arch/sh/drivers/dma/dma-sh.c

   1 /*
   2  * arch/sh/drivers/dma/dma-sh.c
   3  *
   4  * SuperH On-chip DMAC Support
   5  *
   6  * Copyright (C) 2000 Takashi YOSHII
   7  * Copyright (C) 2003, 2004 Paul Mundt
   8  * Copyright (C) 2005 Andriy Skulysh
   9  *
  10  * This file is subject to the terms and conditions of the GNU General Public
  11  * License.  See the file "COPYING" in the main directory of this archive
  12  * for more details.
  13  */
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/io.h>
  18 #include <mach-dreamcast/mach/dma.h>
  19 #include <asm/dma.h>
  20 #include <asm/dma-register.h>
  21 #include <cpu/dma-register.h>
  22 #include <cpu/dma.h>
  23
  24 /*
  25  * Define the default configuration for dual address memory-memory transfer.
  26  * The 0x400 value represents auto-request, external->external.
  27  */
  28 #define RS_DUAL (DM_INC | SM_INC | RS_AUTO | TS_INDEX2VAL(XMIT_SZ_32BIT))
  29
  30 static unsigned long dma_find_base(unsigned int chan)
  31 {
  32         unsigned long base = SH_DMAC_BASE0;
  33
  34 #ifdef SH_DMAC_BASE1
  35         if (chan >= 6)
  36                 base = SH_DMAC_BASE1;
  37 #endif
  38
  39         return base;
  40 }
  41
  42 static unsigned long dma_base_addr(unsigned int chan)
  43 {
  44         unsigned long base = dma_find_base(chan);
  45
  46         /* Normalize offset calculation */
  47         if (chan >= 9)
  48                 chan -= 6;
  49         if (chan >= 4)
  50                 base += 0x10;
  51
  52         return base + (chan * 0x10);
  53 }
  54
  55 #ifdef CONFIG_SH_DMA_IRQ_MULTI
  56 static inline unsigned int get_dmte_irq(unsigned int chan)
  57 {
  58         return chan >= 6 ? DMTE6_IRQ : DMTE0_IRQ;
  59 }
  60 #else
  61
  62 static unsigned int dmte_irq_map[] = {
  63         DMTE0_IRQ, DMTE0_IRQ + 1, DMTE0_IRQ + 2, DMTE0_IRQ + 3,
  64
  65 #ifdef DMTE4_IRQ
  66         DMTE4_IRQ, DMTE4_IRQ + 1,
  67 #endif
  68
  69 #ifdef DMTE6_IRQ
  70         DMTE6_IRQ, DMTE6_IRQ + 1,
  71 #endif
  72
  73 #ifdef DMTE8_IRQ
  74         DMTE8_IRQ, DMTE9_IRQ, DMTE10_IRQ, DMTE11_IRQ,
  75 #endif
  76 };
  77
  78 static inline unsigned int get_dmte_irq(unsigned int chan)
  79 {
  80         return dmte_irq_map[chan];
  81 }
  82 #endif
  83
  84 /*
  85  * We determine the correct shift size based off of the CHCR transmit size
  86  * for the given channel. Since we know that it will take:
  87  *
  88  *      info->count >> ts_shift[transmit_size]
  89  *
  90  * iterations to complete the transfer.
  91  */
  92 static unsigned int ts_shift[] = TS_SHIFT;
  93
  94 static inline unsigned int calc_xmit_shift(struct dma_channel *chan)
  95 {
  96         u32 chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
  97         int cnt = ((chcr & CHCR_TS_LOW_MASK) >> CHCR_TS_LOW_SHIFT) |
  98                 ((chcr & CHCR_TS_HIGH_MASK) >> CHCR_TS_HIGH_SHIFT);
  99
 100         return ts_shift[cnt];
 101 }
 102
 103 /*
 104  * The transfer end interrupt must read the chcr register to end the
 105  * hardware interrupt active condition.
 106  * Besides that it needs to waken any waiting process, which should handle
 107  * setting up the next transfer.
