port, UARTWATER);
 604                 txcnt = txcnt >> UARTWATER_TXCNT_OFF;
 605                 txcnt &= UARTWATER_COUNT_MASK;
 606         }
 607
 608         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 609                 uart_write_wakeup(&sport->port);
 610
 611         if (uart_circ_empty(xmit))
 612                 lpuart32_stop_tx(&sport->port);
 613 }
 614
 615 static void lpuart_start_tx(struct uart_port *port)
 616 {
 617         struct lpuart_port *sport = container_of(port,
 618                         struct lpuart_port, port);
 619         struct circ_buf *xmit = &sport->port.state->xmit;
 620         unsigned char temp;
 621
 622         temp = readb(port->membase + UARTCR2);
 623         writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
 624
 625         if (sport->lpuart_dma_tx_use) {
 626                 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port))
 627                         lpuart_dma_tx(sport);
 628         } else {
 629                 if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
 630                         lpuart_transmit_buffer(sport);
 631         }
 632 }
 633
 634 static void lpuart32_start_tx(struct uart_port *port)
 635 {
 636         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 637         unsigned long temp;
 638
 639         temp = lpuart32_read(port, UARTCTRL);
 640         lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL);
 641
 642         if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE)
 643                 lpuart32_transmit_buffer(sport);
 644 }
 645
 646 /* return TIOCSER_TEMT when transmitter is not busy */
 647 static unsigned int lpuart_tx_empty(struct uart_port *port)
 648 {
 649         struct lpuart_port *sport = container_of(port,
 650                         struct lpuart_port, port);
 651         unsigned char sr1 = readb(port->membase + UARTSR1);
 652         unsigned char sfifo = readb(port->membase + UARTSFIFO);
 653
 654         if (sport->dma_tx_in_progress)
 655                 return 0;
 656
 657         if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT)
 658                 return TIOCSER_TEMT;
 659
 660         return 0;
 661 }
 662
 663 static unsigned int lpuart32_tx_empty(struct uart_port *port)
 664 {
 665         return (lpuart32_read(port, UARTSTAT) & UARTSTAT_TC) ?
 666                 TIOCSER_TEMT : 0;
 667 }
 668
 669 static bool lpuart_is_32(struct lpuart_port *sport)
 670 {
 671         return sport->port.iotype == UPIO_MEM32 ||
 672                sport->port.iotype ==  UPIO_MEM32BE;
 673 }
 674
 675 static irqreturn_t lpuart_txint(int irq, void *dev_id)
 676 {
 677         struct lpuart_port *sport = dev_id;
 678         struct circ_buf *xmit = &sport->port.state->xmit;
 679         unsigned long flags;
 680
 681         spin_lock_irqsave(&sport->port.lock, flags);
 682         if (sport->port.x_char) {
 683                 if (lpuart_is_32(sport))
 684                         lpuart32_write(&sport->port, sport->port.x_char, UARTDATA);
 685                 else
 686                         writeb(sport->port.x_char, sport->port.membase + UARTDR);
 687                 goto out;
 688         }
 689
 690         if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
 691                 if (lpuart_is_32(sport))
 692                         lpuart32_stop_tx(&sport->port);
 693                 else
 694                         lpuart_stop_tx(&sport->port);
 695                 goto out;
 696         }
 697
 698         if (lpuart_is_32(sport))
 699                 lpuart32_transmit_buffer(sport);
 700         else
 701                 lpuart_transmit_buffer(sport);
 702
 703         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 704                 uart_write_wakeup(&sport->port);
 705
 706 out:
 707         spin_unlock_irqrestore(&sport->port.lock, flags);
 708         return IRQ_HANDLED;
 709 }
 710
 711 static irqreturn_t lpuart_rxint(int irq, void *dev_id)
 712 {
 713         struct lpuart_port *sport = dev_id;
 714         unsigned int flg, ignored = 0;
 715         struct tty_port *port = &sport->port.state->port;
 716         unsigned long flags;
 717         unsigned char rx, sr;
 718
 719         spin_lock_irqsave(&sport->port.lock, flags);
 720
 721         while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
 722                 flg = TTY_NORMAL;
 723                 sport->port.icount.rx++;
 724                 /*
 725                  * to clear the FE, OR, NF, FE, PE flags,
 726                  * read SR1 then read DR
 727                  */
 728                 sr = readb(sport->port.membase + UARTSR1);
 729                 rx = readb(sport->port.membase + UARTDR);
 730
 731                 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 732                         continue;
 733
 734                 if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
 735                         if (sr & UARTSR1_PE)
 736                                 sport->port.icount.parity++;
 737                         else if (sr & UARTSR1_FE)
 738                                 sport->port.icount.frame++;
 739
 740                         if (sr & UARTSR1_OR)
 741                                 sport->port.icount.overrun++;
 742
 743                         if (sr & sport->port.ignore_status_mask) {
 744                                 if (++ignored > 100)
 745                                         goto out;
 746                                 continue;
 747                         }
 748
 749                         sr &= sport->port.read_status_mask;
 750
 751                         if (sr & UARTSR1_PE)
 752                                 flg = TTY_PARITY;
 753                         else if (sr & UARTSR1_FE)
 754                                 flg = TTY_FRAME;
 755
 756                         if (sr & UARTSR1_OR)
 757                                 flg = TTY_OVERRUN;
 758
 759 #ifdef SUPPORT_SYSRQ
 760                         sport->port.sysrq = 0;
 761 #endif
 762                 }
 763
 764                 tty_insert_flip_char(port, rx, flg);
 765         }
 766
 767 out:
 768         spin_unlock_irqrestore(&sport->port.lock, flags);
 769
 770         tty_flip_buffer_push(port);
 771         return IRQ_HANDLED;
 772 }
 773
 774 static irqreturn_t lpuart32_rxint(int irq, void *dev_id)
 775 {
 776         struct lpuart_port *sport = dev_id;
 777         unsigned int flg, ignored = 0;
 778         struct tty_port *port = &sport->port.state->port;
 779         unsigned long flags;
 780         unsigned long rx, sr;
 781
 782         spin_lock_irqsave(&sport->port.lock, flags);
 783
 784         while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) {
 785                 flg = TTY_NORMAL;
 786                 sport->port.icount.rx++;
 787                 /*
 788                  * to clear the FE, OR, NF, FE, PE flags,
 789                  * read STAT then read DATA reg
 790                  */
 791                 sr = lpuart32_read(&sport->port, UARTSTAT);
 792                 rx = lpuart32_read(&sport->port, UARTDATA);
 793                 rx &= 0x3ff;
 794
 795                 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 796                         continue;
 797
 798                 if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) {
 799                         if (sr & UARTSTAT_PE)
 800                                 sport->port.icount.parity++;
 801                         else if (sr & UARTSTAT_FE)
 802                                 sport->port.icount.frame++;
 803
 804                         if (sr & UARTSTAT_OR)
 805                                 sport->port.icount.overrun++;
 806
 807                         if (sr & sport->port.ignore_status_mask) {
 808                                 if (++ignored > 100)
 809                                         goto out;
 810                                 continue;
 811                         }
 812
 813                         sr &= sport->port.read_status_mask;
 814
 815                         if (sr & UARTSTAT_PE)
 816                                 flg = TTY_PARITY;
 817                         else if (sr & UARTSTAT_FE)
 818                                 flg = TTY_FRAME;
 819
 820                         if (sr & UARTSTAT_OR)
 821                                 flg = TTY_OVERRUN;
 822
 823 #ifdef SUPPORT_SYSRQ
 824                         sport->port.sysrq = 0;
 825 #endif
 826                 }
 827
 828                 tty_insert_flip_char(port, rx, flg);
 829         }
 830
 831 out:
 832         spin_unlock_irqrestore(&sport->port.lock, flags);
 833
 834         tty_flip_buffer_push(port);
 835         return IRQ_HANDLED;
 836 }
 837
 838 static irqreturn_t lpuart_int(int irq, void *dev_id)
 839 {
 840         struct lpuart_port *sport = dev_id;
 841         unsigned char sts;
 842
 843         sts = readb(sport->port.membase + UARTSR1);
 844
 845         if (sts & UARTSR1_RDRF)
 846                 lpuart_rxint(irq, dev_id);
 847
 848         if (sts & UARTSR1_TDRE)
 849                 lpuart_txint(irq, dev_id);
 850
 851         return IRQ_HANDLED;
 852 }
 853
 854 static irqreturn_t lpuart32_int(int irq, void *dev_id)
 855 {
 856         struct lpuart_port *sport = dev_id;
 857         unsigned long sts, rxcount;
 858
