drivers/usb/musb/ux500_dma.c

   1 /*
   2  * drivers/usb/musb/ux500_dma.c
   3  *
   4  * U8500 and U5500 DMA support code
   5  *
   6  * Copyright (C) 2009 STMicroelectronics
   7  * Copyright (C) 2011 ST-Ericsson SA
   8  * Authors:
   9  *      Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
  10  *      Praveena Nadahally <praveen.nadahally@stericsson.com>
  11  *      Rajaram Regupathy <ragupathy.rajaram@stericsson.com>
  12  *
  13  * This program is free software: you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation, either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25  */
  26
  27 #include <linux/device.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/dma-mapping.h>
  31 #include <linux/dmaengine.h>
  32 #include <linux/pfn.h>
  33 #include <mach/usb.h>
  34 #include "musb_core.h"
  35
  36 struct ux500_dma_channel {
  37         struct dma_channel channel;
  38         struct ux500_dma_controller *controller;
  39         struct musb_hw_ep *hw_ep;
  40         struct work_struct channel_work;
  41         struct dma_chan *dma_chan;
  42         unsigned int cur_len;
  43         dma_cookie_t cookie;
  44         u8 ch_num;
  45         u8 is_tx;
  46         u8 is_allocated;
  47 };
  48
  49 struct ux500_dma_controller {
  50         struct dma_controller controller;
  51         struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_CHANNELS];
  52         struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_TX_CHANNELS];
  53         u32     num_rx_channels;
  54         u32     num_tx_channels;
  55         void *private_data;
  56         dma_addr_t phy_base;
  57 };
  58
  59 /* Work function invoked from DMA callback to handle tx transfers. */
  60 static void ux500_tx_work(struct work_struct *data)
  61 {
  62         struct ux500_dma_channel *ux500_channel = container_of(data,
  63                 struct ux500_dma_channel, channel_work);
  64         struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
  65         struct musb *musb = hw_ep->musb;
  66         unsigned long flags;
  67
  68         dev_dbg(musb->controller, "DMA tx transfer done on hw_ep=%d\n",
  69                 hw_ep->epnum);
  70
  71         spin_lock_irqsave(&musb->lock, flags);
  72         ux500_channel->channel.actual_len = ux500_channel->cur_len;
  73         ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
  74         musb_dma_completion(musb, hw_ep->epnum,
  75                                 ux500_channel->is_tx);
  76         spin_unlock_irqrestore(&musb->lock, flags);
  77 }
  78
  79 /* Work function invoked from DMA callback to handle rx transfers. */
  80 static void ux500_rx_work(struct work_struct *data)
  81 {
  82         struct ux500_dma_channel *ux500_channel = container_of(data,
  83                 struct ux500_dma_channel, channel_work);
  84         struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
  85         struct musb *musb = hw_ep->musb;
  86         unsigned long flags;
  87
  88         dev_dbg(musb->controller, "DMA rx transfer done on hw_ep=%d\n",
  89                 hw_ep->epnum);
  90
  91         spin_lock_irqsave(&musb->lock, flags);
  92         ux500_channel->channel.actual_len = ux500_channel->cur_len;
  93         ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
  94         musb_dma_completion(musb, hw_ep->epnum,
  95                 ux500_channel->is_tx);
  96         spin_unlock_irqrestore(&musb->lock, flags);
  97 }
  98
  99 void ux500_dma_callback(void *private_data)
 100 {
 101         struct dma_channel *channel = (struct dma_channel *)private_data;
 102         struct ux500_dma_channel *ux500_channel = channel->private_data;
 103
 104         schedule_work(&ux500_channel->channel_work);
 105 }
 106
 107 static bool ux500_configure_channel(struct dma_channel *channel,
 108                                 u16 packet_sz, u8 mode,
 109                                 dma_addr_t dma_addr, u32 len)
 110 {
 111         struct ux500_dma_channel *ux500_channel = channel->private_data;
 112         struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
 113         struct dma_chan *dma_chan = ux500_channel->dma_chan;
 114         struct dma_async_tx_descriptor *dma_desc;
 115         enum dma_data_direction direction;
 116         struct scatterlist sg;
 117         struct dma_slave_config slave_conf;
