drivers/dma/dma-jz4780.c

   1 /*
   2  * Ingenic JZ4780 DMA controller
   3  *
   4  * Copyright (c) 2015 Imagination Technologies
   5  * Author: Alex Smith <alex@alex-smith.me.uk>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/dmapool.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_dma.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/slab.h>
  22
  23 #include "dmaengine.h"
  24 #include "virt-dma.h"
  25
  26 #define JZ_DMA_NR_CHANNELS      32
  27
  28 /* Global registers. */
  29 #define JZ_DMA_REG_DMAC         0x1000
  30 #define JZ_DMA_REG_DIRQP        0x1004
  31 #define JZ_DMA_REG_DDR          0x1008
  32 #define JZ_DMA_REG_DDRS         0x100c
  33 #define JZ_DMA_REG_DMACP        0x101c
  34 #define JZ_DMA_REG_DSIRQP       0x1020
  35 #define JZ_DMA_REG_DSIRQM       0x1024
  36 #define JZ_DMA_REG_DCIRQP       0x1028
  37 #define JZ_DMA_REG_DCIRQM       0x102c
  38
  39 /* Per-channel registers. */
  40 #define JZ_DMA_REG_CHAN(n)      (n * 0x20)
  41 #define JZ_DMA_REG_DSA(n)       (0x00 + JZ_DMA_REG_CHAN(n))
  42 #define JZ_DMA_REG_DTA(n)       (0x04 + JZ_DMA_REG_CHAN(n))
  43 #define JZ_DMA_REG_DTC(n)       (0x08 + JZ_DMA_REG_CHAN(n))
  44 #define JZ_DMA_REG_DRT(n)       (0x0c + JZ_DMA_REG_CHAN(n))
  45 #define JZ_DMA_REG_DCS(n)       (0x10 + JZ_DMA_REG_CHAN(n))
  46 #define JZ_DMA_REG_DCM(n)       (0x14 + JZ_DMA_REG_CHAN(n))
  47 #define JZ_DMA_REG_DDA(n)       (0x18 + JZ_DMA_REG_CHAN(n))
  48 #define JZ_DMA_REG_DSD(n)       (0x1c + JZ_DMA_REG_CHAN(n))
  49
  50 #define JZ_DMA_DMAC_DMAE        BIT(0)
  51 #define JZ_DMA_DMAC_AR          BIT(2)
  52 #define JZ_DMA_DMAC_HLT         BIT(3)
  53 #define JZ_DMA_DMAC_FMSC        BIT(31)
  54
  55 #define JZ_DMA_DRT_AUTO         0x8
  56
  57 #define JZ_DMA_DCS_CTE          BIT(0)
  58 #define JZ_DMA_DCS_HLT          BIT(2)
  59 #define JZ_DMA_DCS_TT           BIT(3)
  60 #define JZ_DMA_DCS_AR           BIT(4)
  61 #define JZ_DMA_DCS_DES8         BIT(30)
  62
  63 #define JZ_DMA_DCM_LINK         BIT(0)
  64 #define JZ_DMA_DCM_TIE          BIT(1)
  65 #define JZ_DMA_DCM_STDE         BIT(2)
  66 #define JZ_DMA_DCM_TSZ_SHIFT    8
  67 #define JZ_DMA_DCM_TSZ_MASK     (0x7 << JZ_DMA_DCM_TSZ_SHIFT)
  68 #define JZ_DMA_DCM_DP_SHIFT     12
  69 #define JZ_DMA_DCM_SP_SHIFT     14
  70 #define JZ_DMA_DCM_DAI          BIT(22)
  71 #define JZ_DMA_DCM_SAI          BIT(23)
  72
  73 #define JZ_DMA_SIZE_4_BYTE      0x0
  74 #define JZ_DMA_SIZE_1_BYTE      0x1
  75 #define JZ_DMA_SIZE_2_BYTE      0x2
  76 #define JZ_DMA_SIZE_16_BYTE     0x3
  77 #define JZ_DMA_SIZE_32_BYTE     0x4
  78 #define JZ_DMA_SIZE_64_BYTE     0x5
  79 #define JZ_DMA_SIZE_128_BYTE    0x6
  80
  81 #define JZ_DMA_WIDTH_32_BIT     0x0
  82 #define JZ_DMA_WIDTH_8_BIT      0x1
  83 #define JZ_DMA_WIDTH_16_BIT     0x2
  84
  85 #define JZ_DMA_BUSWIDTHS        (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)  | \
  86                                  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
  87                                  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
  88
  89 /**
  90  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
  91  * @dcm: value for the DCM (channel command) register
  92  * @dsa: source address
  93  * @dta: target address
  94  * @dtc: transfer count (number of blocks of the transfer size specified in DCM
  95  * to transfer) in the low 24 bits, offset of the next descriptor from the
  96  * descriptor base address in the upper 8 bits.
