drivers/dma/stm32-dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for STM32 DMA controller
   4  *
   5  * Inspired by dma-jz4740.c and tegra20-apb-dma.c
   6  *
   7  * Copyright (C) M'boumba Cedric Madianga 2015
   8  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
   9  *         Pierre-Yves Mordret <pierre-yves.mordret@st.com>
  10  */
  11
  12 #include <linux/bitfield.h>
  13 #include <linux/clk.h>
  14 #include <linux/delay.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/err.h>
  18 #include <linux/init.h>
  19 #include <linux/iopoll.h>
  20 #include <linux/jiffies.h>
  21 #include <linux/list.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_device.h>
  25 #include <linux/of_dma.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/reset.h>
  29 #include <linux/sched.h>
  30 #include <linux/slab.h>
  31
  32 #include "virt-dma.h"
  33
  34 #define STM32_DMA_LISR                  0x0000 /* DMA Low Int Status Reg */
  35 #define STM32_DMA_HISR                  0x0004 /* DMA High Int Status Reg */
  36 #define STM32_DMA_ISR(n)                (((n) & 4) ? STM32_DMA_HISR : STM32_DMA_LISR)
  37 #define STM32_DMA_LIFCR                 0x0008 /* DMA Low Int Flag Clear Reg */
  38 #define STM32_DMA_HIFCR                 0x000c /* DMA High Int Flag Clear Reg */
  39 #define STM32_DMA_IFCR(n)               (((n) & 4) ? STM32_DMA_HIFCR : STM32_DMA_LIFCR)
  40 #define STM32_DMA_TCI                   BIT(5) /* Transfer Complete Interrupt */
  41 #define STM32_DMA_HTI                   BIT(4) /* Half Transfer Interrupt */
  42 #define STM32_DMA_TEI                   BIT(3) /* Transfer Error Interrupt */
  43 #define STM32_DMA_DMEI                  BIT(2) /* Direct Mode Error Interrupt */
  44 #define STM32_DMA_FEI                   BIT(0) /* FIFO Error Interrupt */
  45 #define STM32_DMA_MASKI                 (STM32_DMA_TCI \
  46                                          | STM32_DMA_TEI \
  47                                          | STM32_DMA_DMEI \
  48                                          | STM32_DMA_FEI)
  49 /*
  50  * If (chan->id % 4) is 2 or 3, left shift the mask by 16 bits;
  51  * if (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
  52  */
  53 #define STM32_DMA_FLAGS_SHIFT(n)        ({ typeof(n) (_n) = (n); \
  54                                            (((_n) & 2) << 3) | (((_n) & 1) * 6); })
  55
  56 /* DMA Stream x Configuration Register */
  57 #define STM32_DMA_SCR(x)                (0x0010 + 0x18 * (x)) /* x = 0..7 */
  58 #define STM32_DMA_SCR_REQ_MASK          GENMASK(27, 25)
  59 #define STM32_DMA_SCR_MBURST_MASK       GENMASK(24, 23)
  60 #define STM32_DMA_SCR_PBURST_MASK       GENMASK(22, 21)
  61 #define STM32_DMA_SCR_PL_MASK           GENMASK(17, 16)
  62 #define STM32_DMA_SCR_MSIZE_MASK        GENMASK(14, 13)
  63 #define STM32_DMA_SCR_PSIZE_MASK        GENMASK(12, 11)
  64 #define STM32_DMA_SCR_DIR_MASK          GENMASK(7, 6)
  65 #define STM32_DMA_SCR_TRBUFF            BIT(20) /* Bufferable transfer for USART/UART */
  66 #define STM32_DMA_SCR_CT                BIT(19) /* Target in double buffer */
  67 #define STM32_DMA_SCR_DBM               BIT(18) /* Double Buffer Mode */
  68 #define STM32_DMA_SCR_PINCOS            BIT(15) /* Peripheral inc offset size */
  69 #define STM32_DMA_SCR_MINC              BIT(10) /* Memory increment mode */
  70 #define STM32_DMA_SCR_PINC              BIT(9) /* Peripheral increment mode */
  71 #define STM32_DMA_SCR_CIRC              BIT(8) /* Circular mode */
  72 #define STM32_DMA_SCR_PFCTRL            BIT(5) /* Peripheral Flow Controller */
  73 #define STM32_DMA_SCR_TCIE              BIT(4) /* Transfer Complete Int Enable
  74                                                 */
  75 #define STM32_DMA_SCR_TEIE              BIT(2) /* Transfer Error Int Enable */
  76 #define STM32_DMA_SCR_DMEIE             BIT(1) /* Direct Mode Err Int Enable */
  77 #define STM32_DMA_SCR_EN                BIT(0) /* Stream Enable */
  78 #define STM32_DMA_SCR_CFG_MASK          (STM32_DMA_SCR_PINC \
  79                                         | STM32_DMA_SCR_MINC \
  80                                         | STM32_DMA_SCR_PINCOS \
  81                                         | STM32_DMA_SCR_PL_MASK)
  82 #define STM32_DMA_SCR_IRQ_MASK          (STM32_DMA_SCR_TCIE \
  83                                         | STM32_DMA_SCR_TEIE \
  84                                         | STM32_DMA_SCR_DMEIE)
  85
  86 /* DMA Stream x number of data register */
  87 #define STM32_DMA_SNDTR(x)              (0x0014 + 0x18 * (x))
  88
  89 /* DMA stream peripheral address register */
  90 #define STM32_DMA_SPAR(x)               (0x0018 + 0x18 * (x))
  91
  92 /* DMA stream x memory 0 address register */
  93 #define STM32_DMA_SM0AR(x)              (0x001c + 0x18 * (x))
  94
  95 /* DMA stream x memory 1 address register */
  96 #define STM32_DMA_SM1AR(x)              (0x0020 + 0x18 * (x))
  97
  98 /* DMA stream x FIFO control register */
  99 #define STM32_DMA_SFCR(x)               (0x0024 + 0x18 * (x))
 100 #define STM32_DMA_SFCR_FTH_MASK         GENMASK(1, 0)
 101 #define STM32_DMA_SFCR_FEIE             BIT(7) /* FIFO error interrupt enable */
 102 #define STM32_DMA_SFCR_DMDIS            BIT(2) /* Direct mode disable */
 103 #define STM32_DMA_SFCR_MASK             (STM32_DMA_SFCR_FEIE \
 104                                         | STM32_DMA_SFCR_DMDIS)
 105
 106 /* DMA direction */
 107 #define STM32_DMA_DEV_TO_MEM            0x00
 108 #define STM32_DMA_MEM_TO_DEV            0x01
 109 #define STM32_DMA_MEM_TO_MEM            0x02
 110
 111 /* DMA priority level */
 112 #define STM32_DMA_PRIORITY_LOW          0x00
 113 #define STM32_DMA_PRIORITY_MEDIUM       0x01
 114 #define STM32_DMA_PRIORITY_HIGH         0x02
 115 #define STM32_DMA_PRIORITY_VERY_HIGH    0x03
 116
 117 /* DMA FIFO threshold selection */
 118 #define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL           0x00
 119 #define STM32_DMA_FIFO_THRESHOLD_HALFFULL               0x01
 120 #define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL          0x02
 121 #define STM32_DMA_FIFO_THRESHOLD_FULL                   0x03
 122 #define STM32_DMA_FIFO_THRESHOLD_NONE                   0x04
 123
 124 #define STM32_DMA_MAX_DATA_ITEMS        0xffff
 125 /*
 126  * Valid transfer starts from @0 to @0xFFFE leading to unaligned scatter
 127  * gather at boundary. Thus it's safer to round down this value on FIFO
 128  * size (16 Bytes)
 129  */
 130 #define STM32_DMA_ALIGNED_MAX_DATA_ITEMS        \
 131         ALIGN_DOWN(STM32_DMA_MAX_DATA_ITEMS, 16)
 132 #define STM32_DMA_MAX_CHANNELS          0x08
 133 #define STM32_DMA_MAX_REQUEST_ID        0x08
 134 #define STM32_DMA_MAX_DATA_PARAM        0x03
 135 #define STM32_DMA_FIFO_SIZE             16      /* FIFO is 16 bytes */
 136 #define STM32_DMA_MIN_BURST             4
 137 #define STM32_DMA_MAX_BURST             16
 138
 139 /* DMA Features */
 140 #define STM32_DMA_THRESHOLD_FTR_MASK    GENMASK(1, 0)
 141 #define STM32_DMA_DIRECT_MODE_MASK      BIT(2)
 142 #define STM32_DMA_ALT_ACK_MODE_MASK     BIT(4)
 143 #define STM32_DMA_MDMA_STREAM_ID_MASK   GENMASK(19, 16)
 144
 145 enum stm32_dma_width {
 146         STM32_DMA_BYTE,
 147         STM32_DMA_HALF_WORD,
 148         STM32_DMA_WORD,
 149 };
 150
 151 enum stm32_dma_burst_size {
 152         STM32_DMA_BURST_SINGLE,
 153         STM32_DMA_BURST_INCR4,
 154         STM32_DMA_BURST_INCR8,
 155         STM32_DMA_BURST_INCR16,
 156 };
 157
 158 /**
 159  * struct stm32_dma_cfg - STM32 DMA custom configuration
 160  * @channel_id: channel ID
 161  * @request_line: DMA request
 162  * @stream_config: 32bit mask specifying the DMA channel configuration
 163  * @features: 32bit mask specifying the DMA Feature list
 164  */
 165 struct stm32_dma_cfg {
 166         u32 channel_id;
 167         u32 request_line;
 168         u32 stream_config;
 169         u32 features;
 170 };
 171
 172 struct stm32_dma_chan_reg {
 173         u32 dma_lisr;
 174         u32 dma_hisr;
 175         u32 dma_lifcr;
 176         u32 dma_hifcr;
 177         u32 dma_scr;
 178         u32 dma_sndtr;
 179         u32 dma_spar;
 180         u32 dma_sm0ar;
 181         u32 dma_sm1ar;
 182         u32 dma_sfcr;
 183 };
 184
 185 struct stm32_dma_sg_req {
 186         u32 len;
 187         struct stm32_dma_chan_reg chan_reg;
 188 };
 189
 190 struct stm32_dma_desc {
