arch/frv/kernel/dma.c

   1 /* dma.c: DMA controller management on FR401 and the like
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/sched.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/errno.h>
  16 #include <linux/init.h>
  17 #include <asm/dma.h>
  18 #include <asm/gpio-regs.h>
  19 #include <asm/irc-regs.h>
  20 #include <asm/cpu-irqs.h>
  21
  22 struct frv_dma_channel {
  23         uint8_t                 flags;
  24 #define FRV_DMA_FLAGS_RESERVED  0x01
  25 #define FRV_DMA_FLAGS_INUSE     0x02
  26 #define FRV_DMA_FLAGS_PAUSED    0x04
  27         uint8_t                 cap;            /* capabilities available */
  28         int                     irq;            /* completion IRQ */
  29         uint32_t                dreqbit;
  30         uint32_t                dackbit;
  31         uint32_t                donebit;
  32         const unsigned long     ioaddr;         /* DMA controller regs addr */
  33         const char              *devname;
  34         dma_irq_handler_t       handler;
  35         void                    *data;
  36 };
  37
  38
  39 #define __get_DMAC(IO,X)        ({ *(volatile unsigned long *)((IO) + DMAC_##X##x); })
  40
  41 #define __set_DMAC(IO,X,V)                                      \
  42 do {                                                            \
  43         *(volatile unsigned long *)((IO) + DMAC_##X##x) = (V);  \
  44         mb();                                                   \
  45 } while(0)
  46
  47 #define ___set_DMAC(IO,X,V)                                     \
  48 do {                                                            \
  49         *(volatile unsigned long *)((IO) + DMAC_##X##x) = (V);  \
  50 } while(0)
  51
  52
  53 static struct frv_dma_channel frv_dma_channels[FRV_DMA_NCHANS] = {
  54         [0] = {
  55                 .cap            = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
  56                 .irq            = IRQ_CPU_DMA0,
  57                 .dreqbit        = SIR_DREQ0_INPUT,
  58                 .dackbit        = SOR_DACK0_OUTPUT,
  59                 .donebit        = SOR_DONE0_OUTPUT,
  60                 .ioaddr         = 0xfe000900,
  61         },
  62         [1] = {
  63                 .cap            = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
  64                 .irq            = IRQ_CPU_DMA1,
  65                 .dreqbit        = SIR_DREQ1_INPUT,
  66                 .dackbit        = SOR_DACK1_OUTPUT,
  67                 .donebit        = SOR_DONE1_OUTPUT,
  68                 .ioaddr         = 0xfe000980,
  69         },
  70         [2] = {
  71                 .cap            = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
  72                 .irq            = IRQ_CPU_DMA2,
  73                 .dreqbit        = SIR_DREQ2_INPUT,
  74                 .dackbit        = SOR_DACK2_OUTPUT,
  75                 .ioaddr         = 0xfe000a00,
  76         },
  77         [3] = {
  78                 .cap            = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
  79                 .irq            = IRQ_CPU_DMA3,
  80                 .dreqbit        = SIR_DREQ3_INPUT,
  81                 .dackbit        = SOR_DACK3_OUTPUT,
  82                 .ioaddr         = 0xfe000a80,
  83         },
  84         [4] = {
  85                 .cap            = FRV_DMA_CAP_DREQ,
  86                 .irq            = IRQ_CPU_DMA4,
  87                 .dreqbit        = SIR_DREQ4_INPUT,
  88                 .ioaddr         = 0xfe001000,
  89         },
  90         [5] = {
  91                 .cap            = FRV_DMA_CAP_DREQ,
  92                 .irq            = IRQ_CPU_DMA5,
  93                 .dreqbit        = SIR_DREQ5_INPUT,
  94                 .ioaddr         = 0xfe001080,
  95         },
  96         [6] = {
  97                 .cap            = FRV_DMA_CAP_DREQ,
  98                 .irq            = IRQ_CPU_DMA6,
  99                 .dreqbit        = SIR_DREQ6_INPUT,
 100                 .ioaddr         = 0xfe001100,
 101         },
 102         [7] = {
 103                 .cap            = FRV_DMA_CAP_DREQ,
