arch/arm/plat-stmp3xxx/dma.c

   1 /*
   2  * DMA helper routines for Freescale STMP37XX/STMP378X
   3  *
   4  * Author: dmitry pervushin <dpervushin@embeddedalley.com>
   5  *
   6  * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
   7  * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
   8  */
   9
  10 /*
  11  * The code contained herein is licensed under the GNU General Public
  12  * License. You may obtain a copy of the GNU General Public License
  13  * Version 2 or later at the following locations:
  14  *
  15  * http://www.opensource.org/licenses/gpl-license.html
  16  * http://www.gnu.org/copyleft/gpl.html
  17  */
  18 #include <linux/gfp.h>
  19 #include <linux/kernel.h>
  20 #include <linux/device.h>
  21 #include <linux/dmapool.h>
  22 #include <linux/sysdev.h>
  23 #include <linux/cpufreq.h>
  24
  25 #include <asm/page.h>
  26
  27 #include <mach/platform.h>
  28 #include <mach/dma.h>
  29 #include <mach/regs-apbx.h>
  30 #include <mach/regs-apbh.h>
  31
  32 static const size_t pool_item_size = sizeof(struct stmp3xxx_dma_command);
  33 static const size_t pool_alignment = 8;
  34 static struct stmp3xxx_dma_user {
  35         void *pool;
  36         int inuse;
  37         const char *name;
  38 } channels[MAX_DMA_CHANNELS];
  39
  40 #define IS_VALID_CHANNEL(ch) ((ch) >= 0 && (ch) < MAX_DMA_CHANNELS)
  41 #define IS_USED(ch) (channels[ch].inuse)
  42
  43 int stmp3xxx_dma_request(int ch, struct device *dev, const char *name)
  44 {
  45         struct stmp3xxx_dma_user *user;
  46         int err = 0;
  47
  48         user = channels + ch;
  49         if (!IS_VALID_CHANNEL(ch)) {
  50                 err = -ENODEV;
  51                 goto out;
  52         }
  53         if (IS_USED(ch)) {
  54                 err = -EBUSY;
  55                 goto out;
  56         }
  57         /* Create a pool to allocate dma commands from */
  58         user->pool = dma_pool_create(name, dev, pool_item_size,
  59                                      pool_alignment, PAGE_SIZE);
  60         if (user->pool == NULL) {
  61                 err = -ENOMEM;
  62                 goto out;
  63         }
  64         user->name = name;
  65         user->inuse++;
  66 out:
  67         return err;
  68 }
  69 EXPORT_SYMBOL(stmp3xxx_dma_request);
  70
  71 int stmp3xxx_dma_release(int ch)
  72 {
  73         struct stmp3xxx_dma_user *user = channels + ch;
  74         int err = 0;
  75
  76         if (!IS_VALID_CHANNEL(ch)) {
  77                 err = -ENODEV;
  78                 goto out;
  79         }
  80         if (!IS_USED(ch)) {
  81                 err = -EBUSY;
  82                 goto out;
  83         }
  84         BUG_ON(user->pool == NULL);
  85         dma_pool_destroy(user->pool);
  86         user->inuse--;
  87 out:
  88         return err;
  89 }
  90 EXPORT_SYMBOL(stmp3xxx_dma_release);
  91
  92 int stmp3xxx_dma_read_semaphore(int channel)
  93 {
  94         int sem = -1;
  95
  96         switch (STMP3XXX_DMA_BUS(channel)) {
  97         case STMP3XXX_BUS_APBH:
  98                 sem = __raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA +
  99                                 STMP3XXX_DMA_CHANNEL(channel) * 0x70);
 100                 sem &= BM_APBH_CHn_SEMA_PHORE;
 101                 sem >>= BP_APBH_CHn_SEMA_PHORE;
 102                 break;
 103
 104         case STMP3XXX_BUS_APBX:
 105                 sem = __raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA +
 106                                 STMP3XXX_DMA_CHANNEL(channel) * 0x70);
 107                 sem &= BM_APBX_CHn_SEMA_PHORE;
 108                 sem >>= BP_APBX_CHn_SEMA_PHORE;
 109                 break;
 110         default:
 111                 BUG();
 112         }
 113         return sem;
 114 }
 115 EXPORT_SYMBOL(stmp3xxx_dma_read_semaphore);
 116
 117 int stmp3xxx_dma_allocate_command(int channel,
 118                                   struct stmp3xxx_dma_descriptor *descriptor)
 119 {
 120         struct stmp3xxx_dma_user *user = channels + channel;
 121         int err = 0;
 122
 123         if (!IS_VALID_CHANNEL(channel)) {
 124                 err = -ENODEV;
 125                 goto out;
 126         }
 127         if (!IS_USED(channel)) {
 128                 err = -EBUSY;
 129                 goto out;
 130         }
 131         if (descriptor == NULL) {
 132                 err = -EINVAL;
 133                 goto out;
