drivers/dma/qcom/bam_dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
   4  */
   5 /*
   6  * QCOM BAM DMA engine driver
   7  *
   8  * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
   9  * peripherals on the MSM 8x74.  The configuration of the channels are dependent
  10  * on the way they are hard wired to that specific peripheral.  The peripheral
  11  * device tree entries specify the configuration of each channel.
  12  *
  13  * The DMA controller requires the use of external memory for storage of the
  14  * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
  15  * circular buffer and operations are managed according to the offset within the
  16  * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
  17  * are back to defaults.
  18  *
  19  * During DMA operations, we write descriptors to the FIFO, being careful to
  20  * handle wrapping and then write the last FIFO offset to that channel's
  21  * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
  22  * indicates the current FIFO offset that is being processed, so there is some
  23  * indication of where the hardware is currently working.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/io.h>
  28 #include <linux/init.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/dma-mapping.h>
  33 #include <linux/scatterlist.h>
  34 #include <linux/device.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/of.h>
  37 #include <linux/of_address.h>
  38 #include <linux/of_irq.h>
  39 #include <linux/of_dma.h>
  40 #include <linux/circ_buf.h>
  41 #include <linux/clk.h>
  42 #include <linux/dmaengine.h>
  43 #include <linux/pm_runtime.h>
  44
  45 #include "../dmaengine.h"
  46 #include "../virt-dma.h"
  47
  48 struct bam_desc_hw {
  49         __le32 addr;            /* Buffer physical address */
  50         __le16 size;            /* Buffer size in bytes */
  51         __le16 flags;
  52 };
  53
  54 #define BAM_DMA_AUTOSUSPEND_DELAY 100
  55
  56 #define DESC_FLAG_INT BIT(15)
  57 #define DESC_FLAG_EOT BIT(14)
  58 #define DESC_FLAG_EOB BIT(13)
  59 #define DESC_FLAG_NWD BIT(12)
  60 #define DESC_FLAG_CMD BIT(11)
  61
  62 struct bam_async_desc {
  63         struct virt_dma_desc vd;
  64
  65         u32 num_desc;
  66         u32 xfer_len;
  67
  68         /* transaction flags, EOT|EOB|NWD */
  69         u16 flags;
  70
  71         struct bam_desc_hw *curr_desc;
  72
  73         /* list node for the desc in the bam_chan list of descriptors */
  74         struct list_head desc_node;
  75         enum dma_transfer_direction dir;
  76         size_t length;
  77         struct bam_desc_hw desc[0];
  78 };
  79
  80 enum bam_reg {
  81         BAM_CTRL,
  82         BAM_REVISION,
  83         BAM_NUM_PIPES,
  84         BAM_DESC_CNT_TRSHLD,
  85         BAM_IRQ_SRCS,
  86         BAM_IRQ_SRCS_MSK,
  87         BAM_IRQ_SRCS_UNMASKED,
  88         BAM_IRQ_STTS,
  89         BAM_IRQ_CLR,
  90         BAM_IRQ_EN,
  91         BAM_CNFG_BITS,
  92         BAM_IRQ_SRCS_EE,
  93         BAM_IRQ_SRCS_MSK_EE,
  94         BAM_P_CTRL,
  95         BAM_P_RST,
  96         BAM_P_HALT,
  97         BAM_P_IRQ_STTS,
  98         BAM_P_IRQ_CLR,
  99         BAM_P_IRQ_EN,
 100         BAM_P_EVNT_DEST_ADDR,
 101         BAM_P_EVNT_REG,
 102         BAM_P_SW_OFSTS,
 103         BAM_P_DATA_FIFO_ADDR,
 104         BAM_P_DESC_FIFO_ADDR,
 105         BAM_P_EVNT_GEN_TRSHLD,
 106         BAM_P_FIFO_SIZES,
 107 };
 108
 109 struct reg_offset_data {
 110         u32 base_offset;
 111         unsigned int pipe_mult, evnt_mult, ee_mult;
 112 };
 113
 114 static const struct reg_offset_data bam_v1_3_reg_info[] = {
 115         [BAM_CTRL]              = { 0x0F80, 0x00, 0x00, 0x00 },
 116         [BAM_REVISION]          = { 0x0F84, 0x00, 0x00, 0x00 },
 117         [BAM_NUM_PIPES]         = { 0x0FBC, 0x00, 0x00, 0x00 },
 118         [BAM_DESC_CNT_TRSHLD]   = { 0x0F88, 0x00, 0x00, 0x00 },
 119         [BAM_IRQ_SRCS]          = { 0x0F8C, 0x00, 0x00, 0x00 },
 120         [BAM_IRQ_SRCS_MSK]      = { 0x0F90, 0x00, 0x00, 0x00 },
 121         [BAM_IRQ_SRCS_UNMASKED] = { 0x0FB0, 0x00, 0x00, 0x00 },
 122         [BAM_IRQ_STTS]          = { 0x0F94, 0x00, 0x00, 0x00 },
 123         [BAM_IRQ_CLR]           = { 0x0F98, 0x00, 0x00, 0x00 },
 124         [BAM_IRQ_EN]            = { 0x0F9C, 0x00, 0x00, 0x00 },
 125         [BAM_CNFG_BITS]         = { 0x0FFC, 0x00, 0x00, 0x00 },
 126         [BAM_IRQ_SRCS_EE]       = { 0x1800, 0x00, 0x00, 0x80 },
 127         [BAM_IRQ_SRCS_MSK_EE]   = { 0x1804, 0x00, 0x00, 0x80 },
 128         [BAM_P_CTRL]            = { 0x0000, 0x80, 0x00, 0x00 },
 129         [BAM_P_RST]             = { 0x0004, 0x80, 0x00, 0x00 },
 130         [BAM_P_HALT]            = { 0x0008, 0x80, 0x00, 0x00 },
 131         [BAM_P_IRQ_STTS]        = { 0x0010, 0x80, 0x00, 0x00 },
 132         [BAM_P_IRQ_CLR]         = { 0x0014, 0x80, 0x00, 0x00 },
 133         [BAM_P_IRQ_EN]          = { 0x0018, 0x80, 0x00, 0x00 },
 134         [BAM_P_EVNT_DEST_ADDR]  = { 0x102C, 0x00, 0x40, 0x00 },
 135         [BAM_P_EVNT_REG]        = { 0x1018, 0x00, 0x40, 0x00 },
 136         [BAM_P_SW_OFSTS]        = { 0x1000, 0x00, 0x40, 0x00 },
 137         [BAM_P_DATA_FIFO_ADDR]  = { 0x1024, 0x00, 0x40, 0x00 },
 138         [BAM_P_DESC_FIFO_ADDR]  = { 0x101C, 0x00, 0x40, 0x00 },
 139         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1028, 0x00, 0x40, 0x00 },
 140         [BAM_P_FIFO_SIZES]      = { 0x1020, 0x00, 0x40, 0x00 },
 141 };
 142
 143 static const struct reg_offset_data bam_v1_4_reg_info[] = {
 144         [BAM_CTRL]              = { 0x0000, 0x00, 0x00, 0x00 },
 145         [BAM_REVISION]          = { 0x0004, 0x00, 0x00, 0x00 },
 146         [BAM_NUM_PIPES]         = { 0x003C, 0x00, 0x00, 0x00 },
 147         [BAM_DESC_CNT_TRSHLD]   = { 0x0008, 0x00, 0x00, 0x00 },
 148         [BAM_IRQ_SRCS]          = { 0x000C, 0x00, 0x00, 0x00 },
 149         [BAM_IRQ_SRCS_MSK]      = { 0x0010, 0x00, 0x00, 0x00 },
 150         [BAM_IRQ_SRCS_UNMASKED] = { 0x0030, 0x00, 0x00, 0x00 },
 151         [BAM_IRQ_STTS]          = { 0x0014, 0x00, 0x00, 0x00 },
 152         [BAM_IRQ_CLR]           = { 0x0018, 0x00, 0x00, 0x00 },
 153         [BAM_IRQ_EN]            = { 0x001C, 0x00, 0x00, 0x00 },
 154         [BAM_CNFG_BITS]         = { 0x007C, 0x00, 0x00, 0x00 },
 155         [BAM_IRQ_SRCS_EE]       = { 0x0800, 0x00, 0x00, 0x80 },
 156         [BAM_IRQ_SRCS_MSK_EE]   = { 0x0804, 0x00, 0x00, 0x80 },