 118         enum dma_slave_buswidth addr_width;
 119         dma_addr_t usb_fifo_addr = (MUSB_FIFO_OFFSET(hw_ep->epnum) +
 120                                         ux500_channel->controller->phy_base);
 121         struct musb *musb = ux500_channel->controller->private_data;
 122
 123         dev_dbg(musb->controller,
 124                 "packet_sz=%d, mode=%d, dma_addr=0x%x, len=%d is_tx=%d\n",
 125                 packet_sz, mode, dma_addr, len, ux500_channel->is_tx);
 126
 127         ux500_channel->cur_len = len;
 128
 129         sg_init_table(&sg, 1);
 130         sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
 131                                             offset_in_page(dma_addr));
 132         sg_dma_address(&sg) = dma_addr;
 133         sg_dma_len(&sg) = len;
 134
 135         direction = ux500_channel->is_tx ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 136         addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
 137                                         DMA_SLAVE_BUSWIDTH_4_BYTES;
 138
 139         slave_conf.direction = direction;
 140         slave_conf.src_addr = usb_fifo_addr;
 141         slave_conf.src_addr_width = addr_width;
 142         slave_conf.src_maxburst = 16;
 143         slave_conf.dst_addr = usb_fifo_addr;
 144         slave_conf.dst_addr_width = addr_width;
 145         slave_conf.dst_maxburst = 16;
 146
 147         dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
 148                                              (unsigned long) &slave_conf);
 149
 150         dma_desc = dma_chan->device->
 151                         device_prep_slave_sg(dma_chan, &sg, 1, direction,
 152                                              DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 153         if (!dma_desc)
 154                 return false;
 155
 156         dma_desc->callback = ux500_dma_callback;
 157         dma_desc->callback_param = channel;
 158         ux500_channel->cookie = dma_desc->tx_submit(dma_desc);
 159
 160         dma_async_issue_pending(dma_chan);
 161
 162         return true;
 163 }
 164
 165 static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
 166                                 struct musb_hw_ep *hw_ep, u8 is_tx)
 167 {
 168         struct ux500_dma_controller *controller = container_of(c,
 169                         struct ux500_dma_controller, controller);
 170         struct ux500_dma_channel *ux500_channel = NULL;
 171         struct musb *musb = controller->private_data;
 172         u8 ch_num = hw_ep->epnum - 1;
 173         u32 max_ch;
 174
 175         /* Max 8 DMA channels (0 - 7). Each DMA channel can only be allocated
 176          * to specified hw_ep. For example DMA channel 0 can only be allocated
 177          * to hw_ep 1 and 9.
 178          */
 179         if (ch_num > 7)
 180                 ch_num -= 8;
 181
 182         max_ch = is_tx ? controller->num_tx_channels :
 183                         controller->num_rx_channels;
 184
 185         if (ch_num >= max_ch)
 186                 return NULL;
 187
 188         ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
 189                                 &(controller->rx_channel[ch_num]) ;
 190
 191         /* Check if channel is already used. */
 192         if (ux500_channel->is_allocated)
 193                 return NULL;
 194
 195         ux500_channel->hw_ep = hw_ep;
 196         ux500_channel->is_allocated = 1;
 197
 198         dev_dbg(musb->controller, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
 199                 hw_ep->epnum, is_tx, ch_num);
 200
 201         return &(ux500_channel->channel);
 202 }
 203
 204 static void ux500_dma_channel_release(struct dma_channel *channel)
 205 {
 206         struct ux500_dma_channel *ux500_channel = channel->private_data;
 207         struct musb *musb = ux500_channel->controller->private_data;
 208
 209         dev_dbg(musb->controller, "channel=%d\n", ux500_channel->ch_num);
 210
 211         if (ux500_channel->is_allocated) {
 212                 ux500_channel->is_allocated = 0;
 213                 channel->status = MUSB_DMA_STATUS_FREE;
 214                 channel->actual_len = 0;
 215         }
 216 }
 217
 218 static int ux500_dma_is_compatible(struct dma_channel *channel,
 219                 u16 maxpacket, void *buf, u32 length)
 220 {
 221         if ((maxpacket & 0x3)           ||
 222                 ((int)buf & 0x3)        ||