  97  * @sd: target/source stride difference (in stride transfer mode).
  98  * @drt: request type
  99  */
 100 struct jz4780_dma_hwdesc {
 101         uint32_t dcm;
 102         uint32_t dsa;
 103         uint32_t dta;
 104         uint32_t dtc;
 105         uint32_t sd;
 106         uint32_t drt;
 107         uint32_t reserved[2];
 108 };
 109
 110 /* Size of allocations for hardware descriptor blocks. */
 111 #define JZ_DMA_DESC_BLOCK_SIZE  PAGE_SIZE
 112 #define JZ_DMA_MAX_DESC         \
 113         (JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
 114
 115 struct jz4780_dma_desc {
 116         struct virt_dma_desc vdesc;
 117
 118         struct jz4780_dma_hwdesc *desc;
 119         dma_addr_t desc_phys;
 120         unsigned int count;
 121         enum dma_transaction_type type;
 122         uint32_t status;
 123 };
 124
 125 struct jz4780_dma_chan {
 126         struct virt_dma_chan vchan;
 127         unsigned int id;
 128         struct dma_pool *desc_pool;
 129
 130         uint32_t transfer_type;
 131         uint32_t transfer_shift;
 132         struct dma_slave_config config;
 133
 134         struct jz4780_dma_desc *desc;
 135         unsigned int curr_hwdesc;
 136 };
 137
 138 struct jz4780_dma_dev {
 139         struct dma_device dma_device;
 140         void __iomem *base;
 141         struct clk *clk;
 142         unsigned int irq;
 143
 144         uint32_t chan_reserved;
 145         struct jz4780_dma_chan chan[JZ_DMA_NR_CHANNELS];
 146 };
 147
 148 struct jz4780_dma_filter_data {
 149         struct device_node *of_node;
 150         uint32_t transfer_type;
 151         int channel;
 152 };
 153
 154 static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
 155 {
 156         return container_of(chan, struct jz4780_dma_chan, vchan.chan);
 157 }
 158
 159 static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
 160         struct virt_dma_desc *vdesc)
 161 {
 162         return container_of(vdesc, struct jz4780_dma_desc, vdesc);
 163 }
 164
 165 static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
 166         struct jz4780_dma_chan *jzchan)
 167 {
 168         return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
 169                             dma_device);
 170 }
 171
 172 static inline uint32_t jz4780_dma_readl(struct jz4780_dma_dev *jzdma,
 173         unsigned int reg)
 174 {
 175         return readl(jzdma->base + reg);
 176 }
 177
 178 static inline void jz4780_dma_writel(struct jz4780_dma_dev *jzdma,
 179         unsigned int reg, uint32_t val)
 180 {
 181         writel(val, jzdma->base + reg);
 182 }
 183
 184 static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
 185         struct jz4780_dma_chan *jzchan, unsigned int count,
 186         enum dma_transaction_type type)
 187 {
 188         struct jz4780_dma_desc *desc;
 189
 190         if (count > JZ_DMA_MAX_DESC)
 191                 return NULL;
 192
 193         desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
 194         if (!desc)
 195                 return NULL;
 196
 197         desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_NOWAIT,
 198                                     &desc->desc_phys);
 199         if (!desc->desc) {
 200                 kfree(desc);
 201                 return NULL;
 202         }
 203
 204         desc->count = count;
 205         desc->type = type;
 206         return desc;
 207 }
 208
 209 static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
 210 {
 211         struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
 212         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
 213
 214         dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
 215         kfree(desc);
 216 }
 217
 218 static uint32_t jz4780_dma_transfer_size(unsigned long val, uint32_t *shift)
 219 {
 220         int ord = ffs(val) - 1;
 221
 222         /*
 223          * 8 byte transfer sizes unsupported so fall back on 4. If it's larger
 224          * than the maximum, just limit it. It is perfectly safe to fall back
 225          * in this way since we won't exceed the maximum burst size supported
 226          * by the device, the only effect is reduced efficiency. This is better
 227          * than refusing to perform the request at all.
