drivers/dma/dma-jz4780.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Ingenic JZ4780 DMA controller
   4  *
   5  * Copyright (c) 2015 Imagination Technologies
   6  * Author: Alex Smith <alex@alex-smith.me.uk>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/dmapool.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/of_device.h>
  16 #include <linux/of_dma.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19
  20 #include "dmaengine.h"
  21 #include "virt-dma.h"
  22
  23 /* Global registers. */
  24 #define JZ_DMA_REG_DMAC         0x00
  25 #define JZ_DMA_REG_DIRQP        0x04
  26 #define JZ_DMA_REG_DDR          0x08
  27 #define JZ_DMA_REG_DDRS         0x0c
  28 #define JZ_DMA_REG_DCKE         0x10
  29 #define JZ_DMA_REG_DCKES        0x14
  30 #define JZ_DMA_REG_DCKEC        0x18
  31 #define JZ_DMA_REG_DMACP        0x1c
  32 #define JZ_DMA_REG_DSIRQP       0x20
  33 #define JZ_DMA_REG_DSIRQM       0x24
  34 #define JZ_DMA_REG_DCIRQP       0x28
  35 #define JZ_DMA_REG_DCIRQM       0x2c
  36
  37 /* Per-channel registers. */
  38 #define JZ_DMA_REG_CHAN(n)      (n * 0x20)
  39 #define JZ_DMA_REG_DSA          0x00
  40 #define JZ_DMA_REG_DTA          0x04
  41 #define JZ_DMA_REG_DTC          0x08
  42 #define JZ_DMA_REG_DRT          0x0c
  43 #define JZ_DMA_REG_DCS          0x10
  44 #define JZ_DMA_REG_DCM          0x14
  45 #define JZ_DMA_REG_DDA          0x18
  46 #define JZ_DMA_REG_DSD          0x1c
  47
  48 #define JZ_DMA_DMAC_DMAE        BIT(0)
  49 #define JZ_DMA_DMAC_AR          BIT(2)
  50 #define JZ_DMA_DMAC_HLT         BIT(3)
  51 #define JZ_DMA_DMAC_FAIC        BIT(27)
  52 #define JZ_DMA_DMAC_FMSC        BIT(31)
  53
  54 #define JZ_DMA_DRT_AUTO         0x8
  55
  56 #define JZ_DMA_DCS_CTE          BIT(0)
  57 #define JZ_DMA_DCS_HLT          BIT(2)
  58 #define JZ_DMA_DCS_TT           BIT(3)
  59 #define JZ_DMA_DCS_AR           BIT(4)
  60 #define JZ_DMA_DCS_DES8         BIT(30)
  61
  62 #define JZ_DMA_DCM_LINK         BIT(0)
  63 #define JZ_DMA_DCM_TIE          BIT(1)
  64 #define JZ_DMA_DCM_STDE         BIT(2)
  65 #define JZ_DMA_DCM_TSZ_SHIFT    8
  66 #define JZ_DMA_DCM_TSZ_MASK     (0x7 << JZ_DMA_DCM_TSZ_SHIFT)
  67 #define JZ_DMA_DCM_DP_SHIFT     12
  68 #define JZ_DMA_DCM_SP_SHIFT     14
  69 #define JZ_DMA_DCM_DAI          BIT(22)
  70 #define JZ_DMA_DCM_SAI          BIT(23)
  71
  72 #define JZ_DMA_SIZE_4_BYTE      0x0
  73 #define JZ_DMA_SIZE_1_BYTE      0x1
  74 #define JZ_DMA_SIZE_2_BYTE      0x2
  75 #define JZ_DMA_SIZE_16_BYTE     0x3
  76 #define JZ_DMA_SIZE_32_BYTE     0x4
  77 #define JZ_DMA_SIZE_64_BYTE     0x5
  78 #define JZ_DMA_SIZE_128_BYTE    0x6
  79
  80 #define JZ_DMA_WIDTH_32_BIT     0x0
  81 #define JZ_DMA_WIDTH_8_BIT      0x1
  82 #define JZ_DMA_WIDTH_16_BIT     0x2
  83
  84 #define JZ_DMA_BUSWIDTHS        (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)  | \
  85                                  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
  86                                  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
  87
  88 #define JZ4780_DMA_CTRL_OFFSET  0x1000
  89
  90 /* macros for use with jz4780_dma_soc_data.flags */
  91 #define JZ_SOC_DATA_ALLOW_LEGACY_DT     BIT(0)
  92 #define JZ_SOC_DATA_PROGRAMMABLE_DMA    BIT(1)
  93 #define JZ_SOC_DATA_PER_CHAN_PM         BIT(2)
  94 #define JZ_SOC_DATA_NO_DCKES_DCKEC      BIT(3)
  95
  96 /**
  97  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
  98  * @dcm: value for the DCM (channel command) register
  99  * @dsa: source address
 100  * @dta: target address
 101  * @dtc: transfer count (number of blocks of the transfer size specified in DCM
 102  * to transfer) in the low 24 bits, offset of the next descriptor from the
 103  * descriptor base address in the upper 8 bits.