 157         [BAM_P_CTRL]            = { 0x1000, 0x1000, 0x00, 0x00 },
 158         [BAM_P_RST]             = { 0x1004, 0x1000, 0x00, 0x00 },
 159         [BAM_P_HALT]            = { 0x1008, 0x1000, 0x00, 0x00 },
 160         [BAM_P_IRQ_STTS]        = { 0x1010, 0x1000, 0x00, 0x00 },
 161         [BAM_P_IRQ_CLR]         = { 0x1014, 0x1000, 0x00, 0x00 },
 162         [BAM_P_IRQ_EN]          = { 0x1018, 0x1000, 0x00, 0x00 },
 163         [BAM_P_EVNT_DEST_ADDR]  = { 0x182C, 0x00, 0x1000, 0x00 },
 164         [BAM_P_EVNT_REG]        = { 0x1818, 0x00, 0x1000, 0x00 },
 165         [BAM_P_SW_OFSTS]        = { 0x1800, 0x00, 0x1000, 0x00 },
 166         [BAM_P_DATA_FIFO_ADDR]  = { 0x1824, 0x00, 0x1000, 0x00 },
 167         [BAM_P_DESC_FIFO_ADDR]  = { 0x181C, 0x00, 0x1000, 0x00 },
 168         [BAM_P_EVNT_GEN_TRSHLD] = { 0x1828, 0x00, 0x1000, 0x00 },
 169         [BAM_P_FIFO_SIZES]      = { 0x1820, 0x00, 0x1000, 0x00 },
 170 };
 171
 172 static const struct reg_offset_data bam_v1_7_reg_info[] = {
 173         [BAM_CTRL]              = { 0x00000, 0x00, 0x00, 0x00 },
 174         [BAM_REVISION]          = { 0x01000, 0x00, 0x00, 0x00 },
 175         [BAM_NUM_PIPES]         = { 0x01008, 0x00, 0x00, 0x00 },
 176         [BAM_DESC_CNT_TRSHLD]   = { 0x00008, 0x00, 0x00, 0x00 },
 177         [BAM_IRQ_SRCS]          = { 0x03010, 0x00, 0x00, 0x00 },
 178         [BAM_IRQ_SRCS_MSK]      = { 0x03014, 0x00, 0x00, 0x00 },
 179         [BAM_IRQ_SRCS_UNMASKED] = { 0x03018, 0x00, 0x00, 0x00 },
 180         [BAM_IRQ_STTS]          = { 0x00014, 0x00, 0x00, 0x00 },
 181         [BAM_IRQ_CLR]           = { 0x00018, 0x00, 0x00, 0x00 },
 182         [BAM_IRQ_EN]            = { 0x0001C, 0x00, 0x00, 0x00 },
 183         [BAM_CNFG_BITS]         = { 0x0007C, 0x00, 0x00, 0x00 },
 184         [BAM_IRQ_SRCS_EE]       = { 0x03000, 0x00, 0x00, 0x1000 },
 185         [BAM_IRQ_SRCS_MSK_EE]   = { 0x03004, 0x00, 0x00, 0x1000 },
 186         [BAM_P_CTRL]            = { 0x13000, 0x1000, 0x00, 0x00 },
 187         [BAM_P_RST]             = { 0x13004, 0x1000, 0x00, 0x00 },
 188         [BAM_P_HALT]            = { 0x13008, 0x1000, 0x00, 0x00 },
 189         [BAM_P_IRQ_STTS]        = { 0x13010, 0x1000, 0x00, 0x00 },
 190         [BAM_P_IRQ_CLR]         = { 0x13014, 0x1000, 0x00, 0x00 },
 191         [BAM_P_IRQ_EN]          = { 0x13018, 0x1000, 0x00, 0x00 },
 192         [BAM_P_EVNT_DEST_ADDR]  = { 0x1382C, 0x00, 0x1000, 0x00 },
 193         [BAM_P_EVNT_REG]        = { 0x13818, 0x00, 0x1000, 0x00 },
 194         [BAM_P_SW_OFSTS]        = { 0x13800, 0x00, 0x1000, 0x00 },
 195         [BAM_P_DATA_FIFO_ADDR]  = { 0x13824, 0x00, 0x1000, 0x00 },
 196         [BAM_P_DESC_FIFO_ADDR]  = { 0x1381C, 0x00, 0x1000, 0x00 },
 197         [BAM_P_EVNT_GEN_TRSHLD] = { 0x13828, 0x00, 0x1000, 0x00 },
 198         [BAM_P_FIFO_SIZES]      = { 0x13820, 0x00, 0x1000, 0x00 },
 199 };
 200
 201 /* BAM CTRL */
 202 #define BAM_SW_RST                      BIT(0)
 203 #define BAM_EN                          BIT(1)
 204 #define BAM_EN_ACCUM                    BIT(4)
 205 #define BAM_TESTBUS_SEL_SHIFT           5
 206 #define BAM_TESTBUS_SEL_MASK            0x3F
 207 #define BAM_DESC_CACHE_SEL_SHIFT        13
 208 #define BAM_DESC_CACHE_SEL_MASK         0x3
 209 #define BAM_CACHED_DESC_STORE           BIT(15)
 210 #define IBC_DISABLE                     BIT(16)
 211
 212 /* BAM REVISION */
 213 #define REVISION_SHIFT          0
 214 #define REVISION_MASK           0xFF
 215 #define NUM_EES_SHIFT           8
 216 #define NUM_EES_MASK            0xF
 217 #define CE_BUFFER_SIZE          BIT(13)
 218 #define AXI_ACTIVE              BIT(14)
 219 #define USE_VMIDMT              BIT(15)
 220 #define SECURED                 BIT(16)
 221 #define BAM_HAS_NO_BYPASS       BIT(17)
 222 #define HIGH_FREQUENCY_BAM      BIT(18)
 223 #define INACTIV_TMRS_EXST       BIT(19)
 224 #define NUM_INACTIV_TMRS        BIT(20)
 225 #define DESC_CACHE_DEPTH_SHIFT  21
 226 #define DESC_CACHE_DEPTH_1      (0 << DESC_CACHE_DEPTH_SHIFT)
 227 #define DESC_CACHE_DEPTH_2      (1 << DESC_CACHE_DEPTH_SHIFT)
 228 #define DESC_CACHE_DEPTH_3      (2 << DESC_CACHE_DEPTH_SHIFT)
 229 #define DESC_CACHE_DEPTH_4      (3 << DESC_CACHE_DEPTH_SHIFT)
 230 #define CMD_DESC_EN             BIT(23)
 231 #define INACTIV_TMR_BASE_SHIFT  24
 232 #define INACTIV_TMR_BASE_MASK   0xFF
 233
 234 /* BAM NUM PIPES */
 235 #define BAM_NUM_PIPES_SHIFT             0
 236 #define BAM_NUM_PIPES_MASK              0xFF
 237 #define PERIPH_NON_PIPE_GRP_SHIFT       16
 238 #define PERIPH_NON_PIP_GRP_MASK         0xFF
 239 #define BAM_NON_PIPE_GRP_SHIFT          24
 240 #define BAM_NON_PIPE_GRP_MASK           0xFF
 241
 242 /* BAM CNFG BITS */
 243 #define BAM_PIPE_CNFG           BIT(2)
 244 #define BAM_FULL_PIPE           BIT(11)
 245 #define BAM_NO_EXT_P_RST        BIT(12)
 246 #define BAM_IBC_DISABLE         BIT(13)
 247 #define BAM_SB_CLK_REQ          BIT(14)
 248 #define BAM_PSM_CSW_REQ         BIT(15)
 249 #define BAM_PSM_P_RES           BIT(16)
 250 #define BAM_AU_P_RES            BIT(17)
 251 #define BAM_SI_P_RES            BIT(18)
 252 #define BAM_WB_P_RES            BIT(19)
 253 #define BAM_WB_BLK_CSW          BIT(20)
 254 #define BAM_WB_CSW_ACK_IDL      BIT(21)
 255 #define BAM_WB_RETR_SVPNT       BIT(22)
 256 #define BAM_WB_DSC_AVL_P_RST    BIT(23)
 257 #define BAM_REG_P_EN            BIT(24)
 258 #define BAM_PSM_P_HD_DATA       BIT(25)
 259 #define BAM_AU_ACCUMED          BIT(26)
 260 #define BAM_CMD_ENABLE          BIT(27)
 261
 262 #define BAM_CNFG_BITS_DEFAULT   (BAM_PIPE_CNFG |        \
 263                                  BAM_NO_EXT_P_RST |     \
 264                                  BAM_IBC_DISABLE |      \
 265                                  BAM_SB_CLK_REQ |       \
 266                                  BAM_PSM_CSW_REQ |      \
 267                                  BAM_PSM_P_RES |        \
 268                                  BAM_AU_P_RES |         \
 269                                  BAM_SI_P_RES |         \
 270                                  BAM_WB_P_RES |         \
 271                                  BAM_WB_BLK_CSW |       \
 272                                  BAM_WB_CSW_ACK_IDL |   \
 273                                  BAM_WB_RETR_SVPNT |    \
 274                                  BAM_WB_DSC_AVL_P_RST | \
 275                                  BAM_REG_P_EN |         \
 276                                  BAM_PSM_P_HD_DATA |    \