 228          */
 229         if (ord == 3)
 230                 ord = 2;
 231         else if (ord > 7)
 232                 ord = 7;
 233
 234         *shift = ord;
 235
 236         switch (ord) {
 237         case 0:
 238                 return JZ_DMA_SIZE_1_BYTE;
 239         case 1:
 240                 return JZ_DMA_SIZE_2_BYTE;
 241         case 2:
 242                 return JZ_DMA_SIZE_4_BYTE;
 243         case 4:
 244                 return JZ_DMA_SIZE_16_BYTE;
 245         case 5:
 246                 return JZ_DMA_SIZE_32_BYTE;
 247         case 6:
 248                 return JZ_DMA_SIZE_64_BYTE;
 249         default:
 250                 return JZ_DMA_SIZE_128_BYTE;
 251         }
 252 }
 253
 254 static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
 255         struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
 256         enum dma_transfer_direction direction)
 257 {
 258         struct dma_slave_config *config = &jzchan->config;
 259         uint32_t width, maxburst, tsz;
 260
 261         if (direction == DMA_MEM_TO_DEV) {
 262                 desc->dcm = JZ_DMA_DCM_SAI;
 263                 desc->dsa = addr;
 264                 desc->dta = config->dst_addr;
 265                 desc->drt = jzchan->transfer_type;
 266
 267                 width = config->dst_addr_width;
 268                 maxburst = config->dst_maxburst;
 269         } else {
 270                 desc->dcm = JZ_DMA_DCM_DAI;
 271                 desc->dsa = config->src_addr;
 272                 desc->dta = addr;
 273                 desc->drt = jzchan->transfer_type;
 274
 275                 width = config->src_addr_width;
 276                 maxburst = config->src_maxburst;
 277         }
 278
 279         /*
 280          * This calculates the maximum transfer size that can be used with the
 281          * given address, length, width and maximum burst size. The address
 282          * must be aligned to the transfer size, the total length must be
 283          * divisible by the transfer size, and we must not use more than the
 284          * maximum burst specified by the user.
 285          */
 286         tsz = jz4780_dma_transfer_size(addr | len | (width * maxburst),
 287                                        &jzchan->transfer_shift);
 288
 289         switch (width) {
 290         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 291         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 292                 break;
 293         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 294                 width = JZ_DMA_WIDTH_32_BIT;
 295                 break;
 296         default:
 297                 return -EINVAL;
 298         }
 299
 300         desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
 301         desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
 302         desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
 303
 304         desc->dtc = len >> jzchan->transfer_shift;
 305         return 0;
 306 }
 307
 308 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
 309         struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
 310         enum dma_transfer_direction direction, unsigned long flags,
 311         void *context)
 312 {
 313         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 314         struct jz4780_dma_desc *desc;
 315         unsigned int i;
 316         int err;
 317
 318         desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE);
 319         if (!desc)
 320                 return NULL;
 321
 322         for (i = 0; i < sg_len; i++) {
 323                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
 324                                               sg_dma_address(&sgl[i]),
 325                                               sg_dma_len(&sgl[i]),
 326                                               direction);
 327                 if (err < 0) {
 328                         jz4780_dma_desc_free(&jzchan->desc->vdesc);
 329                         return NULL;
 330                 }
 331
 332                 desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
 333
 334                 if (i != (sg_len - 1)) {
 335                         /* Automatically proceeed to the next descriptor. */
 336                         desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
 337
 338                         /*
 339                          * The upper 8 bits of the DTC field in the descriptor
 340                          * must be set to (offset from descriptor base of next
 341                          * descriptor >> 4).
