1 /* 2 * include/asm-alpha/dma.h 3 * 4 * This is essentially the same as the i386 DMA stuff, as the AlphaPCs 5 * use ISA-compatible dma. The only extension is support for high-page 6 * registers that allow to set the top 8 bits of a 32-bit DMA address. 7 * This register should be written last when setting up a DMA address 8 * as this will also enable DMA across 64 KB boundaries. 9 */ 10 11 /* $Id: dma.h,v 1.7 1992/12/14 00:29:34 root Exp root $ 12 * linux/include/asm/dma.h: Defines for using and allocating dma channels. 13 * Written by Hennus Bergman, 1992. 14 * High DMA channel support & info by Hannu Savolainen 15 * and John Boyd, Nov. 1992. 16 */ 17 18 #ifndef _ASM_DMA_H 19 #define _ASM_DMA_H 20 21 #include <linux/spinlock.h> 22 #include <asm/io.h> 23 24 #define dma_outb outb 25 #define dma_inb inb 26 27 /* 28 * NOTES about DMA transfers: 29 * 30 * controller 1: channels 0-3, byte operations, ports 00-1F 31 * controller 2: channels 4-7, word operations, ports C0-DF 32 * 33 * - ALL registers are 8 bits only, regardless of transfer size 34 * - channel 4 is not used - cascades 1 into 2. 35 * - channels 0-3 are byte - addresses/counts are for physical bytes 36 * - channels 5-7 are word - addresses/counts are for physical words 37 * - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries 38 * - transfer count loaded to registers is 1 less than actual count 39 * - controller 2 offsets are all even (2x offsets for controller 1) 40 * - page registers for 5-7 don't use data bit 0, represent 128K pages 41 * - page registers for 0-3 use bit 0, represent 64K pages 42 * 43 * DMA transfers are limited to the lower 16MB of _physical_ memory. 44 * Note that addresses loaded into registers must be _physical_ addresses, 45 * not logical addresses (which may differ if paging is active). 46 * 47 * Address mapping for channels 0-3: 48 * 49 * A23 ... A16 A15 ... A8 A7 ... A0 (Physical addresses) 50 * | ... | | ... | | ... | 51 * | ... | | ... | | ... | 52 * | ... | | ... | | ... | 53 * P7 ... P0 A7 ... A0 A7 ... A0 54 * | Page | Addr MSB | Addr LSB | (DMA registers) 55 * 56 * Address mapping for channels 5-7: 57 * 58 * A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0 (Physical addresses) 59 * | ... | \ \ ... \ \ \ ... \ \ 60 * | ... | \ \ ... \ \ \ ... \ (not used) 61 * | ... | \ \ ... \ \ \ ... \ 62 * P7 ... P1 (0) A7 A6 ... A0 A7 A6 ... A0 63 * | Page | Addr MSB | Addr LSB | (DMA registers) 64 * 65 * Again, channels 5-7 transfer _physical_ words (16 bits), so addresses 66 * and counts _must_ be word-aligned (the lowest address bit is _ignored_ at 67 * the hardware level, so odd-byte transfers aren't possible). 68 * 69 * Transfer count (_not # bytes_) is limited to 64K, represented as actual 70 * count - 1 : 64K => 0xFFFF, 1 => 0x0000. Thus, count is always 1 or more, 71 * and up to 128K bytes may be transferred on channels 5-7 in one operation. 72 * 73 */ 74 75 #define MAX_DMA_CHANNELS 8 76 77 /* 78 ISA DMA limitations on Alpha platforms, 79 80 These may be due to SIO (PCI<->ISA bridge) chipset limitation, or 81 just a wiring limit. 82 */ 83 84 /* The maximum address for ISA DMA transfer on Alpha XL, due to an 85 hardware SIO limitation, is 64MB. 86 */ 87 #define ALPHA_XL_MAX_ISA_DMA_ADDRESS 0x04000000UL 88 89 /* The maximum address for ISA DMA transfer on RUFFIAN, 90 due to an hardware SIO limitation, is 16MB. 91 */ 92 #define ALPHA_RUFFIAN_MAX_ISA_DMA_ADDRESS 0x01000000UL 93 94 /* The maximum address for ISA DMA transfer on SABLE, and some ALCORs, 95 due to an hardware SIO chip limitation, is 2GB. 96 */ 97 #define ALPHA_SABLE_MAX_ISA_DMA_ADDRESS 0x80000000UL 98 #define ALPHA_ALCOR_MAX_ISA_DMA_ADDRESS 0x80000000UL 99 100 /* 101 Maximum address for all the others is the complete 32-bit bus 102 address space. 