drivers/usb/musb/musbhsdma.c

   1 /*
   2  * MUSB OTG driver - support for Mentor's DMA controller
   3  *
   4  * Copyright 2005 Mentor Graphics Corporation
   5  * Copyright (C) 2005-2007 by Texas Instruments
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  22  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  24  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  28  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  */
  33 #include <linux/device.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/slab.h>
  37 #include "musb_core.h"
  38 #include "musbhsdma.h"
  39
  40 static int dma_controller_start(struct dma_controller *c)
  41 {
  42         /* nothing to do */
  43         return 0;
  44 }
  45
  46 static void dma_channel_release(struct dma_channel *channel);
  47
  48 static int dma_controller_stop(struct dma_controller *c)
  49 {
  50         struct musb_dma_controller *controller = container_of(c,
  51                         struct musb_dma_controller, controller);
  52         struct musb *musb = controller->private_data;
  53         struct dma_channel *channel;
  54         u8 bit;
  55
  56         if (controller->used_channels != 0) {
  57                 dev_err(musb->controller,
  58                         "Stopping DMA controller while channel active\n");
  59
  60                 for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
  61                         if (controller->used_channels & (1 << bit)) {
  62                                 channel = &controller->channel[bit].channel;
  63                                 dma_channel_release(channel);
  64
  65                                 if (!controller->used_channels)
  66                                         break;
  67                         }
  68                 }
  69         }
  70
  71         return 0;
  72 }
  73
  74 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
  75                                 struct musb_hw_ep *hw_ep, u8 transmit)
  76 {
  77         struct musb_dma_controller *controller = container_of(c,
  78                         struct musb_dma_controller, controller);
  79         struct musb_dma_channel *musb_channel = NULL;
  80         struct dma_channel *channel = NULL;
  81         u8 bit;
  82
  83         for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
  84                 if (!(controller->used_channels & (1 << bit))) {
  85                         controller->used_channels |= (1 << bit);
  86                         musb_channel = &(controller->channel[bit]);
  87                         musb_channel->controller = controller;
  88                         musb_channel->idx = bit;
  89                         musb_channel->epnum = hw_ep->epnum;
  90                         musb_channel->transmit = transmit;
  91                         channel = &(musb_channel->channel);
  92                         channel->private_data = musb_channel;
  93                         channel->status = MUSB_DMA_STATUS_FREE;
  94                         channel->max_len = 0x100000;
  95                         /* Tx => mode 1; Rx => mode 0 */
  96                         channel->desired_mode = transmit;
  97                         channel->actual_len = 0;
  98                         break;
  99                 }
 100         }
 101
 102         return channel;
 103 }
 104
 105 static void dma_channel_release(struct dma_channel *channel)
 106 {
 107         struct musb_dma_channel *musb_channel = channel->private_data;
 108
 109         channel->actual_len = 0;
 110         musb_channel->start_addr = 0;
 111         musb_channel->len = 0;
 112
 113         musb_channel->controller->used_channels &=
 114                 ~(1 << musb_channel->idx);
 115
 116         channel->status = MUSB_DMA_STATUS_UNKNOWN;
 117 }
 118
 119 static void configure_channel(struct dma_channel *channel,
 120                                 u16 packet_sz, u8 mode,
 121                                 dma_addr_t dma_addr, u32 len)
 122 {
 123         struct musb_dma_channel *musb_channel = channel->private_data;
 124         struct musb_dma_controller *controller = musb_channel->controller;
 125         struct musb *musb = controller->private_data;
 126         void __iomem *mbase = controller->base;
 127         u8 bchannel = musb_channel->idx;
 128         u16 csr = 0;
 129
 130         dev_dbg(musb->controller, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
 131                         channel, packet_sz, dma_addr, len, mode);
 132
 133         if (mode) {
 134                 csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
 135                 BUG_ON(len < packet_sz);
 136         }
 137         csr |= MUSB_HSDMA_BURSTMODE_INCR16
 138                                 << MUSB_HSDMA_BURSTMODE_SHIFT;
 139
 140         csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
 141                 | (1 << MUSB_HSDMA_ENABLE_SHIFT)
 142                 | (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
 143                 | (musb_channel->transmit
 144                                 ? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
 145                                 : 0);
 146
 147         /* address/count */
 148         musb_write_hsdma_addr(mbase, bchannel, dma_addr);
 149         musb_write_hsdma_count(mbase, bchannel, len);
 150
 151         /* control (this should start things) */
 152         musb_writew(mbase,
 153                 MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 154                 csr);
 155 }
 156
 157 static int dma_channel_program(struct dma_channel *channel,
 158                                 u16 packet_sz, u8 mode,
 159                                 dma_addr_t dma_addr, u32 len)
 160 {
 161         struct musb_dma_channel *musb_channel = channel->private_data;
 162         struct musb_dma_controller *controller = musb_channel->controller;
 163         struct musb *musb = controller->private_data;
 164
 165         dev_dbg(musb->controller, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
 166                 musb_channel->epnum,
 167                 musb_channel->transmit ? "Tx" : "Rx",
 168                 packet_sz, dma_addr, len, mode);
 169
 170         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 171                 channel->status == MUSB_DMA_STATUS_BUSY);
 172
 173         /* Let targets check/tweak the arguments */
 174         if (musb->ops->adjust_channel_params) {
 175                 int ret = musb->ops->adjust_channel_params(channel,
 176                         packet_sz, &mode, &dma_addr, &len);
 177                 if (ret)
 178                         return ret;
 179         }
 180
 181         /*
 182          * The DMA engine in RTL1.8 and above cannot handle
 183          * DMA addresses that are not aligned to a 4 byte boundary.
