ifx6x60.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /****************************************************************************
   3  *
   4  * Driver for the IFX 6x60 spi modem.
   5  *
   6  * Copyright (C) 2008 Option International
   7  * Copyright (C) 2008 Filip Aben <f.aben@option.com>
   8  *                    Denis Joseph Barrow <d.barow@option.com>
   9  *                    Jan Dumon <j.dumon@option.com>
  10  *
  11  * Copyright (C) 2009, 2010 Intel Corp
  12  * Russ Gorby <russ.gorby@intel.com>
  13  *
  14  * Driver modified by Intel from Option gtm501l_spi.c
  15  *
  16  * Notes
  17  * o    The driver currently assumes a single device only. If you need to
  18  *      change this then look for saved_ifx_dev and add a device lookup
  19  * o    The driver is intended to be big-endian safe but has never been
  20  *      tested that way (no suitable hardware). There are a couple of FIXME
  21  *      notes by areas that may need addressing
  22  * o    Some of the GPIO naming/setup assumptions may need revisiting if
  23  *      you need to use this driver for another platform.
  24  *
  25  *****************************************************************************/
  26 #include <linux/dma-mapping.h>
  27 #include <linux/module.h>
  28 #include <linux/termios.h>
  29 #include <linux/tty.h>
  30 #include <linux/device.h>
  31 #include <linux/spi/spi.h>
  32 #include <linux/kfifo.h>
  33 #include <linux/tty_flip.h>
  34 #include <linux/timer.h>
  35 #include <linux/serial.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/irq.h>
  38 #include <linux/rfkill.h>
  39 #include <linux/fs.h>
  40 #include <linux/ip.h>
  41 #include <linux/dmapool.h>
  42 #include <linux/gpio/consumer.h>
  43 #include <linux/sched.h>
  44 #include <linux/time.h>
  45 #include <linux/wait.h>
  46 #include <linux/pm.h>
  47 #include <linux/pm_runtime.h>
  48 #include <linux/spi/ifx_modem.h>
  49 #include <linux/delay.h>
  50 #include <linux/reboot.h>
  51
  52 #include "ifx6x60.h"
  53
  54 #define IFX_SPI_MORE_MASK               0x10
  55 #define IFX_SPI_MORE_BIT                4       /* bit position in u8 */
  56 #define IFX_SPI_CTS_BIT                 6       /* bit position in u8 */
  57 #define IFX_SPI_MODE                    SPI_MODE_1
  58 #define IFX_SPI_TTY_ID                  0
  59 #define IFX_SPI_TIMEOUT_SEC             2
  60 #define IFX_SPI_HEADER_0                (-1)
  61 #define IFX_SPI_HEADER_F                (-2)
  62
  63 #define PO_POST_DELAY           200
  64
  65 /* forward reference */
  66 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
  67 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
  68                                 unsigned long event, void *data);
  69 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev);
  70
  71 /* local variables */
  72 static int spi_bpw = 16;                /* 8, 16 or 32 bit word length */
  73 static struct tty_driver *tty_drv;
  74 static struct ifx_spi_device *saved_ifx_dev;
  75 static struct lock_class_key ifx_spi_key;
  76
  77 static struct notifier_block ifx_modem_reboot_notifier_block = {
  78         .notifier_call = ifx_modem_reboot_callback,
  79 };
  80
  81 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev)
  82 {
  83         gpiod_set_value(ifx_dev->gpio.pmu_reset, 1);
  84         msleep(PO_POST_DELAY);
  85
  86         return 0;
  87 }
  88
  89 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
  90                                  unsigned long event, void *data)
  91 {
  92         if (saved_ifx_dev)
  93                 ifx_modem_power_off(saved_ifx_dev);
  94         else
  95                 pr_warn("no ifx modem active;\n");
  96
  97         return NOTIFY_OK;
  98 }
  99
 100 /* GPIO/GPE settings */
 101
 102 /**
 103  *      mrdy_set_high           -       set MRDY GPIO
 104  *      @ifx: device we are controlling
 105  *
 106  */
 107 static inline void mrdy_set_high(struct ifx_spi_device *ifx)
 108 {
 109         gpiod_set_value(ifx->gpio.mrdy, 1);
 110 }
 111
 112 /**
 113  *      mrdy_set_low            -       clear MRDY GPIO
 114  *      @ifx: device we are controlling
 115  *
 116  */
 117 static inline void mrdy_set_low(struct ifx_spi_device *ifx)
 118 {
 119         gpiod_set_value(ifx->gpio.mrdy, 0);
 120 }
 121
 122 /**
 123  *      ifx_spi_power_state_set
 124  *      @ifx_dev: our SPI device
 125  *      @val: bits to set
 126  *
 127  *      Set bit in power status and signal power system if status becomes non-0
 128  */
 129 static void
 130 ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
 131 {
 132         unsigned long flags;
 133
 134         spin_lock_irqsave(&ifx_dev->power_lock, flags);
 135
 136         /*
 137          * if power status is already non-0, just update, else
 138          * tell power system
 139          */
 140         if (!ifx_dev->power_status)
 141                 pm_runtime_get(&ifx_dev->spi_dev->dev);
 142         ifx_dev->power_status |= val;
 143
 144         spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
 145 }
 146
 147 /**
 148  *      ifx_spi_power_state_clear       -       clear power bit
 149  *      @ifx_dev: our SPI device
 150  *      @val: bits to clear
 151  *
 152  *      clear bit in power status and signal power system if status becomes 0
 153  */
 154 static void
 155 ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
 156 {
 157         unsigned long flags;
 158
 159         spin_lock_irqsave(&ifx_dev->power_lock, flags);
 160
 161         if (ifx_dev->power_status) {
 162                 ifx_dev->power_status &= ~val;
 163                 if (!ifx_dev->power_status)
 164                         pm_runtime_put(&ifx_dev->spi_dev->dev);
 165         }
 166
 167         spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
 168 }
 169
 170 /**
 171  *      swap_buf_8
 172  *      @buf: our buffer
 173  *      @len : number of bytes (not words) in the buffer
 174  *      @end: end of buffer
 175  *
 176  *      Swap the contents of a buffer into big endian format
 177  */
 178 static inline void swap_buf_8(unsigned char *buf, int len, void *end)
 179 {
 180         /* don't swap buffer if SPI word width is 8 bits */
 181         return;
 182 }
 183
 184 /**
 185  *      swap_buf_16
 186  *      @buf: our buffer
 187  *      @len : number of bytes (not words) in the buffer
 188  *      @end: end of buffer
 189  *
 190  *      Swap the contents of a buffer into big endian format
