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 "musb_core.h"
  37 #include "musbhsdma.h"
  38
  39 static int dma_controller_start(struct dma_controller *c)
  40 {
  41         /* nothing to do */
  42         return 0;
  43 }
  44
  45 static void dma_channel_release(struct dma_channel *channel);
  46
  47 static int dma_controller_stop(struct dma_controller *c)
  48 {
  49         struct musb_dma_controller *controller = container_of(c,
  50                         struct musb_dma_controller, controller);
  51         struct musb *musb = controller->private_data;
  52         struct dma_channel *channel;
  53         u8 bit;
  54
  55         if (controller->used_channels != 0) {
  56                 dev_err(musb->controller,
  57                         "Stopping DMA controller while channel active\n");
  58
  59                 for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
  60                         if (controller->used_channels & (1 << bit)) {
  61                                 channel = &controller->channel[bit].channel;
  62                                 dma_channel_release(channel);
  63
  64                                 if (!controller->used_channels)
  65                                         break;
  66                         }
  67                 }
  68         }
  69
  70         return 0;
  71 }
  72
  73 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
  74                                 struct musb_hw_ep *hw_ep, u8 transmit)
  75 {
  76         struct musb_dma_controller *controller = container_of(c,
  77                         struct musb_dma_controller, controller);
  78         struct musb_dma_channel *musb_channel = NULL;
  79         struct dma_channel *channel = NULL;
  80         u8 bit;
  81
  82         for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
  83                 if (!(controller->used_channels & (1 << bit))) {
  84                         controller->used_channels |= (1 << bit);
  85                         musb_channel = &(controller->channel[bit]);
  86                         musb_channel->controller = controller;
  87                         musb_channel->idx = bit;
  88                         musb_channel->epnum = hw_ep->epnum;
  89                         musb_channel->transmit = transmit;
  90                         channel = &(musb_channel->channel);
  91                         channel->private_data = musb_channel;
  92                         channel->status = MUSB_DMA_STATUS_FREE;
  93                         channel->max_len = 0x10000;
  94                         /* Tx => mode 1; Rx => mode 0 */
  95                         channel->desired_mode = transmit;
  96                         channel->actual_len = 0;
  97                         break;
  98                 }
  99         }
 100
 101         return channel;
 102 }
 103
 104 static void dma_channel_release(struct dma_channel *channel)
 105 {
 106         struct musb_dma_channel *musb_channel = channel->private_data;
 107
 108         channel->actual_len = 0;
 109         musb_channel->start_addr = 0;
 110         musb_channel->len = 0;
 111
 112         musb_channel->controller->used_channels &=
 113                 ~(1 << musb_channel->idx);
 114
 115         channel->status = MUSB_DMA_STATUS_UNKNOWN;
 116 }
 117
 118 static void configure_channel(struct dma_channel *channel,
 119                                 u16 packet_sz, u8 mode,
 120                                 dma_addr_t dma_addr, u32 len)
 121 {
 122         struct musb_dma_channel *musb_channel = channel->private_data;
 123         struct musb_dma_controller *controller = musb_channel->controller;
 124         void __iomem *mbase = controller->base;
 125         u8 bchannel = musb_channel->idx;
 126         u16 csr = 0;
 127
 128         DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
 129                         channel, packet_sz, dma_addr, len, mode);
 130
 131         if (mode) {
 132                 csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
 133                 BUG_ON(len < packet_sz);
 134
 135                 if (packet_sz >= 64) {
 136                         csr |= MUSB_HSDMA_BURSTMODE_INCR16
 137                                         << MUSB_HSDMA_BURSTMODE_SHIFT;
 138                 } else if (packet_sz >= 32) {
 139                         csr |= MUSB_HSDMA_BURSTMODE_INCR8
 140                                         << MUSB_HSDMA_BURSTMODE_SHIFT;
 141                 } else if (packet_sz >= 16) {
 142                         csr |= MUSB_HSDMA_BURSTMODE_INCR4
 143                                         << MUSB_HSDMA_BURSTMODE_SHIFT;
 144                 }
 145         }
 146
 147         csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
 148                 | (1 << MUSB_HSDMA_ENABLE_SHIFT)
 149                 | (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
 150                 | (musb_channel->transmit
 151                                 ? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
 152                                 : 0);
 153
 154         /* address/count */
 155         musb_write_hsdma_addr(mbase, bchannel, dma_addr);
 156         musb_write_hsdma_count(mbase, bchannel, len);
 157
 158         /* control (this should start things) */
 159         musb_writew(mbase,
 160                 MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 161                 csr);
 162 }
 163
 164 static int dma_channel_program(struct dma_channel *channel,
 165                                 u16 packet_sz, u8 mode,