 342                          */
 343                         desc->desc[i].dtc |=
 344                                 (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
 345                 }
 346         }
 347
 348         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 349 }
 350
 351 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
 352         struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 353         size_t period_len, enum dma_transfer_direction direction,
 354         unsigned long flags)
 355 {
 356         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 357         struct jz4780_dma_desc *desc;
 358         unsigned int periods, i;
 359         int err;
 360
 361         if (buf_len % period_len)
 362                 return NULL;
 363
 364         periods = buf_len / period_len;
 365
 366         desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC);
 367         if (!desc)
 368                 return NULL;
 369
 370         for (i = 0; i < periods; i++) {
 371                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
 372                                               period_len, direction);
 373                 if (err < 0) {
 374                         jz4780_dma_desc_free(&jzchan->desc->vdesc);
 375                         return NULL;
 376                 }
 377
 378                 buf_addr += period_len;
 379
 380                 /*
 381                  * Set the link bit to indicate that the controller should
 382                  * automatically proceed to the next descriptor. In
 383                  * jz4780_dma_begin(), this will be cleared if we need to issue
 384                  * an interrupt after each period.
 385                  */
 386                 desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
 387
 388                 /*
 389                  * The upper 8 bits of the DTC field in the descriptor must be
 390                  * set to (offset from descriptor base of next descriptor >> 4).
 391                  * If this is the last descriptor, link it back to the first,
 392                  * i.e. leave offset set to 0, otherwise point to the next one.
 393                  */
 394                 if (i != (periods - 1)) {
 395                         desc->desc[i].dtc |=
 396                                 (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
 397                 }
 398         }
 399
 400         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 401 }
 402
 403 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
 404         struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 405         size_t len, unsigned long flags)
 406 {
 407         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 408         struct jz4780_dma_desc *desc;
 409         uint32_t tsz;
 410
 411         desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY);
 412         if (!desc)
 413                 return NULL;
 414
 415         tsz = jz4780_dma_transfer_size(dest | src | len,
 416                                        &jzchan->transfer_shift);
 417
 418         desc->desc[0].dsa = src;
 419         desc->desc[0].dta = dest;
 420         desc->desc[0].drt = JZ_DMA_DRT_AUTO;
 421         desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
 422                             tsz << JZ_DMA_DCM_TSZ_SHIFT |
 423                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
 424                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
 425         desc->desc[0].dtc = len >> jzchan->transfer_shift;
 426
 427         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 428 }
 429
 430 static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
 431 {
 432         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 433         struct virt_dma_desc *vdesc;
 434         unsigned int i;
 435         dma_addr_t desc_phys;
 436
 437         if (!jzchan->desc) {
 438                 vdesc = vchan_next_desc(&jzchan->vchan);
 439                 if (!vdesc)
 440                         return;
 441
 442                 list_del(&vdesc->node);
 443
 444                 jzchan->desc = to_jz4780_dma_desc(vdesc);
 445                 jzchan->curr_hwdesc = 0;
 446
 447                 if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
 448                         /*
 449                          * The DMA controller doesn't support triggering an
 450                          * interrupt after processing each descriptor, only
 451                          * after processing an entire terminated list of
 452                          * descriptors. For a cyclic DMA setup the list of
 453                          * descriptors is not terminated so we can never get an
 454                          * interrupt.