 191  */
 192 static inline void swap_buf_16(unsigned char *buf, int len, void *end)
 193 {
 194         int n;
 195
 196         u16 *buf_16 = (u16 *)buf;
 197         len = ((len + 1) >> 1);
 198         if ((void *)&buf_16[len] > end) {
 199                 pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!",
 200                        &buf_16[len], end);
 201                 return;
 202         }
 203         for (n = 0; n < len; n++) {
 204                 *buf_16 = cpu_to_be16(*buf_16);
 205                 buf_16++;
 206         }
 207 }
 208
 209 /**
 210  *      swap_buf_32
 211  *      @buf: our buffer
 212  *      @len : number of bytes (not words) in the buffer
 213  *      @end: end of buffer
 214  *
 215  *      Swap the contents of a buffer into big endian format
 216  */
 217 static inline void swap_buf_32(unsigned char *buf, int len, void *end)
 218 {
 219         int n;
 220
 221         u32 *buf_32 = (u32 *)buf;
 222         len = (len + 3) >> 2;
 223
 224         if ((void *)&buf_32[len] > end) {
 225                 pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n",
 226                        &buf_32[len], end);
 227                 return;
 228         }
 229         for (n = 0; n < len; n++) {
 230                 *buf_32 = cpu_to_be32(*buf_32);
 231                 buf_32++;
 232         }
 233 }
 234
 235 /**
 236  *      mrdy_assert             -       assert MRDY line
 237  *      @ifx_dev: our SPI device
 238  *
 239  *      Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
 240  *      now.
 241  *
 242  *      FIXME: Can SRDY even go high as we are running this code ?
 243  */
 244 static void mrdy_assert(struct ifx_spi_device *ifx_dev)
 245 {
 246         int val = gpiod_get_value(ifx_dev->gpio.srdy);
 247         if (!val) {
 248                 if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
 249                                       &ifx_dev->flags)) {
 250                         mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ);
 251
 252                 }
 253         }
 254         ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
 255         mrdy_set_high(ifx_dev);
 256 }
 257
 258 /**
 259  *      ifx_spi_timeout         -       SPI timeout
 260  *      @t: timer in our SPI device
 261  *
 262  *      The SPI has timed out: hang up the tty. Users will then see a hangup
 263  *      and error events.
 264  */
 265 static void ifx_spi_timeout(struct timer_list *t)
 266 {
 267         struct ifx_spi_device *ifx_dev = from_timer(ifx_dev, t, spi_timer);
 268
 269         dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
 270         tty_port_tty_hangup(&ifx_dev->tty_port, false);
 271         mrdy_set_low(ifx_dev);
 272         clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 273 }
 274
 275 /* char/tty operations */
 276
 277 /**
 278  *      ifx_spi_tiocmget        -       get modem lines
 279  *      @tty: our tty device
 280  *
 281  *      Map the signal state into Linux modem flags and report the value
 282  *      in Linux terms
 283  */
 284 static int ifx_spi_tiocmget(struct tty_struct *tty)
 285 {
 286         unsigned int value;
 287         struct ifx_spi_device *ifx_dev = tty->driver_data;
 288
 289         value =
 290         (test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
 291         (test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
 292         (test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
 293         (test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
 294         (test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
 295         (test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
 296         return value;
 297 }
 298
 299 /**
 300  *      ifx_spi_tiocmset        -       set modem bits
 301  *      @tty: the tty structure
 302  *      @set: bits to set
 303  *      @clear: bits to clear
 304  *
 305  *      The IFX6x60 only supports DTR and RTS. Set them accordingly
 306  *      and flag that an update to the modem is needed.
 307  *
 308  *      FIXME: do we need to kick the tranfers when we do this ?
 309  */
 310 static int ifx_spi_tiocmset(struct tty_struct *tty,
 311                             unsigned int set, unsigned int clear)
 312 {
 313         struct ifx_spi_device *ifx_dev = tty->driver_data;
 314
 315         if (set & TIOCM_RTS)
 316                 set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
 317         if (set & TIOCM_DTR)
 318                 set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
 319         if (clear & TIOCM_RTS)
 320                 clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
 321         if (clear & TIOCM_DTR)
 322                 clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
 323
 324         set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
 325         return 0;
 326 }
 327
 328 /**
 329  *      ifx_spi_open    -       called on tty open
 330  *      @tty: our tty device
 331  *      @filp: file handle being associated with the tty
 332  *
 333  *      Open the tty interface. We let the tty_port layer do all the work
 334  *      for us.
 335  *
 336  *      FIXME: Remove single device assumption and saved_ifx_dev
 337  */
 338 static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
 339 {
 340         return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
 341 }
 342
 343 /**
 344  *      ifx_spi_close   -       called when our tty closes
 345  *      @tty: the tty being closed
 346  *      @filp: the file handle being closed
 347  *
 348  *      Perform the close of the tty. We use the tty_port layer to do all
 349  *      our hard work.
 350  */
 351 static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
 352 {
 353         struct ifx_spi_device *ifx_dev = tty->driver_data;
 354         tty_port_close(&ifx_dev->tty_port, tty, filp);
 355         /* FIXME: should we do an ifx_spi_reset here ? */
 356 }
 357
 358 /**
 359  *      ifx_decode_spi_header   -       decode received header
 360  *      @buffer: the received data
 361  *      @length: decoded length
 362  *      @more: decoded more flag
 363  *      @received_cts: status of cts we received
 364  *
 365  *      Note how received_cts is handled -- if header is all F it is left
 366  *      the same as it was, if header is all 0 it is set to 0 otherwise it is
 367  *      taken from the incoming header.