 104  */
 105 struct jz4780_dma_hwdesc {
 106         uint32_t dcm;
 107         uint32_t dsa;
 108         uint32_t dta;
 109         uint32_t dtc;
 110 };
 111
 112 /* Size of allocations for hardware descriptor blocks. */
 113 #define JZ_DMA_DESC_BLOCK_SIZE  PAGE_SIZE
 114 #define JZ_DMA_MAX_DESC         \
 115         (JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
 116
 117 struct jz4780_dma_desc {
 118         struct virt_dma_desc vdesc;
 119
 120         struct jz4780_dma_hwdesc *desc;
 121         dma_addr_t desc_phys;
 122         unsigned int count;
 123         enum dma_transaction_type type;
 124         uint32_t status;
 125 };
 126
 127 struct jz4780_dma_chan {
 128         struct virt_dma_chan vchan;
 129         unsigned int id;
 130         struct dma_pool *desc_pool;
 131
 132         uint32_t transfer_type;
 133         uint32_t transfer_shift;
 134         struct dma_slave_config config;
 135
 136         struct jz4780_dma_desc *desc;
 137         unsigned int curr_hwdesc;
 138 };
 139
 140 struct jz4780_dma_soc_data {
 141         unsigned int nb_channels;
 142         unsigned int transfer_ord_max;
 143         unsigned long flags;
 144 };
 145
 146 struct jz4780_dma_dev {
 147         struct dma_device dma_device;
 148         void __iomem *chn_base;
 149         void __iomem *ctrl_base;
 150         struct clk *clk;
 151         unsigned int irq;
 152         const struct jz4780_dma_soc_data *soc_data;
 153
 154         uint32_t chan_reserved;
 155         struct jz4780_dma_chan chan[];
 156 };
 157
 158 struct jz4780_dma_filter_data {
 159         struct device_node *of_node;
 160         uint32_t transfer_type;
 161         int channel;
 162 };
 163
 164 static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
 165 {
 166         return container_of(chan, struct jz4780_dma_chan, vchan.chan);
 167 }
 168
 169 static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
 170         struct virt_dma_desc *vdesc)
 171 {
 172         return container_of(vdesc, struct jz4780_dma_desc, vdesc);
 173 }
 174
 175 static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
 176         struct jz4780_dma_chan *jzchan)
 177 {
 178         return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
 179                             dma_device);
 180 }
 181
 182 static inline uint32_t jz4780_dma_chn_readl(struct jz4780_dma_dev *jzdma,
 183         unsigned int chn, unsigned int reg)
 184 {
 185         return readl(jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
 186 }
 187
 188 static inline void jz4780_dma_chn_writel(struct jz4780_dma_dev *jzdma,
 189         unsigned int chn, unsigned int reg, uint32_t val)
 190 {
 191         writel(val, jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
 192 }
 193
 194 static inline uint32_t jz4780_dma_ctrl_readl(struct jz4780_dma_dev *jzdma,
 195         unsigned int reg)
 196 {
 197         return readl(jzdma->ctrl_base + reg);
 198 }
 199
 200 static inline void jz4780_dma_ctrl_writel(struct jz4780_dma_dev *jzdma,
 201         unsigned int reg, uint32_t val)
 202 {
 203         writel(val, jzdma->ctrl_base + reg);
 204 }
 205
 206 static inline void jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma,
 207         unsigned int chn)
 208 {
 209         if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) {
 210                 unsigned int reg;
 211
 212                 if (jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC)
 213                         reg = JZ_DMA_REG_DCKE;
 214                 else
 215                         reg = JZ_DMA_REG_DCKES;
 216
 217                 jz4780_dma_ctrl_writel(jzdma, reg, BIT(chn));
 218         }
 219 }
 220
 221 static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev *jzdma,
 222         unsigned int chn)
 223 {
 224         if ((jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) &&
 225                         !(jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC))
 226                 jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
 227 }
 228
 229 static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
 230         struct jz4780_dma_chan *jzchan, unsigned int count,
 231         enum dma_transaction_type type)
 232 {
 233         struct jz4780_dma_desc *desc;
 234
 235         if (count > JZ_DMA_MAX_DESC)
 236                 return NULL;
 237
 238         desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
 239         if (!desc)
 240                 return NULL;
 241
 242         desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_NOWAIT,
 243                                     &desc->desc_phys);
 244         if (!desc->desc) {
 245                 kfree(desc);
 246                 return NULL;
 247         }
 248
 249         desc->count = count;
 250         desc->type = type;
 251         return desc;
 252 }
 253
 254 static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
 255 {
 256         struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
 257         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
 258
 259         dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
 260         kfree(desc);
 261 }
 262
 263 static uint32_t jz4780_dma_transfer_size(struct jz4780_dma_chan *jzchan,
 264         unsigned long val, uint32_t *shift)
 265 {
 266         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 267         int ord = ffs(val) - 1;
 268
 269         /*
 270          * 8 byte transfer sizes unsupported so fall back on 4. If it's larger
 271          * than the maximum, just limit it. It is perfectly safe to fall back
 272          * in this way since we won't exceed the maximum burst size supported
 273          * by the device, the only effect is reduced efficiency. This is better
 274          * than refusing to perform the request at all.
