drivers/usb/musb/musbhsdma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MUSB OTG driver - support for Mentor's DMA controller
   4  *
   5  * Copyright 2005 Mentor Graphics Corporation
   6  * Copyright (C) 2005-2007 by Texas Instruments
   7  */
   8 #include <linux/device.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include "musb_core.h"
  13 #include "musb_dma.h"
  14
  15 #define MUSB_HSDMA_CHANNEL_OFFSET(_bchannel, _offset)           \
  16                 (MUSB_HSDMA_BASE + (_bchannel << 4) + _offset)
  17
  18 #define musb_read_hsdma_addr(mbase, bchannel)   \
  19         musb_readl(mbase,       \
  20                    MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_ADDRESS))
  21
  22 #define musb_write_hsdma_addr(mbase, bchannel, addr) \
  23         musb_writel(mbase, \
  24                     MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_ADDRESS), \
  25                     addr)
  26
  27 #define musb_read_hsdma_count(mbase, bchannel)  \
  28         musb_readl(mbase,       \
  29                    MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_COUNT))
  30
  31 #define musb_write_hsdma_count(mbase, bchannel, len) \
  32         musb_writel(mbase, \
  33                     MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_COUNT), \
  34                     len)
  35 /* control register (16-bit): */
  36 #define MUSB_HSDMA_ENABLE_SHIFT         0
  37 #define MUSB_HSDMA_TRANSMIT_SHIFT       1
  38 #define MUSB_HSDMA_MODE1_SHIFT          2
  39 #define MUSB_HSDMA_IRQENABLE_SHIFT      3
  40 #define MUSB_HSDMA_ENDPOINT_SHIFT       4
  41 #define MUSB_HSDMA_BUSERROR_SHIFT       8
  42 #define MUSB_HSDMA_BURSTMODE_SHIFT      9
  43 #define MUSB_HSDMA_BURSTMODE            (3 << MUSB_HSDMA_BURSTMODE_SHIFT)
  44 #define MUSB_HSDMA_BURSTMODE_UNSPEC     0
  45 #define MUSB_HSDMA_BURSTMODE_INCR4      1
  46 #define MUSB_HSDMA_BURSTMODE_INCR8      2
  47 #define MUSB_HSDMA_BURSTMODE_INCR16     3
  48
  49 #define MUSB_HSDMA_CHANNELS             8
  50
  51 struct musb_dma_controller;
  52
  53 struct musb_dma_channel {
  54         struct dma_channel              channel;
  55         struct musb_dma_controller      *controller;
  56         u32                             start_addr;
  57         u32                             len;
  58         u16                             max_packet_sz;
  59         u8                              idx;
  60         u8                              epnum;
  61         u8                              transmit;
  62 };
  63
  64 struct musb_dma_controller {
  65         struct dma_controller           controller;
  66         struct musb_dma_channel         channel[MUSB_HSDMA_CHANNELS];
  67         void                            *private_data;
  68         void __iomem                    *base;
  69         u8                              channel_count;
  70         u8                              used_channels;
  71         int                             irq;
  72 };
  73
  74 static void dma_channel_release(struct dma_channel *channel);
  75
  76 static void dma_controller_stop(struct musb_dma_controller *controller)
  77 {
  78         struct musb *musb = controller->private_data;
  79         struct dma_channel *channel;
  80         u8 bit;
  81
  82         if (controller->used_channels != 0) {
  83                 dev_err(musb->controller,
  84                         "Stopping DMA controller while channel active\n");
  85
  86                 for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
  87                         if (controller->used_channels & (1 << bit)) {
  88                                 channel = &controller->channel[bit].channel;
  89                                 dma_channel_release(channel);
  90
  91                                 if (!controller->used_channels)
  92                                         break;
  93                         }
  94                 }
  95         }
  96 }
  97
  98 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
  99                                 struct musb_hw_ep *hw_ep, u8 transmit)
 100 {
 101         struct musb_dma_controller *controller = container_of(c,
 102                         struct musb_dma_controller, controller);
 103         struct musb_dma_channel *musb_channel = NULL;
 104         struct dma_channel *channel = NULL;
 105         u8 bit;
 106
 107         for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
 108                 if (!(controller->used_channels & (1 << bit))) {
 109                         controller->used_channels |= (1 << bit);
 110                         musb_channel = &(controller->channel[bit]);
 111                         musb_channel->controller = controller;
 112                         musb_channel->idx = bit;
 113                         musb_channel->epnum = hw_ep->epnum;
 114                         musb_channel->transmit = transmit;
 115                         channel = &(musb_channel->channel);
 116                         channel->private_data = musb_channel;
