kernel/drivers/usb/musb/ux500_dma.c

   1 /*
   2  * drivers/usb/musb/ux500_dma.c
   3  *
   4  * U8500 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 <linux/sizes.h>
  34 #include <linux/platform_data/usb-musb-ux500.h>
  35 #include "musb_core.h"
  36
  37 static const char *iep_chan_names[] = { "iep_1_9", "iep_2_10", "iep_3_11", "iep_4_12",
  38                                         "iep_5_13", "iep_6_14", "iep_7_15", "iep_8" };
  39 static const char *oep_chan_names[] = { "oep_1_9", "oep_2_10", "oep_3_11", "oep_4_12",
  40                                         "oep_5_13", "oep_6_14", "oep_7_15", "oep_8" };
  41
  42 struct ux500_dma_channel {
  43         struct dma_channel channel;
  44         struct ux500_dma_controller *controller;
  45         struct musb_hw_ep *hw_ep;
  46         struct dma_chan *dma_chan;
  47         unsigned int cur_len;
  48         dma_cookie_t cookie;
  49         u8 ch_num;
  50         u8 is_tx;
  51         u8 is_allocated;
  52 };
  53
  54 struct ux500_dma_controller {
  55         struct dma_controller controller;
  56         struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_TX_CHANNELS];
  57         struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_RX_TX_CHANNELS];
  58         void *private_data;
  59         dma_addr_t phy_base;
  60 };
  61
  62 /* Work function invoked from DMA callback to handle rx transfers. */
  63 static void ux500_dma_callback(void *private_data)
  64 {
  65         struct dma_channel *channel = private_data;
  66         struct ux500_dma_channel *ux500_channel = channel->private_data;
  67         struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
  68         struct musb *musb = hw_ep->musb;
  69         unsigned long flags;
  70
  71         dev_dbg(musb->controller, "DMA rx transfer done on hw_ep=%d\n",
  72                 hw_ep->epnum);
  73
  74         spin_lock_irqsave(&musb->lock, flags);
  75         ux500_channel->channel.actual_len = ux500_channel->cur_len;
  76         ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
  77         musb_dma_completion(musb, hw_ep->epnum, ux500_channel->is_tx);
  78         spin_unlock_irqrestore(&musb->lock, flags);
  79
  80 }
  81
  82 static bool ux500_configure_channel(struct dma_channel *channel,
  83                                 u16 packet_sz, u8 mode,
  84                                 dma_addr_t dma_addr, u32 len)
  85 {
  86         struct ux500_dma_channel *ux500_channel = channel->private_data;
  87         struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
  88         struct dma_chan *dma_chan = ux500_channel->dma_chan;
  89         struct dma_async_tx_descriptor *dma_desc;
  90         enum dma_transfer_direction direction;
  91         struct scatterlist sg;
  92         struct dma_slave_config slave_conf;
  93         enum dma_slave_buswidth addr_width;
  94         struct musb *musb = ux500_channel->controller->private_data;
  95         dma_addr_t usb_fifo_addr = (musb->io.fifo_offset(hw_ep->epnum) +
  96                                         ux500_channel->controller->phy_base);
  97
  98         dev_dbg(musb->controller,
  99                 "packet_sz=%d, mode=%d, dma_addr=0x%llx, len=%d is_tx=%d\n",
 100                 packet_sz, mode, (unsigned long long) dma_addr,
 101                 len, ux500_channel->is_tx);
 102
 103         ux500_channel->cur_len = len;
 104
 105         sg_init_table(&sg, 1);
 106         sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
 107                                             offset_in_page(dma_addr));
 108         sg_dma_address(&sg) = dma_addr;
 109         sg_dma_len(&sg) = len;
 110
 111         direction = ux500_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
 112         addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
 113                                         DMA_SLAVE_BUSWIDTH_4_BYTES;
 114
 115         slave_conf.direction = direction;
 116         slave_conf.src_addr = usb_fifo_addr;
 117         slave_conf.src_addr_width = addr_width;
 118         slave_conf.src_maxburst = 16;
 119         slave_conf.dst_addr = usb_fifo_addr;
 120         slave_conf.dst_addr_width = addr_width;
 121         slave_conf.dst_maxburst = 16;
 122         slave_conf.device_fc = false;
 123
 124         dmaengine_slave_config(dma_chan, &slave_conf);
 125
 126         dma_desc = dmaengine_prep_slave_sg(dma_chan, &sg, 1, direction,
 127                                              DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 128         if (!dma_desc)
 129                 return false;
 130
 131         dma_desc->callback = ux500_dma_callback;
 132         dma_desc->callback_param = channel;
 133         ux500_channel->cookie = dma_desc->tx_submit(dma_desc);
 134
 135         dma_async_issue_pending(dma_chan);
 136
 137         return true;
 138 }
 139
 140 static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
 141                                 struct musb_hw_ep *hw_ep, u8 is_tx)
 142 {
 143         struct ux500_dma_controller *controller = container_of(c,
 144                         struct ux500_dma_controller, controller);
 145         struct ux500_dma_channel *ux500_channel = NULL;
 146         struct musb *musb = controller->private_data;
 147         u8 ch_num = hw_ep->epnum - 1;
 148
 149         /* 8 DMA channels (0 - 7). Each DMA channel can only be allocated
 150          * to specified hw_ep. For example DMA channel 0 can only be allocated
 151          * to hw_ep 1 and 9.