 859         sts = lpuart32_read(&sport->port, UARTSTAT);
 860         rxcount = lpuart32_read(&sport->port, UARTWATER);
 861         rxcount = rxcount >> UARTWATER_RXCNT_OFF;
 862
 863         if (sts & UARTSTAT_RDRF || rxcount > 0)
 864                 lpuart32_rxint(irq, dev_id);
 865
 866         if ((sts & UARTSTAT_TDRE) &&
 867                 !(lpuart32_read(&sport->port, UARTBAUD) & UARTBAUD_TDMAE))
 868                 lpuart_txint(irq, dev_id);
 869
 870         lpuart32_write(&sport->port, sts, UARTSTAT);
 871         return IRQ_HANDLED;
 872 }
 873
 874 static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 875 {
 876         struct tty_port *port = &sport->port.state->port;
 877         struct dma_tx_state state;
 878         enum dma_status dmastat;
 879         struct circ_buf *ring = &sport->rx_ring;
 880         unsigned long flags;
 881         int count = 0;
 882         unsigned char sr;
 883
 884         sr = readb(sport->port.membase + UARTSR1);
 885
 886         if (sr & (UARTSR1_PE | UARTSR1_FE)) {
 887                 /* Read DR to clear the error flags */
 888                 readb(sport->port.membase + UARTDR);
 889
 890                 if (sr & UARTSR1_PE)
 891                     sport->port.icount.parity++;
 892                 else if (sr & UARTSR1_FE)
 893                     sport->port.icount.frame++;
 894         }
 895
 896         async_tx_ack(sport->dma_rx_desc);
 897
 898         spin_lock_irqsave(&sport->port.lock, flags);
 899
 900         dmastat = dmaengine_tx_status(sport->dma_rx_chan,
 901                                 sport->dma_rx_cookie,
 902                                 &state);
 903
 904         if (dmastat == DMA_ERROR) {
 905                 dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
 906                 spin_unlock_irqrestore(&sport->port.lock, flags);
 907                 return;
 908         }
 909
 910         /* CPU claims ownership of RX DMA buffer */
 911         dma_sync_sg_for_cpu(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
 912
 913         /*
 914          * ring->head points to the end of data already written by the DMA.
 915          * ring->tail points to the beginning of data to be read by the
 916          * framework.
 917          * The current transfer size should not be larger than the dma buffer
 918          * length.
 919          */
 920         ring->head = sport->rx_sgl.length - state.residue;
 921         BUG_ON(ring->head > sport->rx_sgl.length);
 922         /*
 923          * At this point ring->head may point to the first byte right after the
 924          * last byte of the dma buffer:
 925          * 0 <= ring->head <= sport->rx_sgl.length
 926          *
 927          * However ring->tail must always points inside the dma buffer:
 928          * 0 <= ring->tail <= sport->rx_sgl.length - 1
 929          *
 930          * Since we use a ring buffer, we have to handle the case
 931          * where head is lower than tail. In such a case, we first read from
 932          * tail to the end of the buffer then reset tail.
 933          */
 934         if (ring->head < ring->tail) {
 935                 count = sport->rx_sgl.length - ring->tail;
 936
 937                 tty_insert_flip_string(port, ring->buf + ring->tail, count);
 938                 ring->tail = 0;
 939                 sport->port.icount.rx += count;
 940         }
 941
 942         /* Finally we read data from tail to head */
 943         if (ring->tail < ring->head) {
 944                 count = ring->head - ring->tail;
 945                 tty_insert_flip_string(port, ring->buf + ring->tail, count);
 946                 /* Wrap ring->head if needed */
 947                 if (ring->head >= sport->rx_sgl.length)
 948                         ring->head = 0;
 949                 ring->tail = ring->head;
 950                 sport->port.icount.rx += count;
 951         }
 952
 953         dma_sync_sg_for_device(sport->port.dev, &sport->rx_sgl, 1,
 954                                DMA_FROM_DEVICE);
 955
 956         spin_unlock_irqrestore(&sport->port.lock, flags);
 957
 958         tty_flip_buffer_push(port);
 959         mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
 960 }
 961
 962 static void lpuart_dma_rx_complete(void *arg)
 963 {
 964         struct lpuart_port *sport = arg;
 965
 966         lpuart_copy_rx_to_tty(sport);
 967 }
 968
 969 static void lpuart_timer_func(struct timer_list *t)
 970 {
 971         struct lpuart_port *sport = from_timer(sport, t, lpuart_timer);
 972
 973         lpuart_copy_rx_to_tty(sport);
 974 }
 975
 976 static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 977 {
 978         struct dma_slave_config dma_rx_sconfig = {};
 979         struct circ_buf *ring = &sport->rx_ring;
 980         int ret, nent;
 981         int bits, baud;
 982         struct tty_port *port = &sport->port.state->port;
 983         struct tty_struct *tty = port->tty;
 984         struct ktermios *termios = &tty->termios;
 985
 986         baud = tty_get_baud_rate(tty);
 987
 988         bits = (termios->c_cflag & CSIZE) == CS7 ? 9 : 10;
 989         if (termios->c_cflag & PARENB)
 990                 bits++;
 991
 992         /*
 993          * Calculate length of one DMA buffer size to keep latency below
 994          * 10ms at any baud rate.
 995          */
 996         sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud /  bits / 1000) * 2;
 997         sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1));
 998         if (sport->rx_dma_rng_buf_len < 16)
 999                 sport->rx_dma_rng_buf_len = 16;
1000
1001         ring->buf = kmalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
1002         if (!ring->buf) {
1003                 dev_err(sport->port.dev, "Ring buf alloc failed\n");
1004                 return -ENOMEM;
1005         }
1006
1007         sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
1008         sg_set_buf(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
1009         nent = dma_map_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
1010
1011         if (!nent) {
1012                 dev_err(sport->port.dev, "DMA Rx mapping error\n");
1013                 return -EINVAL;
1014         }
1015
1016         dma_rx_sconfig.src_addr = sport->port.mapbase + UARTDR;
1017         dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1018         dma_rx_sconfig.src_maxburst = 1;
1019         dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
1020         ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig);
1021
1022         if (ret < 0) {
1023                 dev_err(sport->port.dev,
1024                                 "DMA Rx slave config failed, err = %d\n", ret);
1025                 return ret;
1026         }
1027
1028         sport->dma_rx_desc = dmaengine_prep_dma_cyclic(sport->dma_rx_chan,
1029                                  sg_dma_address(&sport->rx_sgl),
1030                                  sport->rx_sgl.length,
1031                                  sport->rx_sgl.length / 2,
1032                                  DMA_DEV_TO_MEM,
1033                                  DMA_PREP_INTERRUPT);
1034         if (!sport->dma_rx_desc) {
1035                 dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n");
1036                 return -EFAULT;
1037         }
1038
1039         sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
1040         sport->dma_rx_desc->callback_param = sport;
1041         sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
1042         dma_async_issue_pending(sport->dma_rx_chan);
1043
1044         writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS,
1045                                 sport->port.membase + UARTCR5);
1046
1047         return 0;
1048 }
1049
1050 static void lpuart_dma_rx_free(struct uart_port *port)
1051 {
1052         struct lpuart_port *sport = container_of(port,
1053                                         struct lpuart_port, port);
1054
1055         if (sport->dma_rx_chan)
1056                 dmaengine_terminate_all(sport->dma_rx_chan);
1057
1058         dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
1059         kfree(sport->rx_ring.buf);
1060         sport->rx_ring.tail = 0;
1061         sport->rx_ring.head = 0;
1062         sport->dma_rx_desc = NULL;
1063         sport->dma_rx_cookie = -EINVAL;
1064 }
1065
1066 static int lpuart_config_rs485(struct uart_port *port,
1067                         struct serial_rs485 *rs485)
1068 {
1069         struct lpuart_port *sport = container_of(port,
1070                         struct lpuart_port, port);
1071
1072         u8 modem = readb(sport->port.membase + UARTMODEM) &
1073                 ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE);
1074         writeb(modem, sport->port.membase + UARTMODEM);
1075
1076         /* clear unsupported configurations */
1077         rs485->delay_rts_before_send = 0;
1078         rs485->delay_rts_after_send = 0;
1079         rs485->flags &= ~SER_RS485_RX_DURING_TX;
1080
1081         if (rs485->flags & SER_RS485_ENABLED) {
1082                 /* Enable auto RS-485 RTS mode */
1083                 modem |= UARTMODEM_TXRTSE;
1084
1085                 /*
1086                  * RTS needs to be logic HIGH either during transer _or_ after
1087                  * transfer, other variants are not supported by the hardware.
