include/asm-powerpc/dma.h

   1 #ifndef _ASM_POWERPC_DMA_H
   2 #define _ASM_POWERPC_DMA_H
   3 #ifdef __KERNEL__
   4
   5 /*
   6  * Defines for using and allocating dma channels.
   7  * Written by Hennus Bergman, 1992.
   8  * High DMA channel support & info by Hannu Savolainen
   9  * and John Boyd, Nov. 1992.
  10  * Changes for ppc sound by Christoph Nadig
  11  */
  12
  13 /*
  14  * Note: Adapted for PowerPC by Gary Thomas
  15  * Modified by Cort Dougan <cort@cs.nmt.edu>
  16  *
  17  * None of this really applies for Power Macintoshes.  There is
  18  * basically just enough here to get kernel/dma.c to compile.
  19  *
  20  * There may be some comments or restrictions made here which are
  21  * not valid for the PReP platform.  Take what you read
  22  * with a grain of salt.
  23  */
  24
  25 #include <linux/config.h>
  26 #include <asm/io.h>
  27 #include <linux/spinlock.h>
  28 #include <asm/system.h>
  29
  30 #ifndef MAX_DMA_CHANNELS
  31 #define MAX_DMA_CHANNELS        8
  32 #endif
  33
  34 /* The maximum address that we can perform a DMA transfer to on this platform */
  35 /* Doesn't really apply... */
  36 #define MAX_DMA_ADDRESS         (~0UL)
  37
  38 #if !defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI)
  39
  40 #ifdef HAVE_REALLY_SLOW_DMA_CONTROLLER
  41 #define dma_outb        outb_p
  42 #else
  43 #define dma_outb        outb
  44 #endif
  45
  46 #define dma_inb         inb
  47
  48 /*
  49  * NOTES about DMA transfers:
  50  *
  51  *  controller 1: channels 0-3, byte operations, ports 00-1F
  52  *  controller 2: channels 4-7, word operations, ports C0-DF
  53  *
  54  *  - ALL registers are 8 bits only, regardless of transfer size
  55  *  - channel 4 is not used - cascades 1 into 2.
  56  *  - channels 0-3 are byte - addresses/counts are for physical bytes
  57  *  - channels 5-7 are word - addresses/counts are for physical words
  58  *  - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries
  59  *  - transfer count loaded to registers is 1 less than actual count
  60  *  - controller 2 offsets are all even (2x offsets for controller 1)
  61  *  - page registers for 5-7 don't use data bit 0, represent 128K pages
  62  *  - page registers for 0-3 use bit 0, represent 64K pages
  63  *
  64  * On PReP, DMA transfers are limited to the lower 16MB of _physical_ memory.
  65  * On CHRP, the W83C553F (and VLSI Tollgate?) support full 32 bit addressing.
  66  * Note that addresses loaded into registers must be _physical_ addresses,
  67  * not logical addresses (which may differ if paging is active).
  68  *
  69  *  Address mapping for channels 0-3:
  70  *
  71  *   A23 ... A16 A15 ... A8  A7 ... A0    (Physical addresses)
  72  *    |  ...  |   |  ... |   |  ... |
  73  *    |  ...  |   |  ... |   |  ... |
  74  *    |  ...  |   |  ... |   |  ... |
  75  *   P7  ...  P0  A7 ... A0  A7 ... A0
  76  * |    Page    | Addr MSB | Addr LSB |   (DMA registers)
  77  *
  78  *  Address mapping for channels 5-7:
  79  *
  80  *   A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0    (Physical addresses)
  81  *    |  ...  |   \   \   ... \  \  \  ... \  \
  82  *    |  ...  |    \   \   ... \  \  \  ... \  (not used)
  83  *    |  ...  |     \   \   ... \  \  \  ... \
  84  *   P7  ...  P1 (0) A7 A6  ... A0 A7 A6 ... A0
  85  * |      Page      |  Addr MSB   |  Addr LSB  |   (DMA registers)
  86  *
  87  * Again, channels 5-7 transfer _physical_ words (16 bits), so addresses
  88  * and counts _must_ be word-aligned (the lowest address bit is _ignored_ at
  89  * the hardware level, so odd-byte transfers aren't possible).
  90  *
  91  * Transfer count (_not # bytes_) is limited to 64K, represented as actual
  92  * count - 1 : 64K => 0xFFFF, 1 => 0x0000.  Thus, count is always 1 or more,
  93  * and up to 128K bytes may be transferred on channels 5-7 in one operation.