 223                 (length < 512)          ||
 224                 (length & 0x3))
 225                 return false;
 226         else
 227                 return true;
 228 }
 229
 230 static int ux500_dma_channel_program(struct dma_channel *channel,
 231                                 u16 packet_sz, u8 mode,
 232                                 dma_addr_t dma_addr, u32 len)
 233 {
 234         int ret;
 235
 236         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 237                 channel->status == MUSB_DMA_STATUS_BUSY);
 238
 239         if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
 240                 return false;
 241
 242         channel->status = MUSB_DMA_STATUS_BUSY;
 243         channel->actual_len = 0;
 244         ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
 245         if (!ret)
 246                 channel->status = MUSB_DMA_STATUS_FREE;
 247
 248         return ret;
 249 }
 250
 251 static int ux500_dma_channel_abort(struct dma_channel *channel)
 252 {
 253         struct ux500_dma_channel *ux500_channel = channel->private_data;
 254         struct ux500_dma_controller *controller = ux500_channel->controller;
 255         struct musb *musb = controller->private_data;
 256         void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
 257         u16 csr;
 258
 259         dev_dbg(musb->controller, "channel=%d, is_tx=%d\n",
 260                 ux500_channel->ch_num, ux500_channel->is_tx);
 261
 262         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 263                 if (ux500_channel->is_tx) {
 264                         csr = musb_readw(epio, MUSB_TXCSR);
 265                         csr &= ~(MUSB_TXCSR_AUTOSET |
 266                                  MUSB_TXCSR_DMAENAB |
 267                                  MUSB_TXCSR_DMAMODE);
 268                         musb_writew(epio, MUSB_TXCSR, csr);
 269                 } else {
 270                         csr = musb_readw(epio, MUSB_RXCSR);
 271                         csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 272                                  MUSB_RXCSR_DMAENAB |
 273                                  MUSB_RXCSR_DMAMODE);
 274                         musb_writew(epio, MUSB_RXCSR, csr);
 275                 }
 276
 277                 ux500_channel->dma_chan->device->
 278                                 device_control(ux500_channel->dma_chan,
 279                                         DMA_TERMINATE_ALL, 0);
 280                 channel->status = MUSB_DMA_STATUS_FREE;
 281         }
 282         return 0;
 283 }
 284
 285 static int ux500_dma_controller_stop(struct dma_controller *c)
 286 {
 287         struct ux500_dma_controller *controller = container_of(c,
 288                         struct ux500_dma_controller, controller);
 289         struct ux500_dma_channel *ux500_channel;
 290         struct dma_channel *channel;
 291         u8 ch_num;
 292
 293         for (ch_num = 0; ch_num < controller->num_rx_channels; ch_num++) {
 294                 channel = &controller->rx_channel[ch_num].channel;
 295                 ux500_channel = channel->private_data;
 296
 297                 ux500_dma_channel_release(channel);
 298
 299                 if (ux500_channel->dma_chan)
 300                         dma_release_channel(ux500_channel->dma_chan);
 301         }
 302
 303         for (ch_num = 0; ch_num < controller->num_tx_channels; ch_num++) {
 304                 channel = &controller->tx_channel[ch_num].channel;
 305                 ux500_channel = channel->private_data;
 306
 307                 ux500_dma_channel_release(channel);
 308
 309                 if (ux500_channel->dma_chan)
 310                         dma_release_channel(ux500_channel->dma_chan);
 311         }
 312
 313         return 0;
 314 }
 315
 316 static int ux500_dma_controller_start(struct dma_controller *c)
 317 {
 318         struct ux500_dma_controller *controller = container_of(c,
 319                         struct ux500_dma_controller, controller);
 320         struct ux500_dma_channel *ux500_channel = NULL;
 321         struct musb *musb = controller->private_data;
 322         struct device *dev = musb->controller;
 323         struct musb_hdrc_platform_data *plat = dev->platform_data;
 324         struct ux500_musb_board_data *data = plat->board_data;
 325         struct dma_channel *dma_channel = NULL;