 368  *
 369  *      FIXME: endianness
 370  */
 371 static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
 372                         unsigned char *more, unsigned char *received_cts)
 373 {
 374         u16 h1;
 375         u16 h2;
 376         u16 *in_buffer = (u16 *)buffer;
 377
 378         h1 = *in_buffer;
 379         h2 = *(in_buffer+1);
 380
 381         if (h1 == 0 && h2 == 0) {
 382                 *received_cts = 0;
 383                 *more = 0;
 384                 return IFX_SPI_HEADER_0;
 385         } else if (h1 == 0xffff && h2 == 0xffff) {
 386                 *more = 0;
 387                 /* spi_slave_cts remains as it was */
 388                 return IFX_SPI_HEADER_F;
 389         }
 390
 391         *length = h1 & 0xfff;   /* upper bits of byte are flags */
 392         *more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
 393         *received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
 394         return 0;
 395 }
 396
 397 /**
 398  *      ifx_setup_spi_header    -       set header fields
 399  *      @txbuffer: pointer to start of SPI buffer
 400  *      @tx_count: bytes
 401  *      @more: indicate if more to follow
 402  *
 403  *      Format up an SPI header for a transfer
 404  *
 405  *      FIXME: endianness?
 406  */
 407 static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
 408                                         unsigned char more)
 409 {
 410         *(u16 *)(txbuffer) = tx_count;
 411         *(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
 412         txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
 413 }
 414
 415 /**
 416  *      ifx_spi_prepare_tx_buffer       -       prepare transmit frame
 417  *      @ifx_dev: our SPI device
 418  *
 419  *      The transmit buffr needs a header and various other bits of
 420  *      information followed by as much data as we can pull from the FIFO
 421  *      and transfer. This function formats up a suitable buffer in the
 422  *      ifx_dev->tx_buffer
 423  *
 424  *      FIXME: performance - should we wake the tty when the queue is half
 425  *                           empty ?
 426  */
 427 static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
 428 {
 429         int temp_count;
 430         int queue_length;
 431         int tx_count;
 432         unsigned char *tx_buffer;
 433
 434         tx_buffer = ifx_dev->tx_buffer;
 435
 436         /* make room for required SPI header */
 437         tx_buffer += IFX_SPI_HEADER_OVERHEAD;
 438         tx_count = IFX_SPI_HEADER_OVERHEAD;
 439
 440         /* clear to signal no more data if this turns out to be the
 441          * last buffer sent in a sequence */
 442         ifx_dev->spi_more = 0;
 443
 444         /* if modem cts is set, just send empty buffer */
 445         if (!ifx_dev->spi_slave_cts) {
 446                 /* see if there's tx data */
 447                 queue_length = kfifo_len(&ifx_dev->tx_fifo);
 448                 if (queue_length != 0) {
 449                         /* data to mux -- see if there's room for it */
 450                         temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
 451                         temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
 452                                         tx_buffer, temp_count,
 453                                         &ifx_dev->fifo_lock);
 454
 455                         /* update buffer pointer and data count in message */
 456                         tx_buffer += temp_count;
 457                         tx_count += temp_count;
 458                         if (temp_count == queue_length)
 459                                 /* poke port to get more data */
 460                                 tty_port_tty_wakeup(&ifx_dev->tty_port);
 461                         else /* more data in port, use next SPI message */
 462                                 ifx_dev->spi_more = 1;
 463                 }
 464         }
 465         /* have data and info for header -- set up SPI header in buffer */
 466         /* spi header needs payload size, not entire buffer size */
 467         ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
 468                                         tx_count-IFX_SPI_HEADER_OVERHEAD,
 469                                         ifx_dev->spi_more);
 470         /* swap actual data in the buffer */
 471         ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count,
 472                 &ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
 473         return tx_count;
 474 }
 475
 476 /**
 477  *      ifx_spi_write           -       line discipline write
 478  *      @tty: our tty device
 479  *      @buf: pointer to buffer to write (kernel space)
 480  *      @count: size of buffer
 481  *
 482  *      Write the characters we have been given into the FIFO. If the device
 483  *      is not active then activate it, when the SRDY line is asserted back
 484  *      this will commence I/O
 485  */
 486 static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
 487                          int count)
 488 {
 489         struct ifx_spi_device *ifx_dev = tty->driver_data;
 490         unsigned char *tmp_buf = (unsigned char *)buf;
 491         unsigned long flags;
 492         bool is_fifo_empty;
 493         int tx_count;
 494
 495         spin_lock_irqsave(&ifx_dev->fifo_lock, flags);
 496         is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo);
 497         tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count);
 498         spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags);
 499         if (is_fifo_empty)
 500                 mrdy_assert(ifx_dev);
 501
 502         return tx_count;
 503 }
 504
 505 /**
 506  *      ifx_spi_chars_in_buffer -       line discipline helper
 507  *      @tty: our tty device
 508  *
 509  *      Report how much data we can accept before we drop bytes. As we use
 510  *      a simple FIFO this is nice and easy.
 511  */
 512 static int ifx_spi_write_room(struct tty_struct *tty)
 513 {
 514         struct ifx_spi_device *ifx_dev = tty->driver_data;
 515         return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
 516 }
 517
 518 /**
 519  *      ifx_spi_chars_in_buffer -       line discipline helper
 520  *      @tty: our tty device
 521  *
 522  *      Report how many characters we have buffered. In our case this is the
 523  *      number of bytes sitting in our transmit FIFO.
 524  */
 525 static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
 526 {
 527         struct ifx_spi_device *ifx_dev = tty->driver_data;
 528         return kfifo_len(&ifx_dev->tx_fifo);
 529 }
 530
 531 /**
 532  *      ifx_port_hangup
 533  *      @tty: our tty
 534  *
 535  *      tty port hang up. Called when tty_hangup processing is invoked either
 536  *      by loss of carrier, or by software (eg vhangup). Serialized against
 537  *      activate/shutdown by the tty layer.
 538  */
 539 static void ifx_spi_hangup(struct tty_struct *tty)
 540 {
 541         struct ifx_spi_device *ifx_dev = tty->driver_data;
 542         tty_port_hangup(&ifx_dev->tty_port);
 543 }
 544
 545 /**
 546  *      ifx_port_activate
 547  *      @port: our tty port
 548  *
 549  *      tty port activate method - called for first open. Serialized
 550  *      with hangup and shutdown by the tty layer.