  94  *
  95  */
  96
  97 /* see prep_setup_arch() for detailed informations */
  98 #if defined(CONFIG_SOUND_CS4232) && defined(CONFIG_PPC_PREP)
  99 extern long ppc_cs4232_dma, ppc_cs4232_dma2;
 100 #define SND_DMA1 ppc_cs4232_dma
 101 #define SND_DMA2 ppc_cs4232_dma2
 102 #else
 103 #define SND_DMA1 -1
 104 #define SND_DMA2 -1
 105 #endif
 106
 107 /* 8237 DMA controllers */
 108 #define IO_DMA1_BASE    0x00    /* 8 bit slave DMA, channels 0..3 */
 109 #define IO_DMA2_BASE    0xC0    /* 16 bit master DMA, ch 4(=slave input)..7 */
 110
 111 /* DMA controller registers */
 112 #define DMA1_CMD_REG            0x08    /* command register (w) */
 113 #define DMA1_STAT_REG           0x08    /* status register (r) */
 114 #define DMA1_REQ_REG            0x09    /* request register (w) */
 115 #define DMA1_MASK_REG           0x0A    /* single-channel mask (w) */
 116 #define DMA1_MODE_REG           0x0B    /* mode register (w) */
 117 #define DMA1_CLEAR_FF_REG       0x0C    /* clear pointer flip-flop (w) */
 118 #define DMA1_TEMP_REG           0x0D    /* Temporary Register (r) */
 119 #define DMA1_RESET_REG          0x0D    /* Master Clear (w) */
 120 #define DMA1_CLR_MASK_REG       0x0E    /* Clear Mask */
 121 #define DMA1_MASK_ALL_REG       0x0F    /* all-channels mask (w) */
 122
 123 #define DMA2_CMD_REG            0xD0    /* command register (w) */
 124 #define DMA2_STAT_REG           0xD0    /* status register (r) */
 125 #define DMA2_REQ_REG            0xD2    /* request register (w) */
 126 #define DMA2_MASK_REG           0xD4    /* single-channel mask (w) */
 127 #define DMA2_MODE_REG           0xD6    /* mode register (w) */
 128 #define DMA2_CLEAR_FF_REG       0xD8    /* clear pointer flip-flop (w) */
 129 #define DMA2_TEMP_REG           0xDA    /* Temporary Register (r) */
 130 #define DMA2_RESET_REG          0xDA    /* Master Clear (w) */
 131 #define DMA2_CLR_MASK_REG       0xDC    /* Clear Mask */
 132 #define DMA2_MASK_ALL_REG       0xDE    /* all-channels mask (w) */
 133
 134 #define DMA_ADDR_0              0x00    /* DMA address registers */
 135 #define DMA_ADDR_1              0x02
 136 #define DMA_ADDR_2              0x04
 137 #define DMA_ADDR_3              0x06
 138 #define DMA_ADDR_4              0xC0
 139 #define DMA_ADDR_5              0xC4
 140 #define DMA_ADDR_6              0xC8
 141 #define DMA_ADDR_7              0xCC
 142
 143 #define DMA_CNT_0               0x01    /* DMA count registers */
 144 #define DMA_CNT_1               0x03
 145 #define DMA_CNT_2               0x05
 146 #define DMA_CNT_3               0x07
 147 #define DMA_CNT_4               0xC2
 148 #define DMA_CNT_5               0xC6
 149 #define DMA_CNT_6               0xCA
 150 #define DMA_CNT_7               0xCE
 151
 152 #define DMA_LO_PAGE_0           0x87    /* DMA page registers */
 153 #define DMA_LO_PAGE_1           0x83
 154 #define DMA_LO_PAGE_2           0x81
 155 #define DMA_LO_PAGE_3           0x82
 156 #define DMA_LO_PAGE_5           0x8B
 157 #define DMA_LO_PAGE_6           0x89
 158 #define DMA_LO_PAGE_7           0x8A
 159
 160 #define DMA_HI_PAGE_0           0x487   /* DMA page registers */
 161 #define DMA_HI_PAGE_1           0x483
 162 #define DMA_HI_PAGE_2           0x481
 163 #define DMA_HI_PAGE_3           0x482
 164 #define DMA_HI_PAGE_5           0x48B
 165 #define DMA_HI_PAGE_6           0x489
 166 #define DMA_HI_PAGE_7           0x48A
 167
 168 #define DMA1_EXT_REG            0x40B
 169 #define DMA2_EXT_REG            0x4D6
 170
 171 #ifndef __powerpc64__
 172     /* in arch/ppc/kernel/setup.c -- Cort */
 173     extern unsigned int DMA_MODE_WRITE;
 174     extern unsigned int DMA_MODE_READ;
 175     extern unsigned long ISA_DMA_THRESHOLD;
 176 #else
 177     #define DMA_MODE_READ       0x44    /* I/O to memory, no autoinit, increment, single mode */
 178     #define DMA_MODE_WRITE      0x48    /* memory to I/O, no autoinit, increment, single mode */
 179 #endif
 180
 181 #define DMA_MODE_CASCADE        0xC0    /* pass thru DREQ->HRQ, DACK<-HLDA only */
 182
 183 #define DMA_AUTOINIT            0x10
 184
 185 extern spinlock_t dma_spin_lock;
 186