 191         struct virt_dma_desc vdesc;
 192         bool cyclic;
 193         u32 num_sgs;
 194         struct stm32_dma_sg_req sg_req[];
 195 };
 196
 197 /**
 198  * struct stm32_dma_mdma_config - STM32 DMA MDMA configuration
 199  * @stream_id: DMA request to trigger STM32 MDMA transfer
 200  * @ifcr: DMA interrupt flag clear register address,
 201  *        used by STM32 MDMA to clear DMA Transfer Complete flag
 202  * @tcf: DMA Transfer Complete flag
 203  */
 204 struct stm32_dma_mdma_config {
 205         u32 stream_id;
 206         u32 ifcr;
 207         u32 tcf;
 208 };
 209
 210 struct stm32_dma_chan {
 211         struct virt_dma_chan vchan;
 212         bool config_init;
 213         bool busy;
 214         u32 id;
 215         u32 irq;
 216         struct stm32_dma_desc *desc;
 217         u32 next_sg;
 218         struct dma_slave_config dma_sconfig;
 219         struct stm32_dma_chan_reg chan_reg;
 220         u32 threshold;
 221         u32 mem_burst;
 222         u32 mem_width;
 223         enum dma_status status;
 224         bool trig_mdma;
 225         struct stm32_dma_mdma_config mdma_config;
 226 };
 227
 228 struct stm32_dma_device {
 229         struct dma_device ddev;
 230         void __iomem *base;
 231         struct clk *clk;
 232         bool mem2mem;
 233         struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
 234 };
 235
 236 static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
 237 {
 238         return container_of(chan->vchan.chan.device, struct stm32_dma_device,
 239                             ddev);
 240 }
 241
 242 static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
 243 {
 244         return container_of(c, struct stm32_dma_chan, vchan.chan);
 245 }
 246
 247 static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
 248 {
 249         return container_of(vdesc, struct stm32_dma_desc, vdesc);
 250 }
 251
 252 static struct device *chan2dev(struct stm32_dma_chan *chan)
 253 {
 254         return &chan->vchan.chan.dev->device;
 255 }
 256
 257 static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
 258 {
 259         return readl_relaxed(dmadev->base + reg);
 260 }
 261
 262 static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
 263 {
 264         writel_relaxed(val, dmadev->base + reg);
 265 }
 266
 267 static int stm32_dma_get_width(struct stm32_dma_chan *chan,
 268                                enum dma_slave_buswidth width)
 269 {
 270         switch (width) {
 271         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 272                 return STM32_DMA_BYTE;
 273         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 274                 return STM32_DMA_HALF_WORD;
 275         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 276                 return STM32_DMA_WORD;
 277         default:
 278                 dev_err(chan2dev(chan), "Dma bus width not supported\n");
 279                 return -EINVAL;
 280         }
 281 }
 282
 283 static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len,
 284                                                        dma_addr_t buf_addr,
 285                                                        u32 threshold)
 286 {
 287         enum dma_slave_buswidth max_width;
 288
 289         if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL)
 290                 max_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 291         else
 292                 max_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 293
 294         while ((buf_len < max_width  || buf_len % max_width) &&
 295                max_width > DMA_SLAVE_BUSWIDTH_1_BYTE)
 296                 max_width = max_width >> 1;
 297
 298         if (buf_addr & (max_width - 1))
 299                 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 300
 301         return max_width;
 302 }
 303
 304 static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
 305                                                 enum dma_slave_buswidth width)
 306 {
 307         u32 remaining;
 308
 309         if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
 310                 return false;
 311
 312         if (width != DMA_SLAVE_BUSWIDTH_UNDEFINED) {
 313                 if (burst != 0) {
 314                         /*
 315                          * If number of beats fit in several whole bursts
 316                          * this configuration is allowed.
 317                          */
 318                         remaining = ((STM32_DMA_FIFO_SIZE / width) *
 319                                      (threshold + 1) / 4) % burst;
 320
 321                         if (remaining == 0)
 322                                 return true;
 323                 } else {
 324                         return true;
 325                 }
 326         }
 327
 328         return false;
 329 }
 330
 331 static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
 332 {
 333         /* If FIFO direct mode, burst is not possible */
 334         if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
 335                 return false;
 336
 337         /*
 338          * Buffer or period length has to be aligned on FIFO depth.
 339          * Otherwise bytes may be stuck within FIFO at buffer or period
 340          * length.
 341          */
 342         return ((buf_len % ((threshold + 1) * 4)) == 0);
 343 }
 344
 345 static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
 346                                     enum dma_slave_buswidth width)
 347 {
 348         u32 best_burst = max_burst;
 349
 350         if (best_burst == 1 || !stm32_dma_is_burst_possible(buf_len, threshold))
 351                 return 0;
 352
 353         while ((buf_len < best_burst * width && best_burst > 1) ||
 354                !stm32_dma_fifo_threshold_is_allowed(best_burst, threshold,
 355                                                     width)) {
 356                 if (best_burst > STM32_DMA_MIN_BURST)
 357                         best_burst = best_burst >> 1;
 358                 else
 359                         best_burst = 0;
 360         }
 361
 362         return best_burst;
 363 }
 364
 365 static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
 366 {
 367         switch (maxburst) {
 368         case 0:
 369         case 1:
 370                 return STM32_DMA_BURST_SINGLE;
 371         case 4:
 372                 return STM32_DMA_BURST_INCR4;
 373         case 8:
 374                 return STM32_DMA_BURST_INCR8;
 375         case 16:
 376                 return STM32_DMA_BURST_INCR16;
 377         default:
 378                 dev_err(chan2dev(chan), "Dma burst size not supported\n");
 379                 return -EINVAL;
 380         }
 381 }
 382
 383 static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
 384                                       u32 src_burst, u32 dst_burst)
 385 {
 386         chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
 387         chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
 388
 389         if (!src_burst && !dst_burst) {
 390                 /* Using direct mode */
 391                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
 392         } else {
 393                 /* Using FIFO mode */
 394                 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
 395         }
 396 }
 397
 398 static int stm32_dma_slave_config(struct dma_chan *c,
 399                                   struct dma_slave_config *config)
 400 {
 401         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 402
 403         memcpy(&chan->dma_sconfig, config, sizeof(*config));
 404
 405         /* Check if user is requesting DMA to trigger STM32 MDMA */
 406         if (config->peripheral_size) {
 407                 config->peripheral_config = &chan->mdma_config;
 408                 config->peripheral_size = sizeof(chan->mdma_config);
 409                 chan->trig_mdma = true;
 410         }
 411
 412         chan->config_init = true;
 413
 414         return 0;
 415 }
 416
 417 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
 418 {
 419         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 420         u32 flags, dma_isr;
 421
 422         /*
 423          * Read "flags" from DMA_xISR register corresponding to the selected
 424          * DMA channel at the correct bit offset inside that register.