 551  */
 552 static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
 553 {
 554         struct ifx_spi_device *ifx_dev =
 555                 container_of(port, struct ifx_spi_device, tty_port);
 556
 557         /* clear any old data; can't do this in 'close' */
 558         kfifo_reset(&ifx_dev->tx_fifo);
 559
 560         /* clear any flag which may be set in port shutdown procedure */
 561         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
 562         clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
 563
 564         /* put port data into this tty */
 565         tty->driver_data = ifx_dev;
 566
 567         /* allows flip string push from int context */
 568         port->low_latency = 1;
 569
 570         /* set flag to allows data transfer */
 571         set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
 572
 573         return 0;
 574 }
 575
 576 /**
 577  *      ifx_port_shutdown
 578  *      @port: our tty port
 579  *
 580  *      tty port shutdown method - called for last port close. Serialized
 581  *      with hangup and activate by the tty layer.
 582  */
 583 static void ifx_port_shutdown(struct tty_port *port)
 584 {
 585         struct ifx_spi_device *ifx_dev =
 586                 container_of(port, struct ifx_spi_device, tty_port);
 587
 588         clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
 589         mrdy_set_low(ifx_dev);
 590         del_timer(&ifx_dev->spi_timer);
 591         clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 592         tasklet_kill(&ifx_dev->io_work_tasklet);
 593 }
 594
 595 static const struct tty_port_operations ifx_tty_port_ops = {
 596         .activate = ifx_port_activate,
 597         .shutdown = ifx_port_shutdown,
 598 };
 599
 600 static const struct tty_operations ifx_spi_serial_ops = {
 601         .open = ifx_spi_open,
 602         .close = ifx_spi_close,
 603         .write = ifx_spi_write,
 604         .hangup = ifx_spi_hangup,
 605         .write_room = ifx_spi_write_room,
 606         .chars_in_buffer = ifx_spi_chars_in_buffer,
 607         .tiocmget = ifx_spi_tiocmget,
 608         .tiocmset = ifx_spi_tiocmset,
 609 };
 610
 611 /**
 612  *      ifx_spi_insert_fip_string       -       queue received data
 613  *      @ifx_dev: our SPI device
 614  *      @chars: buffer we have received
 615  *      @size: number of chars reeived
 616  *
 617  *      Queue bytes to the tty assuming the tty side is currently open. If
 618  *      not the discard the data.
 619  */
 620 static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
 621                                     unsigned char *chars, size_t size)
 622 {
 623         tty_insert_flip_string(&ifx_dev->tty_port, chars, size);
 624         tty_flip_buffer_push(&ifx_dev->tty_port);
 625 }
 626
 627 /**
 628  *      ifx_spi_complete        -       SPI transfer completed
 629  *      @ctx: our SPI device
 630  *
 631  *      An SPI transfer has completed. Process any received data and kick off
 632  *      any further transmits we can commence.
 633  */
 634 static void ifx_spi_complete(void *ctx)
 635 {
 636         struct ifx_spi_device *ifx_dev = ctx;
 637         int length;
 638         int actual_length;
 639         unsigned char more = 0;
 640         unsigned char cts;
 641         int local_write_pending = 0;
 642         int queue_length;
 643         int srdy;
 644         int decode_result;
 645
 646         mrdy_set_low(ifx_dev);
 647
 648         if (!ifx_dev->spi_msg.status) {
 649                 /* check header validity, get comm flags */
 650                 ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
 651                         &ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
 652                 decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
 653                                 &length, &more, &cts);
 654                 if (decode_result == IFX_SPI_HEADER_0) {
 655                         dev_dbg(&ifx_dev->spi_dev->dev,
 656                                 "ignore input: invalid header 0");
 657                         ifx_dev->spi_slave_cts = 0;
 658                         goto complete_exit;
 659                 } else if (decode_result == IFX_SPI_HEADER_F) {
 660                         dev_dbg(&ifx_dev->spi_dev->dev,
 661                                 "ignore input: invalid header F");
 662                         goto complete_exit;
 663                 }
 664
 665                 ifx_dev->spi_slave_cts = cts;
 666
 667                 actual_length = min((unsigned int)length,
 668                                         ifx_dev->spi_msg.actual_length);
 669                 ifx_dev->swap_buf(
 670                         (ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
 671                          actual_length,
 672                          &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
 673                 ifx_spi_insert_flip_string(
 674                         ifx_dev,
 675                         ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
 676                         (size_t)actual_length);
 677         } else {
 678                 more = 0;
 679                 dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
 680                        ifx_dev->spi_msg.status);
 681         }
 682
 683 complete_exit:
 684         if (ifx_dev->write_pending) {
 685                 ifx_dev->write_pending = 0;
 686                 local_write_pending = 1;
 687         }
 688
 689         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
 690
 691         queue_length = kfifo_len(&ifx_dev->tx_fifo);
 692         srdy = gpiod_get_value(ifx_dev->gpio.srdy);
 693         if (!srdy)
 694                 ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
 695
 696         /* schedule output if there is more to do */
 697         if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
 698                 tasklet_schedule(&ifx_dev->io_work_tasklet);
 699         else {
 700                 if (more || ifx_dev->spi_more || queue_length > 0 ||
 701                         local_write_pending) {
 702                         if (ifx_dev->spi_slave_cts) {
 703                                 if (more)
 704                                         mrdy_assert(ifx_dev);
 705                         } else
 706                                 mrdy_assert(ifx_dev);
 707                 } else {
 708                         /*
 709                          * poke line discipline driver if any for more data
 710                          * may or may not get more data to write
 711                          * for now, say not busy
 712                          */
 713                         ifx_spi_power_state_clear(ifx_dev,
 714                                                   IFX_SPI_POWER_DATA_PENDING);
 715                         tty_port_tty_wakeup(&ifx_dev->tty_port);
 716                 }
 717         }
 718 }
 719
 720 /**
 721  *      ifx_spio_io             -       I/O tasklet
 722  *      @data: our SPI device
 723  *
 724  *      Queue data for transmission if possible and then kick off the
 725  *      transfer.
