drivers/dma/qcom_bam_dma.c

   1 /*
   2  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14 /*
  15  * QCOM BAM DMA engine driver
  16  *
  17  * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
  18  * peripherals on the MSM 8x74.  The configuration of the channels are dependent
  19  * on the way they are hard wired to that specific peripheral.  The peripheral
  20  * device tree entries specify the configuration of each channel.
  21  *
  22  * The DMA controller requires the use of external memory for storage of the
  23  * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
  24  * circular buffer and operations are managed according to the offset within the
  25  * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
  26  * are back to defaults.
  27  *
  28  * During DMA operations, we write descriptors to the FIFO, being careful to
  29  * handle wrapping and then write the last FIFO offset to that channel's
  30  * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
  31  * indicates the current FIFO offset that is being processed, so there is some
  32  * indication of where the hardware is currently working.
  33  */
  34
  35 #include <linux/kernel.h>
  36 #include <linux/io.h>
  37 #include <linux/init.h>
  38 #include <linux/slab.h>
  39 #include <linux/module.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/dma-mapping.h>
  42 #include <linux/scatterlist.h>
  43 #include <linux/device.h>
  44 #include <linux/platform_device.h>
  45 #include <linux/of.h>
  46 #include <linux/of_address.h>
  47 #include <linux/of_irq.h>
  48 #include <linux/of_dma.h>
  49 #include <linux/clk.h>
  50 #include <linux/dmaengine.h>
  51
  52 #include "dmaengine.h"
  53 #include "virt-dma.h"
  54
  55 struct bam_desc_hw {
  56         u32 addr;               /* Buffer physical address */
  57         u16 size;               /* Buffer size in bytes */
  58         u16 flags;
  59 };
  60
  61 #define DESC_FLAG_INT BIT(15)
  62 #define DESC_FLAG_EOT BIT(14)
  63 #define DESC_FLAG_EOB BIT(13)
  64 #define DESC_FLAG_NWD BIT(12)
  65
  66 struct bam_async_desc {
  67         struct virt_dma_desc vd;
  68
  69         u32 num_desc;
  70         u32 xfer_len;
  71
  72         /* transaction flags, EOT|EOB|NWD */
  73         u16 flags;
  74
  75         struct bam_desc_hw *curr_desc;
  76
  77         enum dma_transfer_direction dir;
  78         size_t length;
  79         struct bam_desc_hw desc[0];
  80 };
  81
  82 enum bam_reg {
  83         BAM_CTRL,
  84         BAM_REVISION,
  85         BAM_NUM_PIPES,
  86         BAM_DESC_CNT_TRSHLD,
  87         BAM_IRQ_SRCS,
  88         BAM_IRQ_SRCS_MSK,
  89         BAM_IRQ_SRCS_UNMASKED,
  90         BAM_IRQ_STTS,
  91         BAM_IRQ_CLR,
  92         BAM_IRQ_EN,
  93         BAM_CNFG_BITS,
  94         BAM_IRQ_SRCS_EE,
  95         BAM_IRQ_SRCS_MSK_EE,
  96         BAM_P_CTRL,
  97         BAM_P_RST,
  98         BAM_P_HALT,
  99         BAM_P_IRQ_STTS,
 100         BAM_P_IRQ_CLR,
 101         BAM_P_IRQ_EN,
 102         BAM_P_EVNT_DEST_ADDR,
 103         BAM_P_EVNT_REG,
 104         BAM_P_SW_OFSTS,
 105         BAM_P_DATA_FIFO_ADDR,
 106         BAM_P_DESC_FIFO_ADDR,
 107         BAM_P_EVNT_GEN_TRSHLD,
 108         BAM_P_FIFO_SIZES,
 109 };
 110
 111 struct reg_offset_data {
 112         u32 base_offset;
 113         unsigned int pipe_mult, evnt_mult, ee_mult;
 114 };
 115
 116 static const struct reg_offset_data bam_v1_3_reg_info[] = {
 117         [BAM_CTRL]              = { 0x0F80, 0x00, 0x00, 0x00 },
 118         [BAM_REVISION]          = { 0x0F84, 0x00, 0x00, 0x00 },
 119         [BAM_NUM_PIPES]         = { 0x0FBC, 0x00, 0x00, 0x00 },
 120         [BAM_DESC_CNT_TRSHLD]   = { 0x0F88, 0x00, 0x00, 0x00 },
 121         [BAM_IRQ_SRCS]          = { 0x0F8C, 0x00, 0x00, 0x00 },
 122         [BAM_IRQ_SRCS_MSK]      = { 0x0F90, 0x00, 0x00, 0x00 },
 123         [BAM_IRQ_SRCS_UNMASKED] = { 0x0FB0, 0x00, 0x00, 0x00 },
 124         [BAM_IRQ_STTS]          = { 0x0F94, 0x00, 0x00, 0x00 },
 125         [BAM_IRQ_CLR]           = { 0x0F98, 0x00, 0x00, 0x00 },
 126         [BAM_IRQ_EN]            = { 0x0F9C, 0x00, 0x00, 0x00 },
 127         [BAM_CNFG_BITS]         = { 0x0FFC, 0x00, 0x00, 0x00 },
 128         [BAM_IRQ_SRCS_EE]       = { 0x1800, 0x00, 0x00, 0x80 },
 129         [BAM_IRQ_SRCS_MSK_EE]   = { 0x1804, 0x00, 0x00, 0x80 },
 130         [BAM_P_CTRL]            = { 0x0000, 0x80, 0x00, 0x00 },
 131         [BAM_P_RST]             = { 0x0004, 0x80, 0x00, 0x00 },
 132         [BAM_P_HALT]            = { 0x0008, 0x80, 0x00, 0x00 },
 133         [BAM_P_IRQ_STTS]        = { 0x0010, 0x80, 0x00, 0x00 },
 134         [BAM_P_IRQ_CLR]         = { 0x0014, 0x80, 0x00, 0x00 },
 135         [BAM_P_IRQ_EN]          = { 0x0018, 0x80, 0x00, 0x00 },
 136         [BAM_P_EVNT_DEST_ADDR]  = { 0x102C, 0x00, 0x40, 0x00 },
 137         [BAM_P_EVNT_REG]        = { 0x1018, 0x00, 0x40, 0x00 },
 138         [BAM_P_SW_OFSTS]        = { 0x1000, 0x00, 0x40, 0x00 },
 139         [BAM_P_DATA_FIFO_ADDR]  = { 0x1024, 0x00, 0x40, 0x00 },
 140         [BAM_P_DESC_FIFO_ADDR]  = { 0x101C, 0x00, 0x40, 0x00 },