 275          */
 276         if (ord == 3)
 277                 ord = 2;
 278         else if (ord > jzdma->soc_data->transfer_ord_max)
 279                 ord = jzdma->soc_data->transfer_ord_max;
 280
 281         *shift = ord;
 282
 283         switch (ord) {
 284         case 0:
 285                 return JZ_DMA_SIZE_1_BYTE;
 286         case 1:
 287                 return JZ_DMA_SIZE_2_BYTE;
 288         case 2:
 289                 return JZ_DMA_SIZE_4_BYTE;
 290         case 4:
 291                 return JZ_DMA_SIZE_16_BYTE;
 292         case 5:
 293                 return JZ_DMA_SIZE_32_BYTE;
 294         case 6:
 295                 return JZ_DMA_SIZE_64_BYTE;
 296         default:
 297                 return JZ_DMA_SIZE_128_BYTE;
 298         }
 299 }
 300
 301 static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
 302         struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
 303         enum dma_transfer_direction direction)
 304 {
 305         struct dma_slave_config *config = &jzchan->config;
 306         uint32_t width, maxburst, tsz;
 307
 308         if (direction == DMA_MEM_TO_DEV) {
 309                 desc->dcm = JZ_DMA_DCM_SAI;
 310                 desc->dsa = addr;
 311                 desc->dta = config->dst_addr;
 312
 313                 width = config->dst_addr_width;
 314                 maxburst = config->dst_maxburst;
 315         } else {
 316                 desc->dcm = JZ_DMA_DCM_DAI;
 317                 desc->dsa = config->src_addr;
 318                 desc->dta = addr;
 319
 320                 width = config->src_addr_width;
 321                 maxburst = config->src_maxburst;
 322         }
 323
 324         /*
 325          * This calculates the maximum transfer size that can be used with the
 326          * given address, length, width and maximum burst size. The address
 327          * must be aligned to the transfer size, the total length must be
 328          * divisible by the transfer size, and we must not use more than the
 329          * maximum burst specified by the user.
 330          */
 331         tsz = jz4780_dma_transfer_size(jzchan, addr | len | (width * maxburst),
 332                                        &jzchan->transfer_shift);
 333
 334         switch (width) {
 335         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 336         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 337                 break;
 338         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 339                 width = JZ_DMA_WIDTH_32_BIT;
 340                 break;
 341         default:
 342                 return -EINVAL;
 343         }
 344
 345         desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
 346         desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
 347         desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
 348
 349         desc->dtc = len >> jzchan->transfer_shift;
 350         return 0;
 351 }
 352
 353 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
 354         struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
 355         enum dma_transfer_direction direction, unsigned long flags,
 356         void *context)
 357 {
 358         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 359         struct jz4780_dma_desc *desc;
 360         unsigned int i;
 361         int err;
 362
 363         desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE);
 364         if (!desc)
 365                 return NULL;
 366
 367         for (i = 0; i < sg_len; i++) {
 368                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
 369                                               sg_dma_address(&sgl[i]),
 370                                               sg_dma_len(&sgl[i]),
 371                                               direction);
 372                 if (err < 0) {
 373                         jz4780_dma_desc_free(&jzchan->desc->vdesc);
 374                         return NULL;
 375                 }
 376
 377                 desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
 378
 379                 if (i != (sg_len - 1)) {
 380                         /* Automatically proceeed to the next descriptor. */
 381                         desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
 382
 383                         /*
 384                          * The upper 8 bits of the DTC field in the descriptor
 385                          * must be set to (offset from descriptor base of next
 386                          * descriptor >> 4).