 152          */
 153         if (ch_num > 7)
 154                 ch_num -= 8;
 155
 156         if (ch_num >= UX500_MUSB_DMA_NUM_RX_TX_CHANNELS)
 157                 return NULL;
 158
 159         ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
 160                                 &(controller->rx_channel[ch_num]) ;
 161
 162         /* Check if channel is already used. */
 163         if (ux500_channel->is_allocated)
 164                 return NULL;
 165
 166         ux500_channel->hw_ep = hw_ep;
 167         ux500_channel->is_allocated = 1;
 168
 169         dev_dbg(musb->controller, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
 170                 hw_ep->epnum, is_tx, ch_num);
 171
 172         return &(ux500_channel->channel);
 173 }
 174
 175 static void ux500_dma_channel_release(struct dma_channel *channel)
 176 {
 177         struct ux500_dma_channel *ux500_channel = channel->private_data;
 178         struct musb *musb = ux500_channel->controller->private_data;
 179
 180         dev_dbg(musb->controller, "channel=%d\n", ux500_channel->ch_num);
 181
 182         if (ux500_channel->is_allocated) {
 183                 ux500_channel->is_allocated = 0;
 184                 channel->status = MUSB_DMA_STATUS_FREE;
 185                 channel->actual_len = 0;
 186         }
 187 }
 188
 189 static int ux500_dma_is_compatible(struct dma_channel *channel,
 190                 u16 maxpacket, void *buf, u32 length)
 191 {
 192         if ((maxpacket & 0x3)           ||
 193                 ((unsigned long int) buf & 0x3) ||
 194                 (length < 512)          ||
 195                 (length & 0x3))
 196                 return false;
 197         else
 198                 return true;
 199 }
 200
 201 static int ux500_dma_channel_program(struct dma_channel *channel,
 202                                 u16 packet_sz, u8 mode,
 203                                 dma_addr_t dma_addr, u32 len)
 204 {
 205         int ret;
 206
 207         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 208                 channel->status == MUSB_DMA_STATUS_BUSY);
 209
 210         if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
 211                 return false;
 212
 213         channel->status = MUSB_DMA_STATUS_BUSY;
 214         channel->actual_len = 0;
 215         ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
 216         if (!ret)
 217                 channel->status = MUSB_DMA_STATUS_FREE;
 218
 219         return ret;
 220 }
 221
 222 static int ux500_dma_channel_abort(struct dma_channel *channel)
 223 {
 224         struct ux500_dma_channel *ux500_channel = channel->private_data;
 225         struct ux500_dma_controller *controller = ux500_channel->controller;
 226         struct musb *musb = controller->private_data;
 227         void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
 228         u16 csr;
 229
 230         dev_dbg(musb->controller, "channel=%d, is_tx=%d\n",
 231                 ux500_channel->ch_num, ux500_channel->is_tx);
 232
 233         if (channel->status == MUSB_DMA_STATUS_BUSY) {
 234                 if (ux500_channel->is_tx) {
 235                         csr = musb_readw(epio, MUSB_TXCSR);
 236                         csr &= ~(MUSB_TXCSR_AUTOSET |
 237                                  MUSB_TXCSR_DMAENAB |
 238                                  MUSB_TXCSR_DMAMODE);
 239                         musb_writew(epio, MUSB_TXCSR, csr);
 240                 } else {
 241                         csr = musb_readw(epio, MUSB_RXCSR);
 242                         csr &= ~(MUSB_RXCSR_AUTOCLEAR |
 243                                  MUSB_RXCSR_DMAENAB |
 244                                  MUSB_RXCSR_DMAMODE);
 245                         musb_writew(epio, MUSB_RXCSR, csr);
 246                 }
 247
 248                 dmaengine_terminate_all(ux500_channel->dma_chan);
 249                 channel->status = MUSB_DMA_STATUS_FREE;
 250         }
 251         return 0;
 252 }
 253
 254 static void ux500_dma_controller_stop(struct ux500_dma_controller *controller)
 255 {
 256         struct ux500_dma_channel *ux500_channel;
 257         struct dma_channel *channel;
 258         u8 ch_num;
 259
 260         for (ch_num = 0; ch_num < UX500_MUSB_DMA_NUM_RX_TX_CHANNELS; ch_num++) {
 261                 channel = &controller->rx_channel[ch_num].channel;
 262                 ux500_channel = channel->private_data;
 263
 264                 ux500_dma_channel_release(channel);
 265
 266                 if (ux500_channel->dma_chan)
 267                         dma_release_channel(ux500_channel->dma_chan);
 268         }
 269
 270         for (ch_num = 0; ch_num < UX500_MUSB_DMA_NUM_RX_TX_CHANNELS; ch_num++) {
 271                 channel = &controller->tx_channel[ch_num].channel;
 272                 ux500_channel = channel->private_data;
 273
 274                 ux500_dma_channel_release(channel);
 275
 276                 if (ux500_channel->dma_chan)
 277                         dma_release_channel(ux500_channel->dma_chan);
 278         }
 279 }
 280
 281 static int ux500_dma_controller_start(struct ux500_dma_controller *controller)
 282 {
 283         struct ux500_dma_channel *ux500_channel = NULL;
 284         struct musb *musb = controller->private_data;