 134         }
 135
 136         /* Allocate memory for a command from the buffer */
 137         descriptor->command =
 138             dma_pool_alloc(user->pool, GFP_KERNEL, &descriptor->handle);
 139
 140         /* Check it worked */
 141         if (!descriptor->command) {
 142                 err = -ENOMEM;
 143                 goto out;
 144         }
 145
 146         memset(descriptor->command, 0, pool_item_size);
 147 out:
 148         WARN_ON(err);
 149         return err;
 150 }
 151 EXPORT_SYMBOL(stmp3xxx_dma_allocate_command);
 152
 153 int stmp3xxx_dma_free_command(int channel,
 154                               struct stmp3xxx_dma_descriptor *descriptor)
 155 {
 156         int err = 0;
 157
 158         if (!IS_VALID_CHANNEL(channel)) {
 159                 err = -ENODEV;
 160                 goto out;
 161         }
 162         if (!IS_USED(channel)) {
 163                 err = -EBUSY;
 164                 goto out;
 165         }
 166
 167         /* Return the command memory to the pool */
 168         dma_pool_free(channels[channel].pool, descriptor->command,
 169                       descriptor->handle);
 170
 171         /* Initialise descriptor so we're not tempted to use it */
 172         descriptor->command = NULL;
 173         descriptor->handle = 0;
 174         descriptor->virtual_buf_ptr = NULL;
 175         descriptor->next_descr = NULL;
 176
 177         WARN_ON(err);
 178 out:
 179         return err;
 180 }
 181 EXPORT_SYMBOL(stmp3xxx_dma_free_command);
 182
 183 void stmp3xxx_dma_go(int channel,
 184                      struct stmp3xxx_dma_descriptor *head, u32 semaphore)
 185 {
 186         int ch = STMP3XXX_DMA_CHANNEL(channel);
 187         void __iomem *c, *s;
 188
 189         switch (STMP3XXX_DMA_BUS(channel)) {
 190         case STMP3XXX_BUS_APBH:
 191                 c = REGS_APBH_BASE + HW_APBH_CHn_NXTCMDAR + 0x70 * ch;
 192                 s = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * ch;
 193                 break;
 194
 195         case STMP3XXX_BUS_APBX:
 196                 c = REGS_APBX_BASE + HW_APBX_CHn_NXTCMDAR + 0x70 * ch;
 197                 s = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * ch;
 198                 break;
 199
 200         default:
 201                 return;
 202         }
 203
 204         /* Set next command */
 205         __raw_writel(head->handle, c);
 206         /* Set counting semaphore (kicks off transfer). Assumes
 207            peripheral has been set up correctly */
 208         __raw_writel(semaphore, s);
 209 }
 210 EXPORT_SYMBOL(stmp3xxx_dma_go);
 211
 212 int stmp3xxx_dma_running(int channel)
 213 {
 214         switch (STMP3XXX_DMA_BUS(channel)) {
 215         case STMP3XXX_BUS_APBH:
 216                 return (__raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA +
 217                         0x70 * STMP3XXX_DMA_CHANNEL(channel))) &
 218                             BM_APBH_CHn_SEMA_PHORE;
 219
 220         case STMP3XXX_BUS_APBX:
 221                 return (__raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA +
 222                         0x70 * STMP3XXX_DMA_CHANNEL(channel))) &
 223                             BM_APBX_CHn_SEMA_PHORE;
 224         default:
 225                 BUG();
 226                 return 0;
 227         }
 228 }
 229 EXPORT_SYMBOL(stmp3xxx_dma_running);
 230
 231 /*
 232  * Circular dma chain management
 233  */
 234 void stmp3xxx_dma_free_chain(struct stmp37xx_circ_dma_chain *chain)
 235 {
 236         int i;
 237
 238         for (i = 0; i < chain->total_count; i++)
 239                 stmp3xxx_dma_free_command(
 240                         STMP3XXX_DMA(chain->channel, chain->bus),
 241                         &chain->chain[i]);
 242 }
 243 EXPORT_SYMBOL(stmp3xxx_dma_free_chain);
 244
 245 int stmp3xxx_dma_make_chain(int ch, struct stmp37xx_circ_dma_chain *chain,
 246                             struct stmp3xxx_dma_descriptor descriptors[],
 247                             unsigned items)
 248 {
 249         int i;
 250         int err = 0;
 251
 252         if (items == 0)
 253                 return err;
 254
 255         for (i = 0; i < items; i++) {
 256                 err = stmp3xxx_dma_allocate_command(ch, &descriptors[i]);
 257                 if (err) {
 258                         WARN_ON(err);
 259                         /*
 260                          * Couldn't allocate the whole chain.