 726  */
 727 static void ifx_spi_io(struct tasklet_struct *t)
 728 {
 729         int retval;
 730         struct ifx_spi_device *ifx_dev = from_tasklet(ifx_dev, t,
 731                                                       io_work_tasklet);
 732
 733         if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) &&
 734                 test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) {
 735                 if (ifx_dev->gpio.unack_srdy_int_nb > 0)
 736                         ifx_dev->gpio.unack_srdy_int_nb--;
 737
 738                 ifx_spi_prepare_tx_buffer(ifx_dev);
 739
 740                 spi_message_init(&ifx_dev->spi_msg);
 741                 INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);
 742
 743                 ifx_dev->spi_msg.context = ifx_dev;
 744                 ifx_dev->spi_msg.complete = ifx_spi_complete;
 745
 746                 /* set up our spi transfer */
 747                 /* note len is BYTES, not transfers */
 748                 ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
 749                 ifx_dev->spi_xfer.cs_change = 0;
 750                 ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz;
 751                 /* ifx_dev->spi_xfer.speed_hz = 390625; */
 752                 ifx_dev->spi_xfer.bits_per_word =
 753                         ifx_dev->spi_dev->bits_per_word;
 754
 755                 ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
 756                 ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;
 757
 758                 /*
 759                  * setup dma pointers
 760                  */
 761                 if (ifx_dev->use_dma) {
 762                         ifx_dev->spi_msg.is_dma_mapped = 1;
 763                         ifx_dev->tx_dma = ifx_dev->tx_bus;
 764                         ifx_dev->rx_dma = ifx_dev->rx_bus;
 765                         ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
 766                         ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
 767                 } else {
 768                         ifx_dev->spi_msg.is_dma_mapped = 0;
 769                         ifx_dev->tx_dma = (dma_addr_t)0;
 770                         ifx_dev->rx_dma = (dma_addr_t)0;
 771                         ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
 772                         ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
 773                 }
 774
 775                 spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);
 776
 777                 /* Assert MRDY. This may have already been done by the write
 778                  * routine.
 779                  */
 780                 mrdy_assert(ifx_dev);
 781
 782                 retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
 783                 if (retval) {
 784                         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
 785                                   &ifx_dev->flags);
 786                         tasklet_schedule(&ifx_dev->io_work_tasklet);
 787                         return;
 788                 }
 789         } else
 790                 ifx_dev->write_pending = 1;
 791 }
 792
 793 /**
 794  *      ifx_spi_free_port       -       free up the tty side
 795  *      @ifx_dev: IFX device going away
 796  *
 797  *      Unregister and free up a port when the device goes away
 798  */
 799 static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
 800 {
 801         if (ifx_dev->tty_dev)
 802                 tty_unregister_device(tty_drv, ifx_dev->minor);
 803         tty_port_destroy(&ifx_dev->tty_port);
 804         kfifo_free(&ifx_dev->tx_fifo);
 805 }
 806
 807 /**
 808  *      ifx_spi_create_port     -       create a new port
 809  *      @ifx_dev: our spi device
 810  *
 811  *      Allocate and initialise the tty port that goes with this interface
 812  *      and add it to the tty layer so that it can be opened.
 813  */
 814 static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
 815 {
 816         int ret = 0;
 817         struct tty_port *pport = &ifx_dev->tty_port;
 818
 819         spin_lock_init(&ifx_dev->fifo_lock);
 820         lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
 821                 &ifx_spi_key, 0);
 822
 823         if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
 824                 ret = -ENOMEM;
 825                 goto error_ret;
 826         }
 827
 828         tty_port_init(pport);
 829         pport->ops = &ifx_tty_port_ops;
 830         ifx_dev->minor = IFX_SPI_TTY_ID;
 831         ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv,
 832                         ifx_dev->minor, &ifx_dev->spi_dev->dev);
 833         if (IS_ERR(ifx_dev->tty_dev)) {
 834                 dev_dbg(&ifx_dev->spi_dev->dev,
 835                         "%s: registering tty device failed", __func__);
 836                 ret = PTR_ERR(ifx_dev->tty_dev);
 837                 goto error_port;
 838         }
 839         return 0;
 840
 841 error_port:
 842         tty_port_destroy(pport);
 843 error_ret:
 844         ifx_spi_free_port(ifx_dev);
 845         return ret;
 846 }
 847
 848 /**
 849  *      ifx_spi_handle_srdy             -       handle SRDY
 850  *      @ifx_dev: device asserting SRDY
 851  *
 852  *      Check our device state and see what we need to kick off when SRDY
 853  *      is asserted. This usually means killing the timer and firing off the
 854  *      I/O processing.
 855  */
 856 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
 857 {
 858         if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
 859                 del_timer(&ifx_dev->spi_timer);
 860                 clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 861         }
 862
 863         ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);
 864
 865         if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
 866                 tasklet_schedule(&ifx_dev->io_work_tasklet);
 867         else
 868                 set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
 869 }
 870
 871 /**
 872  *      ifx_spi_srdy_interrupt  -       SRDY asserted
 873  *      @irq: our IRQ number
 874  *      @dev: our ifx device
 875  *
 876  *      The modem asserted SRDY. Handle the srdy event
 877  */
 878 static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
 879 {
 880         struct ifx_spi_device *ifx_dev = dev;
 881         ifx_dev->gpio.unack_srdy_int_nb++;
 882         ifx_spi_handle_srdy(ifx_dev);
 883         return IRQ_HANDLED;
 884 }
 885
 886 /**
 887  *      ifx_spi_reset_interrupt -       Modem has changed reset state
 888  *      @irq: interrupt number
 889  *      @dev: our device pointer
 890  *
 891  *      The modem has either entered or left reset state. Check the GPIO
 892  *      line to see which.