 455                          *
 456                          * If the user requested a callback for a cyclic DMA
 457                          * setup then we workaround this hardware limitation
 458                          * here by degrading to a set of unlinked descriptors
 459                          * which we will submit in sequence in response to the
 460                          * completion of processing the previous descriptor.
 461                          */
 462                         for (i = 0; i < jzchan->desc->count; i++)
 463                                 jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
 464                 }
 465         } else {
 466                 /*
 467                  * There is an existing transfer, therefore this must be one
 468                  * for which we unlinked the descriptors above. Advance to the
 469                  * next one in the list.
 470                  */
 471                 jzchan->curr_hwdesc =
 472                         (jzchan->curr_hwdesc + 1) % jzchan->desc->count;
 473         }
 474
 475         /* Use 8-word descriptors. */
 476         jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), JZ_DMA_DCS_DES8);
 477
 478         /* Write descriptor address and initiate descriptor fetch. */
 479         desc_phys = jzchan->desc->desc_phys +
 480                     (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
 481         jz4780_dma_writel(jzdma, JZ_DMA_REG_DDA(jzchan->id), desc_phys);
 482         jz4780_dma_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
 483
 484         /* Enable the channel. */
 485         jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id),
 486                           JZ_DMA_DCS_DES8 | JZ_DMA_DCS_CTE);
 487 }
 488
 489 static void jz4780_dma_issue_pending(struct dma_chan *chan)
 490 {
 491         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 492         unsigned long flags;
 493
 494         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 495
 496         if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
 497                 jz4780_dma_begin(jzchan);
 498
 499         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 500 }
 501
 502 static int jz4780_dma_terminate_all(struct dma_chan *chan)
 503 {
 504         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 505         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 506         unsigned long flags;
 507         LIST_HEAD(head);
 508
 509         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 510
 511         /* Clear the DMA status and stop the transfer. */
 512         jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), 0);
 513         if (jzchan->desc) {
 514                 jz4780_dma_desc_free(&jzchan->desc->vdesc);
 515                 jzchan->desc = NULL;
 516         }
 517
 518         vchan_get_all_descriptors(&jzchan->vchan, &head);
 519
 520         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 521
 522         vchan_dma_desc_free_list(&jzchan->vchan, &head);
 523         return 0;
 524 }
 525
 526 static int jz4780_dma_config(struct dma_chan *chan,
 527         struct dma_slave_config *config)
 528 {
 529         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 530
 531         if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 532            || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
 533                 return -EINVAL;
 534
 535         /* Copy the reset of the slave configuration, it is used later. */
 536         memcpy(&jzchan->config, config, sizeof(jzchan->config));
 537
 538         return 0;
 539 }
 540
 541 static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
 542         struct jz4780_dma_desc *desc, unsigned int next_sg)
 543 {
 544         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 545         unsigned int residue, count;
 546         unsigned int i;
 547
 548         residue = 0;
 549
 550         for (i = next_sg; i < desc->count; i++)
 551                 residue += desc->desc[i].dtc << jzchan->transfer_shift;
 552
 553         if (next_sg != 0) {
 554                 count = jz4780_dma_readl(jzdma,
 555                                          JZ_DMA_REG_DTC(jzchan->id));
 556                 residue += count << jzchan->transfer_shift;
 557         }
 558
 559         return residue;
 560 }
 561
 562 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
 563         dma_cookie_t cookie, struct dma_tx_state *txstate)
 564 {
 565         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 566         struct virt_dma_desc *vdesc;
 567         enum dma_status status;
 568         unsigned long flags;
 569
 570         status = dma_cookie_status(chan, cookie, txstate);
 571         if ((status == DMA_COMPLETE) || (txstate == NULL))
 572                 return status;
 573
 574         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 575