1088                  */
1089
1090                 if (!(rs485->flags & (SER_RS485_RTS_ON_SEND |
1091                                 SER_RS485_RTS_AFTER_SEND)))
1092                         rs485->flags |= SER_RS485_RTS_ON_SEND;
1093
1094                 if (rs485->flags & SER_RS485_RTS_ON_SEND &&
1095                                 rs485->flags & SER_RS485_RTS_AFTER_SEND)
1096                         rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
1097
1098                 /*
1099                  * The hardware defaults to RTS logic HIGH while transfer.
1100                  * Switch polarity in case RTS shall be logic HIGH
1101                  * after transfer.
1102                  * Note: UART is assumed to be active high.
1103                  */
1104                 if (rs485->flags & SER_RS485_RTS_ON_SEND)
1105                         modem &= ~UARTMODEM_TXRTSPOL;
1106                 else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
1107                         modem |= UARTMODEM_TXRTSPOL;
1108         }
1109
1110         /* Store the new configuration */
1111         sport->port.rs485 = *rs485;
1112
1113         writeb(modem, sport->port.membase + UARTMODEM);
1114         return 0;
1115 }
1116
1117 static unsigned int lpuart_get_mctrl(struct uart_port *port)
1118 {
1119         unsigned int temp = 0;
1120         unsigned char reg;
1121
1122         reg = readb(port->membase + UARTMODEM);
1123         if (reg & UARTMODEM_TXCTSE)
1124                 temp |= TIOCM_CTS;
1125
1126         if (reg & UARTMODEM_RXRTSE)
1127                 temp |= TIOCM_RTS;
1128
1129         return temp;
1130 }
1131
1132 static unsigned int lpuart32_get_mctrl(struct uart_port *port)
1133 {
1134         unsigned int temp = 0;
1135         unsigned long reg;
1136
1137         reg = lpuart32_read(port, UARTMODIR);
1138         if (reg & UARTMODIR_TXCTSE)
1139                 temp |= TIOCM_CTS;
1140
1141         if (reg & UARTMODIR_RXRTSE)
1142                 temp |= TIOCM_RTS;
1143
1144         return temp;
1145 }
1146
1147 static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1148 {
1149         unsigned char temp;
1150         struct lpuart_port *sport = container_of(port,
1151                                 struct lpuart_port, port);
1152
1153         /* Make sure RXRTSE bit is not set when RS485 is enabled */
1154         if (!(sport->port.rs485.flags & SER_RS485_ENABLED)) {
1155                 temp = readb(sport->port.membase + UARTMODEM) &
1156                         ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1157
1158                 if (mctrl & TIOCM_RTS)
1159                         temp |= UARTMODEM_RXRTSE;
1160
1161                 if (mctrl & TIOCM_CTS)
1162                         temp |= UARTMODEM_TXCTSE;
1163
1164                 writeb(temp, port->membase + UARTMODEM);
1165         }
1166 }
1167
1168 static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
1169 {
1170         unsigned long temp;
1171
1172         temp = lpuart32_read(port, UARTMODIR) &
1173                         ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
1174
1175         if (mctrl & TIOCM_RTS)
1176                 temp |= UARTMODIR_RXRTSE;
1177
1178         if (mctrl & TIOCM_CTS)
1179                 temp |= UARTMODIR_TXCTSE;
1180
1181         lpuart32_write(port, temp, UARTMODIR);
1182 }
1183
1184 static void lpuart_break_ctl(struct uart_port *port, int break_state)
1185 {
1186         unsigned char temp;
1187
1188         temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK;
1189
1190         if (break_state != 0)
1191                 temp |= UARTCR2_SBK;
1192
1193         writeb(temp, port->membase + UARTCR2);
1194 }
1195
1196 static void lpuart32_break_ctl(struct uart_port *port, int break_state)
1197 {
1198         unsigned long temp;
1199
1200         temp = lpuart32_read(port, UARTCTRL) & ~UARTCTRL_SBK;
1201
1202         if (break_state != 0)
1203                 temp |= UARTCTRL_SBK;
1204
1205         lpuart32_write(port, temp, UARTCTRL);
1206 }
1207
1208 static void lpuart_setup_watermark(struct lpuart_port *sport)
1209 {
1210         unsigned char val, cr2;
1211         unsigned char cr2_saved;
1212
1213         cr2 = readb(sport->port.membase + UARTCR2);
1214         cr2_saved = cr2;
1215         cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE |
1216                         UARTCR2_RIE | UARTCR2_RE);
1217         writeb(cr2, sport->port.membase + UARTCR2);
1218
1219         val = readb(sport->port.membase + UARTPFIFO);
1220         writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE,
1221                         sport->port.membase + UARTPFIFO);
1222
1223         /* flush Tx and Rx FIFO */
1224         writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
1225                         sport->port.membase + UARTCFIFO);
1226
1227         /* explicitly clear RDRF */
1228         if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
1229                 readb(sport->port.membase + UARTDR);
1230                 writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
1231         }
1232
1233         writeb(0, sport->port.membase + UARTTWFIFO);
1234         writeb(1, sport->port.membase + UARTRWFIFO);
1235
1236         /* Restore cr2 */
1237         writeb(cr2_saved, sport->port.membase + UARTCR2);
1238 }
1239
1240 static void lpuart32_setup_watermark(struct lpuart_port *sport)
1241 {
1242         unsigned long val, ctrl;
1243         unsigned long ctrl_saved;
1244
1245         ctrl = lpuart32_read(&sport->port, UARTCTRL);
1246         ctrl_saved = ctrl;
1247         ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE |
1248                         UARTCTRL_RIE | UARTCTRL_RE);
1249         lpuart32_write(&sport->port, ctrl, UARTCTRL);
1250
1251         /* enable FIFO mode */
1252         val = lpuart32_read(&sport->port, UARTFIFO);
1253         val |= UARTFIFO_TXFE | UARTFIFO_RXFE;
1254         val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
1255         lpuart32_write(&sport->port, val, UARTFIFO);
1256
1257         /* set the watermark */
1258         val = (0x1 << UARTWATER_RXWATER_OFF) | (0x0 << UARTWATER_TXWATER_OFF);
1259         lpuart32_write(&sport->port, val, UARTWATER);
1260
1261         /* Restore cr2 */
1262         lpuart32_write(&sport->port, ctrl_saved, UARTCTRL);
1263 }
1264
1265 static void rx_dma_timer_init(struct lpuart_port *sport)
1266 {
1267                 timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0);
1268                 sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
1269                 add_timer(&sport->lpuart_timer);
1270 }
1271
1272 static int lpuart_startup(struct uart_port *port)
1273 {
1274         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1275         unsigned long flags;
1276         unsigned char temp;
1277
1278         /* determine FIFO size and enable FIFO mode */
1279         temp = readb(sport->port.membase + UARTPFIFO);
1280
1281         sport->txfifo_size = 0x1 << (((temp >> UARTPFIFO_TXSIZE_OFF) &
1282                 UARTPFIFO_FIFOSIZE_MASK) + 1);
1283
1284         sport->port.fifosize = sport->txfifo_size;
1285
1286         sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &
1287                 UARTPFIFO_FIFOSIZE_MASK) + 1);
1288
1289         spin_lock_irqsave(&sport->port.lock, flags);
1290
1291         lpuart_setup_watermark(sport);
1292
1293         temp = readb(sport->port.membase + UARTCR2);
1294         temp |= (UARTCR2_RIE | UARTCR2_TIE | UARTCR2_RE | UARTCR2_TE);
1295         writeb(temp, sport->port.membase + UARTCR2);
1296
1297         if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