 425          */
 426
 427         dma_isr = stm32_dma_read(dmadev, STM32_DMA_ISR(chan->id));
 428         flags = dma_isr >> STM32_DMA_FLAGS_SHIFT(chan->id);
 429
 430         return flags & STM32_DMA_MASKI;
 431 }
 432
 433 static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
 434 {
 435         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 436         u32 dma_ifcr;
 437
 438         /*
 439          * Write "flags" to the DMA_xIFCR register corresponding to the selected
 440          * DMA channel at the correct bit offset inside that register.
 441          */
 442         flags &= STM32_DMA_MASKI;
 443         dma_ifcr = flags << STM32_DMA_FLAGS_SHIFT(chan->id);
 444
 445         stm32_dma_write(dmadev, STM32_DMA_IFCR(chan->id), dma_ifcr);
 446 }
 447
 448 static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
 449 {
 450         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 451         u32 dma_scr, id, reg;
 452
 453         id = chan->id;
 454         reg = STM32_DMA_SCR(id);
 455         dma_scr = stm32_dma_read(dmadev, reg);
 456
 457         if (dma_scr & STM32_DMA_SCR_EN) {
 458                 dma_scr &= ~STM32_DMA_SCR_EN;
 459                 stm32_dma_write(dmadev, reg, dma_scr);
 460
 461                 return readl_relaxed_poll_timeout_atomic(dmadev->base + reg,
 462                                         dma_scr, !(dma_scr & STM32_DMA_SCR_EN),
 463                                         10, 1000000);
 464         }
 465
 466         return 0;
 467 }
 468
 469 static void stm32_dma_stop(struct stm32_dma_chan *chan)
 470 {
 471         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 472         u32 dma_scr, dma_sfcr, status;
 473         int ret;
 474
 475         /* Disable interrupts */
 476         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
 477         dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
 478         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
 479         dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
 480         dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
 481         stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
 482
 483         /* Disable DMA */
 484         ret = stm32_dma_disable_chan(chan);
 485         if (ret < 0)
 486                 return;
 487
 488         /* Clear interrupt status if it is there */
 489         status = stm32_dma_irq_status(chan);
 490         if (status) {
 491                 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
 492                         __func__, status);
 493                 stm32_dma_irq_clear(chan, status);
 494         }
 495
 496         chan->busy = false;
 497         chan->status = DMA_COMPLETE;
 498 }
 499
 500 static int stm32_dma_terminate_all(struct dma_chan *c)
 501 {
 502         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 503         unsigned long flags;
 504         LIST_HEAD(head);
 505
 506         spin_lock_irqsave(&chan->vchan.lock, flags);
 507
 508         if (chan->desc) {
 509                 dma_cookie_complete(&chan->desc->vdesc.tx);
 510                 vchan_terminate_vdesc(&chan->desc->vdesc);
 511                 if (chan->busy)
 512                         stm32_dma_stop(chan);
 513                 chan->desc = NULL;
 514         }
 515
 516         vchan_get_all_descriptors(&chan->vchan, &head);
 517         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 518         vchan_dma_desc_free_list(&chan->vchan, &head);
 519
 520         return 0;
 521 }
 522
 523 static void stm32_dma_synchronize(struct dma_chan *c)
 524 {
 525         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 526
 527         vchan_synchronize(&chan->vchan);
 528 }
 529
 530 static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
 531 {
 532         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 533         u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
 534         u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
 535         u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
 536         u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
 537         u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
 538         u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
 539
 540         dev_dbg(chan2dev(chan), "SCR:   0x%08x\n", scr);
 541         dev_dbg(chan2dev(chan), "NDTR:  0x%08x\n", ndtr);
 542         dev_dbg(chan2dev(chan), "SPAR:  0x%08x\n", spar);
 543         dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
 544         dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
 545         dev_dbg(chan2dev(chan), "SFCR:  0x%08x\n", sfcr);
 546 }
 547
 548 static void stm32_dma_sg_inc(struct stm32_dma_chan *chan)
 549 {
 550         chan->next_sg++;
 551         if (chan->desc->cyclic && (chan->next_sg == chan->desc->num_sgs))
 552                 chan->next_sg = 0;
 553 }
 554
 555 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
 556
 557 static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
 558 {
 559         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 560         struct virt_dma_desc *vdesc;
 561         struct stm32_dma_sg_req *sg_req;
 562         struct stm32_dma_chan_reg *reg;
 563         u32 status;
 564         int ret;
 565
 566         ret = stm32_dma_disable_chan(chan);
 567         if (ret < 0)
 568                 return;
 569
 570         if (!chan->desc) {
 571                 vdesc = vchan_next_desc(&chan->vchan);
 572                 if (!vdesc)
 573                         return;
 574
 575                 list_del(&vdesc->node);
 576
 577                 chan->desc = to_stm32_dma_desc(vdesc);
 578                 chan->next_sg = 0;
 579         }
 580
 581         if (chan->next_sg == chan->desc->num_sgs)
 582                 chan->next_sg = 0;
 583
 584         sg_req = &chan->desc->sg_req[chan->next_sg];
 585         reg = &sg_req->chan_reg;
 586
 587         /* When DMA triggers STM32 MDMA, DMA Transfer Complete is managed by STM32 MDMA */
 588         if (chan->trig_mdma && chan->dma_sconfig.direction != DMA_MEM_TO_DEV)
 589                 reg->dma_scr &= ~STM32_DMA_SCR_TCIE;
 590
 591         reg->dma_scr &= ~STM32_DMA_SCR_EN;
 592         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
 593         stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
 594         stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
 595         stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
 596         stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
 597         stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
 598
 599         stm32_dma_sg_inc(chan);
 600
 601         /* Clear interrupt status if it is there */
 602         status = stm32_dma_irq_status(chan);
 603         if (status)
 604                 stm32_dma_irq_clear(chan, status);
 605
 606         if (chan->desc->cyclic)
 607                 stm32_dma_configure_next_sg(chan);
 608
 609         stm32_dma_dump_reg(chan);
 610
 611         /* Start DMA */
 612         chan->busy = true;
 613         chan->status = DMA_IN_PROGRESS;
 614         reg->dma_scr |= STM32_DMA_SCR_EN;
 615         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
 616
 617         dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
 618 }
 619
 620 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
 621 {
 622         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 623         struct stm32_dma_sg_req *sg_req;
 624         u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
 625
 626         id = chan->id;
 627         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
 628
 629         sg_req = &chan->desc->sg_req[chan->next_sg];
 630
 631         if (dma_scr & STM32_DMA_SCR_CT) {
 632                 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
 633                 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
 634                 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
 635                         stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
 636         } else {
 637                 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
 638                 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
 639                 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
 640                         stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
 641         }
 642 }
 643
 644 static void stm32_dma_handle_chan_paused(struct stm32_dma_chan *chan)
 645 {
 646         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 647         u32 dma_scr;
 648
 649         /*
 650          * Read and store current remaining data items and peripheral/memory addresses to be
 651          * updated on resume
 652          */
 653         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
 654         /*
 655          * Transfer can be paused while between a previous resume and reconfiguration on transfer
 656          * complete. If transfer is cyclic and CIRC and DBM have been deactivated for resume, need
 657          * to set it here in SCR backup to ensure a good reconfiguration on transfer complete.