 261                          * deallocate what has been allocated
 262                          */
 263                         if (i) {
 264                                 do {
 265                                         stmp3xxx_dma_free_command(ch,
 266                                                                   &descriptors
 267                                                                   [i]);
 268                                 } while (i-- > 0);
 269                         }
 270                         return err;
 271                 }
 272
 273                 /* link them! */
 274                 if (i > 0) {
 275                         descriptors[i - 1].next_descr = &descriptors[i];
 276                         descriptors[i - 1].command->next =
 277                                                 descriptors[i].handle;
 278                 }
 279         }
 280
 281         /* make list circular */
 282         descriptors[items - 1].next_descr = &descriptors[0];
 283         descriptors[items - 1].command->next = descriptors[0].handle;
 284
 285         chain->total_count = items;
 286         chain->chain = descriptors;
 287         chain->free_index = 0;
 288         chain->active_index = 0;
 289         chain->cooked_index = 0;
 290         chain->free_count = items;
 291         chain->active_count = 0;
 292         chain->cooked_count = 0;
 293         chain->bus = STMP3XXX_DMA_BUS(ch);
 294         chain->channel = STMP3XXX_DMA_CHANNEL(ch);
 295         return err;
 296 }
 297 EXPORT_SYMBOL(stmp3xxx_dma_make_chain);
 298
 299 void stmp37xx_circ_clear_chain(struct stmp37xx_circ_dma_chain *chain)
 300 {
 301         BUG_ON(stmp3xxx_dma_running(STMP3XXX_DMA(chain->channel, chain->bus)));
 302         chain->free_index = 0;
 303         chain->active_index = 0;
 304         chain->cooked_index = 0;
 305         chain->free_count = chain->total_count;
 306         chain->active_count = 0;
 307         chain->cooked_count = 0;
 308 }
 309 EXPORT_SYMBOL(stmp37xx_circ_clear_chain);
 310
 311 void stmp37xx_circ_advance_free(struct stmp37xx_circ_dma_chain *chain,
 312                 unsigned count)
 313 {
 314         BUG_ON(chain->cooked_count < count);
 315
 316         chain->cooked_count -= count;
 317         chain->cooked_index += count;
 318         chain->cooked_index %= chain->total_count;
 319         chain->free_count += count;
 320 }
 321 EXPORT_SYMBOL(stmp37xx_circ_advance_free);
 322
 323 void stmp37xx_circ_advance_active(struct stmp37xx_circ_dma_chain *chain,
 324                 unsigned count)
 325 {
 326         void __iomem *c;
 327         u32 mask_clr, mask;
 328         BUG_ON(chain->free_count < count);
 329
 330         chain->free_count -= count;
 331         chain->free_index += count;
 332         chain->free_index %= chain->total_count;
 333         chain->active_count += count;
 334
 335         switch (chain->bus) {
 336         case STMP3XXX_BUS_APBH:
 337                 c = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * chain->channel;
 338                 mask_clr = BM_APBH_CHn_SEMA_INCREMENT_SEMA;
 339                 mask = BF(count, APBH_CHn_SEMA_INCREMENT_SEMA);
 340                 break;
 341         case STMP3XXX_BUS_APBX:
 342                 c = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * chain->channel;
 343                 mask_clr = BM_APBX_CHn_SEMA_INCREMENT_SEMA;
 344                 mask = BF(count, APBX_CHn_SEMA_INCREMENT_SEMA);
 345                 break;
 346         default:
 347                 BUG();
 348                 return;
 349         }
 350
 351         /* Set counting semaphore (kicks off transfer). Assumes
 352            peripheral has been set up correctly */