 184          * It ends up masking the last two bits of the address
 185          * programmed in DMA_ADDR.
 186          *
 187          * Fail such DMA transfers, so that the backup PIO mode
 188          * can carry out the transfer
 189          */
 190         if ((musb->hwvers >= MUSB_HWVERS_1800) && (dma_addr % 4))
 191                 return false;
 192
 193         channel->actual_len = 0;
 194         musb_channel->start_addr = dma_addr;
 195         musb_channel->len = len;
 196         musb_channel->max_packet_sz = packet_sz;
 197         channel->status = MUSB_DMA_STATUS_BUSY;
 198
 199         configure_channel(channel, packet_sz, mode, dma_addr, len);
 200
 201         return true;
 202 }
 203
 204 static int dma_channel_abort(struct dma_channel *channel)
 205 {
 206         struct musb_dma_channel *musb_channel = channel->private_data;
 207         void __iomem *mbase = musb_channel->controller->base;
 208
 209         u8 bchannel = musb_channel->idx;
 210         int offset;
 211         u16 csr;
 212
 213         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 214                 if (musb_channel->transmit) {
 215                         offset = MUSB_EP_OFFSET(musb_channel->epnum,
 216                                                 MUSB_TXCSR);
 217
 218                         /*
 219                          * The programming guide says that we must clear
 220                          * the DMAENAB bit before the DMAMODE bit...
 221                          */
 222                         csr = musb_readw(mbase, offset);
 223                         csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
 224                         musb_writew(mbase, offset, csr);
 225                         csr &= ~MUSB_TXCSR_DMAMODE;
 226                         musb_writew(mbase, offset, csr);
 227                 } else {
 228                         offset = MUSB_EP_OFFSET(musb_channel->epnum,
 229                                                 MUSB_RXCSR);
 230
 231                         csr = musb_readw(mbase, offset);
 232                         csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 233                                  MUSB_RXCSR_DMAENAB |
 234                                  MUSB_RXCSR_DMAMODE);
 235                         musb_writew(mbase, offset, csr);
 236                 }
 237
 238                 musb_writew(mbase,
 239                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 240                         0);
 241                 musb_write_hsdma_addr(mbase, bchannel, 0);
 242                 musb_write_hsdma_count(mbase, bchannel, 0);
 243                 channel->status = MUSB_DMA_STATUS_FREE;
 244         }
 245
 246         return 0;
 247 }
 248
 249 static irqreturn_t dma_controller_irq(int irq, void *private_data)
 250 {
 251         struct musb_dma_controller *controller = private_data;
 252         struct musb *musb = controller->private_data;
 253         struct musb_dma_channel *musb_channel;
 254         struct dma_channel *channel;
 255
 256         void __iomem *mbase = controller->base;
 257
 258         irqreturn_t retval = IRQ_NONE;
 259
 260         unsigned long flags;
 261
 262         u8 bchannel;
 263         u8 int_hsdma;
 264
 265         u32 addr, count;
 266         u16 csr;
 267
 268         spin_lock_irqsave(&musb->lock, flags);
 269
 270         int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
 271
 272 #ifdef CONFIG_BLACKFIN
 273         /* Clear DMA interrupt flags */
 274         musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
 275 #endif
 276
 277         if (!int_hsdma) {
 278                 dev_dbg(musb->controller, "spurious DMA irq\n");
 279
 280                 for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 281                         musb_channel = (struct musb_dma_channel *)
 282                                         &(controller->channel[bchannel]);
 283                         channel = &musb_channel->channel;
 284                         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 285                                 count = musb_read_hsdma_count(mbase, bchannel);
 286
 287                                 if (count == 0)
 288                                         int_hsdma |= (1 << bchannel);
 289                         }
 290                 }
 291
 292                 dev_dbg(musb->controller, "int_hsdma = 0x%x\n", int_hsdma);
 293
 294                 if (!int_hsdma)
 295                         goto done;
 296         }
 297
 298         for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 299                 if (int_hsdma & (1 << bchannel)) {
 300                         musb_channel = (struct musb_dma_channel *)
 301                                         &(controller->channel[bchannel]);
 302                         channel = &musb_channel->channel;
 303
 304                         csr = musb_readw(mbase,
 305                                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
 306                                                         MUSB_HSDMA_CONTROL));
 307
 308                         if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
 309                                 musb_channel->channel.status =
 310                                         MUSB_DMA_STATUS_BUS_ABORT;
 311                         } else {
 312                                 u8 devctl;
 313
 314                                 addr = musb_read_hsdma_addr(mbase,
 315                                                 bchannel);
 316                                 channel->actual_len = addr
 317                                         - musb_channel->start_addr;
 318
 319                                 dev_dbg(musb->controller, "ch %p, 0x%x -> 0x%x (%zu / %d) %s\n",
 320                                         channel, musb_channel->start_addr,
 321                                         addr, channel->actual_len,
 322                                         musb_channel->len,
 323                                         (channel->actual_len
 324                                                 < musb_channel->len) ?