1298                 /* set Rx DMA timeout */
1299                 sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
1300                 if (!sport->dma_rx_timeout)
1301                      sport->dma_rx_timeout = 1;
1302
1303                 sport->lpuart_dma_rx_use = true;
1304                 rx_dma_timer_init(sport);
1305         } else {
1306                 sport->lpuart_dma_rx_use = false;
1307         }
1308
1309         if (sport->dma_tx_chan && !lpuart_dma_tx_request(port)) {
1310                 init_waitqueue_head(&sport->dma_wait);
1311                 sport->lpuart_dma_tx_use = true;
1312                 temp = readb(port->membase + UARTCR5);
1313                 writeb(temp | UARTCR5_TDMAS, port->membase + UARTCR5);
1314         } else {
1315                 sport->lpuart_dma_tx_use = false;
1316         }
1317
1318         spin_unlock_irqrestore(&sport->port.lock, flags);
1319
1320         return 0;
1321 }
1322
1323 static int lpuart32_startup(struct uart_port *port)
1324 {
1325         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1326         unsigned long flags;
1327         unsigned long temp;
1328
1329         /* determine FIFO size */
1330         temp = lpuart32_read(&sport->port, UARTFIFO);
1331
1332         sport->txfifo_size = 0x1 << (((temp >> UARTFIFO_TXSIZE_OFF) &
1333                 UARTFIFO_FIFOSIZE_MASK) - 1);
1334
1335         sport->rxfifo_size = 0x1 << (((temp >> UARTFIFO_RXSIZE_OFF) &
1336                 UARTFIFO_FIFOSIZE_MASK) - 1);
1337
1338         spin_lock_irqsave(&sport->port.lock, flags);
1339
1340         lpuart32_setup_watermark(sport);
1341
1342         temp = lpuart32_read(&sport->port, UARTCTRL);
1343         temp |= (UARTCTRL_RIE | UARTCTRL_TIE | UARTCTRL_RE | UARTCTRL_TE);
1344         temp |= UARTCTRL_ILIE;
1345         lpuart32_write(&sport->port, temp, UARTCTRL);
1346
1347         spin_unlock_irqrestore(&sport->port.lock, flags);
1348         return 0;
1349 }
1350
1351 static void lpuart_shutdown(struct uart_port *port)
1352 {
1353         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1354         unsigned char temp;
1355         unsigned long flags;
1356
1357         spin_lock_irqsave(&port->lock, flags);
1358
1359         /* disable Rx/Tx and interrupts */
1360         temp = readb(port->membase + UARTCR2);
1361         temp &= ~(UARTCR2_TE | UARTCR2_RE |
1362                         UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
1363         writeb(temp, port->membase + UARTCR2);
1364
1365         spin_unlock_irqrestore(&port->lock, flags);
1366
1367         if (sport->lpuart_dma_rx_use) {
1368                 del_timer_sync(&sport->lpuart_timer);
1369                 lpuart_dma_rx_free(&sport->port);
1370         }
1371
1372         if (sport->lpuart_dma_tx_use) {
1373                 if (wait_event_interruptible(sport->dma_wait,
1374                         !sport->dma_tx_in_progress) != false) {
1375                         sport->dma_tx_in_progress = false;
1376                         dmaengine_terminate_all(sport->dma_tx_chan);
1377                 }
1378
1379                 lpuart_stop_tx(port);
1380         }
1381 }
1382
1383 static void lpuart32_shutdown(struct uart_port *port)
1384 {
1385         unsigned long temp;
1386         unsigned long flags;
1387
1388         spin_lock_irqsave(&port->lock, flags);
1389
1390         /* disable Rx/Tx and interrupts */
1391         temp = lpuart32_read(port, UARTCTRL);
1392         temp &= ~(UARTCTRL_TE | UARTCTRL_RE |
1393                         UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
1394         lpuart32_write(port, temp, UARTCTRL);
1395
1396         spin_unlock_irqrestore(&port->lock, flags);
1397 }
1398
1399 static void
1400 lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
1401                    struct ktermios *old)
1402 {
1403         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1404         unsigned long flags;
1405         unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem;
1406         unsigned int  baud;
1407         unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1408         unsigned int sbr, brfa;
1409
1410         cr1 = old_cr1 = readb(sport->port.membase + UARTCR1);
1411         old_cr2 = readb(sport->port.membase + UARTCR2);
1412         cr3 = readb(sport->port.membase + UARTCR3);
1413         cr4 = readb(sport->port.membase + UARTCR4);
1414         bdh = readb(sport->port.membase + UARTBDH);
1415         modem = readb(sport->port.membase + UARTMODEM);
1416         /*
1417          * only support CS8 and CS7, and for CS7 must enable PE.
1418          * supported mode:
1419          *  - (7,e/o,1)
1420          *  - (8,n,1)
1421          *  - (8,m/s,1)
1422          *  - (8,e/o,1)
1423          */
1424         while ((termios->c_cflag & CSIZE) != CS8 &&
1425                 (termios->c_cflag & CSIZE) != CS7) {
1426                 termios->c_cflag &= ~CSIZE;
1427                 termios->c_cflag |= old_csize;
1428                 old_csize = CS8;
1429         }
1430
1431         if ((termios->c_cflag & CSIZE) == CS8 ||
1432                 (termios->c_cflag & CSIZE) == CS7)
1433                 cr1 = old_cr1 & ~UARTCR1_M;
1434
1435         if (termios->c_cflag & CMSPAR) {
1436                 if ((termios->c_cflag & CSIZE) != CS8) {
1437                         termios->c_cflag &= ~CSIZE;
1438                         termios->c_cflag |= CS8;
1439                 }
1440                 cr1 |= UARTCR1_M;
1441         }
1442
1443         /*
1444          * When auto RS-485 RTS mode is enabled,
1445          * hardware flow control need to be disabled.
1446          */
1447         if (sport->port.rs485.flags & SER_RS485_ENABLED)
1448                 termios->c_cflag &= ~CRTSCTS;
1449
1450         if (termios->c_cflag & CRTSCTS) {
1451                 modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1452         } else {
1453                 termios->c_cflag &= ~CRTSCTS;
1454                 modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1455         }
1456
1457         if (termios->c_cflag & CSTOPB)
1458                 termios->c_cflag &= ~CSTOPB;
1459
1460         /* parity must be enabled when CS7 to match 8-bits format */
1461         if ((termios->c_cflag & CSIZE) == CS7)
1462                 termios->c_cflag |= PARENB;
1463
1464         if ((termios->c_cflag & PARENB)) {
1465                 if (termios->c_cflag & CMSPAR) {
1466                         cr1 &= ~UARTCR1_PE;
1467                         if (termios->c_cflag & PARODD)
1468                                 cr3 |= UARTCR3_T8;
1469                         else
1470                                 cr3 &= ~UARTCR3_T8;
1471                 } else {
1472                         cr1 |= UARTCR1_PE;
1473                         if ((termios->c_cflag & CSIZE) == CS8)
1474                                 cr1 |= UARTCR1_M;
1475                         if (termios->c_cflag & PARODD)
1476                                 cr1 |= UARTCR1_PT;
1477                         else
1478                                 cr1 &= ~UARTCR1_PT;
1479                 }
1480         } else {
1481                 cr1 &= ~UARTCR1_PE;
1482         }
1483
1484         /* ask the core to calculate the divisor */
1485         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1486
1487         /*
1488          * Need to update the Ring buffer length according to the selected
1489          * baud rate and restart Rx DMA path.
1490          *
1491          * Since timer function acqures sport->port.lock, need to stop before
1492          * acquring same lock because otherwise del_timer_sync() can deadlock.