 104                 .irq            = IRQ_CPU_DMA7,
 105                 .dreqbit        = SIR_DREQ7_INPUT,
 106                 .ioaddr         = 0xfe001180,
 107         },
 108 };
 109
 110 static DEFINE_RWLOCK(frv_dma_channels_lock);
 111
 112 unsigned int frv_dma_inprogress;
 113
 114 #define frv_clear_dma_inprogress(channel) \
 115         (void)__atomic32_fetch_and(~(1 << (channel)), &frv_dma_inprogress);
 116
 117 #define frv_set_dma_inprogress(channel) \
 118         (void)__atomic32_fetch_or(1 << (channel), &frv_dma_inprogress);
 119
 120 /*****************************************************************************/
 121 /*
 122  * DMA irq handler - determine channel involved, grab status and call real handler
 123  */
 124 static irqreturn_t dma_irq_handler(int irq, void *_channel)
 125 {
 126         struct frv_dma_channel *channel = _channel;
 127
 128         frv_clear_dma_inprogress(channel - frv_dma_channels);
 129         return channel->handler(channel - frv_dma_channels,
 130                                 __get_DMAC(channel->ioaddr, CSTR),
 131                                 channel->data);
 132
 133 } /* end dma_irq_handler() */
 134
 135 /*****************************************************************************/
 136 /*
 137  * Determine which DMA controllers are present on this CPU
 138  */
 139 void __init frv_dma_init(void)
 140 {
 141         unsigned long psr = __get_PSR();
 142         int num_dma, i;
 143
 144         /* First, determine how many DMA channels are available */
 145         switch (PSR_IMPLE(psr)) {
 146         case PSR_IMPLE_FR405:
 147         case PSR_IMPLE_FR451:
 148         case PSR_IMPLE_FR501:
 149         case PSR_IMPLE_FR551:
 150                 num_dma = FRV_DMA_8CHANS;
 151                 break;
 152
 153         case PSR_IMPLE_FR401:
 154         default:
 155                 num_dma = FRV_DMA_4CHANS;
 156                 break;
 157         }
 158
 159         /* Now mark all of the non-existent channels as reserved */
 160         for(i = num_dma; i < FRV_DMA_NCHANS; i++)
 161                 frv_dma_channels[i].flags = FRV_DMA_FLAGS_RESERVED;
 162
 163 } /* end frv_dma_init() */
 164
 165 /*****************************************************************************/
 166 /*
 167  * allocate a DMA controller channel and the IRQ associated with it
 168  */
 169 int frv_dma_open(const char *devname,
 170                  unsigned long dmamask,
 171                  int dmacap,
 172                  dma_irq_handler_t handler,
 173                  unsigned long irq_flags,
 174                  void *data)
 175 {
 176         struct frv_dma_channel *channel;
 177         int dma, ret;
 178         uint32_t val;
 179
 180         write_lock(&frv_dma_channels_lock);
 181
 182         ret = -ENOSPC;
 183
 184         for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
 185                 channel = &frv_dma_channels[dma];
 186
 187                 if (!test_bit(dma, &dmamask))
 188                         continue;
 189
 190                 if ((channel->cap & dmacap) != dmacap)
 191                         continue;
 192
 193                 if (!frv_dma_channels[dma].flags)
 194                         goto found;
 195         }
 196
 197         goto out;
 198
 199  found:
 200         ret = request_irq(channel->irq, dma_irq_handler, irq_flags, devname, channel);
 201         if (ret < 0)
 202                 goto out;
 203
 204         /* okay, we've allocated all the resources */
 205         channel = &frv_dma_channels[dma];
 206
 207         channel->flags          |= FRV_DMA_FLAGS_INUSE;
 208         channel->devname        = devname;
 209         channel->handler        = handler;
 210         channel->data           = data;
 211
 212         /* Now make sure we are set up for DMA and not GPIO */
 213         /* SIR bit must be set for DMA to work */
 214         __set_SIR(channel->dreqbit | __get_SIR());
 215         /* SOR bits depend on what the caller requests */
 216         val = __get_SOR();
 217         if(dmacap & FRV_DMA_CAP_DACK)
 218                 val |= channel->dackbit;
