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