1493          */
1494         if (old && sport->lpuart_dma_rx_use) {
1495                 del_timer_sync(&sport->lpuart_timer);
1496                 lpuart_dma_rx_free(&sport->port);
1497         }
1498
1499         spin_lock_irqsave(&sport->port.lock, flags);
1500
1501         sport->port.read_status_mask = 0;
1502         if (termios->c_iflag & INPCK)
1503                 sport->port.read_status_mask |= (UARTSR1_FE | UARTSR1_PE);
1504         if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1505                 sport->port.read_status_mask |= UARTSR1_FE;
1506
1507         /* characters to ignore */
1508         sport->port.ignore_status_mask = 0;
1509         if (termios->c_iflag & IGNPAR)
1510                 sport->port.ignore_status_mask |= UARTSR1_PE;
1511         if (termios->c_iflag & IGNBRK) {
1512                 sport->port.ignore_status_mask |= UARTSR1_FE;
1513                 /*
1514                  * if we're ignoring parity and break indicators,
1515                  * ignore overruns too (for real raw support).
1516                  */
1517                 if (termios->c_iflag & IGNPAR)
1518                         sport->port.ignore_status_mask |= UARTSR1_OR;
1519         }
1520
1521         /* update the per-port timeout */
1522         uart_update_timeout(port, termios->c_cflag, baud);
1523
1524         /* wait transmit engin complete */
1525         while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
1526                 barrier();
1527
1528         /* disable transmit and receive */
1529         writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
1530                         sport->port.membase + UARTCR2);
1531
1532         sbr = sport->port.uartclk / (16 * baud);
1533         brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud;
1534         bdh &= ~UARTBDH_SBR_MASK;
1535         bdh |= (sbr >> 8) & 0x1F;
1536         cr4 &= ~UARTCR4_BRFA_MASK;
1537         brfa &= UARTCR4_BRFA_MASK;
1538         writeb(cr4 | brfa, sport->port.membase + UARTCR4);
1539         writeb(bdh, sport->port.membase + UARTBDH);
1540         writeb(sbr & 0xFF, sport->port.membase + UARTBDL);
1541         writeb(cr3, sport->port.membase + UARTCR3);
1542         writeb(cr1, sport->port.membase + UARTCR1);
1543         writeb(modem, sport->port.membase + UARTMODEM);
1544
1545         /* restore control register */
1546         writeb(old_cr2, sport->port.membase + UARTCR2);
1547
1548         if (old && sport->lpuart_dma_rx_use) {
1549                 if (!lpuart_start_rx_dma(sport))
1550                         rx_dma_timer_init(sport);
1551                 else
1552                         sport->lpuart_dma_rx_use = false;
1553         }
1554
1555         spin_unlock_irqrestore(&sport->port.lock, flags);
1556 }
1557
1558 static void
1559 lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate)
1560 {
1561         u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
1562         u32 clk = sport->port.uartclk;
1563
1564         /*
1565          * The idea is to use the best OSR (over-sampling rate) possible.
1566          * Note, OSR is typically hard-set to 16 in other LPUART instantiations.
1567          * Loop to find the best OSR value possible, one that generates minimum
1568          * baud_diff iterate through the rest of the supported values of OSR.
1569          *
1570          * Calculation Formula:
1571          *  Baud Rate = baud clock / ((OSR+1) × SBR)
1572          */
1573         baud_diff = baudrate;
1574         osr = 0;
1575         sbr = 0;
1576
1577         for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) {
1578                 /* calculate the temporary sbr value  */
1579                 tmp_sbr = (clk / (baudrate * tmp_osr));
1580                 if (tmp_sbr == 0)
1581                         tmp_sbr = 1;
1582
1583                 /*
1584                  * calculate the baud rate difference based on the temporary
1585                  * osr and sbr values
1586                  */
1587                 tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate;
1588
1589                 /* select best values between sbr and sbr+1 */
1590                 tmp = clk / (tmp_osr * (tmp_sbr + 1));
1591                 if (tmp_diff > (baudrate - tmp)) {
1592                         tmp_diff = baudrate - tmp;
1593                         tmp_sbr++;
1594                 }
1595
1596                 if (tmp_diff <= baud_diff) {
1597                         baud_diff = tmp_diff;
1598                         osr = tmp_osr;
1599                         sbr = tmp_sbr;
1600
1601                         if (!baud_diff)
1602                                 break;
1603                 }
1604         }
1605
1606         /* handle buadrate outside acceptable rate */
1607         if (baud_diff > ((baudrate / 100) * 3))
1608                 dev_warn(sport->port.dev,
1609                          "unacceptable baud rate difference of more than 3%%\n");
1610
1611         tmp = lpuart32_read(&sport->port, UARTBAUD);
1612
1613         if ((osr > 3) && (osr < 8))
1614                 tmp |= UARTBAUD_BOTHEDGE;
1615
1616         tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT);
1617         tmp |= (((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT);
1618
1619         tmp &= ~UARTBAUD_SBR_MASK;
1620         tmp |= sbr & UARTBAUD_SBR_MASK;
1621
1622         tmp &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE);
1623
1624         lpuart32_write(&sport->port, tmp, UARTBAUD);
1625 }
1626
1627 static void
1628 lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
1629                    struct ktermios *old)
1630 {
1631         struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1632         unsigned long flags;
1633         unsigned long ctrl, old_ctrl, modem;
1634         unsigned int  baud;
1635         unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1636
1637         ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL);
1638         modem = lpuart32_read(&sport->port, UARTMODIR);
1639         /*
1640          * only support CS8 and CS7, and for CS7 must enable PE.
1641          * supported mode:
1642          *  - (7,e/o,1)
1643          *  - (8,n,1)
1644          *  - (8,m/s,1)
1645          *  - (8,e/o,1)
1646          */
1647         while ((termios->c_cflag & CSIZE) != CS8 &&
1648                 (termios->c_cflag & CSIZE) != CS7) {
1649                 termios->c_cflag &= ~CSIZE;
1650                 termios->c_cflag |= old_csize;
1651                 old_csize = CS8;
1652         }
1653
1654         if ((termios->c_cflag & CSIZE) == CS8 ||
1655                 (termios->c_cflag & CSIZE) == CS7)
1656                 ctrl = old_ctrl & ~UARTCTRL_M;
1657
1658         if (termios->c_cflag & CMSPAR) {
1659                 if ((termios->c_cflag & CSIZE) != CS8) {
1660                         termios->c_cflag &= ~CSIZE;
1661                         termios->c_cflag |= CS8;
1662                 }
1663                 ctrl |= UARTCTRL_M;
1664         }
1665
1666         if (termios->c_cflag & CRTSCTS) {
1667                 modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1668         } else {
1669                 termios->c_cflag &= ~CRTSCTS;
1670                 modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1671         }
1672
1673         if (termios->c_cflag & CSTOPB)
1674                 termios->c_cflag &= ~CSTOPB;
1675
1676         /* parity must be enabled when CS7 to match 8-bits format */
1677         if ((termios->c_cflag & CSIZE) == CS7)
1678                 termios->c_cflag |= PARENB;
1679
1680         if ((termios->c_cflag & PARENB)) {
1681                 if (termios->c_cflag & CMSPAR) {
1682                         ctrl &= ~UARTCTRL_PE;
1683                         ctrl |= UARTCTRL_M;
1684                 } else {
1685                         ctrl |= UARTCR1_PE;
1686                         if ((termios->c_cflag & CSIZE) == CS8)
1687                                 ctrl |= UARTCTRL_M;
1688                         if (termios->c_cflag & PARODD)
1689                                 ctrl |= UARTCTRL_PT;
1690                         else
1691                                 ctrl &= ~UARTCTRL_PT;
1692                 }
1693         } else {
1694                 ctrl &= ~UARTCTRL_PE;
1695         }
1696
1697         /* ask the core to calculate the divisor */
1698         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4);
1699
1700         spin_lock_irqsave(&sport->port.lock, flags);
1701
1702         sport->port.read_status_mask = 0;
1703         if (termios->c_iflag & INPCK)
1704                 sport->port.read_status_mask |= (UARTSTAT_FE | UARTSTAT_PE);
1705         if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1706                 sport->port.read_status_mask |= UARTSTAT_FE;
1707
1708         /* characters to ignore */
1709         sport->port.ignore_status_mask = 0;
1710         if (termios->c_iflag & IGNPAR)
1711                 sport->port.ignore_status_mask |= UARTSTAT_PE;
1712         if (termios->c_iflag & IGNBRK) {
1713                 sport->port.ignore_status_mask |= UARTSTAT_FE;
1714                 /*
1715                  * if we're ignoring parity and break indicators,
1716                  * ignore overruns too (for real raw support).