 117                         channel->status = MUSB_DMA_STATUS_FREE;
 118                         channel->max_len = 0x100000;
 119                         /* Tx => mode 1; Rx => mode 0 */
 120                         channel->desired_mode = transmit;
 121                         channel->actual_len = 0;
 122                         break;
 123                 }
 124         }
 125
 126         return channel;
 127 }
 128
 129 static void dma_channel_release(struct dma_channel *channel)
 130 {
 131         struct musb_dma_channel *musb_channel = channel->private_data;
 132
 133         channel->actual_len = 0;
 134         musb_channel->start_addr = 0;
 135         musb_channel->len = 0;
 136
 137         musb_channel->controller->used_channels &=
 138                 ~(1 << musb_channel->idx);
 139
 140         channel->status = MUSB_DMA_STATUS_UNKNOWN;
 141 }
 142
 143 static void configure_channel(struct dma_channel *channel,
 144                                 u16 packet_sz, u8 mode,
 145                                 dma_addr_t dma_addr, u32 len)
 146 {
 147         struct musb_dma_channel *musb_channel = channel->private_data;
 148         struct musb_dma_controller *controller = musb_channel->controller;
 149         struct musb *musb = controller->private_data;
 150         void __iomem *mbase = controller->base;
 151         u8 bchannel = musb_channel->idx;
 152         u16 csr = 0;
 153
 154         musb_dbg(musb, "%p, pkt_sz %d, addr %pad, len %d, mode %d",
 155                         channel, packet_sz, &dma_addr, len, mode);
 156
 157         if (mode) {
 158                 csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
 159                 BUG_ON(len < packet_sz);
 160         }
 161         csr |= MUSB_HSDMA_BURSTMODE_INCR16
 162                                 << MUSB_HSDMA_BURSTMODE_SHIFT;
 163
 164         csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
 165                 | (1 << MUSB_HSDMA_ENABLE_SHIFT)
 166                 | (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
 167                 | (musb_channel->transmit
 168                                 ? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
 169                                 : 0);
 170
 171         /* address/count */
 172         musb_write_hsdma_addr(mbase, bchannel, dma_addr);
 173         musb_write_hsdma_count(mbase, bchannel, len);
 174
 175         /* control (this should start things) */
 176         musb_writew(mbase,
 177                 MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 178                 csr);
 179 }
 180
 181 static int dma_channel_program(struct dma_channel *channel,
 182                                 u16 packet_sz, u8 mode,
 183                                 dma_addr_t dma_addr, u32 len)
 184 {
 185         struct musb_dma_channel *musb_channel = channel->private_data;
 186         struct musb_dma_controller *controller = musb_channel->controller;
 187         struct musb *musb = controller->private_data;
 188
 189         musb_dbg(musb, "ep%d-%s pkt_sz %d, dma_addr %pad length %d, mode %d",
 190                 musb_channel->epnum,
 191                 musb_channel->transmit ? "Tx" : "Rx",
 192                 packet_sz, &dma_addr, len, mode);
 193
 194         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 195                 channel->status == MUSB_DMA_STATUS_BUSY);
 196
 197         /*
 198          * The DMA engine in RTL1.8 and above cannot handle
 199          * DMA addresses that are not aligned to a 4 byte boundary.
 200          * It ends up masking the last two bits of the address
 201          * programmed in DMA_ADDR.
 202          *
 203          * Fail such DMA transfers, so that the backup PIO mode
 204          * can carry out the transfer
 205          */
 206         if ((musb->hwvers >= MUSB_HWVERS_1800) && (dma_addr % 4))
 207                 return false;
 208
 209         channel->actual_len = 0;
 210         musb_channel->start_addr = dma_addr;
 211         musb_channel->len = len;
 212         musb_channel->max_packet_sz = packet_sz;
 213         channel->status = MUSB_DMA_STATUS_BUSY;
 214
 215         configure_channel(channel, packet_sz, mode, dma_addr, len);
 216
 217         return true;
 218 }
 219
 220 static int dma_channel_abort(struct dma_channel *channel)
 221 {
 222         struct musb_dma_channel *musb_channel = channel->private_data;
 223         void __iomem *mbase = musb_channel->controller->base;
 224         struct musb *musb = musb_channel->controller->private_data;
 225
 226         u8 bchannel = musb_channel->idx;
 227         int offset;
 228         u16 csr;
 229
 230         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 231                 if (musb_channel->transmit) {
 232                         offset = musb->io.ep_offset(musb_channel->epnum,
 233                                                 MUSB_TXCSR);
 234
 235                         /*
 236                          * The programming guide says that we must clear
 237                          * the DMAENAB bit before the DMAMODE bit...