 277                                  BAM_AU_ACCUMED |       \
 278                                  BAM_CMD_ENABLE)
 279
 280 /* PIPE CTRL */
 281 #define P_EN                    BIT(1)
 282 #define P_DIRECTION             BIT(3)
 283 #define P_SYS_STRM              BIT(4)
 284 #define P_SYS_MODE              BIT(5)
 285 #define P_AUTO_EOB              BIT(6)
 286 #define P_AUTO_EOB_SEL_SHIFT    7
 287 #define P_AUTO_EOB_SEL_512      (0 << P_AUTO_EOB_SEL_SHIFT)
 288 #define P_AUTO_EOB_SEL_256      (1 << P_AUTO_EOB_SEL_SHIFT)
 289 #define P_AUTO_EOB_SEL_128      (2 << P_AUTO_EOB_SEL_SHIFT)
 290 #define P_AUTO_EOB_SEL_64       (3 << P_AUTO_EOB_SEL_SHIFT)
 291 #define P_PREFETCH_LIMIT_SHIFT  9
 292 #define P_PREFETCH_LIMIT_32     (0 << P_PREFETCH_LIMIT_SHIFT)
 293 #define P_PREFETCH_LIMIT_16     (1 << P_PREFETCH_LIMIT_SHIFT)
 294 #define P_PREFETCH_LIMIT_4      (2 << P_PREFETCH_LIMIT_SHIFT)
 295 #define P_WRITE_NWD             BIT(11)
 296 #define P_LOCK_GROUP_SHIFT      16
 297 #define P_LOCK_GROUP_MASK       0x1F
 298
 299 /* BAM_DESC_CNT_TRSHLD */
 300 #define CNT_TRSHLD              0xffff
 301 #define DEFAULT_CNT_THRSHLD     0x4
 302
 303 /* BAM_IRQ_SRCS */
 304 #define BAM_IRQ                 BIT(31)
 305 #define P_IRQ                   0x7fffffff
 306
 307 /* BAM_IRQ_SRCS_MSK */
 308 #define BAM_IRQ_MSK             BAM_IRQ
 309 #define P_IRQ_MSK               P_IRQ
 310
 311 /* BAM_IRQ_STTS */
 312 #define BAM_TIMER_IRQ           BIT(4)
 313 #define BAM_EMPTY_IRQ           BIT(3)
 314 #define BAM_ERROR_IRQ           BIT(2)
 315 #define BAM_HRESP_ERR_IRQ       BIT(1)
 316
 317 /* BAM_IRQ_CLR */
 318 #define BAM_TIMER_CLR           BIT(4)
 319 #define BAM_EMPTY_CLR           BIT(3)
 320 #define BAM_ERROR_CLR           BIT(2)
 321 #define BAM_HRESP_ERR_CLR       BIT(1)
 322
 323 /* BAM_IRQ_EN */
 324 #define BAM_TIMER_EN            BIT(4)
 325 #define BAM_EMPTY_EN            BIT(3)
 326 #define BAM_ERROR_EN            BIT(2)
 327 #define BAM_HRESP_ERR_EN        BIT(1)
 328
 329 /* BAM_P_IRQ_EN */
 330 #define P_PRCSD_DESC_EN         BIT(0)
 331 #define P_TIMER_EN              BIT(1)
 332 #define P_WAKE_EN               BIT(2)
 333 #define P_OUT_OF_DESC_EN        BIT(3)
 334 #define P_ERR_EN                BIT(4)
 335 #define P_TRNSFR_END_EN         BIT(5)
 336 #define P_DEFAULT_IRQS_EN       (P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
 337
 338 /* BAM_P_SW_OFSTS */
 339 #define P_SW_OFSTS_MASK         0xffff
 340
 341 #define BAM_DESC_FIFO_SIZE      SZ_32K
 342 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
 343 #define BAM_FIFO_SIZE   (SZ_32K - 8)
 344 #define IS_BUSY(chan)   (CIRC_SPACE(bchan->tail, bchan->head,\
 345                          MAX_DESCRIPTORS + 1) == 0)
 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         /* runtime configuration */
 356         struct dma_slave_config slave;
 357
 358         /* fifo storage */
 359         struct bam_desc_hw *fifo_virt;
 360         dma_addr_t fifo_phys;
 361
 362         /* fifo markers */
 363         unsigned short head;            /* start of active descriptor entries */
 364         unsigned short tail;            /* end of active descriptor entries */
 365
 366         unsigned int initialized;       /* is the channel hw initialized? */
 367         unsigned int paused;            /* is the channel paused? */
 368         unsigned int reconfigure;       /* new slave config? */
 369         /* list of descriptors currently processed */
 370         struct list_head desc_list;
 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         u32 num_ees;
 388
 389         /* execution environment ID, from DT */
 390         u32 ee;
 391         bool controlled_remotely;
 392
 393         const struct reg_offset_data *layout;
 394
 395         struct clk *bamclk;
 396         int irq;
 397
 398         /* dma start transaction tasklet */
 399         struct tasklet_struct task;
 400 };
 401
 402 /**
 403  * bam_addr - returns BAM register address
 404  * @bdev: bam device
 405  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
 406  * @reg:  register enum
 407  */
 408 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
 409                 enum bam_reg reg)
 410 {
 411         const struct reg_offset_data r = bdev->layout[reg];
 412
 413         return bdev->regs + r.base_offset +
 414                 r.pipe_mult * pipe +
 415                 r.evnt_mult * pipe +
 416                 r.ee_mult * bdev->ee;
 417 }
 418
 419 /**
 420  * bam_reset_channel - Reset individual BAM DMA channel
 421  * @bchan: bam channel
 422  *
 423  * This function resets a specific BAM channel
 424  */
 425 static void bam_reset_channel(struct bam_chan *bchan)
 426 {
 427         struct bam_device *bdev = bchan->bdev;
 428
 429         lockdep_assert_held(&bchan->vc.lock);
 430
 431         /* reset channel */
 432         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
 433         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
 434
 435         /* don't allow cpu to reorder BAM register accesses done after this */
 436         wmb();
 437
 438         /* make sure hw is initialized when channel is used the first time  */
 439         bchan->initialized = 0;
 440 }
 441
 442 /**
 443  * bam_chan_init_hw - Initialize channel hardware
 444  * @bchan: bam channel
 445  * @dir: DMA transfer direction
 446  *
 447  * This function resets and initializes the BAM channel
 448  */
 449 static void bam_chan_init_hw(struct bam_chan *bchan,
 450         enum dma_transfer_direction dir)
 451 {
 452         struct bam_device *bdev = bchan->bdev;
 453         u32 val;
 454
 455         /* Reset the channel to clear internal state of the FIFO */
 456         bam_reset_channel(bchan);
 457
 458         /*
 459          * write out 8 byte aligned address.  We have enough space for this
 460          * because we allocated 1 more descriptor (8 bytes) than we can use
 461          */
 462         writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
 463                         bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
 464         writel_relaxed(BAM_FIFO_SIZE,
 465                         bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
 466
 467         /* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
 468         writel_relaxed(P_DEFAULT_IRQS_EN,
 469                         bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 470