 141         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1028, 0x00, 0x40, 0x00 },
 142         [BAM_P_FIFO_SIZES]      = { 0x1020, 0x00, 0x40, 0x00 },
 143 };
 144
 145 static const struct reg_offset_data bam_v1_4_reg_info[] = {
 146         [BAM_CTRL]              = { 0x0000, 0x00, 0x00, 0x00 },
 147         [BAM_REVISION]          = { 0x0004, 0x00, 0x00, 0x00 },
 148         [BAM_NUM_PIPES]         = { 0x003C, 0x00, 0x00, 0x00 },
 149         [BAM_DESC_CNT_TRSHLD]   = { 0x0008, 0x00, 0x00, 0x00 },
 150         [BAM_IRQ_SRCS]          = { 0x000C, 0x00, 0x00, 0x00 },
 151         [BAM_IRQ_SRCS_MSK]      = { 0x0010, 0x00, 0x00, 0x00 },
 152         [BAM_IRQ_SRCS_UNMASKED] = { 0x0030, 0x00, 0x00, 0x00 },
 153         [BAM_IRQ_STTS]          = { 0x0014, 0x00, 0x00, 0x00 },
 154         [BAM_IRQ_CLR]           = { 0x0018, 0x00, 0x00, 0x00 },
 155         [BAM_IRQ_EN]            = { 0x001C, 0x00, 0x00, 0x00 },
 156         [BAM_CNFG_BITS]         = { 0x007C, 0x00, 0x00, 0x00 },
 157         [BAM_IRQ_SRCS_EE]       = { 0x0800, 0x00, 0x00, 0x80 },
 158         [BAM_IRQ_SRCS_MSK_EE]   = { 0x0804, 0x00, 0x00, 0x80 },
 159         [BAM_P_CTRL]            = { 0x1000, 0x1000, 0x00, 0x00 },
 160         [BAM_P_RST]             = { 0x1004, 0x1000, 0x00, 0x00 },
 161         [BAM_P_HALT]            = { 0x1008, 0x1000, 0x00, 0x00 },
 162         [BAM_P_IRQ_STTS]        = { 0x1010, 0x1000, 0x00, 0x00 },
 163         [BAM_P_IRQ_CLR]         = { 0x1014, 0x1000, 0x00, 0x00 },
 164         [BAM_P_IRQ_EN]          = { 0x1018, 0x1000, 0x00, 0x00 },
 165         [BAM_P_EVNT_DEST_ADDR]  = { 0x182C, 0x00, 0x1000, 0x00 },
 166         [BAM_P_EVNT_REG]        = { 0x1818, 0x00, 0x1000, 0x00 },
 167         [BAM_P_SW_OFSTS]        = { 0x1800, 0x00, 0x1000, 0x00 },
 168         [BAM_P_DATA_FIFO_ADDR]  = { 0x1824, 0x00, 0x1000, 0x00 },
 169         [BAM_P_DESC_FIFO_ADDR]  = { 0x181C, 0x00, 0x1000, 0x00 },
 170         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1828, 0x00, 0x1000, 0x00 },
 171         [BAM_P_FIFO_SIZES]      = { 0x1820, 0x00, 0x1000, 0x00 },
 172 };
 173
 174 static const struct reg_offset_data bam_v1_7_reg_info[] = {
 175         [BAM_CTRL]              = { 0x00000, 0x00, 0x00, 0x00 },
 176         [BAM_REVISION]          = { 0x01000, 0x00, 0x00, 0x00 },
 177         [BAM_NUM_PIPES]         = { 0x01008, 0x00, 0x00, 0x00 },
 178         [BAM_DESC_CNT_TRSHLD]   = { 0x00008, 0x00, 0x00, 0x00 },
 179         [BAM_IRQ_SRCS]          = { 0x03010, 0x00, 0x00, 0x00 },
 180         [BAM_IRQ_SRCS_MSK]      = { 0x03014, 0x00, 0x00, 0x00 },
 181         [BAM_IRQ_SRCS_UNMASKED] = { 0x03018, 0x00, 0x00, 0x00 },
 182         [BAM_IRQ_STTS]          = { 0x00014, 0x00, 0x00, 0x00 },
 183         [BAM_IRQ_CLR]           = { 0x00018, 0x00, 0x00, 0x00 },
 184         [BAM_IRQ_EN]            = { 0x0001C, 0x00, 0x00, 0x00 },
 185         [BAM_CNFG_BITS]         = { 0x0007C, 0x00, 0x00, 0x00 },
 186         [BAM_IRQ_SRCS_EE]       = { 0x03000, 0x00, 0x00, 0x1000 },
 187         [BAM_IRQ_SRCS_MSK_EE]   = { 0x03004, 0x00, 0x00, 0x1000 },
 188         [BAM_P_CTRL]            = { 0x13000, 0x1000, 0x00, 0x00 },
 189         [BAM_P_RST]             = { 0x13004, 0x1000, 0x00, 0x00 },
 190         [BAM_P_HALT]            = { 0x13008, 0x1000, 0x00, 0x00 },
 191         [BAM_P_IRQ_STTS]        = { 0x13010, 0x1000, 0x00, 0x00 },
 192         [BAM_P_IRQ_CLR]         = { 0x13014, 0x1000, 0x00, 0x00 },
 193         [BAM_P_IRQ_EN]          = { 0x13018, 0x1000, 0x00, 0x00 },
 194         [BAM_P_EVNT_DEST_ADDR]  = { 0x1382C, 0x00, 0x1000, 0x00 },
 195         [BAM_P_EVNT_REG]        = { 0x13818, 0x00, 0x1000, 0x00 },
 196         [BAM_P_SW_OFSTS]        = { 0x13800, 0x00, 0x1000, 0x00 },
 197         [BAM_P_DATA_FIFO_ADDR]  = { 0x13824, 0x00, 0x1000, 0x00 },
 198         [BAM_P_DESC_FIFO_ADDR]  = { 0x1381C, 0x00, 0x1000, 0x00 },
 199         [BAM_P_EVNT_GEN_TRSHLD] = { 0x13828, 0x00, 0x1000, 0x00 },
 200         [BAM_P_FIFO_SIZES]      = { 0x13820, 0x00, 0x1000, 0x00 },
 201 };
 202
 203 /* BAM CTRL */
 204 #define BAM_SW_RST                      BIT(0)
 205 #define BAM_EN                          BIT(1)
 206 #define BAM_EN_ACCUM                    BIT(4)
 207 #define BAM_TESTBUS_SEL_SHIFT           5
 208 #define BAM_TESTBUS_SEL_MASK            0x3F
 209 #define BAM_DESC_CACHE_SEL_SHIFT        13
 210 #define BAM_DESC_CACHE_SEL_MASK         0x3
 211 #define BAM_CACHED_DESC_STORE           BIT(15)
 212 #define IBC_DISABLE                     BIT(16)
 213
 214 /* BAM REVISION */
 215 #define REVISION_SHIFT          0
 216 #define REVISION_MASK           0xFF
 217 #define NUM_EES_SHIFT           8
 218 #define NUM_EES_MASK            0xF
 219 #define CE_BUFFER_SIZE          BIT(13)
 220 #define AXI_ACTIVE              BIT(14)
 221 #define USE_VMIDMT              BIT(15)
 222 #define SECURED                 BIT(16)
 223 #define BAM_HAS_NO_BYPASS       BIT(17)
 224 #define HIGH_FREQUENCY_BAM      BIT(18)
 225 #define INACTIV_TMRS_EXST       BIT(19)
 226 #define NUM_INACTIV_TMRS        BIT(20)