 187 static __inline__ unsigned long claim_dma_lock(void)
 188 {
 189         unsigned long flags;
 190         spin_lock_irqsave(&dma_spin_lock, flags);
 191         return flags;
 192 }
 193
 194 static __inline__ void release_dma_lock(unsigned long flags)
 195 {
 196         spin_unlock_irqrestore(&dma_spin_lock, flags);
 197 }
 198
 199 /* enable/disable a specific DMA channel */
 200 static __inline__ void enable_dma(unsigned int dmanr)
 201 {
 202         unsigned char ucDmaCmd = 0x00;
 203
 204         if (dmanr != 4) {
 205                 dma_outb(0, DMA2_MASK_REG);     /* This may not be enabled */
 206                 dma_outb(ucDmaCmd, DMA2_CMD_REG);       /* Enable group */
 207         }
 208         if (dmanr <= 3) {
 209                 dma_outb(dmanr, DMA1_MASK_REG);
 210                 dma_outb(ucDmaCmd, DMA1_CMD_REG);       /* Enable group */
 211         } else {
 212                 dma_outb(dmanr & 3, DMA2_MASK_REG);
 213         }
 214 }
 215
 216 static __inline__ void disable_dma(unsigned int dmanr)
 217 {
 218         if (dmanr <= 3)
 219                 dma_outb(dmanr | 4, DMA1_MASK_REG);
 220         else
 221                 dma_outb((dmanr & 3) | 4, DMA2_MASK_REG);
 222 }
 223
 224 /* Clear the 'DMA Pointer Flip Flop'.
 225  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
 226  * Use this once to initialize the FF to a known state.
 227  * After that, keep track of it. :-)
 228  * --- In order to do that, the DMA routines below should ---
 229  * --- only be used while interrupts are disabled! ---
 230  */
 231 static __inline__ void clear_dma_ff(unsigned int dmanr)
 232 {
 233         if (dmanr <= 3)
 234                 dma_outb(0, DMA1_CLEAR_FF_REG);
 235         else
 236                 dma_outb(0, DMA2_CLEAR_FF_REG);
 237 }
 238
 239 /* set mode (above) for a specific DMA channel */
 240 static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
 241 {
 242         if (dmanr <= 3)
 243                 dma_outb(mode | dmanr, DMA1_MODE_REG);
 244         else
 245                 dma_outb(mode | (dmanr & 3), DMA2_MODE_REG);
 246 }
 247
 248 /* Set only the page register bits of the transfer address.
 249  * This is used for successive transfers when we know the contents of
 250  * the lower 16 bits of the DMA current address register, but a 64k boundary
 251  * may have been crossed.
 252  */
 253 static __inline__ void set_dma_page(unsigned int dmanr, int pagenr)
 254 {
 255         switch (dmanr) {
 256         case 0:
 257                 dma_outb(pagenr, DMA_LO_PAGE_0);
 258                 dma_outb(pagenr >> 8, DMA_HI_PAGE_0);
 259                 break;
 260         case 1:
 261                 dma_outb(pagenr, DMA_LO_PAGE_1);
 262                 dma_outb(pagenr >> 8, DMA_HI_PAGE_1);
 263                 break;
 264         case 2:
 265                 dma_outb(pagenr, DMA_LO_PAGE_2);
 266                 dma_outb(pagenr >> 8, DMA_HI_PAGE_2);
 267                 break;
 268         case 3:
 269                 dma_outb(pagenr, DMA_LO_PAGE_3);
 270                 dma_outb(pagenr >> 8, DMA_HI_PAGE_3);
 271                 break;
 272         case 5:
 273                 if (SND_DMA1 == 5 || SND_DMA2 == 5)
 274                         dma_outb(pagenr, DMA_LO_PAGE_5);
 275                 else
 276                         dma_outb(pagenr & 0xfe, DMA_LO_PAGE_5);
 277                 dma_outb(pagenr >> 8, DMA_HI_PAGE_5);
 278                 break;
 279         case 6:
 280                 if (SND_DMA1 == 6 || SND_DMA2 == 6)
 281                         dma_outb(pagenr, DMA_LO_PAGE_6);
 282                 else
 283                         dma_outb(pagenr & 0xfe, DMA_LO_PAGE_6);
 284                 dma_outb(pagenr >> 8, DMA_HI_PAGE_6);
 285                 break;
 286         case 7:
 287                 if (SND_DMA1 == 7 || SND_DMA2 == 7)
 288                         dma_outb(pagenr, DMA_LO_PAGE_7);
 289                 else
 290                         dma_outb(pagenr & 0xfe, DMA_LO_PAGE_7);
 291                 dma_outb(pagenr >> 8, DMA_HI_PAGE_7);
 292                 break;
 293         }
 294 }
 295
 296 /* Set transfer address & page bits for specific DMA channel.