1717                  */
1718                 if (termios->c_iflag & IGNPAR)
1719                         sport->port.ignore_status_mask |= UARTSTAT_OR;
1720         }
1721
1722         /* update the per-port timeout */
1723         uart_update_timeout(port, termios->c_cflag, baud);
1724
1725         /* wait transmit engin complete */
1726         while (!(lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_TC))
1727                 barrier();
1728
1729         /* disable transmit and receive */
1730         lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE),
1731                        UARTCTRL);
1732
1733         lpuart32_serial_setbrg(sport, baud);
1734         lpuart32_write(&sport->port, modem, UARTMODIR);
1735         lpuart32_write(&sport->port, ctrl, UARTCTRL);
1736         /* restore control register */
1737
1738         spin_unlock_irqrestore(&sport->port.lock, flags);
1739 }
1740
1741 static const char *lpuart_type(struct uart_port *port)
1742 {
1743         return "FSL_LPUART";
1744 }
1745
1746 static void lpuart_release_port(struct uart_port *port)
1747 {
1748         /* nothing to do */
1749 }
1750
1751 static int lpuart_request_port(struct uart_port *port)
1752 {
1753         return  0;
1754 }
1755
1756 /* configure/autoconfigure the port */
1757 static void lpuart_config_port(struct uart_port *port, int flags)
1758 {
1759         if (flags & UART_CONFIG_TYPE)
1760                 port->type = PORT_LPUART;
1761 }
1762
1763 static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser)
1764 {
1765         int ret = 0;
1766
1767         if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART)
1768                 ret = -EINVAL;
1769         if (port->irq != ser->irq)
1770                 ret = -EINVAL;
1771         if (ser->io_type != UPIO_MEM)
1772                 ret = -EINVAL;
1773         if (port->uartclk / 16 != ser->baud_base)
1774                 ret = -EINVAL;
1775         if (port->iobase != ser->port)
1776                 ret = -EINVAL;
1777         if (ser->hub6 != 0)
1778                 ret = -EINVAL;
1779         return ret;
1780 }
1781
1782 static const struct uart_ops lpuart_pops = {
1783         .tx_empty       = lpuart_tx_empty,
1784         .set_mctrl      = lpuart_set_mctrl,
1785         .get_mctrl      = lpuart_get_mctrl,
1786         .stop_tx        = lpuart_stop_tx,
1787         .start_tx       = lpuart_start_tx,
1788         .stop_rx        = lpuart_stop_rx,
1789         .break_ctl      = lpuart_break_ctl,
1790         .startup        = lpuart_startup,
1791         .shutdown       = lpuart_shutdown,
1792         .set_termios    = lpuart_set_termios,
1793         .type           = lpuart_type,
1794         .request_port   = lpuart_request_port,
1795         .release_port   = lpuart_release_port,
1796         .config_port    = lpuart_config_port,
1797         .verify_port    = lpuart_verify_port,
1798         .flush_buffer   = lpuart_flush_buffer,
1799 #if defined(CONFIG_CONSOLE_POLL)
1800         .poll_init      = lpuart_poll_init,
1801         .poll_get_char  = lpuart_poll_get_char,
1802         .poll_put_char  = lpuart_poll_put_char,
1803 #endif
1804 };
1805
1806 static const struct uart_ops lpuart32_pops = {
1807         .tx_empty       = lpuart32_tx_empty,
1808         .set_mctrl      = lpuart32_set_mctrl,
1809         .get_mctrl      = lpuart32_get_mctrl,
1810         .stop_tx        = lpuart32_stop_tx,
1811         .start_tx       = lpuart32_start_tx,
1812         .stop_rx        = lpuart32_stop_rx,
1813         .break_ctl      = lpuart32_break_ctl,
1814         .startup        = lpuart32_startup,
1815         .shutdown       = lpuart32_shutdown,
1816         .set_termios    = lpuart32_set_termios,
1817         .type           = lpuart_type,
1818         .request_port   = lpuart_request_port,
1819         .release_port   = lpuart_release_port,
1820         .config_port    = lpuart_config_port,
1821         .verify_port    = lpuart_verify_port,
1822         .flush_buffer   = lpuart_flush_buffer,
1823 #if defined(CONFIG_CONSOLE_POLL)
1824         .poll_init      = lpuart32_poll_init,
1825         .poll_get_char  = lpuart32_poll_get_char,
1826         .poll_put_char  = lpuart32_poll_put_char,
1827 #endif
1828 };
1829
1830 static struct lpuart_port *lpuart_ports[UART_NR];
1831
1832 #ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
1833 static void lpuart_console_putchar(struct uart_port *port, int ch)
1834 {
1835         while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
1836                 barrier();
1837
1838         writeb(ch, port->membase + UARTDR);
1839 }
1840
1841 static void lpuart32_console_putchar(struct uart_port *port, int ch)
1842 {
1843         while (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE))
1844                 barrier();
1845
1846         lpuart32_write(port, ch, UARTDATA);
1847 }
1848
1849 static void
1850 lpuart_console_write(struct console *co, const char *s, unsigned int count)
1851 {
1852         struct lpuart_port *sport = lpuart_ports[co->index];
1853         unsigned char  old_cr2, cr2;
1854         unsigned long flags;
1855         int locked = 1;
1856
1857         if (sport->port.sysrq || oops_in_progress)
1858                 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1859         else
1860                 spin_lock_irqsave(&sport->port.lock, flags);
1861
1862         /* first save CR2 and then disable interrupts */
1863         cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
1864         cr2 |= (UARTCR2_TE |  UARTCR2_RE);
1865         cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
1866         writeb(cr2, sport->port.membase + UARTCR2);
1867
1868         uart_console_write(&sport->port, s, count, lpuart_console_putchar);
1869
1870         /* wait for transmitter finish complete and restore CR2 */
1871         while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
1872                 barrier();
1873
1874         writeb(old_cr2, sport->port.membase + UARTCR2);
1875
1876         if (locked)
1877                 spin_unlock_irqrestore(&sport->port.lock, flags);
1878 }
1879
1880 static void
1881 lpuart32_console_write(struct console *co, const char *s, unsigned int count)
1882 {
1883         struct lpuart_port *sport = lpuart_ports[co->index];
1884         unsigned long  old_cr, cr;
1885         unsigned long flags;
1886         int locked = 1;
1887
1888         if (sport->port.sysrq || oops_in_progress)
1889                 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1890         else
1891                 spin_lock_irqsave(&sport->port.lock, flags);
1892
1893         /* first save CR2 and then disable interrupts */
1894         cr = old_cr = lpuart32_read(&sport->port, UARTCTRL);
1895         cr |= (UARTCTRL_TE |  UARTCTRL_RE);
1896         cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
1897         lpuart32_write(&sport->port, cr, UARTCTRL);
1898
1899         uart_console_write(&sport->port, s, count, lpuart32_console_putchar);
1900
1901         /* wait for transmitter finish complete and restore CR2 */
1902         while (!(lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_TC))
1903                 barrier();
1904
1905         lpuart32_write(&sport->port, old_cr, UARTCTRL);
1906
1907         if (locked)
1908                 spin_unlock_irqrestore(&sport->port.lock, flags);
1909 }
1910
1911 /*
1912  * if the port was already initialised (eg, by a boot loader),
1913  * try to determine the current setup.