 227 #define DESC_CACHE_DEPTH_SHIFT  21
 228 #define DESC_CACHE_DEPTH_1      (0 << DESC_CACHE_DEPTH_SHIFT)
 229 #define DESC_CACHE_DEPTH_2      (1 << DESC_CACHE_DEPTH_SHIFT)
 230 #define DESC_CACHE_DEPTH_3      (2 << DESC_CACHE_DEPTH_SHIFT)
 231 #define DESC_CACHE_DEPTH_4      (3 << DESC_CACHE_DEPTH_SHIFT)
 232 #define CMD_DESC_EN             BIT(23)
 233 #define INACTIV_TMR_BASE_SHIFT  24
 234 #define INACTIV_TMR_BASE_MASK   0xFF
 235
 236 /* BAM NUM PIPES */
 237 #define BAM_NUM_PIPES_SHIFT             0
 238 #define BAM_NUM_PIPES_MASK              0xFF
 239 #define PERIPH_NON_PIPE_GRP_SHIFT       16
 240 #define PERIPH_NON_PIP_GRP_MASK         0xFF
 241 #define BAM_NON_PIPE_GRP_SHIFT          24
 242 #define BAM_NON_PIPE_GRP_MASK           0xFF
 243
 244 /* BAM CNFG BITS */
 245 #define BAM_PIPE_CNFG           BIT(2)
 246 #define BAM_FULL_PIPE           BIT(11)
 247 #define BAM_NO_EXT_P_RST        BIT(12)
 248 #define BAM_IBC_DISABLE         BIT(13)
 249 #define BAM_SB_CLK_REQ          BIT(14)
 250 #define BAM_PSM_CSW_REQ         BIT(15)
 251 #define BAM_PSM_P_RES           BIT(16)
 252 #define BAM_AU_P_RES            BIT(17)
 253 #define BAM_SI_P_RES            BIT(18)
 254 #define BAM_WB_P_RES            BIT(19)
 255 #define BAM_WB_BLK_CSW          BIT(20)
 256 #define BAM_WB_CSW_ACK_IDL      BIT(21)
 257 #define BAM_WB_RETR_SVPNT       BIT(22)
 258 #define BAM_WB_DSC_AVL_P_RST    BIT(23)
 259 #define BAM_REG_P_EN            BIT(24)
 260 #define BAM_PSM_P_HD_DATA       BIT(25)
 261 #define BAM_AU_ACCUMED          BIT(26)
 262 #define BAM_CMD_ENABLE          BIT(27)
 263
 264 #define BAM_CNFG_BITS_DEFAULT   (BAM_PIPE_CNFG |        \
 265                                  BAM_NO_EXT_P_RST |     \
 266                                  BAM_IBC_DISABLE |      \
 267                                  BAM_SB_CLK_REQ |       \
 268                                  BAM_PSM_CSW_REQ |      \
 269                                  BAM_PSM_P_RES |        \
 270                                  BAM_AU_P_RES |         \
 271                                  BAM_SI_P_RES |         \
 272                                  BAM_WB_P_RES |         \
 273                                  BAM_WB_BLK_CSW |       \
 274                                  BAM_WB_CSW_ACK_IDL |   \
 275                                  BAM_WB_RETR_SVPNT |    \
 276                                  BAM_WB_DSC_AVL_P_RST | \
 277                                  BAM_REG_P_EN |         \
 278                                  BAM_PSM_P_HD_DATA |    \
 279                                  BAM_AU_ACCUMED |       \
 280                                  BAM_CMD_ENABLE)
 281
 282 /* PIPE CTRL */
 283 #define P_EN                    BIT(1)
 284 #define P_DIRECTION             BIT(3)
 285 #define P_SYS_STRM              BIT(4)
 286 #define P_SYS_MODE              BIT(5)
 287 #define P_AUTO_EOB              BIT(6)
 288 #define P_AUTO_EOB_SEL_SHIFT    7
 289 #define P_AUTO_EOB_SEL_512      (0 << P_AUTO_EOB_SEL_SHIFT)
 290 #define P_AUTO_EOB_SEL_256      (1 << P_AUTO_EOB_SEL_SHIFT)
 291 #define P_AUTO_EOB_SEL_128      (2 << P_AUTO_EOB_SEL_SHIFT)
 292 #define P_AUTO_EOB_SEL_64       (3 << P_AUTO_EOB_SEL_SHIFT)
 293 #define P_PREFETCH_LIMIT_SHIFT  9
 294 #define P_PREFETCH_LIMIT_32     (0 << P_PREFETCH_LIMIT_SHIFT)
 295 #define P_PREFETCH_LIMIT_16     (1 << P_PREFETCH_LIMIT_SHIFT)
 296 #define P_PREFETCH_LIMIT_4      (2 << P_PREFETCH_LIMIT_SHIFT)
 297 #define P_WRITE_NWD             BIT(11)
 298 #define P_LOCK_GROUP_SHIFT      16
 299 #define P_LOCK_GROUP_MASK       0x1F
 300
 301 /* BAM_DESC_CNT_TRSHLD */
 302 #define CNT_TRSHLD              0xffff
 303 #define DEFAULT_CNT_THRSHLD     0x4
 304
 305 /* BAM_IRQ_SRCS */
 306 #define BAM_IRQ                 BIT(31)
 307 #define P_IRQ                   0x7fffffff
 308
 309 /* BAM_IRQ_SRCS_MSK */
 310 #define BAM_IRQ_MSK             BAM_IRQ
 311 #define P_IRQ_MSK               P_IRQ
 312
 313 /* BAM_IRQ_STTS */
 314 #define BAM_TIMER_IRQ           BIT(4)
 315 #define BAM_EMPTY_IRQ           BIT(3)
 316 #define BAM_ERROR_IRQ           BIT(2)
 317 #define BAM_HRESP_ERR_IRQ       BIT(1)
 318
 319 /* BAM_IRQ_CLR */
 320 #define BAM_TIMER_CLR           BIT(4)
 321 #define BAM_EMPTY_CLR           BIT(3)
 322 #define BAM_ERROR_CLR           BIT(2)
 323 #define BAM_HRESP_ERR_CLR       BIT(1)
 324
 325 /* BAM_IRQ_EN */
 326 #define BAM_TIMER_EN            BIT(4)
 327 #define BAM_EMPTY_EN            BIT(3)
 328 #define BAM_ERROR_EN            BIT(2)
 329 #define BAM_HRESP_ERR_EN        BIT(1)
 330
 331 /* BAM_P_IRQ_EN */
 332 #define P_PRCSD_DESC_EN         BIT(0)
 333 #define P_TIMER_EN              BIT(1)
 334 #define P_WAKE_EN               BIT(2)
 335 #define P_OUT_OF_DESC_EN        BIT(3)
 336 #define P_ERR_EN                BIT(4)
 337 #define P_TRNSFR_END_EN         BIT(5)
 338 #define P_DEFAULT_IRQS_EN       (P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
 339
 340 /* BAM_P_SW_OFSTS */
 341 #define P_SW_OFSTS_MASK         0xffff
 342
 343 #define BAM_DESC_FIFO_SIZE      SZ_32K