 658          */
 659         if (chan->desc && chan->desc->cyclic) {
 660                 if (chan->desc->num_sgs == 1)
 661                         dma_scr |= STM32_DMA_SCR_CIRC;
 662                 else
 663                         dma_scr |= STM32_DMA_SCR_DBM;
 664         }
 665         chan->chan_reg.dma_scr = dma_scr;
 666
 667         /*
 668          * Need to temporarily deactivate CIRC/DBM until next Transfer Complete interrupt, otherwise
 669          * on resume NDTR autoreload value will be wrong (lower than the initial period length)
 670          */
 671         if (chan->desc && chan->desc->cyclic) {
 672                 dma_scr &= ~(STM32_DMA_SCR_DBM | STM32_DMA_SCR_CIRC);
 673                 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
 674         }
 675
 676         chan->chan_reg.dma_sndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
 677
 678         dev_dbg(chan2dev(chan), "vchan %pK: paused\n", &chan->vchan);
 679 }
 680
 681 static void stm32_dma_post_resume_reconfigure(struct stm32_dma_chan *chan)
 682 {
 683         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 684         struct stm32_dma_sg_req *sg_req;
 685         u32 dma_scr, status, id;
 686
 687         id = chan->id;
 688         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
 689
 690         /* Clear interrupt status if it is there */
 691         status = stm32_dma_irq_status(chan);
 692         if (status)
 693                 stm32_dma_irq_clear(chan, status);
 694
 695         if (!chan->next_sg)
 696                 sg_req = &chan->desc->sg_req[chan->desc->num_sgs - 1];
 697         else
 698                 sg_req = &chan->desc->sg_req[chan->next_sg - 1];
 699
 700         /* Reconfigure NDTR with the initial value */
 701         stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), sg_req->chan_reg.dma_sndtr);
 702
 703         /* Restore SPAR */
 704         stm32_dma_write(dmadev, STM32_DMA_SPAR(id), sg_req->chan_reg.dma_spar);
 705
 706         /* Restore SM0AR/SM1AR whatever DBM/CT as they may have been modified */
 707         stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), sg_req->chan_reg.dma_sm0ar);
 708         stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sg_req->chan_reg.dma_sm1ar);
 709
 710         /* Reactivate CIRC/DBM if needed */
 711         if (chan->chan_reg.dma_scr & STM32_DMA_SCR_DBM) {
 712                 dma_scr |= STM32_DMA_SCR_DBM;
 713                 /* Restore CT */
 714                 if (chan->chan_reg.dma_scr & STM32_DMA_SCR_CT)
 715                         dma_scr &= ~STM32_DMA_SCR_CT;
 716                 else
 717                         dma_scr |= STM32_DMA_SCR_CT;
 718         } else if (chan->chan_reg.dma_scr & STM32_DMA_SCR_CIRC) {
 719                 dma_scr |= STM32_DMA_SCR_CIRC;
 720         }
 721         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
 722
 723         stm32_dma_configure_next_sg(chan);
 724
 725         stm32_dma_dump_reg(chan);
 726
 727         dma_scr |= STM32_DMA_SCR_EN;
 728         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
 729
 730         dev_dbg(chan2dev(chan), "vchan %pK: reconfigured after pause/resume\n", &chan->vchan);
 731 }
 732
 733 static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan, u32 scr)
 734 {
 735         if (!chan->desc)
 736                 return;
 737
 738         if (chan->desc->cyclic) {
 739                 vchan_cyclic_callback(&chan->desc->vdesc);
 740                 if (chan->trig_mdma)
 741                         return;
 742                 stm32_dma_sg_inc(chan);
 743                 /* cyclic while CIRC/DBM disable => post resume reconfiguration needed */
 744                 if (!(scr & (STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM)))
 745                         stm32_dma_post_resume_reconfigure(chan);
 746                 else if (scr & STM32_DMA_SCR_DBM)
 747                         stm32_dma_configure_next_sg(chan);
 748         } else {
 749                 chan->busy = false;
 750                 chan->status = DMA_COMPLETE;
 751                 if (chan->next_sg == chan->desc->num_sgs) {
 752                         vchan_cookie_complete(&chan->desc->vdesc);
 753                         chan->desc = NULL;
 754                 }
 755                 stm32_dma_start_transfer(chan);
 756         }
 757 }
 758
 759 static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
 760 {
 761         struct stm32_dma_chan *chan = devid;
 762         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 763         u32 status, scr, sfcr;
 764
 765         spin_lock(&chan->vchan.lock);
 766
 767         status = stm32_dma_irq_status(chan);
 768         scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
 769         sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
 770
 771         if (status & STM32_DMA_FEI) {
 772                 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
 773                 status &= ~STM32_DMA_FEI;
 774                 if (sfcr & STM32_DMA_SFCR_FEIE) {
 775                         if (!(scr & STM32_DMA_SCR_EN) &&
 776                             !(status & STM32_DMA_TCI))
 777                                 dev_err(chan2dev(chan), "FIFO Error\n");
 778                         else
 779                                 dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
 780                 }
 781         }
 782         if (status & STM32_DMA_DMEI) {
 783                 stm32_dma_irq_clear(chan, STM32_DMA_DMEI);
 784                 status &= ~STM32_DMA_DMEI;
 785                 if (sfcr & STM32_DMA_SCR_DMEIE)
 786                         dev_dbg(chan2dev(chan), "Direct mode overrun\n");
 787         }
 788
 789         if (status & STM32_DMA_TCI) {
 790                 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
 791                 if (scr & STM32_DMA_SCR_TCIE) {
 792                         if (chan->status == DMA_PAUSED && !(scr & STM32_DMA_SCR_EN))
 793                                 stm32_dma_handle_chan_paused(chan);
 794                         else
 795                                 stm32_dma_handle_chan_done(chan, scr);
 796                 }
 797                 status &= ~STM32_DMA_TCI;
 798         }
 799
 800         if (status & STM32_DMA_HTI) {
 801                 stm32_dma_irq_clear(chan, STM32_DMA_HTI);
 802                 status &= ~STM32_DMA_HTI;
 803         }
 804
 805         if (status) {
 806                 stm32_dma_irq_clear(chan, status);
 807                 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
 808                 if (!(scr & STM32_DMA_SCR_EN))
 809                         dev_err(chan2dev(chan), "chan disabled by HW\n");
 810         }
 811
 812         spin_unlock(&chan->vchan.lock);
 813
 814         return IRQ_HANDLED;
 815 }
 816
 817 static void stm32_dma_issue_pending(struct dma_chan *c)
 818 {
 819         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 820         unsigned long flags;
 821
 822         spin_lock_irqsave(&chan->vchan.lock, flags);
 823         if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
 824                 dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
 825                 stm32_dma_start_transfer(chan);
 826
 827         }
 828         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 829 }
 830
 831 static int stm32_dma_pause(struct dma_chan *c)
 832 {
 833         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 834         unsigned long flags;
 835         int ret;
 836
 837         if (chan->status != DMA_IN_PROGRESS)
 838                 return -EPERM;
 839
 840         spin_lock_irqsave(&chan->vchan.lock, flags);
 841         ret = stm32_dma_disable_chan(chan);
 842         /*
 843          * A transfer complete flag is set to indicate the end of transfer due to the stream
 844          * interruption, so wait for interrupt
 845          */
 846         if (!ret)
 847                 chan->status = DMA_PAUSED;
 848         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 849
 850         return ret;
 851 }
 852
 853 static int stm32_dma_resume(struct dma_chan *c)
 854 {
 855         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
 856         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
 857         struct stm32_dma_chan_reg chan_reg = chan->chan_reg;
 858         u32 id = chan->id, scr, ndtr, offset, spar, sm0ar, sm1ar;
 859         struct stm32_dma_sg_req *sg_req;
 860         unsigned long flags;
 861
 862         if (chan->status != DMA_PAUSED)
 863                 return -EPERM;
 864
 865         scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
 866         if (WARN_ON(scr & STM32_DMA_SCR_EN))
 867                 return -EPERM;
 868
 869         spin_lock_irqsave(&chan->vchan.lock, flags);
 870
 871         /* sg_reg[prev_sg] contains original ndtr, sm0ar and sm1ar before pausing the transfer */
 872         if (!chan->next_sg)
 873                 sg_req = &chan->desc->sg_req[chan->desc->num_sgs - 1];
 874         else
 875                 sg_req = &chan->desc->sg_req[chan->next_sg - 1];
 876
 877         ndtr = sg_req->chan_reg.dma_sndtr;
 878         offset = (ndtr - chan_reg.dma_sndtr);
 879         offset <<= FIELD_GET(STM32_DMA_SCR_PSIZE_MASK, chan_reg.dma_scr);
 880         spar = sg_req->chan_reg.dma_spar;
 881         sm0ar = sg_req->chan_reg.dma_sm0ar;
 882         sm1ar = sg_req->chan_reg.dma_sm1ar;
 883
 884         /*
 885          * The peripheral and/or memory addresses have to be updated in order to adjust the
 886          * address pointers. Need to check increment.