 166                                 dma_addr_t dma_addr, u32 len)
 167 {
 168         struct musb_dma_channel *musb_channel = channel->private_data;
 169
 170         DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
 171                 musb_channel->epnum,
 172                 musb_channel->transmit ? "Tx" : "Rx",
 173                 packet_sz, dma_addr, len, mode);
 174
 175         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 176                 channel->status == MUSB_DMA_STATUS_BUSY);
 177
 178         channel->actual_len = 0;
 179         musb_channel->start_addr = dma_addr;
 180         musb_channel->len = len;
 181         musb_channel->max_packet_sz = packet_sz;
 182         channel->status = MUSB_DMA_STATUS_BUSY;
 183
 184         if ((mode == 1) && (len >= packet_sz))
 185                 configure_channel(channel, packet_sz, 1, dma_addr, len);
 186         else
 187                 configure_channel(channel, packet_sz, 0, dma_addr, len);
 188
 189         return true;
 190 }
 191
 192 static int dma_channel_abort(struct dma_channel *channel)
 193 {
 194         struct musb_dma_channel *musb_channel = channel->private_data;
 195         void __iomem *mbase = musb_channel->controller->base;
 196
 197         u8 bchannel = musb_channel->idx;
 198         int offset;
 199         u16 csr;
 200
 201         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 202                 if (musb_channel->transmit) {
 203                         offset = MUSB_EP_OFFSET(musb_channel->epnum,
 204                                                 MUSB_TXCSR);
 205
 206                         /*
 207                          * The programming guide says that we must clear
 208                          * the DMAENAB bit before the DMAMODE bit...
 209                          */
 210                         csr = musb_readw(mbase, offset);
 211                         csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
 212                         musb_writew(mbase, offset, csr);
 213                         csr &= ~MUSB_TXCSR_DMAMODE;
 214                         musb_writew(mbase, offset, csr);
 215                 } else {
 216                         offset = MUSB_EP_OFFSET(musb_channel->epnum,
 217                                                 MUSB_RXCSR);
 218
 219                         csr = musb_readw(mbase, offset);
 220                         csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 221                                  MUSB_RXCSR_DMAENAB |
 222                                  MUSB_RXCSR_DMAMODE);
 223                         musb_writew(mbase, offset, csr);
 224                 }
 225
 226                 musb_writew(mbase,
 227                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
 228                         0);
 229                 musb_write_hsdma_addr(mbase, bchannel, 0);
 230                 musb_write_hsdma_count(mbase, bchannel, 0);
 231                 channel->status = MUSB_DMA_STATUS_FREE;
 232         }
 233
 234         return 0;
 235 }
 236
 237 static irqreturn_t dma_controller_irq(int irq, void *private_data)
 238 {
 239         struct musb_dma_controller *controller = private_data;
 240         struct musb *musb = controller->private_data;
 241         struct musb_dma_channel *musb_channel;
 242         struct dma_channel *channel;
 243
 244         void __iomem *mbase = controller->base;
 245
 246         irqreturn_t retval = IRQ_NONE;
 247
 248         unsigned long flags;
 249
 250         u8 bchannel;
 251         u8 int_hsdma;
 252
 253         u32 addr;
 254         u16 csr;
 255
 256         spin_lock_irqsave(&musb->lock, flags);
 257
 258         int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
 259         if (!int_hsdma)
 260                 goto done;
 261
 262 #ifdef CONFIG_BLACKFIN
 263         /* Clear DMA interrupt flags */
 264         musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
 265 #endif
 266
 267         for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 268                 if (int_hsdma & (1 << bchannel)) {
 269                         musb_channel = (struct musb_dma_channel *)
 270                                         &(controller->channel[bchannel]);
 271                         channel = &musb_channel->channel;
 272
 273                         csr = musb_readw(mbase,
 274                                         MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
 275                                                         MUSB_HSDMA_CONTROL));
 276
 277                         if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
 278                                 musb_channel->channel.status =
 279                                         MUSB_DMA_STATUS_BUS_ABORT;
 280                         } else {
 281                                 u8 devctl;
 282
 283                                 addr = musb_read_hsdma_addr(mbase,
 284                                                 bchannel);
 285                                 channel->actual_len = addr
 286                                         - musb_channel->start_addr;
 287
 288                                 DBG(2, "ch %p, 0x%x -> 0x%x (%zu / %d) %s\n",
 289                                         channel, musb_channel->start_addr,
 290                                         addr, channel->actual_len,
 291                                         musb_channel->len,
 292                                         (channel->actual_len
 293                                                 < musb_channel->len) ?