 344 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
 345 #define BAM_MAX_DATA_SIZE       (SZ_32K - 8)
 346
 347 struct bam_chan {
 348         struct virt_dma_chan vc;
 349
 350         struct bam_device *bdev;
 351
 352         /* configuration from device tree */
 353         u32 id;
 354
 355         struct bam_async_desc *curr_txd;        /* current running dma */
 356
 357         /* runtime configuration */
 358         struct dma_slave_config slave;
 359
 360         /* fifo storage */
 361         struct bam_desc_hw *fifo_virt;
 362         dma_addr_t fifo_phys;
 363
 364         /* fifo markers */
 365         unsigned short head;            /* start of active descriptor entries */
 366         unsigned short tail;            /* end of active descriptor entries */
 367
 368         unsigned int initialized;       /* is the channel hw initialized? */
 369         unsigned int paused;            /* is the channel paused? */
 370         unsigned int reconfigure;       /* new slave config? */
 371
 372         struct list_head node;
 373 };
 374
 375 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
 376 {
 377         return container_of(common, struct bam_chan, vc.chan);
 378 }
 379
 380 struct bam_device {
 381         void __iomem *regs;
 382         struct device *dev;
 383         struct dma_device common;
 384         struct device_dma_parameters dma_parms;
 385         struct bam_chan *channels;
 386         u32 num_channels;
 387
 388         /* execution environment ID, from DT */
 389         u32 ee;
 390
 391         const struct reg_offset_data *layout;
 392
 393         struct clk *bamclk;
 394         int irq;
 395
 396         /* dma start transaction tasklet */
 397         struct tasklet_struct task;
 398 };
 399
 400 /**
 401  * bam_addr - returns BAM register address
 402  * @bdev: bam device
 403  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
 404  * @reg:  register enum
 405  */
 406 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
 407                 enum bam_reg reg)
 408 {
 409         const struct reg_offset_data r = bdev->layout[reg];
 410
 411         return bdev->regs + r.base_offset +
 412                 r.pipe_mult * pipe +
 413                 r.evnt_mult * pipe +
 414                 r.ee_mult * bdev->ee;
 415 }
 416
 417 /**
 418  * bam_reset_channel - Reset individual BAM DMA channel
 419  * @bchan: bam channel
 420  *
 421  * This function resets a specific BAM channel
 422  */
 423 static void bam_reset_channel(struct bam_chan *bchan)
 424 {
 425         struct bam_device *bdev = bchan->bdev;
 426
 427         lockdep_assert_held(&bchan->vc.lock);
 428
 429         /* reset channel */
 430         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
 431         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
 432
 433         /* don't allow cpu to reorder BAM register accesses done after this */
 434         wmb();
 435
 436         /* make sure hw is initialized when channel is used the first time  */
 437         bchan->initialized = 0;
 438 }
 439
 440 /**
 441  * bam_chan_init_hw - Initialize channel hardware
 442  * @bchan: bam channel
 443  *
 444  * This function resets and initializes the BAM channel
 445  */
 446 static void bam_chan_init_hw(struct bam_chan *bchan,
 447         enum dma_transfer_direction dir)
 448 {
 449         struct bam_device *bdev = bchan->bdev;
 450         u32 val;
 451
 452         /* Reset the channel to clear internal state of the FIFO */
 453         bam_reset_channel(bchan);
 454
 455         /*
 456          * write out 8 byte aligned address.  We have enough space for this
 457          * because we allocated 1 more descriptor (8 bytes) than we can use
 458          */
 459         writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
 460                         bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
 461         writel_relaxed(BAM_DESC_FIFO_SIZE,
 462                         bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
 463
 464         /* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
 465         writel_relaxed(P_DEFAULT_IRQS_EN,
 466                         bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 467
 468         /* unmask the specific pipe and EE combo */
 469         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 470         val |= BIT(bchan->id);
 471         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 472
 473         /* don't allow cpu to reorder the channel enable done below */
 474         wmb();
 475
 476         /* set fixed direction and mode, then enable channel */
 477         val = P_EN | P_SYS_MODE;
 478         if (dir == DMA_DEV_TO_MEM)
 479                 val |= P_DIRECTION;
 480
 481         writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
 482
 483         bchan->initialized = 1;
 484
 485         /* init FIFO pointers */
 486         bchan->head = 0;
 487         bchan->tail = 0;
 488 }
 489
 490 /**
 491  * bam_alloc_chan - Allocate channel resources for DMA channel.