 387                          */
 388                         desc->desc[i].dtc |=
 389                                 (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
 390                 }
 391         }
 392
 393         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 394 }
 395
 396 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
 397         struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 398         size_t period_len, enum dma_transfer_direction direction,
 399         unsigned long flags)
 400 {
 401         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 402         struct jz4780_dma_desc *desc;
 403         unsigned int periods, i;
 404         int err;
 405
 406         if (buf_len % period_len)
 407                 return NULL;
 408
 409         periods = buf_len / period_len;
 410
 411         desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC);
 412         if (!desc)
 413                 return NULL;
 414
 415         for (i = 0; i < periods; i++) {
 416                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
 417                                               period_len, direction);
 418                 if (err < 0) {
 419                         jz4780_dma_desc_free(&jzchan->desc->vdesc);
 420                         return NULL;
 421                 }
 422
 423                 buf_addr += period_len;
 424
 425                 /*
 426                  * Set the link bit to indicate that the controller should
 427                  * automatically proceed to the next descriptor. In
 428                  * jz4780_dma_begin(), this will be cleared if we need to issue
 429                  * an interrupt after each period.
 430                  */
 431                 desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
 432
 433                 /*
 434                  * The upper 8 bits of the DTC field in the descriptor must be
 435                  * set to (offset from descriptor base of next descriptor >> 4).
 436                  * If this is the last descriptor, link it back to the first,
 437                  * i.e. leave offset set to 0, otherwise point to the next one.
 438                  */
 439                 if (i != (periods - 1)) {
 440                         desc->desc[i].dtc |=
 441                                 (((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
 442                 }
 443         }
 444
 445         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 446 }
 447
 448 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
 449         struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 450         size_t len, unsigned long flags)
 451 {
 452         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 453         struct jz4780_dma_desc *desc;
 454         uint32_t tsz;
 455
 456         desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY);
 457         if (!desc)
 458                 return NULL;
 459
 460         tsz = jz4780_dma_transfer_size(jzchan, dest | src | len,
 461                                        &jzchan->transfer_shift);
 462
 463         jzchan->transfer_type = JZ_DMA_DRT_AUTO;
 464
 465         desc->desc[0].dsa = src;
 466         desc->desc[0].dta = dest;
 467         desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
 468                             tsz << JZ_DMA_DCM_TSZ_SHIFT |
 469                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
 470                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
 471         desc->desc[0].dtc = len >> jzchan->transfer_shift;
 472
 473         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 474 }
 475
 476 static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
 477 {
 478         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 479         struct virt_dma_desc *vdesc;
 480         unsigned int i;
 481         dma_addr_t desc_phys;
 482
 483         if (!jzchan->desc) {
 484                 vdesc = vchan_next_desc(&jzchan->vchan);
 485                 if (!vdesc)
 486                         return;
 487
 488                 list_del(&vdesc->node);
 489
 490                 jzchan->desc = to_jz4780_dma_desc(vdesc);
 491                 jzchan->curr_hwdesc = 0;
 492
 493                 if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
 494                         /*
 495                          * The DMA controller doesn't support triggering an
 496                          * interrupt after processing each descriptor, only
 497                          * after processing an entire terminated list of
 498                          * descriptors. For a cyclic DMA setup the list of
 499                          * descriptors is not terminated so we can never get an
 500                          * interrupt.
 501                          *
 502                          * If the user requested a callback for a cyclic DMA
 503                          * setup then we workaround this hardware limitation
 504                          * here by degrading to a set of unlinked descriptors
 505                          * which we will submit in sequence in response to the
 506                          * completion of processing the previous descriptor.
 507                          */
 508                         for (i = 0; i < jzchan->desc->count; i++)
 509                                 jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
 510                 }
 511         } else {
 512                 /*
 513                  * There is an existing transfer, therefore this must be one
 514                  * for which we unlinked the descriptors above. Advance to the
 515                  * next one in the list.