 471         /* unmask the specific pipe and EE combo */
 472         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 473         val |= BIT(bchan->id);
 474         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 475
 476         /* don't allow cpu to reorder the channel enable done below */
 477         wmb();
 478
 479         /* set fixed direction and mode, then enable channel */
 480         val = P_EN | P_SYS_MODE;
 481         if (dir == DMA_DEV_TO_MEM)
 482                 val |= P_DIRECTION;
 483
 484         writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
 485
 486         bchan->initialized = 1;
 487
 488         /* init FIFO pointers */
 489         bchan->head = 0;
 490         bchan->tail = 0;
 491 }
 492
 493 /**
 494  * bam_alloc_chan - Allocate channel resources for DMA channel.
 495  * @chan: specified channel
 496  *
 497  * This function allocates the FIFO descriptor memory
 498  */
 499 static int bam_alloc_chan(struct dma_chan *chan)
 500 {
 501         struct bam_chan *bchan = to_bam_chan(chan);
 502         struct bam_device *bdev = bchan->bdev;
 503
 504         if (bchan->fifo_virt)
 505                 return 0;
 506
 507         /* allocate FIFO descriptor space, but only if necessary */
 508         bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
 509                                         &bchan->fifo_phys, GFP_KERNEL);
 510
 511         if (!bchan->fifo_virt) {
 512                 dev_err(bdev->dev, "Failed to allocate desc fifo\n");
 513                 return -ENOMEM;
 514         }
 515
 516         return 0;
 517 }
 518
 519 static int bam_pm_runtime_get_sync(struct device *dev)
 520 {
 521         if (pm_runtime_enabled(dev))
 522                 return pm_runtime_get_sync(dev);
 523
 524         return 0;
 525 }
 526
 527 /**
 528  * bam_free_chan - Frees dma resources associated with specific channel
 529  * @chan: specified channel
 530  *
 531  * Free the allocated fifo descriptor memory and channel resources
 532  *
 533  */
 534 static void bam_free_chan(struct dma_chan *chan)
 535 {
 536         struct bam_chan *bchan = to_bam_chan(chan);
 537         struct bam_device *bdev = bchan->bdev;
 538         u32 val;
 539         unsigned long flags;
 540         int ret;
 541
 542         ret = bam_pm_runtime_get_sync(bdev->dev);
 543         if (ret < 0)
 544                 return;
 545
 546         vchan_free_chan_resources(to_virt_chan(chan));
 547
 548         if (!list_empty(&bchan->desc_list)) {
 549                 dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
 550                 goto err;
 551         }
 552
 553         spin_lock_irqsave(&bchan->vc.lock, flags);
 554         bam_reset_channel(bchan);
 555         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 556
 557         dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
 558                     bchan->fifo_phys);
 559         bchan->fifo_virt = NULL;
 560
 561         /* mask irq for pipe/channel */
 562         val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 563         val &= ~BIT(bchan->id);
 564         writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
 565
 566         /* disable irq */
 567         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 568
 569 err:
 570         pm_runtime_mark_last_busy(bdev->dev);
 571         pm_runtime_put_autosuspend(bdev->dev);
 572 }
 573
 574 /**
 575  * bam_slave_config - set slave configuration for channel
 576  * @chan: dma channel
 577  * @cfg: slave configuration
 578  *
 579  * Sets slave configuration for channel
 580  *
 581  */
 582 static int bam_slave_config(struct dma_chan *chan,
 583                             struct dma_slave_config *cfg)
 584 {
 585         struct bam_chan *bchan = to_bam_chan(chan);
 586         unsigned long flag;
 587
 588         spin_lock_irqsave(&bchan->vc.lock, flag);
 589         memcpy(&bchan->slave, cfg, sizeof(*cfg));
 590         bchan->reconfigure = 1;
 591         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 592
 593         return 0;
 594 }
 595
 596 /**
 597  * bam_prep_slave_sg - Prep slave sg transaction
 598  *
 599  * @chan: dma channel
 600  * @sgl: scatter gather list
 601  * @sg_len: length of sg
 602  * @direction: DMA transfer direction
 603  * @flags: DMA flags
 604  * @context: transfer context (unused)
 605  */
 606 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 607         struct scatterlist *sgl, unsigned int sg_len,
 608         enum dma_transfer_direction direction, unsigned long flags,
 609         void *context)
 610 {
 611         struct bam_chan *bchan = to_bam_chan(chan);
 612         struct bam_device *bdev = bchan->bdev;
 613         struct bam_async_desc *async_desc;
 614         struct scatterlist *sg;
 615         u32 i;
 616         struct bam_desc_hw *desc;
 617         unsigned int num_alloc = 0;
 618
 619
 620         if (!is_slave_direction(direction)) {
 621                 dev_err(bdev->dev, "invalid dma direction\n");
 622                 return NULL;
 623         }
 624
 625         /* calculate number of required entries */
 626         for_each_sg(sgl, sg, sg_len, i)
 627                 num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
 628
 629         /* allocate enough room to accomodate the number of entries */
 630         async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
 631                              GFP_NOWAIT);
 632
 633         if (!async_desc)
 634                 goto err_out;
 635
 636         if (flags & DMA_PREP_FENCE)
 637                 async_desc->flags |= DESC_FLAG_NWD;
 638
 639         if (flags & DMA_PREP_INTERRUPT)
 640                 async_desc->flags |= DESC_FLAG_EOT;
 641
 642         async_desc->num_desc = num_alloc;
 643         async_desc->curr_desc = async_desc->desc;
 644         async_desc->dir = direction;
 645
 646         /* fill in temporary descriptors */
 647         desc = async_desc->desc;
 648         for_each_sg(sgl, sg, sg_len, i) {
 649                 unsigned int remainder = sg_dma_len(sg);
 650                 unsigned int curr_offset = 0;
 651
 652                 do {
 653                         if (flags & DMA_PREP_CMD)
 654                                 desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
 655
 656                         desc->addr = cpu_to_le32(sg_dma_address(sg) +