 893  *
 894  *      FIXME: review locking on MR_INPROGRESS versus
 895  *      parallel unsolicited reset/solicited reset
 896  */
 897 static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
 898 {
 899         struct ifx_spi_device *ifx_dev = dev;
 900         int val = gpiod_get_value(ifx_dev->gpio.reset_out);
 901         int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
 902
 903         if (val == 0) {
 904                 /* entered reset */
 905                 set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
 906                 if (!solreset) {
 907                         /* unsolicited reset  */
 908                         tty_port_tty_hangup(&ifx_dev->tty_port, false);
 909                 }
 910         } else {
 911                 /* exited reset */
 912                 clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
 913                 if (solreset) {
 914                         set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
 915                         wake_up(&ifx_dev->mdm_reset_wait);
 916                 }
 917         }
 918         return IRQ_HANDLED;
 919 }
 920
 921 /**
 922  *      ifx_spi_free_device - free device
 923  *      @ifx_dev: device to free
 924  *
 925  *      Free the IFX device
 926  */
 927 static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
 928 {
 929         ifx_spi_free_port(ifx_dev);
 930         dma_free_coherent(&ifx_dev->spi_dev->dev,
 931                                 IFX_SPI_TRANSFER_SIZE,
 932                                 ifx_dev->tx_buffer,
 933                                 ifx_dev->tx_bus);
 934         dma_free_coherent(&ifx_dev->spi_dev->dev,
 935                                 IFX_SPI_TRANSFER_SIZE,
 936                                 ifx_dev->rx_buffer,
 937                                 ifx_dev->rx_bus);
 938 }
 939
 940 /**
 941  *      ifx_spi_reset   -       reset modem
 942  *      @ifx_dev: modem to reset
 943  *
 944  *      Perform a reset on the modem
 945  */
 946 static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
 947 {
 948         int ret;
 949         /*
 950          * set up modem power, reset
 951          *
 952          * delays are required on some platforms for the modem
 953          * to reset properly
 954          */
 955         set_bit(MR_START, &ifx_dev->mdm_reset_state);
 956         gpiod_set_value(ifx_dev->gpio.po, 0);
 957         gpiod_set_value(ifx_dev->gpio.reset, 0);
 958         msleep(25);
 959         gpiod_set_value(ifx_dev->gpio.reset, 1);
 960         msleep(1);
 961         gpiod_set_value(ifx_dev->gpio.po, 1);
 962         msleep(1);
 963         gpiod_set_value(ifx_dev->gpio.po, 0);
 964         ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
 965                                  test_bit(MR_COMPLETE,
 966                                           &ifx_dev->mdm_reset_state),
 967                                  IFX_RESET_TIMEOUT);
 968         if (!ret)
 969                 dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
 970                          ifx_dev->mdm_reset_state);
 971
 972         ifx_dev->mdm_reset_state = 0;
 973         return ret;
 974 }
 975
 976 /**
 977  *      ifx_spi_spi_probe       -       probe callback
 978  *      @spi: our possible matching SPI device
 979  *
 980  *      Probe for a 6x60 modem on SPI bus. Perform any needed device and
 981  *      GPIO setup.
 982  *
 983  *      FIXME:
 984  *      -       Support for multiple devices
 985  *      -       Split out MID specific GPIO handling eventually
 986  */
 987
 988 static int ifx_spi_spi_probe(struct spi_device *spi)
 989 {
 990         int ret;
 991         int srdy;
 992         struct ifx_modem_platform_data *pl_data;
 993         struct ifx_spi_device *ifx_dev;
 994         struct device *dev = &spi->dev;
 995
 996         if (saved_ifx_dev) {
 997                 dev_dbg(dev, "ignoring subsequent detection");
 998                 return -ENODEV;
 999         }
1000
1001         pl_data = dev_get_platdata(dev);
1002         if (!pl_data) {
1003                 dev_err(dev, "missing platform data!");
1004                 return -ENODEV;
1005         }
1006
1007         /* initialize structure to hold our device variables */
1008         ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
1009         if (!ifx_dev) {
1010                 dev_err(dev, "spi device allocation failed");
1011                 return -ENOMEM;
1012         }
1013         saved_ifx_dev = ifx_dev;
1014         ifx_dev->spi_dev = spi;
1015         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
1016         spin_lock_init(&ifx_dev->write_lock);
1017         spin_lock_init(&ifx_dev->power_lock);
1018         ifx_dev->power_status = 0;
1019         timer_setup(&ifx_dev->spi_timer, ifx_spi_timeout, 0);
1020         ifx_dev->modem = pl_data->modem_type;
1021         ifx_dev->use_dma = pl_data->use_dma;
1022         ifx_dev->max_hz = pl_data->max_hz;
1023         /* initialize spi mode, etc */
1024         spi->max_speed_hz = ifx_dev->max_hz;
1025         spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
1026         spi->bits_per_word = spi_bpw;
1027         ret = spi_setup(spi);
1028         if (ret) {
1029                 dev_err(dev, "SPI setup wasn't successful %d", ret);
1030                 kfree(ifx_dev);
1031                 return -ENODEV;
1032         }
1033
1034         /* init swap_buf function according to word width configuration */
1035         if (spi->bits_per_word == 32)
1036                 ifx_dev->swap_buf = swap_buf_32;
1037         else if (spi->bits_per_word == 16)
1038                 ifx_dev->swap_buf = swap_buf_16;
1039         else
1040                 ifx_dev->swap_buf = swap_buf_8;
1041
1042         /* ensure SPI protocol flags are initialized to enable transfer */
1043         ifx_dev->spi_more = 0;
1044         ifx_dev->spi_slave_cts = 0;
1045
1046         /*initialize transfer and dma buffers */
1047         ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1048                                 IFX_SPI_TRANSFER_SIZE,
1049                                 &ifx_dev->tx_bus,
1050                                 GFP_KERNEL);
1051         if (!ifx_dev->tx_buffer) {
1052                 dev_err(dev, "DMA-TX buffer allocation failed");
1053                 ret = -ENOMEM;
1054                 goto error_ret;
1055         }
1056         ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1057                                 IFX_SPI_TRANSFER_SIZE,