 492  * @chan: specified channel
 493  *
 494  * This function allocates the FIFO descriptor memory
 495  */
 496 static int bam_alloc_chan(struct dma_chan *chan)
 497 {
 498         struct bam_chan *bchan = to_bam_chan(chan);
 499         struct bam_device *bdev = bchan->bdev;
 500
 501         if (bchan->fifo_virt)
 502                 return 0;
 503
 504         /* allocate FIFO descriptor space, but only if necessary */
 505         bchan->fifo_virt = dma_alloc_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE,
 506                                 &bchan->fifo_phys, GFP_KERNEL);
 507
 508         if (!bchan->fifo_virt) {
 509                 dev_err(bdev->dev, "Failed to allocate desc fifo\n");
 510                 return -ENOMEM;
 511         }
 512
 513         return 0;
 514 }
 515
 516 /**
 517  * bam_free_chan - Frees dma resources associated with specific channel
 518  * @chan: specified channel
 519  *
 520  * Free the allocated fifo descriptor memory and channel resources
 521  *
 522  */
 523 static void bam_free_chan(struct dma_chan *chan)
 524 {
 525         struct bam_chan *bchan = to_bam_chan(chan);
 526         struct bam_device *bdev = bchan->bdev;
 527         u32 val;
 528         unsigned long flags;
 529
 530         vchan_free_chan_resources(to_virt_chan(chan));
 531
 532         if (bchan->curr_txd) {
 533                 dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
 534                 return;
 535         }
 536
 537         spin_lock_irqsave(&bchan->vc.lock, flags);
 538         bam_reset_channel(bchan);
 539         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 540
 541         dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
 542                                 bchan->fifo_phys);
 543         bchan->fifo_virt = NULL;
 544
 545         /* mask irq for pipe/channel */
 546         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 547         val &= ~BIT(bchan->id);
 548         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 549
 550         /* disable irq */
 551         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 552 }
 553
 554 /**
 555  * bam_slave_config - set slave configuration for channel
 556  * @chan: dma channel
 557  * @cfg: slave configuration
 558  *
 559  * Sets slave configuration for channel
 560  *
 561  */
 562 static int bam_slave_config(struct dma_chan *chan,
 563                             struct dma_slave_config *cfg)
 564 {
 565         struct bam_chan *bchan = to_bam_chan(chan);
 566         unsigned long flag;
 567
 568         spin_lock_irqsave(&bchan->vc.lock, flag);
 569         memcpy(&bchan->slave, cfg, sizeof(*cfg));
 570         bchan->reconfigure = 1;
 571         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 572
 573         return 0;
 574 }
 575
 576 /**
 577  * bam_prep_slave_sg - Prep slave sg transaction
 578  *
 579  * @chan: dma channel
 580  * @sgl: scatter gather list
 581  * @sg_len: length of sg
 582  * @direction: DMA transfer direction
 583  * @flags: DMA flags
 584  * @context: transfer context (unused)
 585  */
 586 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 587         struct scatterlist *sgl, unsigned int sg_len,
 588         enum dma_transfer_direction direction, unsigned long flags,
 589         void *context)
 590 {
 591         struct bam_chan *bchan = to_bam_chan(chan);
 592         struct bam_device *bdev = bchan->bdev;
 593         struct bam_async_desc *async_desc;
 594         struct scatterlist *sg;
 595         u32 i;
 596         struct bam_desc_hw *desc;
 597         unsigned int num_alloc = 0;
 598
 599
 600         if (!is_slave_direction(direction)) {
 601                 dev_err(bdev->dev, "invalid dma direction\n");
 602                 return NULL;
 603         }
 604
 605         /* calculate number of required entries */
 606         for_each_sg(sgl, sg, sg_len, i)
 607                 num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_MAX_DATA_SIZE);
 608
 609         /* allocate enough room to accomodate the number of entries */
 610         async_desc = kzalloc(sizeof(*async_desc) +
 611                         (num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
 612
 613         if (!async_desc)
 614                 goto err_out;
 615
 616         if (flags & DMA_PREP_FENCE)
 617                 async_desc->flags |= DESC_FLAG_NWD;
 618
 619         if (flags & DMA_PREP_INTERRUPT)
 620                 async_desc->flags |= DESC_FLAG_EOT;
 621         else
 622                 async_desc->flags |= DESC_FLAG_INT;
 623
 624         async_desc->num_desc = num_alloc;
 625         async_desc->curr_desc = async_desc->desc;
 626         async_desc->dir = direction;
 627
 628         /* fill in temporary descriptors */
 629         desc = async_desc->desc;
 630         for_each_sg(sgl, sg, sg_len, i) {
 631                 unsigned int remainder = sg_dma_len(sg);
 632                 unsigned int curr_offset = 0;
 633
 634                 do {
 635                         desc->addr = sg_dma_address(sg) + curr_offset;
 636
 637                         if (remainder > BAM_MAX_DATA_SIZE) {
 638                                 desc->size = BAM_MAX_DATA_SIZE;
 639                                 remainder -= BAM_MAX_DATA_SIZE;
 640                                 curr_offset += BAM_MAX_DATA_SIZE;
 641                         } else {
 642                                 desc->size = remainder;
 643                                 remainder = 0;
 644                         }
 645
 646                         async_desc->length += desc->size;
 647                         desc++;
 648                 } while (remainder > 0);
 649         }
 650
 651         return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
 652
 653 err_out:
 654         kfree(async_desc);
 655         return NULL;
 656 }
 657
 658 /**
 659  * bam_dma_terminate_all - terminate all transactions on a channel
 660  * @bchan: bam dma channel
 661  *
 662  * Dequeues and frees all transactions
 663  * No callbacks are done
 664  *
 665  */
 666 static int bam_dma_terminate_all(struct dma_chan *chan)
 667 {
 668         struct bam_chan *bchan = to_bam_chan(chan);
 669         unsigned long flag;
 670         LIST_HEAD(head);
 671
 672         /* remove all transactions, including active transaction */
 673         spin_lock_irqsave(&bchan->vc.lock, flag);
 674         /*
 675          * If we have transactions queued, then some might be committed to the
 676          * hardware in the desc fifo.  The only way to reset the desc fifo is
 677          * to do a hardware reset (either by pipe or the entire block).