 297  * Assumes dma flipflop is clear.
 298  */
 299 static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int phys)
 300 {
 301         if (dmanr <= 3) {
 302                 dma_outb(phys & 0xff,
 303                          ((dmanr & 3) << 1) + IO_DMA1_BASE);
 304                 dma_outb((phys >> 8) & 0xff,
 305                          ((dmanr & 3) << 1) + IO_DMA1_BASE);
 306         } else if (dmanr == SND_DMA1 || dmanr == SND_DMA2) {
 307                 dma_outb(phys & 0xff,
 308                          ((dmanr & 3) << 2) + IO_DMA2_BASE);
 309                 dma_outb((phys >> 8) & 0xff,
 310                          ((dmanr & 3) << 2) + IO_DMA2_BASE);
 311                 dma_outb((dmanr & 3), DMA2_EXT_REG);
 312         } else {
 313                 dma_outb((phys >> 1) & 0xff,
 314                          ((dmanr & 3) << 2) + IO_DMA2_BASE);
 315                 dma_outb((phys >> 9) & 0xff,
 316                          ((dmanr & 3) << 2) + IO_DMA2_BASE);
 317         }
 318         set_dma_page(dmanr, phys >> 16);
 319 }
 320
 321
 322 /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
 323  * a specific DMA channel.
 324  * You must ensure the parameters are valid.
 325  * NOTE: from a manual: "the number of transfers is one more
 326  * than the initial word count"! This is taken into account.
 327  * Assumes dma flip-flop is clear.
 328  * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
 329  */
 330 static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
 331 {
 332         count--;
 333         if (dmanr <= 3) {
 334                 dma_outb(count & 0xff,
 335                          ((dmanr & 3) << 1) + 1 + IO_DMA1_BASE);
 336                 dma_outb((count >> 8) & 0xff,
 337                          ((dmanr & 3) << 1) + 1 + IO_DMA1_BASE);
 338         } else if (dmanr == SND_DMA1 || dmanr == SND_DMA2) {
 339                 dma_outb(count & 0xff,
 340                          ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE);
 341                 dma_outb((count >> 8) & 0xff,
 342                          ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE);
 343         } else {
 344                 dma_outb((count >> 1) & 0xff,
 345                          ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE);
 346                 dma_outb((count >> 9) & 0xff,
 347                          ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE);
 348         }
 349 }
 350
 351
 352 /* Get DMA residue count. After a DMA transfer, this
 353  * should return zero. Reading this while a DMA transfer is
 354  * still in progress will return unpredictable results.
 355  * If called before the channel has been used, it may return 1.
 356  * Otherwise, it returns the number of _bytes_ left to transfer.
 357  *
 358  * Assumes DMA flip-flop is clear.
 359  */
 360 static __inline__ int get_dma_residue(unsigned int dmanr)
 361 {
 362         unsigned int io_port = (dmanr <= 3)
 363             ? ((dmanr & 3) << 1) + 1 + IO_DMA1_BASE
 364             : ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE;
 365
 366         /* using short to get 16-bit wrap around */
 367         unsigned short count;
 368
 369         count = 1 + dma_inb(io_port);
 370         count += dma_inb(io_port) << 8;
 371
 372         return (dmanr <= 3 || dmanr == SND_DMA1 || dmanr == SND_DMA2)
 373             ? count : (count << 1);
 374 }
 375
 376 /* These are in kernel/dma.c: */
 377
 378 /* reserve a DMA channel */
 379 extern int request_dma(unsigned int dmanr, const char *device_id);
 380 /* release it again */
 381 extern void free_dma(unsigned int dmanr);
 382
 383 #ifdef CONFIG_PCI
 384 extern int isa_dma_bridge_buggy;
 385 #else
 386 #define isa_dma_bridge_buggy    (0)
 387 #endif
 388
 389 #endif  /* !defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI) */
 390
 391 #endif /* __KERNEL__ */
 392 #endif  /* _ASM_POWERPC_DMA_H */