1058                                 &ifx_dev->rx_bus,
1059                                 GFP_KERNEL);
1060         if (!ifx_dev->rx_buffer) {
1061                 dev_err(dev, "DMA-RX buffer allocation failed");
1062                 ret = -ENOMEM;
1063                 goto error_ret;
1064         }
1065
1066         /* initialize waitq for modem reset */
1067         init_waitqueue_head(&ifx_dev->mdm_reset_wait);
1068
1069         spi_set_drvdata(spi, ifx_dev);
1070         tasklet_setup(&ifx_dev->io_work_tasklet, ifx_spi_io);
1071
1072         set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);
1073
1074         /* create our tty port */
1075         ret = ifx_spi_create_port(ifx_dev);
1076         if (ret != 0) {
1077                 dev_err(dev, "create default tty port failed");
1078                 goto error_ret;
1079         }
1080
1081         ifx_dev->gpio.reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
1082         if (IS_ERR(ifx_dev->gpio.reset)) {
1083                 dev_err(dev, "could not obtain reset GPIO\n");
1084                 ret = PTR_ERR(ifx_dev->gpio.reset);
1085                 goto error_ret;
1086         }
1087         gpiod_set_consumer_name(ifx_dev->gpio.reset, "ifxModem reset");
1088         ifx_dev->gpio.po = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW);
1089         if (IS_ERR(ifx_dev->gpio.po)) {
1090                 dev_err(dev, "could not obtain power GPIO\n");
1091                 ret = PTR_ERR(ifx_dev->gpio.po);
1092                 goto error_ret;
1093         }
1094         gpiod_set_consumer_name(ifx_dev->gpio.po, "ifxModem power");
1095         ifx_dev->gpio.mrdy = devm_gpiod_get(dev, "mrdy", GPIOD_OUT_LOW);
1096         if (IS_ERR(ifx_dev->gpio.mrdy)) {
1097                 dev_err(dev, "could not obtain mrdy GPIO\n");
1098                 ret = PTR_ERR(ifx_dev->gpio.mrdy);
1099                 goto error_ret;
1100         }
1101         gpiod_set_consumer_name(ifx_dev->gpio.mrdy, "ifxModem mrdy");
1102         ifx_dev->gpio.srdy = devm_gpiod_get(dev, "srdy", GPIOD_IN);
1103         if (IS_ERR(ifx_dev->gpio.srdy)) {
1104                 dev_err(dev, "could not obtain srdy GPIO\n");
1105                 ret = PTR_ERR(ifx_dev->gpio.srdy);
1106                 goto error_ret;
1107         }
1108         gpiod_set_consumer_name(ifx_dev->gpio.srdy, "ifxModem srdy");
1109         ifx_dev->gpio.reset_out = devm_gpiod_get(dev, "rst_out", GPIOD_IN);
1110         if (IS_ERR(ifx_dev->gpio.reset_out)) {
1111                 dev_err(dev, "could not obtain rst_out GPIO\n");
1112                 ret = PTR_ERR(ifx_dev->gpio.reset_out);
1113                 goto error_ret;
1114         }
1115         gpiod_set_consumer_name(ifx_dev->gpio.reset_out, "ifxModem reset out");
1116         ifx_dev->gpio.pmu_reset = devm_gpiod_get(dev, "pmu_reset", GPIOD_ASIS);
1117         if (IS_ERR(ifx_dev->gpio.pmu_reset)) {
1118                 dev_err(dev, "could not obtain pmu_reset GPIO\n");
1119                 ret = PTR_ERR(ifx_dev->gpio.pmu_reset);
1120                 goto error_ret;
1121         }
1122         gpiod_set_consumer_name(ifx_dev->gpio.pmu_reset, "ifxModem PMU reset");
1123
1124         ret = request_irq(gpiod_to_irq(ifx_dev->gpio.reset_out),
1125                           ifx_spi_reset_interrupt,
1126                           IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
1127                           ifx_dev);
1128         if (ret) {
1129                 dev_err(dev, "Unable to get irq %x\n",
1130                         gpiod_to_irq(ifx_dev->gpio.reset_out));
1131                 goto error_ret;
1132         }
1133
1134         ret = ifx_spi_reset(ifx_dev);
1135
1136         ret = request_irq(gpiod_to_irq(ifx_dev->gpio.srdy),
1137                           ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME,
1138                           ifx_dev);
1139         if (ret) {
1140                 dev_err(dev, "Unable to get irq %x",
1141                         gpiod_to_irq(ifx_dev->gpio.srdy));
1142                 goto error_ret2;
1143         }
1144
1145         /* set pm runtime power state and register with power system */
1146         pm_runtime_set_active(dev);
1147         pm_runtime_enable(dev);
1148
1149         /* handle case that modem is already signaling SRDY */
1150         /* no outgoing tty open at this point, this just satisfies the
1151          * modem's read and should reset communication properly
1152          */
1153         srdy = gpiod_get_value(ifx_dev->gpio.srdy);
1154
1155         if (srdy) {
1156                 mrdy_assert(ifx_dev);
1157                 ifx_spi_handle_srdy(ifx_dev);
1158         } else
1159                 mrdy_set_low(ifx_dev);
1160         return 0;
1161
1162 error_ret2:
1163         free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1164 error_ret:
1165         ifx_spi_free_device(ifx_dev);
1166         saved_ifx_dev = NULL;
1167         return ret;
1168 }
1169
1170 /**
1171  *      ifx_spi_spi_remove      -       SPI device was removed
1172  *      @spi: SPI device
1173  *
1174  *      FIXME: We should be shutting the device down here not in
1175  *      the module unload path.
1176  */
1177
1178 static int ifx_spi_spi_remove(struct spi_device *spi)
1179 {
1180         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1181         /* stop activity */
1182         tasklet_kill(&ifx_dev->io_work_tasklet);
1183
1184         pm_runtime_disable(&spi->dev);
1185
1186         /* free irq */
1187         free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1188         free_irq(gpiod_to_irq(ifx_dev->gpio.srdy), ifx_dev);
1189
1190         /* free allocations */
1191         ifx_spi_free_device(ifx_dev);
1192
1193         saved_ifx_dev = NULL;
1194         return 0;
1195 }
1196
1197 /**
1198  *      ifx_spi_spi_shutdown    -       called on SPI shutdown
1199  *      @spi: SPI device
1200  *
1201  *      No action needs to be taken here
1202  */
1203
1204 static void ifx_spi_spi_shutdown(struct spi_device *spi)
1205 {
1206         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1207
1208         ifx_modem_power_off(ifx_dev);
1209 }
1210
1211 /*
1212  * various suspends and resumes have nothing to do
1213  * no hardware to save state for
1214  */
1215
1216 /**
1217  *      ifx_spi_pm_suspend      -       suspend modem on system suspend
1218  *      @dev: device being suspended
1219  *
1220  *      Suspend the modem. No action needed on Intel MID platforms, may
1221  *      need extending for other systems.