 678          * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
 679          * pipe.  If the pipe is left disabled (default state after pipe reset)
 680          * and is accessed by a connected hardware engine, a fatal error in
 681          * the BAM will occur.  There is a small window where this could happen
 682          * with bam_chan_init_hw(), but it is assumed that the caller has
 683          * stopped activity on any attached hardware engine.  Make sure to do
 684          * this first so that the BAM hardware doesn't cause memory corruption
 685          * by accessing freed resources.
 686          */
 687         if (bchan->curr_txd) {
 688                 bam_chan_init_hw(bchan, bchan->curr_txd->dir);
 689                 list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
 690                 bchan->curr_txd = NULL;
 691         }
 692
 693         vchan_get_all_descriptors(&bchan->vc, &head);
 694         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 695
 696         vchan_dma_desc_free_list(&bchan->vc, &head);
 697
 698         return 0;
 699 }
 700
 701 /**
 702  * bam_pause - Pause DMA channel
 703  * @chan: dma channel
 704  *
 705  */
 706 static int bam_pause(struct dma_chan *chan)
 707 {
 708         struct bam_chan *bchan = to_bam_chan(chan);
 709         struct bam_device *bdev = bchan->bdev;
 710         unsigned long flag;
 711
 712         spin_lock_irqsave(&bchan->vc.lock, flag);
 713         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
 714         bchan->paused = 1;
 715         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 716
 717         return 0;
 718 }
 719
 720 /**
 721  * bam_resume - Resume DMA channel operations
 722  * @chan: dma channel
 723  *
 724  */
 725 static int bam_resume(struct dma_chan *chan)
 726 {
 727         struct bam_chan *bchan = to_bam_chan(chan);
 728         struct bam_device *bdev = bchan->bdev;
 729         unsigned long flag;
 730
 731         spin_lock_irqsave(&bchan->vc.lock, flag);
 732         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
 733         bchan->paused = 0;
 734         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 735
 736         return 0;
 737 }
 738
 739 /**
 740  * process_channel_irqs - processes the channel interrupts
 741  * @bdev: bam controller
 742  *
 743  * This function processes the channel interrupts
 744  *
 745  */
 746 static u32 process_channel_irqs(struct bam_device *bdev)
 747 {
 748         u32 i, srcs, pipe_stts;
 749         unsigned long flags;
 750         struct bam_async_desc *async_desc;
 751
 752         srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
 753
 754         /* return early if no pipe/channel interrupts are present */
 755         if (!(srcs & P_IRQ))
 756                 return srcs;
 757
 758         for (i = 0; i < bdev->num_channels; i++) {
 759                 struct bam_chan *bchan = &bdev->channels[i];
 760
 761                 if (!(srcs & BIT(i)))
 762                         continue;
 763
 764                 /* clear pipe irq */
 765                 pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
 766
 767                 writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
 768
 769                 spin_lock_irqsave(&bchan->vc.lock, flags);
 770                 async_desc = bchan->curr_txd;
 771
 772                 if (async_desc) {
 773                         async_desc->num_desc -= async_desc->xfer_len;
 774                         async_desc->curr_desc += async_desc->xfer_len;
 775                         bchan->curr_txd = NULL;
 776
 777                         /* manage FIFO */
 778                         bchan->head += async_desc->xfer_len;
 779                         bchan->head %= MAX_DESCRIPTORS;
 780
 781                         /*
 782                          * if complete, process cookie.  Otherwise
 783                          * push back to front of desc_issued so that
 784                          * it gets restarted by the tasklet
 785                          */
 786                         if (!async_desc->num_desc)
 787                                 vchan_cookie_complete(&async_desc->vd);
 788                         else
 789                                 list_add(&async_desc->vd.node,
 790                                         &bchan->vc.desc_issued);
 791                 }
 792
 793                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
 794         }
 795
 796         return srcs;
 797 }
 798
 799 /**
 800  * bam_dma_irq - irq handler for bam controller
 801  * @irq: IRQ of interrupt
 802  * @data: callback data
 803  *
 804  * IRQ handler for the bam controller
 805  */
 806 static irqreturn_t bam_dma_irq(int irq, void *data)
 807 {
 808         struct bam_device *bdev = data;
 809         u32 clr_mask = 0, srcs = 0;
 810
 811         srcs |= process_channel_irqs(bdev);
 812
 813         /* kick off tasklet to start next dma transfer */
 814         if (srcs & P_IRQ)
 815                 tasklet_schedule(&bdev->task);
 816
 817         if (srcs & BAM_IRQ)
 818                 clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
 819
 820         /* don't allow reorder of the various accesses to the BAM registers */
 821         mb();
 822
 823         writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
 824
 825         return IRQ_HANDLED;
 826 }
 827
 828 /**
 829  * bam_tx_status - returns status of transaction
 830  * @chan: dma channel
 831  * @cookie: transaction cookie
 832  * @txstate: DMA transaction state
 833  *
 834  * Return status of dma transaction
 835  */
 836 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 837                 struct dma_tx_state *txstate)
 838 {
 839         struct bam_chan *bchan = to_bam_chan(chan);
 840         struct virt_dma_desc *vd;
 841         int ret;
 842         size_t residue = 0;
 843         unsigned int i;
 844         unsigned long flags;
 845
 846         ret = dma_cookie_status(chan, cookie, txstate);
 847         if (ret == DMA_COMPLETE)
 848                 return ret;
 849
 850         if (!txstate)
 851                 return bchan->paused ? DMA_PAUSED : ret;
 852
 853         spin_lock_irqsave(&bchan->vc.lock, flags);
 854         vd = vchan_find_desc(&bchan->vc, cookie);
 855         if (vd)
 856                 residue = container_of(vd, struct bam_async_desc, vd)->length;
 857         else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
 858                 for (i = 0; i < bchan->curr_txd->num_desc; i++)
 859                         residue += bchan->curr_txd->curr_desc[i].size;
 860
 861         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 862
 863         dma_set_residue(txstate, residue);
 864
 865         if (ret == DMA_IN_PROGRESS && bchan->paused)
 866                 ret = DMA_PAUSED;
 867
 868         return ret;
 869 }
 870
 871 /**
 872  * bam_apply_new_config
 873  * @bchan: bam dma channel
 874  * @dir: DMA direction
 875  */
 876 static void bam_apply_new_config(struct bam_chan *bchan,
 877         enum dma_transfer_direction dir)
 878 {
 879         struct bam_device *bdev = bchan->bdev;
 880         u32 maxburst;
 881