 576         vdesc = vchan_find_desc(&jzchan->vchan, cookie);
 577         if (vdesc) {
 578                 /* On the issued list, so hasn't been processed yet */
 579                 txstate->residue = jz4780_dma_desc_residue(jzchan,
 580                                         to_jz4780_dma_desc(vdesc), 0);
 581         } else if (cookie == jzchan->desc->vdesc.tx.cookie) {
 582                 txstate->residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
 583                           (jzchan->curr_hwdesc + 1) % jzchan->desc->count);
 584         } else
 585                 txstate->residue = 0;
 586
 587         if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
 588             && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
 589                 status = DMA_ERROR;
 590
 591         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 592         return status;
 593 }
 594
 595 static void jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
 596         struct jz4780_dma_chan *jzchan)
 597 {
 598         uint32_t dcs;
 599
 600         spin_lock(&jzchan->vchan.lock);
 601
 602         dcs = jz4780_dma_readl(jzdma, JZ_DMA_REG_DCS(jzchan->id));
 603         jz4780_dma_writel(jzdma, JZ_DMA_REG_DCS(jzchan->id), 0);
 604
 605         if (dcs & JZ_DMA_DCS_AR) {
 606                 dev_warn(&jzchan->vchan.chan.dev->device,
 607                          "address error (DCS=0x%x)\n", dcs);
 608         }
 609
 610         if (dcs & JZ_DMA_DCS_HLT) {
 611                 dev_warn(&jzchan->vchan.chan.dev->device,
 612                          "channel halt (DCS=0x%x)\n", dcs);
 613         }
 614
 615         if (jzchan->desc) {
 616                 jzchan->desc->status = dcs;
 617
 618                 if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
 619                         if (jzchan->desc->type == DMA_CYCLIC) {
 620                                 vchan_cyclic_callback(&jzchan->desc->vdesc);
 621                         } else {
 622                                 vchan_cookie_complete(&jzchan->desc->vdesc);
 623                                 jzchan->desc = NULL;
 624                         }
 625
 626                         jz4780_dma_begin(jzchan);
 627                 }
 628         } else {
 629                 dev_err(&jzchan->vchan.chan.dev->device,
 630                         "channel IRQ with no active transfer\n");
 631         }
 632
 633         spin_unlock(&jzchan->vchan.lock);
 634 }
 635
 636 static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
 637 {
 638         struct jz4780_dma_dev *jzdma = data;
 639         uint32_t pending, dmac;
 640         int i;
 641
 642         pending = jz4780_dma_readl(jzdma, JZ_DMA_REG_DIRQP);
 643
 644         for (i = 0; i < JZ_DMA_NR_CHANNELS; i++) {
 645                 if (!(pending & (1<<i)))
 646                         continue;
 647
 648                 jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]);
 649         }
 650
 651         /* Clear halt and address error status of all channels. */
 652         dmac = jz4780_dma_readl(jzdma, JZ_DMA_REG_DMAC);
 653         dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
 654         jz4780_dma_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
 655
 656         /* Clear interrupt pending status. */
 657         jz4780_dma_writel(jzdma, JZ_DMA_REG_DIRQP, 0);
 658
 659         return IRQ_HANDLED;
 660 }
 661
 662 static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
 663 {
 664         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 665
 666         jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
 667                                             chan->device->dev,
 668                                             JZ_DMA_DESC_BLOCK_SIZE,
 669                                             PAGE_SIZE, 0);
 670         if (!jzchan->desc_pool) {
 671                 dev_err(&chan->dev->device,
 672                         "failed to allocate descriptor pool\n");
 673                 return -ENOMEM;
 674         }
 675
 676         return 0;
 677 }
 678
 679 static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
 680 {
 681         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 682
 683         vchan_free_chan_resources(&jzchan->vchan);
 684         dma_pool_destroy(jzchan->desc_pool);
 685         jzchan->desc_pool = NULL;
 686 }
 687
 688 static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
 689 {
 690         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 691         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 692         struct jz4780_dma_filter_data *data = param;
 693
 694         if (jzdma->dma_device.dev->of_node != data->of_node)
 695                 return false;
 696
 697         if (data->channel > -1) {
 698                 if (data->channel != jzchan->id)
 699                         return false;
 700         } else if (jzdma->chan_reserved & BIT(jzchan->id)) {