1222  */
1223 static int ifx_spi_pm_suspend(struct device *dev)
1224 {
1225         return 0;
1226 }
1227
1228 /**
1229  *      ifx_spi_pm_resume       -       resume modem on system resume
1230  *      @dev: device being suspended
1231  *
1232  *      Allow the modem to resume. No action needed.
1233  *
1234  *      FIXME: do we need to reset anything here ?
1235  */
1236 static int ifx_spi_pm_resume(struct device *dev)
1237 {
1238         return 0;
1239 }
1240
1241 /**
1242  *      ifx_spi_pm_runtime_resume       -       suspend modem
1243  *      @dev: device being suspended
1244  *
1245  *      Allow the modem to resume. No action needed.
1246  */
1247 static int ifx_spi_pm_runtime_resume(struct device *dev)
1248 {
1249         return 0;
1250 }
1251
1252 /**
1253  *      ifx_spi_pm_runtime_suspend      -       suspend modem
1254  *      @dev: device being suspended
1255  *
1256  *      Allow the modem to suspend and thus suspend to continue up the
1257  *      device tree.
1258  */
1259 static int ifx_spi_pm_runtime_suspend(struct device *dev)
1260 {
1261         return 0;
1262 }
1263
1264 /**
1265  *      ifx_spi_pm_runtime_idle         -       check if modem idle
1266  *      @dev: our device
1267  *
1268  *      Check conditions and queue runtime suspend if idle.
1269  */
1270 static int ifx_spi_pm_runtime_idle(struct device *dev)
1271 {
1272         struct spi_device *spi = to_spi_device(dev);
1273         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1274
1275         if (!ifx_dev->power_status)
1276                 pm_runtime_suspend(dev);
1277
1278         return 0;
1279 }
1280
1281 static const struct dev_pm_ops ifx_spi_pm = {
1282         .resume = ifx_spi_pm_resume,
1283         .suspend = ifx_spi_pm_suspend,
1284         .runtime_resume = ifx_spi_pm_runtime_resume,
1285         .runtime_suspend = ifx_spi_pm_runtime_suspend,
1286         .runtime_idle = ifx_spi_pm_runtime_idle
1287 };
1288
1289 static const struct spi_device_id ifx_id_table[] = {
1290         {"ifx6160", 0},
1291         {"ifx6260", 0},
1292         { }
1293 };
1294 MODULE_DEVICE_TABLE(spi, ifx_id_table);
1295
1296 /* spi operations */
1297 static struct spi_driver ifx_spi_driver = {
1298         .driver = {
1299                 .name = DRVNAME,
1300                 .pm = &ifx_spi_pm,
1301         },
1302         .probe = ifx_spi_spi_probe,
1303         .shutdown = ifx_spi_spi_shutdown,
1304         .remove = ifx_spi_spi_remove,
1305         .id_table = ifx_id_table
1306 };
1307
1308 /**
1309  *      ifx_spi_exit    -       module exit
1310  *
1311  *      Unload the module.
1312  */
1313
1314 static void __exit ifx_spi_exit(void)
1315 {
1316         /* unregister */
1317         spi_unregister_driver(&ifx_spi_driver);
1318         tty_unregister_driver(tty_drv);
1319         put_tty_driver(tty_drv);
1320         unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
1321 }
1322
1323 /**
1324  *      ifx_spi_init            -       module entry point
1325  *
1326  *      Initialise the SPI and tty interfaces for the IFX SPI driver
1327  *      We need to initialize upper-edge spi driver after the tty
1328  *      driver because otherwise the spi probe will race
1329  */
1330
1331 static int __init ifx_spi_init(void)
1332 {
1333         int result;
1334
1335         tty_drv = alloc_tty_driver(1);
1336         if (!tty_drv) {
1337                 pr_err("%s: alloc_tty_driver failed", DRVNAME);
1338                 return -ENOMEM;
1339         }
1340
1341         tty_drv->driver_name = DRVNAME;
1342         tty_drv->name = TTYNAME;
1343         tty_drv->minor_start = IFX_SPI_TTY_ID;
1344         tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1345         tty_drv->subtype = SERIAL_TYPE_NORMAL;
1346         tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1347         tty_drv->init_termios = tty_std_termios;
1348
1349         tty_set_operations(tty_drv, &ifx_spi_serial_ops);
1350
1351         result = tty_register_driver(tty_drv);
1352         if (result) {
1353                 pr_err("%s: tty_register_driver failed(%d)",
1354                         DRVNAME, result);
1355                 goto err_free_tty;
1356         }
1357
1358         result = spi_register_driver(&ifx_spi_driver);
1359         if (result) {
1360                 pr_err("%s: spi_register_driver failed(%d)",
1361                         DRVNAME, result);
1362                 goto err_unreg_tty;
1363         }
1364
1365         result = register_reboot_notifier(&ifx_modem_reboot_notifier_block);
1366         if (result) {
1367                 pr_err("%s: register ifx modem reboot notifier failed(%d)",
1368                         DRVNAME, result);
1369                 goto err_unreg_spi;
1370         }
1371
1372         return 0;
1373 err_unreg_spi:
1374         spi_unregister_driver(&ifx_spi_driver);
1375 err_unreg_tty:
1376         tty_unregister_driver(tty_drv);
1377 err_free_tty:
1378         put_tty_driver(tty_drv);
1379
1380         return result;
1381 }
1382
1383 module_init(ifx_spi_init);
1384 module_exit(ifx_spi_exit);
1385
1386 MODULE_AUTHOR("Intel");
1387 MODULE_DESCRIPTION("IFX6x60 spi driver");
1388 MODULE_LICENSE("GPL");
1389 MODULE_INFO(Version, "0.1-IFX6x60");