 882         if (dir == DMA_DEV_TO_MEM)
 883                 maxburst = bchan->slave.src_maxburst;
 884         else
 885                 maxburst = bchan->slave.dst_maxburst;
 886
 887         writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
 888
 889         bchan->reconfigure = 0;
 890 }
 891
 892 /**
 893  * bam_start_dma - start next transaction
 894  * @bchan - bam dma channel
 895  */
 896 static void bam_start_dma(struct bam_chan *bchan)
 897 {
 898         struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
 899         struct bam_device *bdev = bchan->bdev;
 900         struct bam_async_desc *async_desc;
 901         struct bam_desc_hw *desc;
 902         struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
 903                                         sizeof(struct bam_desc_hw));
 904
 905         lockdep_assert_held(&bchan->vc.lock);
 906
 907         if (!vd)
 908                 return;
 909
 910         list_del(&vd->node);
 911
 912         async_desc = container_of(vd, struct bam_async_desc, vd);
 913         bchan->curr_txd = async_desc;
 914
 915         /* on first use, initialize the channel hardware */
 916         if (!bchan->initialized)
 917                 bam_chan_init_hw(bchan, async_desc->dir);
 918
 919         /* apply new slave config changes, if necessary */
 920         if (bchan->reconfigure)
 921                 bam_apply_new_config(bchan, async_desc->dir);
 922
 923         desc = bchan->curr_txd->curr_desc;
 924
 925         if (async_desc->num_desc > MAX_DESCRIPTORS)
 926                 async_desc->xfer_len = MAX_DESCRIPTORS;
 927         else
 928                 async_desc->xfer_len = async_desc->num_desc;
 929
 930         /* set any special flags on the last descriptor */
 931         if (async_desc->num_desc == async_desc->xfer_len)
 932                 desc[async_desc->xfer_len - 1].flags = async_desc->flags;
 933         else
 934                 desc[async_desc->xfer_len - 1].flags |= DESC_FLAG_INT;
 935
 936         if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
 937                 u32 partial = MAX_DESCRIPTORS - bchan->tail;
 938
 939                 memcpy(&fifo[bchan->tail], desc,
 940                                 partial * sizeof(struct bam_desc_hw));
 941                 memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
 942                                 sizeof(struct bam_desc_hw));
 943         } else {
 944                 memcpy(&fifo[bchan->tail], desc,
 945                         async_desc->xfer_len * sizeof(struct bam_desc_hw));
 946         }
 947
 948         bchan->tail += async_desc->xfer_len;
 949         bchan->tail %= MAX_DESCRIPTORS;
 950
 951         /* ensure descriptor writes and dma start not reordered */
 952         wmb();
 953         writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
 954                         bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
 955 }
 956
 957 /**
 958  * dma_tasklet - DMA IRQ tasklet
 959  * @data: tasklet argument (bam controller structure)
 960  *
 961  * Sets up next DMA operation and then processes all completed transactions
 962  */
 963 static void dma_tasklet(unsigned long data)
 964 {
 965         struct bam_device *bdev = (struct bam_device *)data;
 966         struct bam_chan *bchan;
 967         unsigned long flags;
 968         unsigned int i;
 969
 970         /* go through the channels and kick off transactions */
 971         for (i = 0; i < bdev->num_channels; i++) {
 972                 bchan = &bdev->channels[i];
 973                 spin_lock_irqsave(&bchan->vc.lock, flags);
 974
 975                 if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
 976                         bam_start_dma(bchan);
 977                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
 978         }
 979 }
 980
 981 /**
 982  * bam_issue_pending - starts pending transactions
 983  * @chan: dma channel
 984  *
 985  * Calls tasklet directly which in turn starts any pending transactions
 986  */
 987 static void bam_issue_pending(struct dma_chan *chan)
 988 {
 989         struct bam_chan *bchan = to_bam_chan(chan);
 990         unsigned long flags;
 991
 992         spin_lock_irqsave(&bchan->vc.lock, flags);
 993
 994         /* if work pending and idle, start a transaction */
 995         if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
 996                 bam_start_dma(bchan);
 997
 998         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 999 }
1000
1001 /**
1002  * bam_dma_free_desc - free descriptor memory
1003  * @vd: virtual descriptor
1004  *
1005  */
1006 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1007 {
1008         struct bam_async_desc *async_desc = container_of(vd,
1009                         struct bam_async_desc, vd);
1010
1011         kfree(async_desc);
1012 }
1013
1014 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1015                 struct of_dma *of)
1016 {
1017         struct bam_device *bdev = container_of(of->of_dma_data,
1018                                         struct bam_device, common);
1019         unsigned int request;
1020
1021         if (dma_spec->args_count != 1)
1022                 return NULL;
1023
1024         request = dma_spec->args[0];
1025         if (request >= bdev->num_channels)
1026                 return NULL;
1027
1028         return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1029 }
1030
1031 /**
1032  * bam_init
1033  * @bdev: bam device
1034  *
1035  * Initialization helper for global bam registers
1036  */
1037 static int bam_init(struct bam_device *bdev)
1038 {
1039         u32 val;
1040
1041         /* read revision and configuration information */
1042         val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;
1043         val &= NUM_EES_MASK;
1044
1045         /* check that configured EE is within range */
1046         if (bdev->ee >= val)
1047                 return -EINVAL;
1048
1049         val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1050         bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1051
1052         /* s/w reset bam */
1053         /* after reset all pipes are disabled and idle */
1054         val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1055         val |= BAM_SW_RST;
1056         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1057         val &= ~BAM_SW_RST;
1058         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1059
1060         /* make sure previous stores are visible before enabling BAM */
1061         wmb();
1062
1063         /* enable bam */
1064         val |= BAM_EN;
1065         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1066
1067         /* set descriptor threshhold, start with 4 bytes */
1068         writel_relaxed(DEFAULT_CNT_THRSHLD,
1069                         bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1070
1071         /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1072         writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1073
1074         /* enable irqs for errors */
1075         writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1076                         bam_addr(bdev, 0, BAM_IRQ_EN));
1077