 108  */
 109 static irqreturn_t dma_tei(int irq, void *dev_id)
 110 {
 111         struct dma_channel *chan = dev_id;
 112         u32 chcr;
 113
 114         chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
 115
 116         if (!(chcr & CHCR_TE))
 117                 return IRQ_NONE;
 118
 119         chcr &= ~(CHCR_IE | CHCR_DE);
 120         __raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
 121
 122         wake_up(&chan->wait_queue);
 123
 124         return IRQ_HANDLED;
 125 }
 126
 127 static int sh_dmac_request_dma(struct dma_channel *chan)
 128 {
 129         if (unlikely(!(chan->flags & DMA_TEI_CAPABLE)))
 130                 return 0;
 131
 132         return request_irq(get_dmte_irq(chan->chan), dma_tei, IRQF_SHARED,
 133                            chan->dev_id, chan);
 134 }
 135
 136 static void sh_dmac_free_dma(struct dma_channel *chan)
 137 {
 138         free_irq(get_dmte_irq(chan->chan), chan);
 139 }
 140
 141 static int
 142 sh_dmac_configure_channel(struct dma_channel *chan, unsigned long chcr)
 143 {
 144         if (!chcr)
 145                 chcr = RS_DUAL | CHCR_IE;
 146
 147         if (chcr & CHCR_IE) {
 148                 chcr &= ~CHCR_IE;
 149                 chan->flags |= DMA_TEI_CAPABLE;
 150         } else {
 151                 chan->flags &= ~DMA_TEI_CAPABLE;
 152         }
 153
 154         __raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
 155
 156         chan->flags |= DMA_CONFIGURED;
 157         return 0;
 158 }
 159
 160 static void sh_dmac_enable_dma(struct dma_channel *chan)
 161 {
 162         int irq;
 163         u32 chcr;
 164
 165         chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
 166         chcr |= CHCR_DE;
 167
 168         if (chan->flags & DMA_TEI_CAPABLE)
 169                 chcr |= CHCR_IE;
 170
 171         __raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
 172
 173         if (chan->flags & DMA_TEI_CAPABLE) {
 174                 irq = get_dmte_irq(chan->chan);
 175                 enable_irq(irq);
 176         }
 177 }
 178
 179 static void sh_dmac_disable_dma(struct dma_channel *chan)
 180 {
 181         int irq;
 182         u32 chcr;
 183
 184         if (chan->flags & DMA_TEI_CAPABLE) {
 185                 irq = get_dmte_irq(chan->chan);
 186                 disable_irq(irq);
 187         }
 188
 189         chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
 190         chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
 191         __raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
 192 }
 193
 194 static int sh_dmac_xfer_dma(struct dma_channel *chan)
 195 {
 196         /*
 197          * If we haven't pre-configured the channel with special flags, use
 198          * the defaults.
 199          */
 200         if (unlikely(!(chan->flags & DMA_CONFIGURED)))
 201                 sh_dmac_configure_channel(chan, 0);
 202
 203         sh_dmac_disable_dma(chan);
 204
 205         /*
 206          * Single-address mode usage note!
 207          *
 208          * It's important that we don't accidentally write any value to SAR/DAR
 209          * (this includes 0) that hasn't been directly specified by the user if
 210          * we're in single-address mode.
 211          *
 212          * In this case, only one address can be defined, anything else will
 213          * result in a DMA address error interrupt (at least on the SH-4),
 214          * which will subsequently halt the transfer.
 215          *
 216          * Channel 2 on the Dreamcast is a special case, as this is used for
 217          * cascading to the PVR2 DMAC. In this case, we still need to write
 218          * SAR and DAR, regardless of value, in order for cascading to work.
 219          */
 220         if (chan->sar || (mach_is_dreamcast() &&
 221                           chan->chan == PVR2_CASCADE_CHAN))
 222                 __raw_writel(chan->sar, (dma_base_addr(chan->chan) + SAR));
 223         if (chan->dar || (mach_is_dreamcast() &&
 224                           chan->chan == PVR2_CASCADE_CHAN))
 225                 __raw_writel(chan->dar, (dma_base_addr(chan->chan) + DAR));
 226
 227         __raw_writel(chan->count >> calc_xmit_shift(chan),
 228                 (dma_base_addr(chan->chan) + TCR));
 229
 230         sh_dmac_enable_dma(chan);
 231
 232         return 0;
 233 }
 234
 235 static int sh_dmac_get_dma_residue(struct dma_channel *chan)
 236 {
 237         if (!(__raw_readl(dma_base_addr(chan->chan) + CHCR) & CHCR_DE))
 238                 return 0;
 239
 240         return __raw_readl(dma_base_addr(chan->chan) + TCR)
 241                  << calc_xmit_shift(chan);
 242 }
 243
 244 /*
 245  * DMAOR handling
 246  */
 247 #if defined(CONFIG_CPU_SUBTYPE_SH7723)  || \
 248     defined(CONFIG_CPU_SUBTYPE_SH7724)  || \
 249     defined(CONFIG_CPU_SUBTYPE_SH7780)  || \
 250     defined(CONFIG_CPU_SUBTYPE_SH7785)
 251 #define NR_DMAOR        2
 252 #else
 253 #define NR_DMAOR        1
 254 #endif
 255
 256 /*
 257  * DMAOR bases are broken out amongst channel groups. DMAOR0 manages
 258  * channels 0 - 5, DMAOR1 6 - 11 (optional).