 219         else
 220                 val &= ~channel->dackbit;
 221         if(dmacap & FRV_DMA_CAP_DONE)
 222                 val |= channel->donebit;
 223         else
 224                 val &= ~channel->donebit;
 225         __set_SOR(val);
 226
 227         ret = dma;
 228  out:
 229         write_unlock(&frv_dma_channels_lock);
 230         return ret;
 231 } /* end frv_dma_open() */
 232
 233 EXPORT_SYMBOL(frv_dma_open);
 234
 235 /*****************************************************************************/
 236 /*
 237  * close a DMA channel and its associated interrupt
 238  */
 239 void frv_dma_close(int dma)
 240 {
 241         struct frv_dma_channel *channel = &frv_dma_channels[dma];
 242         unsigned long flags;
 243
 244         write_lock_irqsave(&frv_dma_channels_lock, flags);
 245
 246         free_irq(channel->irq, channel);
 247         frv_dma_stop(dma);
 248
 249         channel->flags &= ~FRV_DMA_FLAGS_INUSE;
 250
 251         write_unlock_irqrestore(&frv_dma_channels_lock, flags);
 252 } /* end frv_dma_close() */
 253
 254 EXPORT_SYMBOL(frv_dma_close);
 255
 256 /*****************************************************************************/
 257 /*
 258  * set static configuration on a DMA channel
 259  */
 260 void frv_dma_config(int dma, unsigned long ccfr, unsigned long cctr, unsigned long apr)
 261 {
 262         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 263
 264         ___set_DMAC(ioaddr, CCFR, ccfr);
 265         ___set_DMAC(ioaddr, CCTR, cctr);
 266         ___set_DMAC(ioaddr, APR,  apr);
 267         mb();
 268
 269 } /* end frv_dma_config() */
 270
 271 EXPORT_SYMBOL(frv_dma_config);
 272
 273 /*****************************************************************************/
 274 /*
 275  * start a DMA channel
 276  */
 277 void frv_dma_start(int dma,
 278                    unsigned long sba, unsigned long dba,
 279                    unsigned long pix, unsigned long six, unsigned long bcl)
 280 {
 281         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 282
 283         ___set_DMAC(ioaddr, SBA,  sba);
 284         ___set_DMAC(ioaddr, DBA,  dba);
 285         ___set_DMAC(ioaddr, PIX,  pix);
 286         ___set_DMAC(ioaddr, SIX,  six);
 287         ___set_DMAC(ioaddr, BCL,  bcl);
 288         ___set_DMAC(ioaddr, CSTR, 0);
 289         mb();
 290
 291         __set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
 292         frv_set_dma_inprogress(dma);
 293
 294 } /* end frv_dma_start() */
 295
 296 EXPORT_SYMBOL(frv_dma_start);
 297
 298 /*****************************************************************************/
 299 /*
 300  * restart a DMA channel that's been stopped in circular addressing mode by comparison-end
 301  */
 302 void frv_dma_restart_circular(int dma, unsigned long six)
 303 {
 304         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 305
 306         ___set_DMAC(ioaddr, SIX,  six);
 307         ___set_DMAC(ioaddr, CSTR, __get_DMAC(ioaddr, CSTR) & ~DMAC_CSTRx_CE);
 308         mb();
 309
 310         __set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
 311         frv_set_dma_inprogress(dma);
 312
 313 } /* end frv_dma_restart_circular() */
 314
 315 EXPORT_SYMBOL(frv_dma_restart_circular);
 316
 317 /*****************************************************************************/
 318 /*
 319  * stop a DMA channel
 320  */
 321 void frv_dma_stop(int dma)
 322 {
 323         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 324         uint32_t cctr;
 325
 326         ___set_DMAC(ioaddr, CSTR, 0);
 327         cctr = __get_DMAC(ioaddr, CCTR);
 328         cctr &= ~(DMAC_CCTRx_IE | DMAC_CCTRx_ACT);
 329         cctr |= DMAC_CCTRx_FC;  /* fifo clear */
 330         __set_DMAC(ioaddr, CCTR, cctr);
 331         __set_DMAC(ioaddr, BCL,  0);
 332         frv_clear_dma_inprogress(dma);
 333 } /* end frv_dma_stop() */
 334
 335 EXPORT_SYMBOL(frv_dma_stop);
 336
 337 /*****************************************************************************/
 338 /*
 339  * test interrupt status of DMA channel
 340  */
 341 int is_frv_dma_interrupting(int dma)
 342 {