 887          */
 888         if (chan_reg.dma_scr & STM32_DMA_SCR_PINC)
 889                 stm32_dma_write(dmadev, STM32_DMA_SPAR(id), spar + offset);
 890         else
 891                 stm32_dma_write(dmadev, STM32_DMA_SPAR(id), spar);
 892
 893         if (!(chan_reg.dma_scr & STM32_DMA_SCR_MINC))
 894                 offset = 0;
 895
 896         /*
 897          * In case of DBM, the current target could be SM1AR.
 898          * Need to temporarily deactivate CIRC/DBM to finish the current transfer, so
 899          * SM0AR becomes the current target and must be updated with SM1AR + offset if CT=1.
 900          */
 901         if ((chan_reg.dma_scr & STM32_DMA_SCR_DBM) && (chan_reg.dma_scr & STM32_DMA_SCR_CT))
 902                 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sm1ar + offset);
 903         else
 904                 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), sm0ar + offset);
 905
 906         /* NDTR must be restored otherwise internal HW counter won't be correctly reset */
 907         stm32_dma_write(dmadev, STM32_DMA_SNDTR(id), chan_reg.dma_sndtr);
 908
 909         /*
 910          * Need to temporarily deactivate CIRC/DBM until next Transfer Complete interrupt,
 911          * otherwise NDTR autoreload value will be wrong (lower than the initial period length)
 912          */
 913         if (chan_reg.dma_scr & (STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM))
 914                 chan_reg.dma_scr &= ~(STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM);
 915
 916         if (chan_reg.dma_scr & STM32_DMA_SCR_DBM)
 917                 stm32_dma_configure_next_sg(chan);
 918
 919         stm32_dma_dump_reg(chan);
 920
 921         /* The stream may then be re-enabled to restart transfer from the point it was stopped */
 922         chan->status = DMA_IN_PROGRESS;
 923         chan_reg.dma_scr |= STM32_DMA_SCR_EN;
 924         stm32_dma_write(dmadev, STM32_DMA_SCR(id), chan_reg.dma_scr);
 925
 926         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 927
 928         dev_dbg(chan2dev(chan), "vchan %pK: resumed\n", &chan->vchan);
 929
 930         return 0;
 931 }
 932
 933 static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
 934                                     enum dma_transfer_direction direction,
 935                                     enum dma_slave_buswidth *buswidth,
 936                                     u32 buf_len, dma_addr_t buf_addr)
 937 {
 938         enum dma_slave_buswidth src_addr_width, dst_addr_width;
 939         int src_bus_width, dst_bus_width;
 940         int src_burst_size, dst_burst_size;
 941         u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
 942         u32 dma_scr, fifoth;
 943
 944         src_addr_width = chan->dma_sconfig.src_addr_width;
 945         dst_addr_width = chan->dma_sconfig.dst_addr_width;
 946         src_maxburst = chan->dma_sconfig.src_maxburst;
 947         dst_maxburst = chan->dma_sconfig.dst_maxburst;
 948         fifoth = chan->threshold;
 949
 950         switch (direction) {
 951         case DMA_MEM_TO_DEV:
 952                 /* Set device data size */
 953                 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
 954                 if (dst_bus_width < 0)
 955                         return dst_bus_width;
 956
 957                 /* Set device burst size */
 958                 dst_best_burst = stm32_dma_get_best_burst(buf_len,
 959                                                           dst_maxburst,
 960                                                           fifoth,
 961                                                           dst_addr_width);
 962
 963                 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
 964                 if (dst_burst_size < 0)
 965                         return dst_burst_size;
 966
 967                 /* Set memory data size */
 968                 src_addr_width = stm32_dma_get_max_width(buf_len, buf_addr,
 969                                                          fifoth);
 970                 chan->mem_width = src_addr_width;
 971                 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
 972                 if (src_bus_width < 0)
 973                         return src_bus_width;
 974
 975                 /*
 976                  * Set memory burst size - burst not possible if address is not aligned on
 977                  * the address boundary equal to the size of the transfer
 978                  */
 979                 if (buf_addr & (buf_len - 1))
 980                         src_maxburst = 1;
 981                 else
 982                         src_maxburst = STM32_DMA_MAX_BURST;
 983                 src_best_burst = stm32_dma_get_best_burst(buf_len,
 984                                                           src_maxburst,
 985                                                           fifoth,
 986                                                           src_addr_width);
 987                 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
 988                 if (src_burst_size < 0)
 989                         return src_burst_size;
 990
 991                 dma_scr = FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_MEM_TO_DEV) |
 992                         FIELD_PREP(STM32_DMA_SCR_PSIZE_MASK, dst_bus_width) |
 993                         FIELD_PREP(STM32_DMA_SCR_MSIZE_MASK, src_bus_width) |
 994                         FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dst_burst_size) |
 995                         FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, src_burst_size);
 996
 997                 /* Set FIFO threshold */
 998                 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
 999                 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
1000                         chan->chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, fifoth);
1001
1002                 /* Set peripheral address */
1003                 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
1004                 *buswidth = dst_addr_width;
1005                 break;
1006
1007         case DMA_DEV_TO_MEM:
1008                 /* Set device data size */
1009                 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
1010                 if (src_bus_width < 0)
1011                         return src_bus_width;
1012
1013                 /* Set device burst size */
1014                 src_best_burst = stm32_dma_get_best_burst(buf_len,
1015                                                           src_maxburst,
1016                                                           fifoth,
1017                                                           src_addr_width);
1018                 chan->mem_burst = src_best_burst;
1019                 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
1020                 if (src_burst_size < 0)
1021                         return src_burst_size;
1022
1023                 /* Set memory data size */
1024                 dst_addr_width = stm32_dma_get_max_width(buf_len, buf_addr,
1025                                                          fifoth);
1026                 chan->mem_width = dst_addr_width;
1027                 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
1028                 if (dst_bus_width < 0)
1029                         return dst_bus_width;
1030
1031                 /*
1032                  * Set memory burst size - burst not possible if address is not aligned on
1033                  * the address boundary equal to the size of the transfer
1034                  */
1035                 if (buf_addr & (buf_len - 1))
1036                         dst_maxburst = 1;
1037                 else
1038                         dst_maxburst = STM32_DMA_MAX_BURST;
1039                 dst_best_burst = stm32_dma_get_best_burst(buf_len,
1040                                                           dst_maxburst,
1041                                                           fifoth,
1042                                                           dst_addr_width);
1043                 chan->mem_burst = dst_best_burst;
1044                 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
1045                 if (dst_burst_size < 0)
1046                         return dst_burst_size;
1047
1048                 dma_scr = FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_DEV_TO_MEM) |
1049                         FIELD_PREP(STM32_DMA_SCR_PSIZE_MASK, src_bus_width) |
1050                         FIELD_PREP(STM32_DMA_SCR_MSIZE_MASK, dst_bus_width) |
1051                         FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, src_burst_size) |
1052                         FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, dst_burst_size);
1053
1054                 /* Set FIFO threshold */
1055                 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
1056                 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
1057                         chan->chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, fifoth);
1058
1059                 /* Set peripheral address */
1060                 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
1061                 *buswidth = chan->dma_sconfig.src_addr_width;
1062                 break;
1063
1064         default:
1065                 dev_err(chan2dev(chan), "Dma direction is not supported\n");
1066                 return -EINVAL;
1067         }
1068
1069         stm32_dma_set_fifo_config(chan, src_best_burst, dst_best_burst);
1070
1071         /* Set DMA control register */
1072         chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
1073                         STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
1074                         STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
1075         chan->chan_reg.dma_scr |= dma_scr;
1076
1077         return 0;
1078 }
1079
1080 static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
1081 {
1082         memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
1083 }
1084