 325                                         "=> reconfig 0" : "=> complete");
 326
 327                                 devctl = musb_readb(mbase, MUSB_DEVCTL);
 328
 329                                 channel->status = MUSB_DMA_STATUS_FREE;
 330
 331                                 /* completed */
 332                                 if ((devctl & MUSB_DEVCTL_HM)
 333                                         && (musb_channel->transmit)
 334                                         && ((channel->desired_mode == 0)
 335                                             || (channel->actual_len &
 336                                             (musb_channel->max_packet_sz - 1)))
 337                                     ) {
 338                                         u8  epnum  = musb_channel->epnum;
 339                                         int offset = MUSB_EP_OFFSET(epnum,
 340                                                                     MUSB_TXCSR);
 341                                         u16 txcsr;
 342
 343                                         /*
 344                                          * The programming guide says that we
 345                                          * must clear DMAENAB before DMAMODE.
 346                                          */
 347                                         musb_ep_select(mbase, epnum);
 348                                         txcsr = musb_readw(mbase, offset);
 349                                         txcsr &= ~(MUSB_TXCSR_DMAENAB
 350                                                         | MUSB_TXCSR_AUTOSET);
 351                                         musb_writew(mbase, offset, txcsr);
 352                                         /* Send out the packet */
 353                                         txcsr &= ~MUSB_TXCSR_DMAMODE;
 354                                         txcsr |=  MUSB_TXCSR_TXPKTRDY;
 355                                         musb_writew(mbase, offset, txcsr);
 356                                 }
 357                                 musb_dma_completion(musb, musb_channel->epnum,
 358                                                     musb_channel->transmit);
 359                         }
 360                 }
 361         }
 362
 363         retval = IRQ_HANDLED;
 364 done:
 365         spin_unlock_irqrestore(&musb->lock, flags);
 366         return retval;
 367 }
 368
 369 void dma_controller_destroy(struct dma_controller *c)
 370 {
 371         struct musb_dma_controller *controller = container_of(c,
 372                         struct musb_dma_controller, controller);
 373
 374         if (!controller)
 375                 return;
 376
 377         if (controller->irq)
 378                 free_irq(controller->irq, c);
 379
 380         kfree(controller);
 381 }
 382
 383 struct dma_controller *dma_controller_create(struct musb *musb, void __iomem *base)
 384 {
 385         struct musb_dma_controller *controller;
 386         struct device *dev = musb->controller;
 387         struct platform_device *pdev = to_platform_device(dev);
 388         int irq = platform_get_irq_byname(pdev, "dma");
 389
 390         if (irq <= 0) {
 391                 dev_err(dev, "No DMA interrupt line!\n");
 392                 return NULL;
 393         }
 394
 395         controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 396         if (!controller)
 397                 return NULL;
 398
 399         controller->channel_count = MUSB_HSDMA_CHANNELS;
 400         controller->private_data = musb;
 401         controller->base = base;
 402
 403         controller->controller.start = dma_controller_start;
 404         controller->controller.stop = dma_controller_stop;
 405         controller->controller.channel_alloc = dma_channel_allocate;
 406         controller->controller.channel_release = dma_channel_release;
 407         controller->controller.channel_program = dma_channel_program;
 408         controller->controller.channel_abort = dma_channel_abort;
 409
 410         if (request_irq(irq, dma_controller_irq, 0,
 411                         dev_name(musb->controller), &controller->controller)) {
 412                 dev_err(dev, "request_irq %d failed!\n", irq);
 413                 dma_controller_destroy(&controller->controller);
 414
 415                 return NULL;
 416         }
 417
 418         controller->irq = irq;
 419
 420         return &controller->controller;
 421 }