 516                  */
 517                 jzchan->curr_hwdesc =
 518                         (jzchan->curr_hwdesc + 1) % jzchan->desc->count;
 519         }
 520
 521         /* Enable the channel's clock. */
 522         jz4780_dma_chan_enable(jzdma, jzchan->id);
 523
 524         /* Use 4-word descriptors. */
 525         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
 526
 527         /* Set transfer type. */
 528         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DRT,
 529                               jzchan->transfer_type);
 530
 531         /*
 532          * Set the transfer count. This is redundant for a descriptor-driven
 533          * transfer. However, there can be a delay between the transfer start
 534          * time and when DTCn reg contains the new transfer count. Setting
 535          * it explicitly ensures residue is computed correctly at all times.
 536          */
 537         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DTC,
 538                                 jzchan->desc->desc[jzchan->curr_hwdesc].dtc);
 539
 540         /* Write descriptor address and initiate descriptor fetch. */
 541         desc_phys = jzchan->desc->desc_phys +
 542                     (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
 543         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DDA, desc_phys);
 544         jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
 545
 546         /* Enable the channel. */
 547         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS,
 548                               JZ_DMA_DCS_CTE);
 549 }
 550
 551 static void jz4780_dma_issue_pending(struct dma_chan *chan)
 552 {
 553         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 554         unsigned long flags;
 555
 556         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 557
 558         if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
 559                 jz4780_dma_begin(jzchan);
 560
 561         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 562 }
 563
 564 static int jz4780_dma_terminate_all(struct dma_chan *chan)
 565 {
 566         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 567         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 568         unsigned long flags;
 569         LIST_HEAD(head);
 570
 571         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 572
 573         /* Clear the DMA status and stop the transfer. */
 574         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
 575         if (jzchan->desc) {
 576                 vchan_terminate_vdesc(&jzchan->desc->vdesc);
 577                 jzchan->desc = NULL;
 578         }
 579
 580         jz4780_dma_chan_disable(jzdma, jzchan->id);
 581
 582         vchan_get_all_descriptors(&jzchan->vchan, &head);
 583
 584         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 585
 586         vchan_dma_desc_free_list(&jzchan->vchan, &head);
 587         return 0;
 588 }
 589
 590 static void jz4780_dma_synchronize(struct dma_chan *chan)
 591 {
 592         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 593         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 594
 595         vchan_synchronize(&jzchan->vchan);
 596         jz4780_dma_chan_disable(jzdma, jzchan->id);
 597 }
 598
 599 static int jz4780_dma_config(struct dma_chan *chan,
 600         struct dma_slave_config *config)
 601 {
 602         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 603
 604         if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 605            || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
 606                 return -EINVAL;
 607
 608         /* Copy the reset of the slave configuration, it is used later. */
 609         memcpy(&jzchan->config, config, sizeof(jzchan->config));
 610
 611         return 0;
 612 }
 613
 614 static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
 615         struct jz4780_dma_desc *desc, unsigned int next_sg)
 616 {
 617         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 618         unsigned int count = 0;
 619         unsigned int i;
 620
 621         for (i = next_sg; i < desc->count; i++)
 622                 count += desc->desc[i].dtc & GENMASK(23, 0);
 623
 624         if (next_sg != 0)
 625                 count += jz4780_dma_chn_readl(jzdma, jzchan->id,
 626                                          JZ_DMA_REG_DTC);
 627
 628         return count << jzchan->transfer_shift;
 629 }
 630
 631 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
 632         dma_cookie_t cookie, struct dma_tx_state *txstate)
 633 {
 634         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 635         struct virt_dma_desc *vdesc;
 636         enum dma_status status;
 637         unsigned long flags;
 638         unsigned long residue = 0;
 639
 640         status = dma_cookie_status(chan, cookie, txstate);
 641         if ((status == DMA_COMPLETE) || (txstate == NULL))
 642                 return status;
 643
 644         spin_lock_irqsave(&jzchan->vchan.lock, flags);
 645
 646         vdesc = vchan_find_desc(&jzchan->vchan, cookie);
 647         if (vdesc) {
 648                 /* On the issued list, so hasn't been processed yet */
 649                 residue = jz4780_dma_desc_residue(jzchan,
 650                                         to_jz4780_dma_desc(vdesc), 0);
 651         } else if (cookie == jzchan->desc->vdesc.tx.cookie) {
 652                 residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
 653                                         jzchan->curr_hwdesc + 1);
 654         }
 655         dma_set_residue(txstate, residue);
 656
