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