 701                 return false;
 702         }
 703
 704         jzchan->transfer_type = data->transfer_type;
 705
 706         return true;
 707 }
 708
 709 static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
 710         struct of_dma *ofdma)
 711 {
 712         struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
 713         dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
 714         struct jz4780_dma_filter_data data;
 715
 716         if (dma_spec->args_count != 2)
 717                 return NULL;
 718
 719         data.of_node = ofdma->of_node;
 720         data.transfer_type = dma_spec->args[0];
 721         data.channel = dma_spec->args[1];
 722
 723         if (data.channel > -1) {
 724                 if (data.channel >= JZ_DMA_NR_CHANNELS) {
 725                         dev_err(jzdma->dma_device.dev,
 726                                 "device requested non-existent channel %u\n",
 727                                 data.channel);
 728                         return NULL;
 729                 }
 730
 731                 /* Can only select a channel marked as reserved. */
 732                 if (!(jzdma->chan_reserved & BIT(data.channel))) {
 733                         dev_err(jzdma->dma_device.dev,
 734                                 "device requested unreserved channel %u\n",
 735                                 data.channel);
 736                         return NULL;
 737                 }
 738
 739                 jzdma->chan[data.channel].transfer_type = data.transfer_type;
 740
 741                 return dma_get_slave_channel(
 742                         &jzdma->chan[data.channel].vchan.chan);
 743         } else {
 744                 return dma_request_channel(mask, jz4780_dma_filter_fn, &data);
 745         }
 746 }
 747
 748 static int jz4780_dma_probe(struct platform_device *pdev)
 749 {
 750         struct device *dev = &pdev->dev;
 751         struct jz4780_dma_dev *jzdma;
 752         struct jz4780_dma_chan *jzchan;
 753         struct dma_device *dd;
 754         struct resource *res;
 755         int i, ret;
 756
 757         jzdma = devm_kzalloc(dev, sizeof(*jzdma), GFP_KERNEL);
 758         if (!jzdma)
 759                 return -ENOMEM;
 760
 761         platform_set_drvdata(pdev, jzdma);
 762
 763         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 764         if (!res) {
 765                 dev_err(dev, "failed to get I/O memory\n");
 766                 return -EINVAL;
 767         }
 768
 769         jzdma->base = devm_ioremap_resource(dev, res);
 770         if (IS_ERR(jzdma->base))
 771                 return PTR_ERR(jzdma->base);
 772
 773         ret = platform_get_irq(pdev, 0);
 774         if (ret < 0) {
 775                 dev_err(dev, "failed to get IRQ: %d\n", ret);
 776                 return ret;
 777         }
 778
 779         jzdma->irq = ret;
 780
 781         ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev),
 782                           jzdma);
 783         if (ret) {
 784                 dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
 785                 return ret;
 786         }
 787
 788         jzdma->clk = devm_clk_get(dev, NULL);
 789         if (IS_ERR(jzdma->clk)) {
 790                 dev_err(dev, "failed to get clock\n");
 791                 ret = PTR_ERR(jzdma->clk);
 792                 goto err_free_irq;
 793         }
 794
 795         clk_prepare_enable(jzdma->clk);
 796
 797         /* Property is optional, if it doesn't exist the value will remain 0. */
 798         of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
 799                                    0, &jzdma->chan_reserved);
 800
 801         dd = &jzdma->dma_device;
 802
 803         dma_cap_set(DMA_MEMCPY, dd->cap_mask);
 804         dma_cap_set(DMA_SLAVE, dd->cap_mask);
 805         dma_cap_set(DMA_CYCLIC, dd->cap_mask);
 806
 807         dd->dev = dev;
 808         dd->copy_align = DMAENGINE_ALIGN_4_BYTES;
 809         dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
 810         dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
 811         dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
 812         dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
 813         dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
 814         dd->device_config = jz4780_dma_config;
 815         dd->device_terminate_all = jz4780_dma_terminate_all;
 816         dd->device_tx_status = jz4780_dma_tx_status;
 817         dd->device_issue_pending = jz4780_dma_issue_pending;
 818         dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
 819         dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
 820         dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 821         dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 822
 823         /*
 824          * Enable DMA controller, mark all channels as not programmable.