 343         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 344
 345         return __get_DMAC(ioaddr, CSTR) & (1 << 23);
 346
 347 } /* end is_frv_dma_interrupting() */
 348
 349 EXPORT_SYMBOL(is_frv_dma_interrupting);
 350
 351 /*****************************************************************************/
 352 /*
 353  * dump data about a DMA channel
 354  */
 355 void frv_dma_dump(int dma)
 356 {
 357         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 358         unsigned long cstr, pix, six, bcl;
 359
 360         cstr = __get_DMAC(ioaddr, CSTR);
 361         pix  = __get_DMAC(ioaddr, PIX);
 362         six  = __get_DMAC(ioaddr, SIX);
 363         bcl  = __get_DMAC(ioaddr, BCL);
 364
 365         printk("DMA[%d] cstr=%lx pix=%lx six=%lx bcl=%lx\n", dma, cstr, pix, six, bcl);
 366
 367 } /* end frv_dma_dump() */
 368
 369 EXPORT_SYMBOL(frv_dma_dump);
 370
 371 /*****************************************************************************/
 372 /*
 373  * pause all DMA controllers
 374  * - called by clock mangling routines
 375  * - caller must be holding interrupts disabled
 376  */
 377 void frv_dma_pause_all(void)
 378 {
 379         struct frv_dma_channel *channel;
 380         unsigned long ioaddr;
 381         unsigned long cstr, cctr;
 382         int dma;
 383
 384         write_lock(&frv_dma_channels_lock);
 385
 386         for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
 387                 channel = &frv_dma_channels[dma];
 388
 389                 if (!(channel->flags & FRV_DMA_FLAGS_INUSE))
 390                         continue;
 391
 392                 ioaddr = channel->ioaddr;
 393                 cctr = __get_DMAC(ioaddr, CCTR);
 394                 if (cctr & DMAC_CCTRx_ACT) {
 395                         cctr &= ~DMAC_CCTRx_ACT;
 396                         __set_DMAC(ioaddr, CCTR, cctr);
 397
 398                         do {
 399                                 cstr = __get_DMAC(ioaddr, CSTR);
 400                         } while (cstr & DMAC_CSTRx_BUSY);
 401
 402                         if (cstr & DMAC_CSTRx_FED)
 403                                 channel->flags |= FRV_DMA_FLAGS_PAUSED;
 404                         frv_clear_dma_inprogress(dma);
 405                 }
 406         }
 407
 408 } /* end frv_dma_pause_all() */
 409
 410 EXPORT_SYMBOL(frv_dma_pause_all);
 411
 412 /*****************************************************************************/
 413 /*
 414  * resume paused DMA controllers
 415  * - called by clock mangling routines
 416  * - caller must be holding interrupts disabled
 417  */
 418 void frv_dma_resume_all(void)
 419 {
 420         struct frv_dma_channel *channel;
 421         unsigned long ioaddr;
 422         unsigned long cstr, cctr;
 423         int dma;
 424
 425         for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
 426                 channel = &frv_dma_channels[dma];
 427
 428                 if (!(channel->flags & FRV_DMA_FLAGS_PAUSED))
 429                         continue;
 430
 431                 ioaddr = channel->ioaddr;
 432                 cstr = __get_DMAC(ioaddr, CSTR);
 433                 cstr &= ~(DMAC_CSTRx_FED | DMAC_CSTRx_INT);
 434                 __set_DMAC(ioaddr, CSTR, cstr);
 435
 436                 cctr = __get_DMAC(ioaddr, CCTR);
 437                 cctr |= DMAC_CCTRx_ACT;
 438                 __set_DMAC(ioaddr, CCTR, cctr);
 439
 440                 channel->flags &= ~FRV_DMA_FLAGS_PAUSED;
 441                 frv_set_dma_inprogress(dma);
 442         }
 443
 444         write_unlock(&frv_dma_channels_lock);
 445
 446 } /* end frv_dma_resume_all() */
 447
 448 EXPORT_SYMBOL(frv_dma_resume_all);
 449
 450 /*****************************************************************************/
 451 /*
 452  * dma status clear
 453  */
 454 void frv_dma_status_clear(int dma)
 455 {
 456         unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
 457         uint32_t cctr;
 458         ___set_DMAC(ioaddr, CSTR, 0);
 459
 460         cctr = __get_DMAC(ioaddr, CCTR);
 461 } /* end frv_dma_status_clear() */
 462
 463 EXPORT_SYMBOL(frv_dma_status_clear);