 657                                                  curr_offset);
 658
 659                         if (remainder > BAM_FIFO_SIZE) {
 660                                 desc->size = cpu_to_le16(BAM_FIFO_SIZE);
 661                                 remainder -= BAM_FIFO_SIZE;
 662                                 curr_offset += BAM_FIFO_SIZE;
 663                         } else {
 664                                 desc->size = cpu_to_le16(remainder);
 665                                 remainder = 0;
 666                         }
 667
 668                         async_desc->length += le16_to_cpu(desc->size);
 669                         desc++;
 670                 } while (remainder > 0);
 671         }
 672
 673         return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
 674
 675 err_out:
 676         kfree(async_desc);
 677         return NULL;
 678 }
 679
 680 /**
 681  * bam_dma_terminate_all - terminate all transactions on a channel
 682  * @chan: bam dma channel
 683  *
 684  * Dequeues and frees all transactions
 685  * No callbacks are done
 686  *
 687  */
 688 static int bam_dma_terminate_all(struct dma_chan *chan)
 689 {
 690         struct bam_chan *bchan = to_bam_chan(chan);
 691         struct bam_async_desc *async_desc, *tmp;
 692         unsigned long flag;
 693         LIST_HEAD(head);
 694
 695         /* remove all transactions, including active transaction */
 696         spin_lock_irqsave(&bchan->vc.lock, flag);
 697         list_for_each_entry_safe(async_desc, tmp,
 698                                  &bchan->desc_list, desc_node) {
 699                 list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
 700                 list_del(&async_desc->desc_node);
 701         }
 702
 703         vchan_get_all_descriptors(&bchan->vc, &head);
 704         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 705
 706         vchan_dma_desc_free_list(&bchan->vc, &head);
 707
 708         return 0;
 709 }
 710
 711 /**
 712  * bam_pause - Pause DMA channel
 713  * @chan: dma channel
 714  *
 715  */
 716 static int bam_pause(struct dma_chan *chan)
 717 {
 718         struct bam_chan *bchan = to_bam_chan(chan);
 719         struct bam_device *bdev = bchan->bdev;
 720         unsigned long flag;
 721         int ret;
 722
 723         ret = bam_pm_runtime_get_sync(bdev->dev);
 724         if (ret < 0)
 725                 return ret;
 726
 727         spin_lock_irqsave(&bchan->vc.lock, flag);
 728         writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
 729         bchan->paused = 1;
 730         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 731         pm_runtime_mark_last_busy(bdev->dev);
 732         pm_runtime_put_autosuspend(bdev->dev);
 733
 734         return 0;
 735 }
 736
 737 /**
 738  * bam_resume - Resume DMA channel operations
 739  * @chan: dma channel
 740  *
 741  */
 742 static int bam_resume(struct dma_chan *chan)
 743 {
 744         struct bam_chan *bchan = to_bam_chan(chan);
 745         struct bam_device *bdev = bchan->bdev;
 746         unsigned long flag;
 747         int ret;
 748
 749         ret = bam_pm_runtime_get_sync(bdev->dev);
 750         if (ret < 0)
 751                 return ret;
 752
 753         spin_lock_irqsave(&bchan->vc.lock, flag);
 754         writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
 755         bchan->paused = 0;
 756         spin_unlock_irqrestore(&bchan->vc.lock, flag);
 757         pm_runtime_mark_last_busy(bdev->dev);
 758         pm_runtime_put_autosuspend(bdev->dev);
 759
 760         return 0;
 761 }
 762
 763 /**
 764  * process_channel_irqs - processes the channel interrupts
 765  * @bdev: bam controller
 766  *
 767  * This function processes the channel interrupts
 768  *
 769  */
 770 static u32 process_channel_irqs(struct bam_device *bdev)
 771 {
 772         u32 i, srcs, pipe_stts, offset, avail;
 773         unsigned long flags;
 774         struct bam_async_desc *async_desc, *tmp;
 775
 776         srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
 777
 778         /* return early if no pipe/channel interrupts are present */
 779         if (!(srcs & P_IRQ))
 780                 return srcs;
 781
 782         for (i = 0; i < bdev->num_channels; i++) {
 783                 struct bam_chan *bchan = &bdev->channels[i];
 784
 785                 if (!(srcs & BIT(i)))
 786                         continue;
 787
 788                 /* clear pipe irq */
 789                 pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
 790
 791                 writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
 792
 793                 spin_lock_irqsave(&bchan->vc.lock, flags);
 794
 795                 offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
 796                                        P_SW_OFSTS_MASK;
 797                 offset /= sizeof(struct bam_desc_hw);
 798
 799                 /* Number of bytes available to read */
 800                 avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
 801
 802                 if (offset < bchan->head)
 803                         avail--;
 804
 805                 list_for_each_entry_safe(async_desc, tmp,
 806                                          &bchan->desc_list, desc_node) {
 807                         /* Not enough data to read */
 808                         if (avail < async_desc->xfer_len)
 809                                 break;
 810
 811                         /* manage FIFO */
 812                         bchan->head += async_desc->xfer_len;
 813                         bchan->head %= MAX_DESCRIPTORS;
 814
 815                         async_desc->num_desc -= async_desc->xfer_len;
 816                         async_desc->curr_desc += async_desc->xfer_len;
 817                         avail -= async_desc->xfer_len;
 818
 819                         /*
 820                          * if complete, process cookie. Otherwise
 821                          * push back to front of desc_issued so that
 822                          * it gets restarted by the tasklet
 823                          */
 824                         if (!async_desc->num_desc) {
 825                                 vchan_cookie_complete(&async_desc->vd);
 826                         } else {
 827                                 list_add(&async_desc->vd.node,
 828                                          &bchan->vc.desc_issued);
 829                         }