1914  */
1915 static void __init
1916 lpuart_console_get_options(struct lpuart_port *sport, int *baud,
1917                            int *parity, int *bits)
1918 {
1919         unsigned char cr, bdh, bdl, brfa;
1920         unsigned int sbr, uartclk, baud_raw;
1921
1922         cr = readb(sport->port.membase + UARTCR2);
1923         cr &= UARTCR2_TE | UARTCR2_RE;
1924         if (!cr)
1925                 return;
1926
1927         /* ok, the port was enabled */
1928
1929         cr = readb(sport->port.membase + UARTCR1);
1930
1931         *parity = 'n';
1932         if (cr & UARTCR1_PE) {
1933                 if (cr & UARTCR1_PT)
1934                         *parity = 'o';
1935                 else
1936                         *parity = 'e';
1937         }
1938
1939         if (cr & UARTCR1_M)
1940                 *bits = 9;
1941         else
1942                 *bits = 8;
1943
1944         bdh = readb(sport->port.membase + UARTBDH);
1945         bdh &= UARTBDH_SBR_MASK;
1946         bdl = readb(sport->port.membase + UARTBDL);
1947         sbr = bdh;
1948         sbr <<= 8;
1949         sbr |= bdl;
1950         brfa = readb(sport->port.membase + UARTCR4);
1951         brfa &= UARTCR4_BRFA_MASK;
1952
1953         uartclk = clk_get_rate(sport->clk);
1954         /*
1955          * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
1956          */
1957         baud_raw = uartclk / (16 * (sbr + brfa / 32));
1958
1959         if (*baud != baud_raw)
1960                 printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
1961                                 "from %d to %d\n", baud_raw, *baud);
1962 }
1963
1964 static void __init
1965 lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
1966                            int *parity, int *bits)
1967 {
1968         unsigned long cr, bd;
1969         unsigned int sbr, uartclk, baud_raw;
1970
1971         cr = lpuart32_read(&sport->port, UARTCTRL);
1972         cr &= UARTCTRL_TE | UARTCTRL_RE;
1973         if (!cr)
1974                 return;
1975
1976         /* ok, the port was enabled */
1977
1978         cr = lpuart32_read(&sport->port, UARTCTRL);
1979
1980         *parity = 'n';
1981         if (cr & UARTCTRL_PE) {
1982                 if (cr & UARTCTRL_PT)
1983                         *parity = 'o';
1984                 else
1985                         *parity = 'e';
1986         }
1987
1988         if (cr & UARTCTRL_M)
1989                 *bits = 9;
1990         else
1991                 *bits = 8;
1992
1993         bd = lpuart32_read(&sport->port, UARTBAUD);
1994         bd &= UARTBAUD_SBR_MASK;
1995         if (!bd)
1996                 return;
1997
1998         sbr = bd;
1999         uartclk = clk_get_rate(sport->clk);
2000         /*
2001          * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
2002          */
2003         baud_raw = uartclk / (16 * sbr);
2004
2005         if (*baud != baud_raw)
2006                 printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
2007                                 "from %d to %d\n", baud_raw, *baud);
2008 }
2009
2010 static int __init lpuart_console_setup(struct console *co, char *options)
2011 {
2012         struct lpuart_port *sport;
2013         int baud = 115200;
2014         int bits = 8;
2015         int parity = 'n';
2016         int flow = 'n';
2017
2018         /*
2019          * check whether an invalid uart number has been specified, and
2020          * if so, search for the first available port that does have
2021          * console support.
2022          */
2023         if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports))
2024                 co->index = 0;
2025
2026         sport = lpuart_ports[co->index];
2027         if (sport == NULL)
2028                 return -ENODEV;
2029
2030         if (options)
2031                 uart_parse_options(options, &baud, &parity, &bits, &flow);
2032         else
2033                 if (lpuart_is_32(sport))
2034                         lpuart32_console_get_options(sport, &baud, &parity, &bits);
2035                 else
2036                         lpuart_console_get_options(sport, &baud, &parity, &bits);
2037
2038         if (lpuart_is_32(sport))
2039                 lpuart32_setup_watermark(sport);
2040         else
2041                 lpuart_setup_watermark(sport);
2042
2043         return uart_set_options(&sport->port, co, baud, parity, bits, flow);
2044 }
2045
2046 static struct uart_driver lpuart_reg;
2047 static struct console lpuart_console = {
2048         .name           = DEV_NAME,
2049         .write          = lpuart_console_write,
2050         .device         = uart_console_device,
2051         .setup          = lpuart_console_setup,
2052         .flags          = CON_PRINTBUFFER,
2053         .index          = -1,
2054         .data           = &lpuart_reg,
2055 };
2056
2057 static struct console lpuart32_console = {
2058         .name           = DEV_NAME,
2059         .write          = lpuart32_console_write,
2060         .device         = uart_console_device,
2061         .setup          = lpuart_console_setup,
2062         .flags          = CON_PRINTBUFFER,
2063         .index          = -1,
2064         .data           = &lpuart_reg,
2065 };
2066
2067 static void lpuart_early_write(struct console *con, const char *s, unsigned n)
2068 {
2069         struct earlycon_device *dev = con->data;
2070
2071         uart_console_write(&dev->port, s, n, lpuart_console_putchar);
2072 }
2073
2074 static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
2075 {
2076         struct earlycon_device *dev = con->data;
2077
2078         uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
2079 }
2080
2081 static int __init lpuart_early_console_setup(struct earlycon_device *device,
2082                                           const char *opt)
2083 {
2084         if (!device->port.membase)
2085                 return -ENODEV;
2086
2087         device->con->write = lpuart_early_write;
2088         return 0;
2089 }
2090
2091 static int __init lpuart32_early_console_setup(struct earlycon_device *device,
2092                                           const char *opt)
2093 {
2094         if (!device->port.membase)
2095                 return -ENODEV;
2096
2097         device->port.iotype = UPIO_MEM32BE;
2098         device->con->write = lpuart32_early_write;
2099         return 0;
2100 }
2101
2102 static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device,
2103                                                    const char *opt)
2104 {
2105         if (!device->port.membase)
2106                 return -ENODEV;
2107
2108         device->port.iotype = UPIO_MEM32;
2109         device->port.membase += IMX_REG_OFF;
2110         device->con->write = lpuart32_early_write;
2111
2112         return 0;
2113 }
2114 OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
2115 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
2116 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
2117 EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
2118 EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
2119
2120 #define LPUART_CONSOLE  (&lpuart_console)
2121 #define LPUART32_CONSOLE        (&lpuart32_console)
2122 #else
2123 #define LPUART_CONSOLE  NULL
2124 #define LPUART32_CONSOLE        NULL
2125 #endif
2126
2127 static struct uart_driver lpuart_reg = {
2128         .owner          = THIS_MODULE,
2129         .driver_name    = DRIVER_NAME,
2130         .dev_name       = DEV_NAME,
2131         .nr             = ARRAY_SIZE(lpuart_ports),
2132         .cons           = LPUART_CONSOLE,
2133 };
2134
2135 static int lpuart_probe(struct platform_device *pdev)
2136 {
2137         const struct of_device_id *of_id = of_match_device(lpuart_dt_ids,
2138                                                            &pdev->dev);
2139         const struct lpuart_soc_data *sdata = of_id->data;
2140         struct device_node *np = pdev->dev.of_node;
2141         struct lpuart_port *sport;
2142         struct resource *res;
2143         int ret;
2144
2145         sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2146         if (!sport)
2147                 return -ENOMEM;
2148
2149         pdev->dev.coherent_dma_mask = 0;
2150
2151         ret = of_alias_get_id(np, "serial");
2152         if (ret < 0) {
2153                 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2154                 return ret;
2155         }
2156         if (ret >= ARRAY_SIZE(lpuart_ports)) {
2157                 dev_err(&pdev->dev, "serial%d out of range\n", ret);
2158                 return -EINVAL;
2159         }
2160         sport->port.line = ret;
2161         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2162         sport->port.membase = devm_ioremap_resource(&pdev->dev, res);
2163         if (IS_ERR(sport->port.membase))
2164                 return PTR_ERR(sport->port.membase);
2165
2166         sport->port.membase += sdata->reg_off;
2167         sport->port.mapbase = res->start + sdata->reg_off;
2168         sport->port.dev = &pdev->dev;