 657         if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
 658             && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
 659                 status = DMA_ERROR;
 660
 661         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
 662         return status;
 663 }
 664
 665 static bool jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
 666                                 struct jz4780_dma_chan *jzchan)
 667 {
 668         uint32_t dcs;
 669         bool ack = true;
 670
 671         spin_lock(&jzchan->vchan.lock);
 672
 673         dcs = jz4780_dma_chn_readl(jzdma, jzchan->id, JZ_DMA_REG_DCS);
 674         jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
 675
 676         if (dcs & JZ_DMA_DCS_AR) {
 677                 dev_warn(&jzchan->vchan.chan.dev->device,
 678                          "address error (DCS=0x%x)\n", dcs);
 679         }
 680
 681         if (dcs & JZ_DMA_DCS_HLT) {
 682                 dev_warn(&jzchan->vchan.chan.dev->device,
 683                          "channel halt (DCS=0x%x)\n", dcs);
 684         }
 685
 686         if (jzchan->desc) {
 687                 jzchan->desc->status = dcs;
 688
 689                 if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
 690                         if (jzchan->desc->type == DMA_CYCLIC) {
 691                                 vchan_cyclic_callback(&jzchan->desc->vdesc);
 692
 693                                 jz4780_dma_begin(jzchan);
 694                         } else if (dcs & JZ_DMA_DCS_TT) {
 695                                 vchan_cookie_complete(&jzchan->desc->vdesc);
 696                                 jzchan->desc = NULL;
 697
 698                                 jz4780_dma_begin(jzchan);
 699                         } else {
 700                                 /* False positive - continue the transfer */
 701                                 ack = false;
 702                                 jz4780_dma_chn_writel(jzdma, jzchan->id,
 703                                                       JZ_DMA_REG_DCS,
 704                                                       JZ_DMA_DCS_CTE);
 705                         }
 706                 }
 707         } else {
 708                 dev_err(&jzchan->vchan.chan.dev->device,
 709                         "channel IRQ with no active transfer\n");
 710         }
 711
 712         spin_unlock(&jzchan->vchan.lock);
 713
 714         return ack;
 715 }
 716
 717 static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
 718 {
 719         struct jz4780_dma_dev *jzdma = data;
 720         unsigned int nb_channels = jzdma->soc_data->nb_channels;
 721         uint32_t pending, dmac;
 722         int i;
 723
 724         pending = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DIRQP);
 725
 726         for_each_set_bit(i, (unsigned long *)&pending, nb_channels) {
 727                 if (jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]))
 728                         pending &= ~BIT(i);
 729         }
 730
 731         /* Clear halt and address error status of all channels. */
 732         dmac = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DMAC);
 733         dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
 734         jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
 735
 736         /* Clear interrupt pending status. */
 737         jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DIRQP, pending);
 738
 739         return IRQ_HANDLED;
 740 }
 741
 742 static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
 743 {
 744         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 745
 746         jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
 747                                             chan->device->dev,
 748                                             JZ_DMA_DESC_BLOCK_SIZE,
 749                                             PAGE_SIZE, 0);
 750         if (!jzchan->desc_pool) {
 751                 dev_err(&chan->dev->device,
 752                         "failed to allocate descriptor pool\n");
 753                 return -ENOMEM;
 754         }
 755
 756         return 0;
 757 }
 758
 759 static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
 760 {
 761         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 762
 763         vchan_free_chan_resources(&jzchan->vchan);
 764         dma_pool_destroy(jzchan->desc_pool);
 765         jzchan->desc_pool = NULL;
 766 }
 767
 768 static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
 769 {
 770         struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
 771         struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 772         struct jz4780_dma_filter_data *data = param;
 773
 774         if (jzdma->dma_device.dev->of_node != data->of_node)
 775                 return false;
 776
 777         if (data->channel > -1) {
 778                 if (data->channel != jzchan->id)
 779                         return false;
 780         } else if (jzdma->chan_reserved & BIT(jzchan->id)) {
 781                 return false;
 782         }
 783
 784         jzchan->transfer_type = data->transfer_type;
 785
 786         return true;
 787 }
 788
 789 static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
 790         struct of_dma *ofdma)
 791 {
 792         struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
 793         dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
 794         struct jz4780_dma_filter_data data;
 795
 796         if (dma_spec->args_count != 2)
 797                 return NULL;
 798
 799         data.of_node = ofdma->of_node;
 800         data.transfer_type = dma_spec->args[0];