 238                          */
 239                         csr = musb_readw(mbase, offset);
 240                         csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
 241                         musb_writew(mbase, offset, csr);
 242                         csr &= ~MUSB_TXCSR_DMAMODE;
 243                         musb_writew(mbase, offset, csr);
 244                 } else {
 245                         offset = musb->io.ep_offset(musb_channel->epnum,
 246                                                 MUSB_RXCSR);
 247
 248                         csr = musb_readw(mbase, offset);
 249                         csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 250                                  MUSB_RXCSR_DMAENAB |
 251                                  MUSB_RXCSR_DMAMODE);
 252                         musb_writew(mbase, offset, csr);
 253                 }
 254
 255                 musb_writew(mbase,
 256                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 257                         0);
 258                 musb_write_hsdma_addr(mbase, bchannel, 0);
 259                 musb_write_hsdma_count(mbase, bchannel, 0);
 260                 channel->status = MUSB_DMA_STATUS_FREE;
 261         }
 262
 263         return 0;
 264 }
 265
 266 irqreturn_t dma_controller_irq(int irq, void *private_data)
 267 {
 268         struct musb_dma_controller *controller = private_data;
 269         struct musb *musb = controller->private_data;
 270         struct musb_dma_channel *musb_channel;
 271         struct dma_channel *channel;
 272
 273         void __iomem *mbase = controller->base;
 274
 275         irqreturn_t retval = IRQ_NONE;
 276
 277         unsigned long flags;
 278
 279         u8 bchannel;
 280         u8 int_hsdma;
 281
 282         u32 addr, count;
 283         u16 csr;
 284
 285         spin_lock_irqsave(&musb->lock, flags);
 286
 287         int_hsdma = musb_clearb(mbase, MUSB_HSDMA_INTR);
 288
 289         if (!int_hsdma) {
 290                 musb_dbg(musb, "spurious DMA irq");
 291
 292                 for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 293                         musb_channel = (struct musb_dma_channel *)
 294                                         &(controller->channel[bchannel]);
 295                         channel = &musb_channel->channel;
 296                         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 297                                 count = musb_read_hsdma_count(mbase, bchannel);
 298
 299                                 if (count == 0)
 300                                         int_hsdma |= (1 << bchannel);
 301                         }
 302                 }
 303
 304                 musb_dbg(musb, "int_hsdma = 0x%x", int_hsdma);
 305
 306                 if (!int_hsdma)
 307                         goto done;
 308         }
 309
 310         for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 311                 if (int_hsdma & (1 << bchannel)) {
 312                         musb_channel = (struct musb_dma_channel *)
 313                                         &(controller->channel[bchannel]);
 314                         channel = &musb_channel->channel;
 315
 316                         csr = musb_readw(mbase,
 317                                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
 318                                                         MUSB_HSDMA_CONTROL));
 319
 320                         if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
 321                                 musb_channel->channel.status =
 322                                         MUSB_DMA_STATUS_BUS_ABORT;
 323                         } else {
 324                                 addr = musb_read_hsdma_addr(mbase,
 325                                                 bchannel);
 326                                 channel->actual_len = addr
 327                                         - musb_channel->start_addr;
 328
 329                                 musb_dbg(musb, "ch %p, 0x%x -> 0x%x (%zu / %d) %s",
 330                                         channel, musb_channel->start_addr,
 331                                         addr, channel->actual_len,
 332                                         musb_channel->len,
 333                                         (channel->actual_len
 334                                                 < musb_channel->len) ?