1078         /* unmask global bam interrupt */
1079         writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1080
1081         return 0;
1082 }
1083
1084 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1085         u32 index)
1086 {
1087         bchan->id = index;
1088         bchan->bdev = bdev;
1089
1090         vchan_init(&bchan->vc, &bdev->common);
1091         bchan->vc.desc_free = bam_dma_free_desc;
1092 }
1093
1094 static const struct of_device_id bam_of_match[] = {
1095         { .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1096         { .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1097         { .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1098         {}
1099 };
1100
1101 MODULE_DEVICE_TABLE(of, bam_of_match);
1102
1103 static int bam_dma_probe(struct platform_device *pdev)
1104 {
1105         struct bam_device *bdev;
1106         const struct of_device_id *match;
1107         struct resource *iores;
1108         int ret, i;
1109
1110         bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1111         if (!bdev)
1112                 return -ENOMEM;
1113
1114         bdev->dev = &pdev->dev;
1115
1116         match = of_match_node(bam_of_match, pdev->dev.of_node);
1117         if (!match) {
1118                 dev_err(&pdev->dev, "Unsupported BAM module\n");
1119                 return -ENODEV;
1120         }
1121
1122         bdev->layout = match->data;
1123
1124         iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1125         bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1126         if (IS_ERR(bdev->regs))
1127                 return PTR_ERR(bdev->regs);
1128
1129         bdev->irq = platform_get_irq(pdev, 0);
1130         if (bdev->irq < 0)
1131                 return bdev->irq;
1132
1133         ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1134         if (ret) {
1135                 dev_err(bdev->dev, "Execution environment unspecified\n");
1136                 return ret;
1137         }
1138
1139         bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1140         if (IS_ERR(bdev->bamclk))
1141                 return PTR_ERR(bdev->bamclk);
1142
1143         ret = clk_prepare_enable(bdev->bamclk);
1144         if (ret) {
1145                 dev_err(bdev->dev, "failed to prepare/enable clock\n");
1146                 return ret;
1147         }
1148
1149         ret = bam_init(bdev);
1150         if (ret)
1151                 goto err_disable_clk;
1152
1153         tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1154
1155         bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1156                                 sizeof(*bdev->channels), GFP_KERNEL);
1157
1158         if (!bdev->channels) {
1159                 ret = -ENOMEM;
1160                 goto err_tasklet_kill;
1161         }
1162
1163         /* allocate and initialize channels */
1164         INIT_LIST_HEAD(&bdev->common.channels);
1165
1166         for (i = 0; i < bdev->num_channels; i++)
1167                 bam_channel_init(bdev, &bdev->channels[i], i);
1168
1169         ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1170                         IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1171         if (ret)
1172                 goto err_bam_channel_exit;
1173
1174         /* set max dma segment size */
1175         bdev->common.dev = bdev->dev;
1176         bdev->common.dev->dma_parms = &bdev->dma_parms;
1177         ret = dma_set_max_seg_size(bdev->common.dev, BAM_MAX_DATA_SIZE);
1178         if (ret) {
1179                 dev_err(bdev->dev, "cannot set maximum segment size\n");
1180                 goto err_bam_channel_exit;
1181         }
1182
1183         platform_set_drvdata(pdev, bdev);
1184
1185         /* set capabilities */
1186         dma_cap_zero(bdev->common.cap_mask);
1187         dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1188
1189         /* initialize dmaengine apis */
1190         bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1191         bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1192         bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1193         bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1194         bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1195         bdev->common.device_free_chan_resources = bam_free_chan;
1196         bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1197         bdev->common.device_config = bam_slave_config;
1198         bdev->common.device_pause = bam_pause;
1199         bdev->common.device_resume = bam_resume;
1200         bdev->common.device_terminate_all = bam_dma_terminate_all;
1201         bdev->common.device_issue_pending = bam_issue_pending;
1202         bdev->common.device_tx_status = bam_tx_status;
1203         bdev->common.dev = bdev->dev;
1204
1205         ret = dma_async_device_register(&bdev->common);
1206         if (ret) {
1207                 dev_err(bdev->dev, "failed to register dma async device\n");
1208                 goto err_bam_channel_exit;
1209         }
1210
1211         ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1212                                         &bdev->common);
1213         if (ret)
1214                 goto err_unregister_dma;
1215
1216         return 0;
1217
1218 err_unregister_dma:
1219         dma_async_device_unregister(&bdev->common);
1220 err_bam_channel_exit:
1221         for (i = 0; i < bdev->num_channels; i++)
1222                 tasklet_kill(&bdev->channels[i].vc.task);
1223 err_tasklet_kill:
1224         tasklet_kill(&bdev->task);
1225 err_disable_clk:
1226         clk_disable_unprepare(bdev->bamclk);
1227
1228         return ret;
1229 }
1230
1231 static int bam_dma_remove(struct platform_device *pdev)
1232 {
1233         struct bam_device *bdev = platform_get_drvdata(pdev);
1234         u32 i;
1235
1236         of_dma_controller_free(pdev->dev.of_node);
1237         dma_async_device_unregister(&bdev->common);
1238
1239         /* mask all interrupts for this execution environment */
1240         writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1241
1242         devm_free_irq(bdev->dev, bdev->irq, bdev);
1243
1244         for (i = 0; i < bdev->num_channels; i++) {
1245                 bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1246                 tasklet_kill(&bdev->channels[i].vc.task);
1247
1248                 dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE,
1249                         bdev->channels[i].fifo_virt,
1250                         bdev->channels[i].fifo_phys);
1251         }
1252
1253         tasklet_kill(&bdev->task);
1254
1255         clk_disable_unprepare(bdev->bamclk);
1256
1257         return 0;
1258 }
1259
1260 static struct platform_driver bam_dma_driver = {
1261         .probe = bam_dma_probe,
1262         .remove = bam_dma_remove,
1263         .driver = {
1264                 .name = "bam-dma-engine",
1265                 .of_match_table = bam_of_match,
1266         },
1267 };
1268
1269 module_platform_driver(bam_dma_driver);
1270
1271 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1272 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1273 MODULE_LICENSE("GPL v2");