 830                         list_del(&async_desc->desc_node);
 831                 }
 832
 833                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
 834         }
 835
 836         return srcs;
 837 }
 838
 839 /**
 840  * bam_dma_irq - irq handler for bam controller
 841  * @irq: IRQ of interrupt
 842  * @data: callback data
 843  *
 844  * IRQ handler for the bam controller
 845  */
 846 static irqreturn_t bam_dma_irq(int irq, void *data)
 847 {
 848         struct bam_device *bdev = data;
 849         u32 clr_mask = 0, srcs = 0;
 850         int ret;
 851
 852         srcs |= process_channel_irqs(bdev);
 853
 854         /* kick off tasklet to start next dma transfer */
 855         if (srcs & P_IRQ)
 856                 tasklet_schedule(&bdev->task);
 857
 858         ret = bam_pm_runtime_get_sync(bdev->dev);
 859         if (ret < 0)
 860                 return ret;
 861
 862         if (srcs & BAM_IRQ) {
 863                 clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
 864
 865                 /*
 866                  * don't allow reorder of the various accesses to the BAM
 867                  * registers
 868                  */
 869                 mb();
 870
 871                 writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
 872         }
 873
 874         pm_runtime_mark_last_busy(bdev->dev);
 875         pm_runtime_put_autosuspend(bdev->dev);
 876
 877         return IRQ_HANDLED;
 878 }
 879
 880 /**
 881  * bam_tx_status - returns status of transaction
 882  * @chan: dma channel
 883  * @cookie: transaction cookie
 884  * @txstate: DMA transaction state
 885  *
 886  * Return status of dma transaction
 887  */
 888 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 889                 struct dma_tx_state *txstate)
 890 {
 891         struct bam_chan *bchan = to_bam_chan(chan);
 892         struct bam_async_desc *async_desc;
 893         struct virt_dma_desc *vd;
 894         int ret;
 895         size_t residue = 0;
 896         unsigned int i;
 897         unsigned long flags;
 898
 899         ret = dma_cookie_status(chan, cookie, txstate);
 900         if (ret == DMA_COMPLETE)
 901                 return ret;
 902
 903         if (!txstate)
 904                 return bchan->paused ? DMA_PAUSED : ret;
 905
 906         spin_lock_irqsave(&bchan->vc.lock, flags);
 907         vd = vchan_find_desc(&bchan->vc, cookie);
 908         if (vd) {
 909                 residue = container_of(vd, struct bam_async_desc, vd)->length;
 910         } else {
 911                 list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
 912                         if (async_desc->vd.tx.cookie != cookie)
 913                                 continue;
 914
 915                         for (i = 0; i < async_desc->num_desc; i++)
 916                                 residue += le16_to_cpu(
 917                                                 async_desc->curr_desc[i].size);
 918                 }
 919         }
 920
 921         spin_unlock_irqrestore(&bchan->vc.lock, flags);
 922
 923         dma_set_residue(txstate, residue);
 924
 925         if (ret == DMA_IN_PROGRESS && bchan->paused)
 926                 ret = DMA_PAUSED;
 927
 928         return ret;
 929 }
 930
 931 /**
 932  * bam_apply_new_config
 933  * @bchan: bam dma channel
 934  * @dir: DMA direction
 935  */
 936 static void bam_apply_new_config(struct bam_chan *bchan,
 937         enum dma_transfer_direction dir)
 938 {
 939         struct bam_device *bdev = bchan->bdev;
 940         u32 maxburst;
 941
 942         if (!bdev->controlled_remotely) {
 943                 if (dir == DMA_DEV_TO_MEM)
 944                         maxburst = bchan->slave.src_maxburst;
 945                 else
 946                         maxburst = bchan->slave.dst_maxburst;
 947
 948                 writel_relaxed(maxburst,
 949                                bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
 950         }
 951
 952         bchan->reconfigure = 0;
 953 }
 954
 955 /**
 956  * bam_start_dma - start next transaction
 957  * @bchan: bam dma channel
 958  */
 959 static void bam_start_dma(struct bam_chan *bchan)
 960 {
 961         struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
 962         struct bam_device *bdev = bchan->bdev;
 963         struct bam_async_desc *async_desc = NULL;
 964         struct bam_desc_hw *desc;
 965         struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
 966                                         sizeof(struct bam_desc_hw));
 967         int ret;
 968         unsigned int avail;
 969         struct dmaengine_desc_callback cb;
 970
 971         lockdep_assert_held(&bchan->vc.lock);
 972
 973         if (!vd)
 974                 return;
 975
 976         ret = bam_pm_runtime_get_sync(bdev->dev);
 977         if (ret < 0)
 978                 return;
 979
 980         while (vd && !IS_BUSY(bchan)) {
 981                 list_del(&vd->node);
 982
 983                 async_desc = container_of(vd, struct bam_async_desc, vd);
 984
 985                 /* on first use, initialize the channel hardware */
 986                 if (!bchan->initialized)
 987                         bam_chan_init_hw(bchan, async_desc->dir);
 988
 989                 /* apply new slave config changes, if necessary */
 990                 if (bchan->reconfigure)
 991                         bam_apply_new_config(bchan, async_desc->dir);
 992
 993                 desc = async_desc->curr_desc;
 994                 avail = CIRC_SPACE(bchan->tail, bchan->head,
 995                                    MAX_DESCRIPTORS + 1);
 996
 997                 if (async_desc->num_desc > avail)
 998                         async_desc->xfer_len = avail;
 999                 else
1000                         async_desc->xfer_len = async_desc->num_desc;
1001
1002                 /* set any special flags on the last descriptor */
1003                 if (async_desc->num_desc == async_desc->xfer_len)
1004                         desc[async_desc->xfer_len - 1].flags |=
1005                                                 cpu_to_le16(async_desc->flags);
1006
1007                 vd = vchan_next_desc(&bchan->vc);
1008
1009                 dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1010
1011                 /*
1012                  * An interrupt is generated at this desc, if
1013                  *  - FIFO is FULL.