 335                                         "=> reconfig 0" : "=> complete");
 336
 337                                 channel->status = MUSB_DMA_STATUS_FREE;
 338
 339                                 /* completed */
 340                                 if (musb_channel->transmit &&
 341                                         (!channel->desired_mode ||
 342                                         (channel->actual_len %
 343                                             musb_channel->max_packet_sz))) {
 344                                         u8  epnum  = musb_channel->epnum;
 345                                         int offset = musb->io.ep_offset(epnum,
 346                                                                     MUSB_TXCSR);
 347                                         u16 txcsr;
 348
 349                                         /*
 350                                          * The programming guide says that we
 351                                          * must clear DMAENAB before DMAMODE.
 352                                          */
 353                                         musb_ep_select(mbase, epnum);
 354                                         txcsr = musb_readw(mbase, offset);
 355                                         if (channel->desired_mode == 1) {
 356                                                 txcsr &= ~(MUSB_TXCSR_DMAENAB
 357                                                         | MUSB_TXCSR_AUTOSET);
 358                                                 musb_writew(mbase, offset, txcsr);
 359                                                 /* Send out the packet */
 360                                                 txcsr &= ~MUSB_TXCSR_DMAMODE;
 361                                                 txcsr |= MUSB_TXCSR_DMAENAB;
 362                                         }
 363                                         txcsr |=  MUSB_TXCSR_TXPKTRDY;
 364                                         musb_writew(mbase, offset, txcsr);
 365                                 }
 366                                 musb_dma_completion(musb, musb_channel->epnum,
 367                                                     musb_channel->transmit);
 368                         }
 369                 }
 370         }
 371
 372         retval = IRQ_HANDLED;
 373 done:
 374         spin_unlock_irqrestore(&musb->lock, flags);
 375         return retval;
 376 }
 377 EXPORT_SYMBOL_GPL(dma_controller_irq);
 378
 379 void musbhs_dma_controller_destroy(struct dma_controller *c)
 380 {
 381         struct musb_dma_controller *controller = container_of(c,
 382                         struct musb_dma_controller, controller);
 383
 384         dma_controller_stop(controller);
 385
 386         if (controller->irq)
 387                 free_irq(controller->irq, c);
 388
 389         kfree(controller);
 390 }
 391 EXPORT_SYMBOL_GPL(musbhs_dma_controller_destroy);
 392
 393 static struct musb_dma_controller *
 394 dma_controller_alloc(struct musb *musb, void __iomem *base)
 395 {
 396         struct musb_dma_controller *controller;
 397
 398         controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 399         if (!controller)
 400                 return NULL;
 401
 402         controller->channel_count = MUSB_HSDMA_CHANNELS;
 403         controller->private_data = musb;
 404         controller->base = base;
 405
 406         controller->controller.channel_alloc = dma_channel_allocate;
 407         controller->controller.channel_release = dma_channel_release;
 408         controller->controller.channel_program = dma_channel_program;
 409         controller->controller.channel_abort = dma_channel_abort;
 410         return controller;
 411 }
 412
 413 struct dma_controller *
 414 musbhs_dma_controller_create(struct musb *musb, void __iomem *base)
 415 {
 416         struct musb_dma_controller *controller;
 417         struct device *dev = musb->controller;
 418         struct platform_device *pdev = to_platform_device(dev);
 419         int irq = platform_get_irq_byname(pdev, "dma");
 420
 421         if (irq <= 0) {
 422                 dev_err(dev, "No DMA interrupt line!\n");
 423                 return NULL;
 424         }
 425
 426         controller = dma_controller_alloc(musb, base);
 427         if (!controller)
 428                 return NULL;
 429
 430         if (request_irq(irq, dma_controller_irq, 0,
 431                         dev_name(musb->controller), controller)) {
 432                 dev_err(dev, "request_irq %d failed!\n", irq);
 433                 musb_dma_controller_destroy(&controller->controller);
 434
 435                 return NULL;
 436         }
 437
 438         controller->irq = irq;
 439
 440         return &controller->controller;
 441 }
 442 EXPORT_SYMBOL_GPL(musbhs_dma_controller_create);
 443
 444 struct dma_controller *
 445 musbhs_dma_controller_create_noirq(struct musb *musb, void __iomem *base)
 446 {
 447         struct musb_dma_controller *controller;
 448
 449         controller = dma_controller_alloc(musb, base);
 450         if (!controller)
 451                 return NULL;
 452
 453         return &controller->controller;
 454 }
 455 EXPORT_SYMBOL_GPL(musbhs_dma_controller_create_noirq);