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