1014                  *  - No more descriptors to add.
1015                  *  - If a callback completion was requested for this DESC,
1016                  *     In this case, BAM will deliver the completion callback
1017                  *     for this desc and continue processing the next desc.
1018                  */
1019                 if (((avail <= async_desc->xfer_len) || !vd ||
1020                      dmaengine_desc_callback_valid(&cb)) &&
1021                     !(async_desc->flags & DESC_FLAG_EOT))
1022                         desc[async_desc->xfer_len - 1].flags |=
1023                                 cpu_to_le16(DESC_FLAG_INT);
1024
1025                 if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1026                         u32 partial = MAX_DESCRIPTORS - bchan->tail;
1027
1028                         memcpy(&fifo[bchan->tail], desc,
1029                                partial * sizeof(struct bam_desc_hw));
1030                         memcpy(fifo, &desc[partial],
1031                                (async_desc->xfer_len - partial) *
1032                                 sizeof(struct bam_desc_hw));
1033                 } else {
1034                         memcpy(&fifo[bchan->tail], desc,
1035                                async_desc->xfer_len *
1036                                sizeof(struct bam_desc_hw));
1037                 }
1038
1039                 bchan->tail += async_desc->xfer_len;
1040                 bchan->tail %= MAX_DESCRIPTORS;
1041                 list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1042         }
1043
1044         /* ensure descriptor writes and dma start not reordered */
1045         wmb();
1046         writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1047                         bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1048
1049         pm_runtime_mark_last_busy(bdev->dev);
1050         pm_runtime_put_autosuspend(bdev->dev);
1051 }
1052
1053 /**
1054  * dma_tasklet - DMA IRQ tasklet
1055  * @data: tasklet argument (bam controller structure)
1056  *
1057  * Sets up next DMA operation and then processes all completed transactions
1058  */
1059 static void dma_tasklet(unsigned long data)
1060 {
1061         struct bam_device *bdev = (struct bam_device *)data;
1062         struct bam_chan *bchan;
1063         unsigned long flags;
1064         unsigned int i;
1065
1066         /* go through the channels and kick off transactions */
1067         for (i = 0; i < bdev->num_channels; i++) {
1068                 bchan = &bdev->channels[i];
1069                 spin_lock_irqsave(&bchan->vc.lock, flags);
1070
1071                 if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1072                         bam_start_dma(bchan);
1073                 spin_unlock_irqrestore(&bchan->vc.lock, flags);
1074         }
1075
1076 }
1077
1078 /**
1079  * bam_issue_pending - starts pending transactions
1080  * @chan: dma channel
1081  *
1082  * Calls tasklet directly which in turn starts any pending transactions
1083  */
1084 static void bam_issue_pending(struct dma_chan *chan)
1085 {
1086         struct bam_chan *bchan = to_bam_chan(chan);
1087         unsigned long flags;
1088
1089         spin_lock_irqsave(&bchan->vc.lock, flags);
1090
1091         /* if work pending and idle, start a transaction */
1092         if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1093                 bam_start_dma(bchan);
1094
1095         spin_unlock_irqrestore(&bchan->vc.lock, flags);
1096 }
1097
1098 /**
1099  * bam_dma_free_desc - free descriptor memory
1100  * @vd: virtual descriptor
1101  *
1102  */
1103 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1104 {
1105         struct bam_async_desc *async_desc = container_of(vd,
1106                         struct bam_async_desc, vd);
1107
1108         kfree(async_desc);
1109 }
1110
1111 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1112                 struct of_dma *of)
1113 {
1114         struct bam_device *bdev = container_of(of->of_dma_data,
1115                                         struct bam_device, common);
1116         unsigned int request;
1117
1118         if (dma_spec->args_count != 1)
1119                 return NULL;
1120
1121         request = dma_spec->args[0];
1122         if (request >= bdev->num_channels)
1123                 return NULL;
1124
1125         return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1126 }
1127
1128 /**
1129  * bam_init
1130  * @bdev: bam device
1131  *
1132  * Initialization helper for global bam registers
1133  */
1134 static int bam_init(struct bam_device *bdev)
1135 {
1136         u32 val;
1137
1138         /* read revision and configuration information */
1139         if (!bdev->num_ees) {
1140                 val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1141                 bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1142         }
1143
1144         /* check that configured EE is within range */
1145         if (bdev->ee >= bdev->num_ees)
1146                 return -EINVAL;
1147
1148         if (!bdev->num_channels) {
1149                 val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1150                 bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1151         }
1152
1153         if (bdev->controlled_remotely)
1154                 return 0;
1155
1156         /* s/w reset bam */
1157         /* after reset all pipes are disabled and idle */
1158         val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1159         val |= BAM_SW_RST;
1160         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1161         val &= ~BAM_SW_RST;
1162         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1163
1164         /* make sure previous stores are visible before enabling BAM */
1165         wmb();
1166
1167         /* enable bam */
1168         val |= BAM_EN;
1169         writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1170
1171         /* set descriptor threshhold, start with 4 bytes */
1172         writel_relaxed(DEFAULT_CNT_THRSHLD,
1173                         bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1174
1175         /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1176         writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1177
1178         /* enable irqs for errors */
1179         writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1180                         bam_addr(bdev, 0, BAM_IRQ_EN));
1181
1182         /* unmask global bam interrupt */
1183         writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1184
1185         return 0;
1186 }
1187
1188 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1189         u32 index)
1190 {
1191         bchan->id = index;
1192         bchan->bdev = bdev;
1193
1194         vchan_init(&bchan->vc, &bdev->common);
1195         bchan->vc.desc_free = bam_dma_free_desc;
1196         INIT_LIST_HEAD(&bchan->desc_list);
1197 }
1198
1199 static const struct of_device_id bam_of_match[] = {
1200         { .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1201         { .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1202         { .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1203         {}
1204 };
1205
1206 MODULE_DEVICE_TABLE(of, bam_of_match);
1207
1208 static int bam_dma_probe(struct platform_device *pdev)
1209 {
1210         struct bam_device *bdev;
1211         const struct of_device_id *match;
1212         struct resource *iores;
1213         int ret, i;
1214
1215         bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1216         if (!bdev)
1217                 return -ENOMEM;
1218
1219         bdev->dev = &pdev->dev;
1220
1221         match = of_match_node(bam_of_match, pdev->dev.of_node);
1222         if (!match) {
1223                 dev_err(&pdev->dev, "Unsupported BAM module\n");
1224                 return -ENODEV;
1225         }
1226
1227         bdev->layout = match->data;
1228
1229         iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1230         bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1231         if (IS_ERR(bdev->regs))
1232                 return PTR_ERR(bdev->regs);
1233
1234         bdev->irq = platform_get_irq(pdev, 0);
1235         if (bdev->irq < 0)
1236                 return bdev->irq;
1237
1238         ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1239         if (ret) {