 285         struct device *dev = musb->controller;
 286         struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
 287         struct ux500_musb_board_data *data;
 288         struct dma_channel *dma_channel = NULL;
 289         char **chan_names;
 290         u32 ch_num;
 291         u8 dir;
 292         u8 is_tx = 0;
 293
 294         void **param_array;
 295         struct ux500_dma_channel *channel_array;
 296         dma_cap_mask_t mask;
 297
 298         if (!plat) {
 299                 dev_err(musb->controller, "No platform data\n");
 300                 return -EINVAL;
 301         }
 302
 303         data = plat->board_data;
 304
 305         dma_cap_zero(mask);
 306         dma_cap_set(DMA_SLAVE, mask);
 307
 308         /* Prepare the loop for RX channels */
 309         channel_array = controller->rx_channel;
 310         param_array = data ? data->dma_rx_param_array : NULL;
 311         chan_names = (char **)iep_chan_names;
 312
 313         for (dir = 0; dir < 2; dir++) {
 314                 for (ch_num = 0;
 315                      ch_num < UX500_MUSB_DMA_NUM_RX_TX_CHANNELS;
 316                      ch_num++) {
 317                         ux500_channel = &channel_array[ch_num];
 318                         ux500_channel->controller = controller;
 319                         ux500_channel->ch_num = ch_num;
 320                         ux500_channel->is_tx = is_tx;
 321
 322                         dma_channel = &(ux500_channel->channel);
 323                         dma_channel->private_data = ux500_channel;
 324                         dma_channel->status = MUSB_DMA_STATUS_FREE;
 325                         dma_channel->max_len = SZ_16M;
 326
 327                         ux500_channel->dma_chan =
 328                                 dma_request_slave_channel(dev, chan_names[ch_num]);
 329
 330                         if (!ux500_channel->dma_chan)
 331                                 ux500_channel->dma_chan =
 332                                         dma_request_channel(mask,
 333                                                             data ?
 334                                                             data->dma_filter :
 335                                                             NULL,
 336                                                             param_array ?
 337                                                             param_array[ch_num] :
 338                                                             NULL);
 339
 340                         if (!ux500_channel->dma_chan) {
 341                                 ERR("Dma pipe allocation error dir=%d ch=%d\n",
 342                                         dir, ch_num);
 343
 344                                 /* Release already allocated channels */
 345                                 ux500_dma_controller_stop(controller);
 346
 347                                 return -EBUSY;
 348                         }
 349
 350                 }
 351
 352                 /* Prepare the loop for TX channels */
 353                 channel_array = controller->tx_channel;
 354                 param_array = data ? data->dma_tx_param_array : NULL;
 355                 chan_names = (char **)oep_chan_names;
 356                 is_tx = 1;
 357         }
 358
 359         return 0;
 360 }
 361
 362 void ux500_dma_controller_destroy(struct dma_controller *c)
 363 {
 364         struct ux500_dma_controller *controller = container_of(c,
 365                         struct ux500_dma_controller, controller);
 366
 367         ux500_dma_controller_stop(controller);
 368         kfree(controller);
 369 }
 370 EXPORT_SYMBOL_GPL(ux500_dma_controller_destroy);
 371
 372 struct dma_controller *
 373 ux500_dma_controller_create(struct musb *musb, void __iomem *base)
 374 {
 375         struct ux500_dma_controller *controller;
 376         struct platform_device *pdev = to_platform_device(musb->controller);
 377         struct resource *iomem;
 378         int ret;
 379
 380         controller = kzalloc(sizeof(*controller), GFP_KERNEL);
 381         if (!controller)
 382                 goto kzalloc_fail;
 383
 384         controller->private_data = musb;
 385
 386         /* Save physical address for DMA controller. */
 387         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 388         if (!iomem) {
 389                 dev_err(musb->controller, "no memory resource defined\n");
 390                 goto plat_get_fail;
 391         }
 392
 393         controller->phy_base = (dma_addr_t) iomem->start;
 394
 395         controller->controller.channel_alloc = ux500_dma_channel_allocate;
 396         controller->controller.channel_release = ux500_dma_channel_release;
 397         controller->controller.channel_program = ux500_dma_channel_program;
 398         controller->controller.channel_abort = ux500_dma_channel_abort;
 399         controller->controller.is_compatible = ux500_dma_is_compatible;
 400
 401         ret = ux500_dma_controller_start(controller);
 402         if (ret)
 403                 goto plat_get_fail;
 404         return &controller->controller;
 405
 406 plat_get_fail:
 407         kfree(controller);
 408 kzalloc_fail:
 409         return NULL;
 410 }
 411 EXPORT_SYMBOL_GPL(ux500_dma_controller_create);