 825          * Also set the FMSC bit - it increases MSC performance, so it makes
 826          * little sense not to enable it.
 827          */
 828         jz4780_dma_writel(jzdma, JZ_DMA_REG_DMAC,
 829                           JZ_DMA_DMAC_DMAE | JZ_DMA_DMAC_FMSC);
 830         jz4780_dma_writel(jzdma, JZ_DMA_REG_DMACP, 0);
 831
 832         INIT_LIST_HEAD(&dd->channels);
 833
 834         for (i = 0; i < JZ_DMA_NR_CHANNELS; i++) {
 835                 jzchan = &jzdma->chan[i];
 836                 jzchan->id = i;
 837
 838                 vchan_init(&jzchan->vchan, dd);
 839                 jzchan->vchan.desc_free = jz4780_dma_desc_free;
 840         }
 841
 842         ret = dma_async_device_register(dd);
 843         if (ret) {
 844                 dev_err(dev, "failed to register device\n");
 845                 goto err_disable_clk;
 846         }
 847
 848         /* Register with OF DMA helpers. */
 849         ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
 850                                          jzdma);
 851         if (ret) {
 852                 dev_err(dev, "failed to register OF DMA controller\n");
 853                 goto err_unregister_dev;
 854         }
 855
 856         dev_info(dev, "JZ4780 DMA controller initialised\n");
 857         return 0;
 858
 859 err_unregister_dev:
 860         dma_async_device_unregister(dd);
 861
 862 err_disable_clk:
 863         clk_disable_unprepare(jzdma->clk);
 864
 865 err_free_irq:
 866         free_irq(jzdma->irq, jzdma);
 867         return ret;
 868 }
 869
 870 static int jz4780_dma_remove(struct platform_device *pdev)
 871 {
 872         struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
 873         int i;
 874
 875         of_dma_controller_free(pdev->dev.of_node);
 876
 877         free_irq(jzdma->irq, jzdma);
 878
 879         for (i = 0; i < JZ_DMA_NR_CHANNELS; i++)
 880                 tasklet_kill(&jzdma->chan[i].vchan.task);
 881
 882         dma_async_device_unregister(&jzdma->dma_device);
 883         return 0;
 884 }
 885
 886 static const struct of_device_id jz4780_dma_dt_match[] = {
 887         { .compatible = "ingenic,jz4780-dma", .data = NULL },
 888         {},
 889 };
 890 MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
 891
 892 static struct platform_driver jz4780_dma_driver = {
 893         .probe          = jz4780_dma_probe,
 894         .remove         = jz4780_dma_remove,
 895         .driver = {
 896                 .name   = "jz4780-dma",
 897                 .of_match_table = of_match_ptr(jz4780_dma_dt_match),
 898         },
 899 };
 900
 901 static int __init jz4780_dma_init(void)
 902 {
 903         return platform_driver_register(&jz4780_dma_driver);
 904 }
 905 subsys_initcall(jz4780_dma_init);
 906
 907 static void __exit jz4780_dma_exit(void)
 908 {
 909         platform_driver_unregister(&jz4780_dma_driver);
 910 }
 911 module_exit(jz4780_dma_exit);
 912
 913 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
 914 MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
 915 MODULE_LICENSE("GPL");