1240                 dev_err(bdev->dev, "Execution environment unspecified\n");
1241                 return ret;
1242         }
1243
1244         bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1245                                                 "qcom,controlled-remotely");
1246
1247         if (bdev->controlled_remotely) {
1248                 ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1249                                            &bdev->num_channels);
1250                 if (ret)
1251                         dev_err(bdev->dev, "num-channels unspecified in dt\n");
1252
1253                 ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1254                                            &bdev->num_ees);
1255                 if (ret)
1256                         dev_err(bdev->dev, "num-ees unspecified in dt\n");
1257         }
1258
1259         bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1260         if (IS_ERR(bdev->bamclk)) {
1261                 if (!bdev->controlled_remotely)
1262                         return PTR_ERR(bdev->bamclk);
1263
1264                 bdev->bamclk = NULL;
1265         }
1266
1267         ret = clk_prepare_enable(bdev->bamclk);
1268         if (ret) {
1269                 dev_err(bdev->dev, "failed to prepare/enable clock\n");
1270                 return ret;
1271         }
1272
1273         ret = bam_init(bdev);
1274         if (ret)
1275                 goto err_disable_clk;
1276
1277         tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1278
1279         bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1280                                 sizeof(*bdev->channels), GFP_KERNEL);
1281
1282         if (!bdev->channels) {
1283                 ret = -ENOMEM;
1284                 goto err_tasklet_kill;
1285         }
1286
1287         /* allocate and initialize channels */
1288         INIT_LIST_HEAD(&bdev->common.channels);
1289
1290         for (i = 0; i < bdev->num_channels; i++)
1291                 bam_channel_init(bdev, &bdev->channels[i], i);
1292
1293         ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1294                         IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1295         if (ret)
1296                 goto err_bam_channel_exit;
1297
1298         /* set max dma segment size */
1299         bdev->common.dev = bdev->dev;
1300         bdev->common.dev->dma_parms = &bdev->dma_parms;
1301         ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1302         if (ret) {
1303                 dev_err(bdev->dev, "cannot set maximum segment size\n");
1304                 goto err_bam_channel_exit;
1305         }
1306
1307         platform_set_drvdata(pdev, bdev);
1308
1309         /* set capabilities */
1310         dma_cap_zero(bdev->common.cap_mask);
1311         dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1312
1313         /* initialize dmaengine apis */
1314         bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1315         bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1316         bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1317         bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1318         bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1319         bdev->common.device_free_chan_resources = bam_free_chan;
1320         bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1321         bdev->common.device_config = bam_slave_config;
1322         bdev->common.device_pause = bam_pause;
1323         bdev->common.device_resume = bam_resume;
1324         bdev->common.device_terminate_all = bam_dma_terminate_all;
1325         bdev->common.device_issue_pending = bam_issue_pending;
1326         bdev->common.device_tx_status = bam_tx_status;
1327         bdev->common.dev = bdev->dev;
1328
1329         ret = dma_async_device_register(&bdev->common);
1330         if (ret) {
1331                 dev_err(bdev->dev, "failed to register dma async device\n");
1332                 goto err_bam_channel_exit;
1333         }
1334
1335         ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1336                                         &bdev->common);
1337         if (ret)
1338                 goto err_unregister_dma;
1339
1340         if (bdev->controlled_remotely) {
1341                 pm_runtime_disable(&pdev->dev);
1342                 return 0;
1343         }
1344
1345         pm_runtime_irq_safe(&pdev->dev);
1346         pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1347         pm_runtime_use_autosuspend(&pdev->dev);
1348         pm_runtime_mark_last_busy(&pdev->dev);
1349         pm_runtime_set_active(&pdev->dev);
1350         pm_runtime_enable(&pdev->dev);
1351
1352         return 0;
1353
1354 err_unregister_dma:
1355         dma_async_device_unregister(&bdev->common);
1356 err_bam_channel_exit:
1357         for (i = 0; i < bdev->num_channels; i++)
1358                 tasklet_kill(&bdev->channels[i].vc.task);
1359 err_tasklet_kill:
1360         tasklet_kill(&bdev->task);
1361 err_disable_clk:
1362         clk_disable_unprepare(bdev->bamclk);
1363
1364         return ret;
1365 }
1366
1367 static int bam_dma_remove(struct platform_device *pdev)
1368 {
1369         struct bam_device *bdev = platform_get_drvdata(pdev);
1370         u32 i;
1371
1372         pm_runtime_force_suspend(&pdev->dev);
1373
1374         of_dma_controller_free(pdev->dev.of_node);
1375         dma_async_device_unregister(&bdev->common);
1376
1377         /* mask all interrupts for this execution environment */
1378         writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1379
1380         devm_free_irq(bdev->dev, bdev->irq, bdev);
1381
1382         for (i = 0; i < bdev->num_channels; i++) {
1383                 bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1384                 tasklet_kill(&bdev->channels[i].vc.task);
1385
1386                 if (!bdev->channels[i].fifo_virt)
1387                         continue;
1388
1389                 dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1390                             bdev->channels[i].fifo_virt,
1391                             bdev->channels[i].fifo_phys);
1392         }
1393
1394         tasklet_kill(&bdev->task);
1395
1396         clk_disable_unprepare(bdev->bamclk);
1397
1398         return 0;
1399 }
1400
1401 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1402 {
1403         struct bam_device *bdev = dev_get_drvdata(dev);
1404
1405         clk_disable(bdev->bamclk);
1406
1407         return 0;
1408 }
1409
1410 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1411 {
1412         struct bam_device *bdev = dev_get_drvdata(dev);
1413         int ret;
1414
1415         ret = clk_enable(bdev->bamclk);
1416         if (ret < 0) {
1417                 dev_err(dev, "clk_enable failed: %d\n", ret);
1418                 return ret;
1419         }
1420
1421         return 0;
1422 }
1423
1424 static int __maybe_unused bam_dma_suspend(struct device *dev)
1425 {
1426         struct bam_device *bdev = dev_get_drvdata(dev);
1427
1428         if (!bdev->controlled_remotely)
1429                 pm_runtime_force_suspend(dev);
1430
1431         clk_unprepare(bdev->bamclk);
1432
1433         return 0;
1434 }
1435
1436 static int __maybe_unused bam_dma_resume(struct device *dev)
1437 {
1438         struct bam_device *bdev = dev_get_drvdata(dev);
1439         int ret;
1440
1441         ret = clk_prepare(bdev->bamclk);
1442         if (ret)
1443                 return ret;
1444
1445         if (!bdev->controlled_remotely)
1446                 pm_runtime_force_resume(dev);
1447
1448         return 0;
1449 }
1450
1451 static const struct dev_pm_ops bam_dma_pm_ops = {
1452         SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1453         SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1454                                 NULL)
1455 };
1456
1457 static struct platform_driver bam_dma_driver = {
1458         .probe = bam_dma_probe,
1459         .remove = bam_dma_remove,
1460         .driver = {
1461                 .name = "bam-dma-engine",
1462                 .pm = &bam_dma_pm_ops,
1463                 .of_match_table = bam_of_match,
1464         },
1465 };
1466
1467 module_platform_driver(bam_dma_driver);
1468
1469 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1470 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1471 MODULE_LICENSE("GPL v2");