1085 static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
1086         struct dma_chan *c, struct scatterlist *sgl,
1087         u32 sg_len, enum dma_transfer_direction direction,
1088         unsigned long flags, void *context)
1089 {
1090         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1091         struct stm32_dma_desc *desc;
1092         struct scatterlist *sg;
1093         enum dma_slave_buswidth buswidth;
1094         u32 nb_data_items;
1095         int i, ret;
1096
1097         if (!chan->config_init) {
1098                 dev_err(chan2dev(chan), "dma channel is not configured\n");
1099                 return NULL;
1100         }
1101
1102         if (sg_len < 1) {
1103                 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
1104                 return NULL;
1105         }
1106
1107         desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT);
1108         if (!desc)
1109                 return NULL;
1110
1111         /* Set peripheral flow controller */
1112         if (chan->dma_sconfig.device_fc)
1113                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
1114         else
1115                 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
1116
1117         /* Activate Double Buffer Mode if DMA triggers STM32 MDMA and more than 1 sg */
1118         if (chan->trig_mdma && sg_len > 1)
1119                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
1120
1121         for_each_sg(sgl, sg, sg_len, i) {
1122                 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth,
1123                                                sg_dma_len(sg),
1124                                                sg_dma_address(sg));
1125                 if (ret < 0)
1126                         goto err;
1127
1128                 desc->sg_req[i].len = sg_dma_len(sg);
1129
1130                 nb_data_items = desc->sg_req[i].len / buswidth;
1131                 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
1132                         dev_err(chan2dev(chan), "nb items not supported\n");
1133                         goto err;
1134                 }
1135
1136                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1137                 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
1138                 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
1139                 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
1140                 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
1141                 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
1142                 if (chan->trig_mdma)
1143                         desc->sg_req[i].chan_reg.dma_sm1ar += sg_dma_len(sg);
1144                 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
1145         }
1146
1147         desc->num_sgs = sg_len;
1148         desc->cyclic = false;
1149
1150         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1151
1152 err:
1153         kfree(desc);
1154         return NULL;
1155 }
1156
1157 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
1158         struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
1159         size_t period_len, enum dma_transfer_direction direction,
1160         unsigned long flags)
1161 {
1162         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1163         struct stm32_dma_desc *desc;
1164         enum dma_slave_buswidth buswidth;
1165         u32 num_periods, nb_data_items;
1166         int i, ret;
1167
1168         if (!buf_len || !period_len) {
1169                 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
1170                 return NULL;
1171         }
1172
1173         if (!chan->config_init) {
1174                 dev_err(chan2dev(chan), "dma channel is not configured\n");
1175                 return NULL;
1176         }
1177
1178         if (buf_len % period_len) {
1179                 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
1180                 return NULL;
1181         }
1182
1183         /*
1184          * We allow to take more number of requests till DMA is
1185          * not started. The driver will loop over all requests.
1186          * Once DMA is started then new requests can be queued only after
1187          * terminating the DMA.
1188          */
1189         if (chan->busy) {
1190                 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
1191                 return NULL;
1192         }
1193
1194         ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len,
1195                                        buf_addr);
1196         if (ret < 0)
1197                 return NULL;
1198
1199         nb_data_items = period_len / buswidth;
1200         if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
1201                 dev_err(chan2dev(chan), "number of items not supported\n");
1202                 return NULL;
1203         }
1204
1205         /*  Enable Circular mode or double buffer mode */
1206         if (buf_len == period_len) {
1207                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
1208         } else {
1209                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
1210                 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_CT;
1211         }
1212
1213         /* Clear periph ctrl if client set it */
1214         chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
1215
1216         num_periods = buf_len / period_len;
1217
1218         desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT);
1219         if (!desc)
1220                 return NULL;
1221
1222         for (i = 0; i < num_periods; i++) {
1223                 desc->sg_req[i].len = period_len;
1224
1225                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1226                 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
1227                 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
1228                 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
1229                 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
1230                 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
1231                 if (chan->trig_mdma)
1232                         desc->sg_req[i].chan_reg.dma_sm1ar += period_len;
1233                 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
1234                 if (!chan->trig_mdma)
1235                         buf_addr += period_len;
1236         }
1237
1238         desc->num_sgs = num_periods;
1239         desc->cyclic = true;
1240
1241         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1242 }
1243
1244 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
1245         struct dma_chan *c, dma_addr_t dest,
1246         dma_addr_t src, size_t len, unsigned long flags)
1247 {
1248         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1249         enum dma_slave_buswidth max_width;
1250         struct stm32_dma_desc *desc;
1251         size_t xfer_count, offset;
1252         u32 num_sgs, best_burst, dma_burst, threshold;
1253         int i;
1254
1255         num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1256         desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT);
1257         if (!desc)
1258                 return NULL;
1259
1260         threshold = chan->threshold;
1261
1262         for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
1263                 xfer_count = min_t(size_t, len - offset,
1264                                    STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1265
1266                 /* Compute best burst size */
1267                 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1268                 best_burst = stm32_dma_get_best_burst(len, STM32_DMA_MAX_BURST,
1269                                                       threshold, max_width);
1270                 dma_burst = stm32_dma_get_burst(chan, best_burst);
1271
1272                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1273                 desc->sg_req[i].chan_reg.dma_scr =
1274                         FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_MEM_TO_MEM) |
1275                         FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dma_burst) |
1276                         FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, dma_burst) |
1277                         STM32_DMA_SCR_MINC |
1278                         STM32_DMA_SCR_PINC |
1279                         STM32_DMA_SCR_TCIE |
1280                         STM32_DMA_SCR_TEIE;
1281                 desc->sg_req[i].chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
1282                 desc->sg_req[i].chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, threshold);
1283                 desc->sg_req[i].chan_reg.dma_spar = src + offset;
1284                 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
1285                 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
1286                 desc->sg_req[i].len = xfer_count;
1287         }
1288
1289         desc->num_sgs = num_sgs;
1290         desc->cyclic = false;
1291
1292         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1293 }
1294
1295 static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
1296 {
1297         u32 dma_scr, width, ndtr;
1298         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1299
1300         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
1301         width = FIELD_GET(STM32_DMA_SCR_PSIZE_MASK, dma_scr);
1302         ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
1303
1304         return ndtr << width;
1305 }
1306
1307 /**
1308  * stm32_dma_is_current_sg - check that expected sg_req is currently transferred
1309  * @chan: dma channel
1310  *
1311  * This function called when IRQ are disable, checks that the hardware has not
1312  * switched on the next transfer in double buffer mode. The test is done by
1313  * comparing the next_sg memory address with the hardware related register
1314  * (based on CT bit value).
1315  *
1316  * Returns true if expected current transfer is still running or double
1317  * buffer mode is not activated.