 294                                         "=> reconfig 0" : "=> complete");
 295
 296                                 devctl = musb_readb(mbase, MUSB_DEVCTL);
 297
 298                                 channel->status = MUSB_DMA_STATUS_FREE;
 299
 300                                 /* completed */
 301                                 if ((devctl & MUSB_DEVCTL_HM)
 302                                         && (musb_channel->transmit)
 303                                         && ((channel->desired_mode == 0)
 304                                             || (channel->actual_len &
 305                                             (musb_channel->max_packet_sz - 1)))
 306                                     ) {
 307                                         u8  epnum  = musb_channel->epnum;
 308                                         int offset = MUSB_EP_OFFSET(epnum,
 309                                                                     MUSB_TXCSR);
 310                                         u16 txcsr;
 311
 312                                         /*
 313                                          * The programming guide says that we
 314                                          * must clear DMAENAB before DMAMODE.
 315                                          */
 316                                         musb_ep_select(mbase, epnum);
 317                                         txcsr = musb_readw(mbase, offset);
 318                                         txcsr &= ~(MUSB_TXCSR_DMAENAB
 319                                                         | MUSB_TXCSR_AUTOSET);
 320                                         musb_writew(mbase, offset, txcsr);
 321                                         /* Send out the packet */
 322                                         txcsr &= ~MUSB_TXCSR_DMAMODE;
 323                                         txcsr |=  MUSB_TXCSR_TXPKTRDY;
 324                                         musb_writew(mbase, offset, txcsr);
 325                                 }
 326                                 musb_dma_completion(musb, musb_channel->epnum,
 327                                                     musb_channel->transmit);
 328                         }
 329                 }
 330         }
 331
 332         retval = IRQ_HANDLED;
 333 done:
 334         spin_unlock_irqrestore(&musb->lock, flags);
 335         return retval;
 336 }
 337
 338 void dma_controller_destroy(struct dma_controller *c)
 339 {
 340         struct musb_dma_controller *controller = container_of(c,
 341                         struct musb_dma_controller, controller);
 342
 343         if (!controller)
 344                 return;
 345
 346         if (controller->irq)
 347                 free_irq(controller->irq, c);
 348
 349         kfree(controller);
 350 }
 351
 352 struct dma_controller *__init
 353 dma_controller_create(struct musb *musb, void __iomem *base)
 354 {
 355         struct musb_dma_controller *controller;
 356         struct device *dev = musb->controller;
 357         struct platform_device *pdev = to_platform_device(dev);
 358         int irq = platform_get_irq(pdev, 1);
 359
 360         if (irq == 0) {
 361                 dev_err(dev, "No DMA interrupt line!\n");
 362                 return NULL;
 363         }
 364
 365         controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 366         if (!controller)
 367                 return NULL;
 368
 369         controller->channel_count = MUSB_HSDMA_CHANNELS;
 370         controller->private_data = musb;
 371         controller->base = base;
 372
 373         controller->controller.start = dma_controller_start;
 374         controller->controller.stop = dma_controller_stop;
 375         controller->controller.channel_alloc = dma_channel_allocate;
 376         controller->controller.channel_release = dma_channel_release;
 377         controller->controller.channel_program = dma_channel_program;
 378         controller->controller.channel_abort = dma_channel_abort;
 379
 380         if (request_irq(irq, dma_controller_irq, IRQF_DISABLED,
 381                         dev_name(musb->controller), &controller->controller)) {
 382                 dev_err(dev, "request_irq %d failed!\n", irq);
 383                 dma_controller_destroy(&controller->controller);
 384
 385                 return NULL;
 386         }
 387
 388         controller->irq = irq;
 389
 390         return &controller->controller;
 391 }