 353         stmp3xxx_clearl(mask_clr, c);
 354         stmp3xxx_setl(mask, c);
 355 }
 356 EXPORT_SYMBOL(stmp37xx_circ_advance_active);
 357
 358 unsigned stmp37xx_circ_advance_cooked(struct stmp37xx_circ_dma_chain *chain)
 359 {
 360         unsigned cooked;
 361
 362         cooked = chain->active_count -
 363           stmp3xxx_dma_read_semaphore(STMP3XXX_DMA(chain->channel, chain->bus));
 364
 365         chain->active_count -= cooked;
 366         chain->active_index += cooked;
 367         chain->active_index %= chain->total_count;
 368
 369         chain->cooked_count += cooked;
 370
 371         return cooked;
 372 }
 373 EXPORT_SYMBOL(stmp37xx_circ_advance_cooked);
 374
 375 void stmp3xxx_dma_set_alt_target(int channel, int function)
 376 {
 377 #if defined(CONFIG_ARCH_STMP37XX)
 378         unsigned bits = 4;
 379 #elif defined(CONFIG_ARCH_STMP378X)
 380         unsigned bits = 2;
 381 #else
 382 #error wrong arch
 383 #endif
 384         int shift = STMP3XXX_DMA_CHANNEL(channel) * bits;
 385         unsigned mask = (1<<bits) - 1;
 386         void __iomem *c;
 387
 388         BUG_ON(function < 0 || function >= (1<<bits));
 389         pr_debug("%s: channel = %d, using mask %x, "
 390                  "shift = %d\n", __func__, channel, mask, shift);
 391
 392         switch (STMP3XXX_DMA_BUS(channel)) {
 393         case STMP3XXX_BUS_APBH:
 394                 c = REGS_APBH_BASE + HW_APBH_DEVSEL;
 395                 break;
 396         case STMP3XXX_BUS_APBX:
 397                 c = REGS_APBX_BASE + HW_APBX_DEVSEL;
 398                 break;
 399         default:
 400                 BUG();
 401         }
 402         stmp3xxx_clearl(mask << shift, c);
 403         stmp3xxx_setl(mask << shift, c);
 404 }
 405 EXPORT_SYMBOL(stmp3xxx_dma_set_alt_target);
 406
 407 void stmp3xxx_dma_suspend(void)
 408 {
 409         stmp3xxx_setl(BM_APBH_CTRL0_CLKGATE, REGS_APBH_BASE + HW_APBH_CTRL0);
 410         stmp3xxx_setl(BM_APBX_CTRL0_CLKGATE, REGS_APBX_BASE + HW_APBX_CTRL0);
 411 }
 412
 413 void stmp3xxx_dma_resume(void)
 414 {
 415         stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST,
 416                         REGS_APBH_BASE + HW_APBH_CTRL0);
 417         stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST,
 418                         REGS_APBX_BASE + HW_APBX_CTRL0);
 419 }
 420
 421 #ifdef CONFIG_CPU_FREQ
 422
 423 struct dma_notifier_block {
 424         struct notifier_block nb;
 425         void *data;
 426 };
 427
 428 static int dma_cpufreq_notifier(struct notifier_block *self,
 429                                 unsigned long phase, void *p)
 430 {
 431         switch (phase) {
 432         case CPUFREQ_POSTCHANGE:
 433                 stmp3xxx_dma_resume();
 434                 break;
 435
 436         case CPUFREQ_PRECHANGE:
 437                 stmp3xxx_dma_suspend();
 438                 break;
 439
 440         default:
 441                 break;
 442         }
 443
 444         return NOTIFY_DONE;
 445 }
 446
 447 static struct dma_notifier_block dma_cpufreq_nb = {
 448         .nb = {
 449                 .notifier_call = dma_cpufreq_notifier,
 450         },
 451 };
 452 #endif /* CONFIG_CPU_FREQ */
 453
 454 void __init stmp3xxx_dma_init(void)
 455 {
 456         stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST,
 457                         REGS_APBH_BASE + HW_APBH_CTRL0);
 458         stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST,
 459                         REGS_APBX_BASE + HW_APBX_CTRL0);
 460 #ifdef CONFIG_CPU_FREQ
 461         cpufreq_register_notifier(&dma_cpufreq_nb.nb,
 462                                 CPUFREQ_TRANSITION_NOTIFIER);
 463 #endif /* CONFIG_CPU_FREQ */
 464 }