 326         u32 ch_num;
 327         u8 dir;
 328         u8 is_tx = 0;
 329
 330         void **param_array;
 331         struct ux500_dma_channel *channel_array;
 332         u32 ch_count;
 333         void (*musb_channel_work)(struct work_struct *);
 334         dma_cap_mask_t mask;
 335
 336         if ((data->num_rx_channels > UX500_MUSB_DMA_NUM_RX_CHANNELS) ||
 337                 (data->num_tx_channels > UX500_MUSB_DMA_NUM_TX_CHANNELS))
 338                 return -EINVAL;
 339
 340         controller->num_rx_channels = data->num_rx_channels;
 341         controller->num_tx_channels = data->num_tx_channels;
 342
 343         dma_cap_zero(mask);
 344         dma_cap_set(DMA_SLAVE, mask);
 345
 346         /* Prepare the loop for RX channels */
 347         channel_array = controller->rx_channel;
 348         ch_count = data->num_rx_channels;
 349         param_array = data->dma_rx_param_array;
 350         musb_channel_work = ux500_rx_work;
 351
 352         for (dir = 0; dir < 2; dir++) {
 353                 for (ch_num = 0; ch_num < ch_count; ch_num++) {
 354                         ux500_channel = &channel_array[ch_num];
 355                         ux500_channel->controller = controller;
 356                         ux500_channel->ch_num = ch_num;
 357                         ux500_channel->is_tx = is_tx;
 358
 359                         dma_channel = &(ux500_channel->channel);
 360                         dma_channel->private_data = ux500_channel;
 361                         dma_channel->status = MUSB_DMA_STATUS_FREE;
 362                         dma_channel->max_len = SZ_16M;
 363
 364                         ux500_channel->dma_chan = dma_request_channel(mask,
 365                                                         data->dma_filter,
 366                                                         param_array[ch_num]);
 367                         if (!ux500_channel->dma_chan) {
 368                                 ERR("Dma pipe allocation error dir=%d ch=%d\n",
 369                                         dir, ch_num);
 370
 371                                 /* Release already allocated channels */
 372                                 ux500_dma_controller_stop(c);
 373
 374                                 return -EBUSY;
 375                         }
 376
 377                         INIT_WORK(&ux500_channel->channel_work,
 378                                 musb_channel_work);
 379                 }
 380
 381                 /* Prepare the loop for TX channels */
 382                 channel_array = controller->tx_channel;
 383                 ch_count = data->num_tx_channels;
 384                 param_array = data->dma_tx_param_array;
 385                 musb_channel_work = ux500_tx_work;
 386                 is_tx = 1;
 387         }
 388
 389         return 0;
 390 }
 391
 392 void dma_controller_destroy(struct dma_controller *c)
 393 {
 394         struct ux500_dma_controller *controller = container_of(c,
 395                         struct ux500_dma_controller, controller);
 396
 397         kfree(controller);
 398 }
 399
 400 struct dma_controller *__init
 401 dma_controller_create(struct musb *musb, void __iomem *base)
 402 {
 403         struct ux500_dma_controller *controller;
 404         struct platform_device *pdev = to_platform_device(musb->controller);
 405         struct resource *iomem;
 406
 407         controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 408         if (!controller)
 409                 return NULL;
 410
 411         controller->private_data = musb;
 412
 413         /* Save physical address for DMA controller. */
 414         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 415         controller->phy_base = (dma_addr_t) iomem->start;
 416
 417         controller->controller.start = ux500_dma_controller_start;
 418         controller->controller.stop = ux500_dma_controller_stop;
 419         controller->controller.channel_alloc = ux500_dma_channel_allocate;
 420         controller->controller.channel_release = ux500_dma_channel_release;
 421         controller->controller.channel_program = ux500_dma_channel_program;
 422         controller->controller.channel_abort = ux500_dma_channel_abort;
 423         controller->controller.is_compatible = ux500_dma_is_compatible;
 424
 425         return &controller->controller;
 426 }