 801         data.channel = dma_spec->args[1];
 802
 803         if (data.channel > -1) {
 804                 if (data.channel >= jzdma->soc_data->nb_channels) {
 805                         dev_err(jzdma->dma_device.dev,
 806                                 "device requested non-existent channel %u\n",
 807                                 data.channel);
 808                         return NULL;
 809                 }
 810
 811                 /* Can only select a channel marked as reserved. */
 812                 if (!(jzdma->chan_reserved & BIT(data.channel))) {
 813                         dev_err(jzdma->dma_device.dev,
 814                                 "device requested unreserved channel %u\n",
 815                                 data.channel);
 816                         return NULL;
 817                 }
 818
 819                 jzdma->chan[data.channel].transfer_type = data.transfer_type;
 820
 821                 return dma_get_slave_channel(
 822                         &jzdma->chan[data.channel].vchan.chan);
 823         } else {
 824                 return dma_request_channel(mask, jz4780_dma_filter_fn, &data);
 825         }
 826 }
 827
 828 static int jz4780_dma_probe(struct platform_device *pdev)
 829 {
 830         struct device *dev = &pdev->dev;
 831         const struct jz4780_dma_soc_data *soc_data;
 832         struct jz4780_dma_dev *jzdma;
 833         struct jz4780_dma_chan *jzchan;
 834         struct dma_device *dd;
 835         struct resource *res;
 836         int i, ret;
 837
 838         if (!dev->of_node) {
 839                 dev_err(dev, "This driver must be probed from devicetree\n");
 840                 return -EINVAL;
 841         }
 842
 843         soc_data = device_get_match_data(dev);
 844         if (!soc_data)
 845                 return -EINVAL;
 846
 847         jzdma = devm_kzalloc(dev, struct_size(jzdma, chan,
 848                              soc_data->nb_channels), GFP_KERNEL);
 849         if (!jzdma)
 850                 return -ENOMEM;
 851
 852         jzdma->soc_data = soc_data;
 853         platform_set_drvdata(pdev, jzdma);
 854
 855         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 856         if (!res) {
 857                 dev_err(dev, "failed to get I/O memory\n");
 858                 return -EINVAL;
 859         }
 860
 861         jzdma->chn_base = devm_ioremap_resource(dev, res);
 862         if (IS_ERR(jzdma->chn_base))
 863                 return PTR_ERR(jzdma->chn_base);
 864
 865         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 866         if (res) {
 867                 jzdma->ctrl_base = devm_ioremap_resource(dev, res);
 868                 if (IS_ERR(jzdma->ctrl_base))
 869                         return PTR_ERR(jzdma->ctrl_base);
 870         } else if (soc_data->flags & JZ_SOC_DATA_ALLOW_LEGACY_DT) {
 871                 /*
 872                  * On JZ4780, if the second memory resource was not supplied,
 873                  * assume we're using an old devicetree, and calculate the
 874                  * offset to the control registers.
 875                  */
 876                 jzdma->ctrl_base = jzdma->chn_base + JZ4780_DMA_CTRL_OFFSET;
 877         } else {
 878                 dev_err(dev, "failed to get I/O memory\n");
 879                 return -EINVAL;
 880         }
 881
 882         ret = platform_get_irq(pdev, 0);
 883         if (ret < 0) {
 884                 dev_err(dev, "failed to get IRQ: %d\n", ret);
 885                 return ret;
 886         }
 887
 888         jzdma->irq = ret;
 889
 890         ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev),
 891                           jzdma);
 892         if (ret) {
 893                 dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
 894                 return ret;
 895         }
 896
 897         jzdma->clk = devm_clk_get(dev, NULL);
 898         if (IS_ERR(jzdma->clk)) {
 899                 dev_err(dev, "failed to get clock\n");
 900                 ret = PTR_ERR(jzdma->clk);
 901                 goto err_free_irq;
 902         }
 903
 904         clk_prepare_enable(jzdma->clk);
 905
 906         /* Property is optional, if it doesn't exist the value will remain 0. */
 907         of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
 908                                    0, &jzdma->chan_reserved);
 909
 910         dd = &jzdma->dma_device;
 911
 912         dma_cap_set(DMA_MEMCPY, dd->cap_mask);
 913         dma_cap_set(DMA_SLAVE, dd->cap_mask);
 914         dma_cap_set(DMA_CYCLIC, dd->cap_mask);
 915
 916         dd->dev = dev;
 917         dd->copy_align = DMAENGINE_ALIGN_4_BYTES;
 918         dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
 919         dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
 920         dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
 921         dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
 922         dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
 923         dd->device_config = jz4780_dma_config;
 924         dd->device_terminate_all = jz4780_dma_terminate_all;
 925         dd->device_synchronize = jz4780_dma_synchronize;
 926         dd->device_tx_status = jz4780_dma_tx_status;
 927         dd->device_issue_pending = jz4780_dma_issue_pending;
 928         dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
 929         dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
 930         dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 931         dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 932
 933         /*
 934          * Enable DMA controller, mark all channels as not programmable.