1318  */
1319 static bool stm32_dma_is_current_sg(struct stm32_dma_chan *chan)
1320 {
1321         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1322         struct stm32_dma_sg_req *sg_req;
1323         u32 dma_scr, dma_smar, id, period_len;
1324
1325         id = chan->id;
1326         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1327
1328         /* In cyclic CIRC but not DBM, CT is not used */
1329         if (!(dma_scr & STM32_DMA_SCR_DBM))
1330                 return true;
1331
1332         sg_req = &chan->desc->sg_req[chan->next_sg];
1333         period_len = sg_req->len;
1334
1335         /* DBM - take care of a previous pause/resume not yet post reconfigured */
1336         if (dma_scr & STM32_DMA_SCR_CT) {
1337                 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(id));
1338                 /*
1339                  * If transfer has been pause/resumed,
1340                  * SM0AR is in the range of [SM0AR:SM0AR+period_len]
1341                  */
1342                 return (dma_smar >= sg_req->chan_reg.dma_sm0ar &&
1343                         dma_smar < sg_req->chan_reg.dma_sm0ar + period_len);
1344         }
1345
1346         dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
1347         /*
1348          * If transfer has been pause/resumed,
1349          * SM1AR is in the range of [SM1AR:SM1AR+period_len]
1350          */
1351         return (dma_smar >= sg_req->chan_reg.dma_sm1ar &&
1352                 dma_smar < sg_req->chan_reg.dma_sm1ar + period_len);
1353 }
1354
1355 static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
1356                                      struct stm32_dma_desc *desc,
1357                                      u32 next_sg)
1358 {
1359         u32 modulo, burst_size;
1360         u32 residue;
1361         u32 n_sg = next_sg;
1362         struct stm32_dma_sg_req *sg_req = &chan->desc->sg_req[chan->next_sg];
1363         int i;
1364
1365         /*
1366          * Calculate the residue means compute the descriptors
1367          * information:
1368          * - the sg_req currently transferred
1369          * - the Hardware remaining position in this sg (NDTR bits field).
1370          *
1371          * A race condition may occur if DMA is running in cyclic or double
1372          * buffer mode, since the DMA register are automatically reloaded at end
1373          * of period transfer. The hardware may have switched to the next
1374          * transfer (CT bit updated) just before the position (SxNDTR reg) is
1375          * read.
1376          * In this case the SxNDTR reg could (or not) correspond to the new
1377          * transfer position, and not the expected one.
1378          * The strategy implemented in the stm32 driver is to:
1379          *  - read the SxNDTR register
1380          *  - crosscheck that hardware is still in current transfer.
1381          * In case of switch, we can assume that the DMA is at the beginning of
1382          * the next transfer. So we approximate the residue in consequence, by
1383          * pointing on the beginning of next transfer.
1384          *
1385          * This race condition doesn't apply for none cyclic mode, as double
1386          * buffer is not used. In such situation registers are updated by the
1387          * software.
1388          */
1389
1390         residue = stm32_dma_get_remaining_bytes(chan);
1391
1392         if (chan->desc->cyclic && !stm32_dma_is_current_sg(chan)) {
1393                 n_sg++;
1394                 if (n_sg == chan->desc->num_sgs)
1395                         n_sg = 0;
1396                 residue = sg_req->len;
1397         }
1398
1399         /*
1400          * In cyclic mode, for the last period, residue = remaining bytes
1401          * from NDTR,
1402          * else for all other periods in cyclic mode, and in sg mode,
1403          * residue = remaining bytes from NDTR + remaining
1404          * periods/sg to be transferred
1405          */
1406         if (!chan->desc->cyclic || n_sg != 0)
1407                 for (i = n_sg; i < desc->num_sgs; i++)
1408                         residue += desc->sg_req[i].len;
1409
1410         if (!chan->mem_burst)
1411                 return residue;
1412
1413         burst_size = chan->mem_burst * chan->mem_width;
1414         modulo = residue % burst_size;
1415         if (modulo)
1416                 residue = residue - modulo + burst_size;
1417
1418         return residue;
1419 }
1420
1421 static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
1422                                            dma_cookie_t cookie,
1423                                            struct dma_tx_state *state)
1424 {
1425         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1426         struct virt_dma_desc *vdesc;
1427         enum dma_status status;
1428         unsigned long flags;
1429         u32 residue = 0;
1430
1431         status = dma_cookie_status(c, cookie, state);
1432         if (status == DMA_COMPLETE)
1433                 return status;
1434
1435         status = chan->status;
1436
1437         if (!state)
1438                 return status;
1439
1440         spin_lock_irqsave(&chan->vchan.lock, flags);
1441         vdesc = vchan_find_desc(&chan->vchan, cookie);
1442         if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1443                 residue = stm32_dma_desc_residue(chan, chan->desc,
1444                                                  chan->next_sg);
1445         else if (vdesc)
1446                 residue = stm32_dma_desc_residue(chan,
1447                                                  to_stm32_dma_desc(vdesc), 0);
1448         dma_set_residue(state, residue);
1449
1450         spin_unlock_irqrestore(&chan->vchan.lock, flags);
1451
1452         return status;
1453 }
1454
1455 static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
1456 {
1457         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1458         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1459         int ret;
1460
1461         chan->config_init = false;
1462
1463         ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
1464         if (ret < 0)
1465                 return ret;
1466
1467         ret = stm32_dma_disable_chan(chan);
1468         if (ret < 0)
1469                 pm_runtime_put(dmadev->ddev.dev);
1470
1471         return ret;
1472 }
1473
1474 static void stm32_dma_free_chan_resources(struct dma_chan *c)
1475 {
1476         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1477         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1478         unsigned long flags;
1479
1480         dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1481
1482         if (chan->busy) {
1483                 spin_lock_irqsave(&chan->vchan.lock, flags);
1484                 stm32_dma_stop(chan);
1485                 chan->desc = NULL;
1486                 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1487         }
1488
1489         pm_runtime_put(dmadev->ddev.dev);
1490
1491         vchan_free_chan_resources(to_virt_chan(c));
1492         stm32_dma_clear_reg(&chan->chan_reg);
1493         chan->threshold = 0;
1494 }
1495
1496 static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
1497 {
1498         kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
1499 }
1500
1501 static void stm32_dma_set_config(struct stm32_dma_chan *chan,
1502                                  struct stm32_dma_cfg *cfg)
1503 {
1504         stm32_dma_clear_reg(&chan->chan_reg);
1505
1506         chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
1507         chan->chan_reg.dma_scr |= FIELD_PREP(STM32_DMA_SCR_REQ_MASK, cfg->request_line);
1508
1509         /* Enable Interrupts  */
1510         chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
1511
1512         chan->threshold = FIELD_GET(STM32_DMA_THRESHOLD_FTR_MASK, cfg->features);
1513         if (FIELD_GET(STM32_DMA_DIRECT_MODE_MASK, cfg->features))
1514                 chan->threshold = STM32_DMA_FIFO_THRESHOLD_NONE;
1515         if (FIELD_GET(STM32_DMA_ALT_ACK_MODE_MASK, cfg->features))
1516                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TRBUFF;
1517         chan->mdma_config.stream_id = FIELD_GET(STM32_DMA_MDMA_STREAM_ID_MASK, cfg->features);
1518 }
1519
1520 static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
1521                                            struct of_dma *ofdma)
1522 {
1523         struct stm32_dma_device *dmadev = ofdma->of_dma_data;
1524         struct device *dev = dmadev->ddev.dev;
1525         struct stm32_dma_cfg cfg;
1526         struct stm32_dma_chan *chan;
1527         struct dma_chan *c;
1528
1529         if (dma_spec->args_count < 4) {
1530                 dev_err(dev, "Bad number of cells\n");
1531                 return NULL;
1532         }
1533
1534         cfg.channel_id = dma_spec->args[0];
1535         cfg.request_line = dma_spec->args[1];
1536         cfg.stream_config = dma_spec->args[2];
1537         cfg.features = dma_spec->args[3];
1538
1539         if (cfg.channel_id >= STM32_DMA_MAX_CHANNELS ||
1540             cfg.request_line >= STM32_DMA_MAX_REQUEST_ID) {
1541                 dev_err(dev, "Bad channel and/or request id\n");
1542                 return NULL;