2169         sport->port.type = PORT_LPUART;
2170         ret = platform_get_irq(pdev, 0);
2171         if (ret < 0) {
2172                 dev_err(&pdev->dev, "cannot obtain irq\n");
2173                 return ret;
2174         }
2175         sport->port.irq = ret;
2176         sport->port.iotype = sdata->iotype;
2177         if (lpuart_is_32(sport))
2178                 sport->port.ops = &lpuart32_pops;
2179         else
2180                 sport->port.ops = &lpuart_pops;
2181         sport->port.flags = UPF_BOOT_AUTOCONF;
2182
2183         sport->port.rs485_config = lpuart_config_rs485;
2184
2185         sport->clk = devm_clk_get(&pdev->dev, "ipg");
2186         if (IS_ERR(sport->clk)) {
2187                 ret = PTR_ERR(sport->clk);
2188                 dev_err(&pdev->dev, "failed to get uart clk: %d\n", ret);
2189                 return ret;
2190         }
2191
2192         ret = clk_prepare_enable(sport->clk);
2193         if (ret) {
2194                 dev_err(&pdev->dev, "failed to enable uart clk: %d\n", ret);
2195                 return ret;
2196         }
2197
2198         sport->port.uartclk = clk_get_rate(sport->clk);
2199
2200         lpuart_ports[sport->port.line] = sport;
2201
2202         platform_set_drvdata(pdev, &sport->port);
2203
2204         if (lpuart_is_32(sport)) {
2205                 lpuart_reg.cons = LPUART32_CONSOLE;
2206                 ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0,
2207                                         DRIVER_NAME, sport);
2208         } else {
2209                 lpuart_reg.cons = LPUART_CONSOLE;
2210                 ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0,
2211                                         DRIVER_NAME, sport);
2212         }
2213
2214         if (ret)
2215                 goto failed_irq_request;
2216
2217         ret = uart_add_one_port(&lpuart_reg, &sport->port);
2218         if (ret)
2219                 goto failed_attach_port;
2220
2221         uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2222
2223         if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX)
2224                 dev_err(&pdev->dev, "driver doesn't support RX during TX\n");
2225
2226         if (sport->port.rs485.delay_rts_before_send ||
2227             sport->port.rs485.delay_rts_after_send)
2228                 dev_err(&pdev->dev, "driver doesn't support RTS delays\n");
2229
2230         lpuart_config_rs485(&sport->port, &sport->port.rs485);
2231
2232         sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
2233         if (!sport->dma_tx_chan)
2234                 dev_info(sport->port.dev, "DMA tx channel request failed, "
2235                                 "operating without tx DMA\n");
2236
2237         sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
2238         if (!sport->dma_rx_chan)
2239                 dev_info(sport->port.dev, "DMA rx channel request failed, "
2240                                 "operating without rx DMA\n");
2241
2242         return 0;
2243
2244 failed_attach_port:
2245 failed_irq_request:
2246         clk_disable_unprepare(sport->clk);
2247         return ret;
2248 }
2249
2250 static int lpuart_remove(struct platform_device *pdev)
2251 {
2252         struct lpuart_port *sport = platform_get_drvdata(pdev);
2253
2254         uart_remove_one_port(&lpuart_reg, &sport->port);
2255
2256         clk_disable_unprepare(sport->clk);
2257
2258         if (sport->dma_tx_chan)
2259                 dma_release_channel(sport->dma_tx_chan);
2260
2261         if (sport->dma_rx_chan)
2262                 dma_release_channel(sport->dma_rx_chan);
2263
2264         return 0;
2265 }
2266
2267 #ifdef CONFIG_PM_SLEEP
2268 static int lpuart_suspend(struct device *dev)
2269 {
2270         struct lpuart_port *sport = dev_get_drvdata(dev);
2271         unsigned long temp;
2272         bool irq_wake;
2273
2274         if (lpuart_is_32(sport)) {
2275                 /* disable Rx/Tx and interrupts */
2276                 temp = lpuart32_read(&sport->port, UARTCTRL);
2277                 temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
2278                 lpuart32_write(&sport->port, temp, UARTCTRL);
2279         } else {
2280                 /* disable Rx/Tx and interrupts */
2281                 temp = readb(sport->port.membase + UARTCR2);
2282                 temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
2283                 writeb(temp, sport->port.membase + UARTCR2);
2284         }
2285
2286         uart_suspend_port(&lpuart_reg, &sport->port);
2287
2288         /* uart_suspend_port() might set wakeup flag */
2289         irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
2290
2291         if (sport->lpuart_dma_rx_use) {
2292                 /*
2293                  * EDMA driver during suspend will forcefully release any
2294                  * non-idle DMA channels. If port wakeup is enabled or if port
2295                  * is console port or 'no_console_suspend' is set the Rx DMA
2296                  * cannot resume as as expected, hence gracefully release the
2297                  * Rx DMA path before suspend and start Rx DMA path on resume.
2298                  */
2299                 if (irq_wake) {
2300                         del_timer_sync(&sport->lpuart_timer);
2301                         lpuart_dma_rx_free(&sport->port);
2302                 }
2303
2304                 /* Disable Rx DMA to use UART port as wakeup source */
2305                 writeb(readb(sport->port.membase + UARTCR5) & ~UARTCR5_RDMAS,
2306                                         sport->port.membase + UARTCR5);
2307         }
2308
2309         if (sport->lpuart_dma_tx_use) {
2310                 sport->dma_tx_in_progress = false;
2311                 dmaengine_terminate_all(sport->dma_tx_chan);
2312         }
2313
2314         if (sport->port.suspended && !irq_wake)
2315                 clk_disable_unprepare(sport->clk);
2316
2317         return 0;
2318 }
2319
2320 static int lpuart_resume(struct device *dev)
2321 {
2322         struct lpuart_port *sport = dev_get_drvdata(dev);
2323         bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
2324         unsigned long temp;
2325
2326         if (sport->port.suspended && !irq_wake)
2327                 clk_prepare_enable(sport->clk);
2328
2329         if (lpuart_is_32(sport)) {
2330                 lpuart32_setup_watermark(sport);
2331                 temp = lpuart32_read(&sport->port, UARTCTRL);
2332                 temp |= (UARTCTRL_RIE | UARTCTRL_TIE | UARTCTRL_RE |
2333                          UARTCTRL_TE | UARTCTRL_ILIE);
2334                 lpuart32_write(&sport->port, temp, UARTCTRL);
2335         } else {
2336                 lpuart_setup_watermark(sport);
2337                 temp = readb(sport->port.membase + UARTCR2);
2338                 temp |= (UARTCR2_RIE | UARTCR2_TIE | UARTCR2_RE | UARTCR2_TE);
2339                 writeb(temp, sport->port.membase + UARTCR2);
2340         }
2341
2342         if (sport->lpuart_dma_rx_use) {
2343                 if (irq_wake) {
2344                         if (!lpuart_start_rx_dma(sport))
2345                                 rx_dma_timer_init(sport);
2346                         else
2347                                 sport->lpuart_dma_rx_use = false;
2348                 }
2349         }
2350
2351         if (sport->dma_tx_chan && !lpuart_dma_tx_request(&sport->port)) {
2352                         init_waitqueue_head(&sport->dma_wait);
2353                         sport->lpuart_dma_tx_use = true;
2354                         writeb(readb(sport->port.membase + UARTCR5) |
2355                                 UARTCR5_TDMAS, sport->port.membase + UARTCR5);
2356         } else {
2357                 sport->lpuart_dma_tx_use = false;
2358         }
2359
2360         uart_resume_port(&lpuart_reg, &sport->port);
2361
2362         return 0;
2363 }
2364 #endif
2365
2366 static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume);
2367
2368 static struct platform_driver lpuart_driver = {
2369         .probe          = lpuart_probe,
2370         .remove         = lpuart_remove,
2371         .driver         = {
2372                 .name   = "fsl-lpuart",
2373                 .of_match_table = lpuart_dt_ids,
2374                 .pm     = &lpuart_pm_ops,
2375         },
2376 };
2377
2378 static int __init lpuart_serial_init(void)
2379 {
2380         int ret = uart_register_driver(&lpuart_reg);
2381
2382         if (ret)
2383                 return ret;
2384
2385         ret = platform_driver_register(&lpuart_driver);
2386         if (ret)
2387                 uart_unregister_driver(&lpuart_reg);
2388
2389         return ret;
2390 }
2391
2392 static void __exit lpuart_serial_exit(void)
2393 {
2394         platform_driver_unregister(&lpuart_driver);
2395         uart_unregister_driver(&lpuart_reg);
2396 }
2397
2398 module_init(lpuart_serial_init);
2399 module_exit(lpuart_serial_exit);
2400
2401 MODULE_DESCRIPTION("Freescale lpuart serial port driver");
2402 MODULE_LICENSE("GPL v2");