 935          * Also set the FMSC bit - it increases MSC performance, so it makes
 936          * little sense not to enable it.
 937          */
 938         jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, JZ_DMA_DMAC_DMAE |
 939                                JZ_DMA_DMAC_FAIC | JZ_DMA_DMAC_FMSC);
 940
 941         if (soc_data->flags & JZ_SOC_DATA_PROGRAMMABLE_DMA)
 942                 jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
 943
 944         INIT_LIST_HEAD(&dd->channels);
 945
 946         for (i = 0; i < soc_data->nb_channels; i++) {
 947                 jzchan = &jzdma->chan[i];
 948                 jzchan->id = i;
 949
 950                 vchan_init(&jzchan->vchan, dd);
 951                 jzchan->vchan.desc_free = jz4780_dma_desc_free;
 952         }
 953
 954         ret = dmaenginem_async_device_register(dd);
 955         if (ret) {
 956                 dev_err(dev, "failed to register device\n");
 957                 goto err_disable_clk;
 958         }
 959
 960         /* Register with OF DMA helpers. */
 961         ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
 962                                          jzdma);
 963         if (ret) {
 964                 dev_err(dev, "failed to register OF DMA controller\n");
 965                 goto err_disable_clk;
 966         }
 967
 968         dev_info(dev, "JZ4780 DMA controller initialised\n");
 969         return 0;
 970
 971 err_disable_clk:
 972         clk_disable_unprepare(jzdma->clk);
 973
 974 err_free_irq:
 975         free_irq(jzdma->irq, jzdma);
 976         return ret;
 977 }
 978
 979 static int jz4780_dma_remove(struct platform_device *pdev)
 980 {
 981         struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
 982         int i;
 983
 984         of_dma_controller_free(pdev->dev.of_node);
 985
 986         free_irq(jzdma->irq, jzdma);
 987
 988         for (i = 0; i < jzdma->soc_data->nb_channels; i++)
 989                 tasklet_kill(&jzdma->chan[i].vchan.task);
 990
 991         return 0;
 992 }
 993
 994 static const struct jz4780_dma_soc_data jz4740_dma_soc_data = {
 995         .nb_channels = 6,
 996         .transfer_ord_max = 5,
 997 };
 998
 999 static const struct jz4780_dma_soc_data jz4725b_dma_soc_data = {
1000         .nb_channels = 6,
1001         .transfer_ord_max = 5,
1002         .flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1003 };
1004
1005 static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {
1006         .nb_channels = 6,
1007         .transfer_ord_max = 6,
1008         .flags = JZ_SOC_DATA_PER_CHAN_PM,
1009 };
1010
1011 static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
1012         .nb_channels = 32,
1013         .transfer_ord_max = 7,
1014         .flags = JZ_SOC_DATA_ALLOW_LEGACY_DT | JZ_SOC_DATA_PROGRAMMABLE_DMA,
1015 };
1016
1017 static const struct of_device_id jz4780_dma_dt_match[] = {
1018         { .compatible = "ingenic,jz4740-dma", .data = &jz4740_dma_soc_data },
1019         { .compatible = "ingenic,jz4725b-dma", .data = &jz4725b_dma_soc_data },
1020         { .compatible = "ingenic,jz4770-dma", .data = &jz4770_dma_soc_data },
1021         { .compatible = "ingenic,jz4780-dma", .data = &jz4780_dma_soc_data },
1022         {},
1023 };
1024 MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
1025
1026 static struct platform_driver jz4780_dma_driver = {
1027         .probe          = jz4780_dma_probe,
1028         .remove         = jz4780_dma_remove,
1029         .driver = {
1030                 .name   = "jz4780-dma",
1031                 .of_match_table = of_match_ptr(jz4780_dma_dt_match),
1032         },
1033 };
1034
1035 static int __init jz4780_dma_init(void)
1036 {
1037         return platform_driver_register(&jz4780_dma_driver);
1038 }
1039 subsys_initcall(jz4780_dma_init);
1040
1041 static void __exit jz4780_dma_exit(void)
1042 {
1043         platform_driver_unregister(&jz4780_dma_driver);
1044 }
1045 module_exit(jz4780_dma_exit);
1046
1047 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
1048 MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
1049 MODULE_LICENSE("GPL");