1543         }
1544
1545         chan = &dmadev->chan[cfg.channel_id];
1546
1547         c = dma_get_slave_channel(&chan->vchan.chan);
1548         if (!c) {
1549                 dev_err(dev, "No more channels available\n");
1550                 return NULL;
1551         }
1552
1553         stm32_dma_set_config(chan, &cfg);
1554
1555         return c;
1556 }
1557
1558 static const struct of_device_id stm32_dma_of_match[] = {
1559         { .compatible = "st,stm32-dma", },
1560         { /* sentinel */ },
1561 };
1562 MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1563
1564 static int stm32_dma_probe(struct platform_device *pdev)
1565 {
1566         struct stm32_dma_chan *chan;
1567         struct stm32_dma_device *dmadev;
1568         struct dma_device *dd;
1569         const struct of_device_id *match;
1570         struct resource *res;
1571         struct reset_control *rst;
1572         int i, ret;
1573
1574         match = of_match_device(stm32_dma_of_match, &pdev->dev);
1575         if (!match) {
1576                 dev_err(&pdev->dev, "Error: No device match found\n");
1577                 return -ENODEV;
1578         }
1579
1580         dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1581         if (!dmadev)
1582                 return -ENOMEM;
1583
1584         dd = &dmadev->ddev;
1585
1586         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1587         dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1588         if (IS_ERR(dmadev->base))
1589                 return PTR_ERR(dmadev->base);
1590
1591         dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1592         if (IS_ERR(dmadev->clk))
1593                 return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk), "Can't get clock\n");
1594
1595         ret = clk_prepare_enable(dmadev->clk);
1596         if (ret < 0) {
1597                 dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1598                 return ret;
1599         }
1600
1601         dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1602                                                 "st,mem2mem");
1603
1604         rst = devm_reset_control_get(&pdev->dev, NULL);
1605         if (IS_ERR(rst)) {
1606                 ret = PTR_ERR(rst);
1607                 if (ret == -EPROBE_DEFER)
1608                         goto clk_free;
1609         } else {
1610                 reset_control_assert(rst);
1611                 udelay(2);
1612                 reset_control_deassert(rst);
1613         }
1614
1615         dma_set_max_seg_size(&pdev->dev, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1616
1617         dma_cap_set(DMA_SLAVE, dd->cap_mask);
1618         dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1619         dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1620         dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1621         dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1622         dd->device_tx_status = stm32_dma_tx_status;
1623         dd->device_issue_pending = stm32_dma_issue_pending;
1624         dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1625         dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1626         dd->device_config = stm32_dma_slave_config;
1627         dd->device_pause = stm32_dma_pause;
1628         dd->device_resume = stm32_dma_resume;
1629         dd->device_terminate_all = stm32_dma_terminate_all;
1630         dd->device_synchronize = stm32_dma_synchronize;
1631         dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1632                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1633                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1634         dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1635                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1636                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1637         dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1638         dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1639         dd->copy_align = DMAENGINE_ALIGN_32_BYTES;
1640         dd->max_burst = STM32_DMA_MAX_BURST;
1641         dd->max_sg_burst = STM32_DMA_ALIGNED_MAX_DATA_ITEMS;
1642         dd->descriptor_reuse = true;
1643         dd->dev = &pdev->dev;
1644         INIT_LIST_HEAD(&dd->channels);
1645
1646         if (dmadev->mem2mem) {
1647                 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1648                 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1649                 dd->directions |= BIT(DMA_MEM_TO_MEM);
1650         }
1651
1652         for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1653                 chan = &dmadev->chan[i];
1654                 chan->id = i;
1655                 chan->vchan.desc_free = stm32_dma_desc_free;
1656                 vchan_init(&chan->vchan, dd);
1657
1658                 chan->mdma_config.ifcr = res->start;
1659                 chan->mdma_config.ifcr += STM32_DMA_IFCR(chan->id);
1660
1661                 chan->mdma_config.tcf = STM32_DMA_TCI;
1662                 chan->mdma_config.tcf <<= STM32_DMA_FLAGS_SHIFT(chan->id);
1663         }
1664
1665         ret = dma_async_device_register(dd);
1666         if (ret)
1667                 goto clk_free;
1668
1669         for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1670                 chan = &dmadev->chan[i];
1671                 ret = platform_get_irq(pdev, i);
1672                 if (ret < 0)
1673                         goto err_unregister;
1674                 chan->irq = ret;
1675
1676                 ret = devm_request_irq(&pdev->dev, chan->irq,
1677                                        stm32_dma_chan_irq, 0,
1678                                        dev_name(chan2dev(chan)), chan);
1679                 if (ret) {
1680                         dev_err(&pdev->dev,
1681                                 "request_irq failed with err %d channel %d\n",
1682                                 ret, i);
1683                         goto err_unregister;
1684                 }
1685         }
1686
1687         ret = of_dma_controller_register(pdev->dev.of_node,
1688                                          stm32_dma_of_xlate, dmadev);
1689         if (ret < 0) {
1690                 dev_err(&pdev->dev,
1691                         "STM32 DMA DMA OF registration failed %d\n", ret);
1692                 goto err_unregister;
1693         }
1694
1695         platform_set_drvdata(pdev, dmadev);
1696
1697         pm_runtime_set_active(&pdev->dev);
1698         pm_runtime_enable(&pdev->dev);
1699         pm_runtime_get_noresume(&pdev->dev);
1700         pm_runtime_put(&pdev->dev);
1701
1702         dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1703
1704         return 0;
1705
1706 err_unregister:
1707         dma_async_device_unregister(dd);
1708 clk_free:
1709         clk_disable_unprepare(dmadev->clk);
1710
1711         return ret;
1712 }
1713
1714 #ifdef CONFIG_PM
1715 static int stm32_dma_runtime_suspend(struct device *dev)
1716 {
1717         struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1718
1719         clk_disable_unprepare(dmadev->clk);
1720
1721         return 0;
1722 }
1723
1724 static int stm32_dma_runtime_resume(struct device *dev)
1725 {
1726         struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1727         int ret;
1728
1729         ret = clk_prepare_enable(dmadev->clk);
1730         if (ret) {
1731                 dev_err(dev, "failed to prepare_enable clock\n");
1732                 return ret;
1733         }
1734
1735         return 0;
1736 }
1737 #endif
1738
1739 #ifdef CONFIG_PM_SLEEP
1740 static int stm32_dma_pm_suspend(struct device *dev)
1741 {
1742         struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1743         int id, ret, scr;
1744
1745         ret = pm_runtime_resume_and_get(dev);
1746         if (ret < 0)
1747                 return ret;
1748
1749         for (id = 0; id < STM32_DMA_MAX_CHANNELS; id++) {
1750                 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1751                 if (scr & STM32_DMA_SCR_EN) {
1752                         dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1753                         return -EBUSY;
1754                 }
1755         }
1756
1757         pm_runtime_put_sync(dev);
1758
1759         pm_runtime_force_suspend(dev);
1760
1761         return 0;
1762 }
1763
1764 static int stm32_dma_pm_resume(struct device *dev)
1765 {
1766         return pm_runtime_force_resume(dev);
1767 }
1768 #endif
1769
1770 static const struct dev_pm_ops stm32_dma_pm_ops = {
1771         SET_SYSTEM_SLEEP_PM_OPS(stm32_dma_pm_suspend, stm32_dma_pm_resume)
1772         SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
1773                            stm32_dma_runtime_resume, NULL)
1774 };
1775
1776 static struct platform_driver stm32_dma_driver = {
1777         .driver = {
1778                 .name = "stm32-dma",
1779                 .of_match_table = stm32_dma_of_match,
1780                 .pm = &stm32_dma_pm_ops,
1781         },
1782         .probe = stm32_dma_probe,
1783 };
1784
1785 static int __init stm32_dma_init(void)
1786 {
1787         return platform_driver_register(&stm32_dma_driver);
1788 }
1789 subsys_initcall(stm32_dma_init);