 259  */
 260 #define dmaor_read_reg(n)               __raw_readw(dma_find_base((n)*6))
 261 #define dmaor_write_reg(n, data)        __raw_writew(data, dma_find_base(n)*6)
 262
 263 static inline int dmaor_reset(int no)
 264 {
 265         unsigned long dmaor = dmaor_read_reg(no);
 266
 267         /* Try to clear the error flags first, incase they are set */
 268         dmaor &= ~(DMAOR_NMIF | DMAOR_AE);
 269         dmaor_write_reg(no, dmaor);
 270
 271         dmaor |= DMAOR_INIT;
 272         dmaor_write_reg(no, dmaor);
 273
 274         /* See if we got an error again */
 275         if ((dmaor_read_reg(no) & (DMAOR_AE | DMAOR_NMIF))) {
 276                 printk(KERN_ERR "dma-sh: Can't initialize DMAOR.\n");
 277                 return -EINVAL;
 278         }
 279
 280         return 0;
 281 }
 282
 283 /*
 284  * DMAE handling
 285  */
 286 #ifdef CONFIG_CPU_SH4
 287
 288 #if defined(DMAE1_IRQ)
 289 #define NR_DMAE         2
 290 #else
 291 #define NR_DMAE         1
 292 #endif
 293
 294 static const char *dmae_name[] = {
 295         "DMAC Address Error0",
 296         "DMAC Address Error1"
 297 };
 298
 299 #ifdef CONFIG_SH_DMA_IRQ_MULTI
 300 static inline unsigned int get_dma_error_irq(int n)
 301 {
 302         return get_dmte_irq(n * 6);
 303 }
 304 #else
 305
 306 static unsigned int dmae_irq_map[] = {
 307         DMAE0_IRQ,
 308
 309 #ifdef DMAE1_IRQ
 310         DMAE1_IRQ,
 311 #endif
 312 };
 313
 314 static inline unsigned int get_dma_error_irq(int n)
 315 {
 316         return dmae_irq_map[n];
 317 }
 318 #endif
 319
 320 static irqreturn_t dma_err(int irq, void *dummy)
 321 {
 322         int i;
 323
 324         for (i = 0; i < NR_DMAOR; i++)
 325                 dmaor_reset(i);
 326
 327         disable_irq(irq);
 328
 329         return IRQ_HANDLED;
 330 }
 331
 332 static int dmae_irq_init(void)
 333 {
 334         int n;
 335
 336         for (n = 0; n < NR_DMAE; n++) {
 337                 int i = request_irq(get_dma_error_irq(n), dma_err,
 338                                     IRQF_SHARED, dmae_name[n], (void *)dmae_name[n]);
 339                 if (unlikely(i < 0)) {
 340                         printk(KERN_ERR "%s request_irq fail\n", dmae_name[n]);
 341                         return i;
 342                 }
 343         }
 344
 345         return 0;
 346 }
 347
 348 static void dmae_irq_free(void)
 349 {
 350         int n;
 351
 352         for (n = 0; n < NR_DMAE; n++)
 353                 free_irq(get_dma_error_irq(n), NULL);
 354 }
 355 #else
 356 static inline int dmae_irq_init(void)
 357 {
 358         return 0;
 359 }
 360
 361 static void dmae_irq_free(void)
 362 {
 363 }
 364 #endif
 365
 366 static struct dma_ops sh_dmac_ops = {
 367         .request        = sh_dmac_request_dma,
 368         .free           = sh_dmac_free_dma,
 369         .get_residue    = sh_dmac_get_dma_residue,
 370         .xfer           = sh_dmac_xfer_dma,
 371         .configure      = sh_dmac_configure_channel,
 372 };
 373
 374 static struct dma_info sh_dmac_info = {
 375         .name           = "sh_dmac",
 376         .nr_channels    = CONFIG_NR_ONCHIP_DMA_CHANNELS,
 377         .ops            = &sh_dmac_ops,
 378         .flags          = DMAC_CHANNELS_TEI_CAPABLE,
 379 };
 380
 381 static int __init sh_dmac_init(void)
 382 {
 383         struct dma_info *info = &sh_dmac_info;
 384         int i, rc;
 385
 386         /*
 387          * Initialize DMAE, for parts that support it.
 388          */
 389         rc = dmae_irq_init();
 390         if (unlikely(rc != 0))
 391                 return rc;
 392
 393         /*
 394          * Initialize DMAOR, and clean up any error flags that may have
 395          * been set.
 396          */
 397         for (i = 0; i < NR_DMAOR; i++) {
 398                 rc = dmaor_reset(i);
 399                 if (unlikely(rc != 0))
 400                         return rc;
 401         }
 402
 403         return register_dmac(info);
 404 }
 405
 406 static void __exit sh_dmac_exit(void)
 407 {
 408         dmae_irq_free();
 409         unregister_dmac(&sh_dmac_info);
 410 }
 411
 412 subsys_initcall(sh_dmac_init);
 413 module_exit(sh_dmac_exit);
 414
 415 MODULE_AUTHOR("Takashi YOSHII, Paul Mundt, Andriy Skulysh");
 416 MODULE_DESCRIPTION("SuperH On-Chip DMAC Support");
 417 MODULE_LICENSE("GPL");