103 */ 104 #define ALPHA_MAX_ISA_DMA_ADDRESS 0x100000000UL 105 106 #ifdef CONFIG_ALPHA_GENERIC 107 # define MAX_ISA_DMA_ADDRESS (alpha_mv.max_isa_dma_address) 108 #else 109 # if defined(CONFIG_ALPHA_XL) 110 # define MAX_ISA_DMA_ADDRESS ALPHA_XL_MAX_ISA_DMA_ADDRESS 111 # elif defined(CONFIG_ALPHA_RUFFIAN) 112 # define MAX_ISA_DMA_ADDRESS ALPHA_RUFFIAN_MAX_ISA_DMA_ADDRESS 113 # elif defined(CONFIG_ALPHA_SABLE) 114 # define MAX_ISA_DMA_ADDRESS ALPHA_SABLE_MAX_ISA_DMA_ADDRESS 115 # elif defined(CONFIG_ALPHA_ALCOR) 116 # define MAX_ISA_DMA_ADDRESS ALPHA_ALCOR_MAX_ISA_DMA_ADDRESS 117 # else 118 # define MAX_ISA_DMA_ADDRESS ALPHA_MAX_ISA_DMA_ADDRESS 119 # endif 120 #endif 121 122 /* If we have the iommu, we don't have any address limitations on DMA. 123 Otherwise (Nautilus, RX164), we have to have 0-16 Mb DMA zone 124 like i386. */ 125 #define MAX_DMA_ADDRESS (alpha_mv.mv_pci_tbi ? \ 126 ~0UL : IDENT_ADDR + 0x01000000) 127 128 /* 8237 DMA controllers */ 129 #define IO_DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */ 130 #define IO_DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */ 131 132 /* DMA controller registers */ 133 #define DMA1_CMD_REG 0x08 /* command register (w) */ 134 #define DMA1_STAT_REG 0x08 /* status register (r) */ 135 #define DMA1_REQ_REG 0x09 /* request register (w) */ 136 #define DMA1_MASK_REG 0x0A /* single-channel mask (w) */ 137 #define DMA1_MODE_REG 0x0B /* mode register (w) */ 138 #define DMA1_CLEAR_FF_REG 0x0C /* clear pointer flip-flop (w) */ 139 #define DMA1_TEMP_REG 0x0D /* Temporary Register (r) */ 140 #define DMA1_RESET_REG 0x0D /* Master Clear (w) */ 141 #define DMA1_CLR_MASK_REG 0x0E /* Clear Mask */ 142 #define DMA1_MASK_ALL_REG 0x0F /* all-channels mask (w) */ 143 #define DMA1_EXT_MODE_REG (0x400 | DMA1_MODE_REG) 144 145 #define DMA2_CMD_REG 0xD0 /* command register (w) */ 146 #define DMA2_STAT_REG 0xD0 /* status register (r) */ 147 #define DMA2_REQ_REG 0xD2 /* request register (w) */ 148 #define DMA2_MASK_REG 0xD4 /* single-channel mask (w) */ 149 #define DMA2_MODE_REG 0xD6 /* mode register (w) */ 150 #define DMA2_CLEAR_FF_REG 0xD8 /* clear pointer flip-flop (w) */ 151 #define DMA2_TEMP_REG 0xDA /* Temporary Register (r) */ 152 #define DMA2_RESET_REG 0xDA /* Master Clear (w) */ 153 #define DMA2_CLR_MASK_REG 0xDC /* Clear Mask */ 154 #define DMA2_MASK_ALL_REG 0xDE /* all-channels mask (w) */ 155 #define DMA2_EXT_MODE_REG (0x400 | DMA2_MODE_REG) 156 157 #define DMA_ADDR_0 0x00 /* DMA address registers */ 158 #define DMA_ADDR_1 0x02 159 #define DMA_ADDR_2 0x04 160 #define DMA_ADDR_3 0x06 161 #define DMA_ADDR_4 0xC0 162 #define DMA_ADDR_5 0xC4 163 #define DMA_ADDR_6 0xC8 164 #define DMA_ADDR_7 0xCC 165 166 #define DMA_CNT_0 0x01 /* DMA count registers */ 167 #define DMA_CNT_1 0x03 168 #define DMA_CNT_2 0x05 169 #define DMA_CNT_3 0x07 170 #define DMA_CNT_4 0xC2 171 #define DMA_CNT_5 0xC6 172 #define DMA_CNT_6 0xCA 173 #define DMA_CNT_7 0xCE 174 175 #define DMA_PAGE_0 0x87 /* DMA page registers */ 176 #define DMA_PAGE_1 0x83 177 #define DMA_PAGE_2 0x81 178 #define DMA_PAGE_3 0x82 179 #define DMA_PAGE_5 0x8B 180 #define DMA_PAGE_6 0x89 181 #define DMA_PAGE_7 0x8A 182 183 #define DMA_HIPAGE_0 (0x400 | DMA_PAGE_0) 184 #define DMA_HIPAGE_1 (0x400 | DMA_PAGE_1) 185 #define DMA_HIPAGE_2 (0x400 | DMA_PAGE_2) 186 #define DMA_HIPAGE_3 (0x400 | DMA_PAGE_3) 187 #define DMA_HIPAGE_4 (0x400 | DMA_PAGE_4) 188 #define DMA_HIPAGE_5 (0x400 | DMA_PAGE_5) 189 #define DMA_HIPAGE_6 (0x400 | DMA_PAGE_6) 190 #define DMA_HIPAGE_7 (0x400 | DMA_PAGE_7) 191 192 #define DMA_MODE_READ 0x44 /* I/O to memory, no autoinit, increment, single mode */ 193 #define DMA_MODE_WRITE 0x48 /* memory to I/O, no autoinit, increment, single mode */ 194 #define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */ 195 196 #define DMA_AUTOINIT 0x10 197 198 extern spinlock_t dma_spin_lock; 199 200 static __inline__ unsigned long claim_dma_lock(void) 201 { 202 unsigned long flags; 203 spin_lock_irqsave(&dma_spin_lock, flags); 204 return flags; 205 } 206 207 static __inline__ void release_dma_lock(unsigned long flags) 208 { 209 spin_unlock_irqrestore(&dma_spin_lock, flags); 210 } 211 212 /* enable/disable a specific DMA channel */ 213 static __inline__ void enable_dma(unsigned int dmanr) 214 { 215 if (dmanr<=3) 216 dma_outb(dmanr, DMA1_MASK_REG); 217 else 218 dma_outb(dmanr & 3, DMA2_MASK_REG); 219 } 220 221 static __inline__ void disable_dma(unsigned int dmanr) 222 { 223 if (dmanr<=3) 224 dma_outb(dmanr | 4, DMA1_MASK_REG); 225 else 226 dma_outb((dmanr & 3) | 4, DMA2_MASK_REG); 227 } 228 229 /* Clear the 'DMA Pointer Flip Flop'. 230 * Write 0 for LSB/MSB, 1 for MSB/LSB access. 231 * Use this once to initialize the FF to a known state. 232 * After that, keep track of it. :-) 233 * --- In order to do that, the DMA routines below should --- 234 * --- only be used while interrupts are disabled! --- 235 */ 236 static __inline__ void clear_dma_ff(unsigned int dmanr) 237 { 238 if (dmanr<=3) 239 dma_outb(0, DMA1_CLEAR_FF_REG); 240 else 241 dma_outb(0, DMA2_CLEAR_FF_REG); 242 } 243 244 /* set mode (above) for a specific DMA channel */ 245 static __inline__ void set_dma_mode(unsigned int dmanr, char mode) 246 { 247 if (dmanr<=3) 248 dma_outb(mode | dmanr, DMA1_MODE_REG); 249 else 250 dma_outb(mode | (dmanr&3), DMA2_MODE_REG); 251 } 252 253 /* set extended mode for a specific DMA channel */ 254 static __inline__ void set_dma_ext_mode(unsigned int dmanr, char ext_mode) 255 { 256 if (dmanr<=3) 257 dma_outb(ext_mode | dmanr, DMA1_EXT_MODE_REG); 258 else 259 dma_outb(ext_mode | (dmanr&3), DMA2_EXT_MODE_REG); 260 } 261 262 /* Set only the page register bits of the transfer address. 263 * This is used for successive transfers when we know the contents of 264 * the lower 16 bits of the DMA current address register. 265 */ 266 static __inline__ void set_dma_page(unsigned int dmanr, unsigned int pagenr) 267 { 268 switch(dmanr) { 269 case 0: 270 dma_outb(pagenr, DMA_PAGE_0); 271 dma_outb((pagenr >> 8), DMA_HIPAGE_0); 272 break; 273 case 1: 274 dma_outb(pagenr, DMA_PAGE_1); 275 dma_outb((pagenr >> 8), DMA_HIPAGE_1); 276 break; 277 case 2: 278 dma_outb(pagenr, DMA_PAGE_2); 279 dma_outb((pagenr >> 8), DMA_HIPAGE_2); 280 break; 281 case 3: 282 dma_outb(pagenr, DMA_PAGE_3); 283 dma_outb((pagenr >> 8), DMA_HIPAGE_3); 284 break; 285 case 5: 286 dma_outb(pagenr & 0xfe, DMA_PAGE_5); 287 dma_outb((pagenr >> 8), DMA_HIPAGE_5); 288 break; 289 case 6: 290 dma_outb(pagenr & 0xfe, DMA_PAGE_6); 291 dma_outb((pagenr >> 8), DMA_HIPAGE_6); 292 break; 293 case 7: 294 dma_outb(pagenr & 0xfe, DMA_PAGE_7); 295 dma_outb((pagenr >> 8), DMA_HIPAGE_7); 296 break; 297 } 298 } 299 300 301 /* Set transfer address & page bits for specific DMA channel. 302 * Assumes dma flipflop is clear. 303 */ 304 static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a) 305 { 306 if (dmanr <= 3) { 307 dma_outb( a & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE ); 308 dma_outb( (a>>8) & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE ); 309 } else { 310 dma_outb( (a>>1) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE ); 311 dma_outb( (a>>9) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE ); 312 } 313 set_dma_page(dmanr, a>>16); /* set hipage last to enable 32-bit mode */ 314 } 315 316 317 /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for 318 * a specific DMA channel. 319 * You must ensure the parameters are valid. 320 * NOTE: from a manual: "the number of transfers is one more 321 * than the initial word count"! This is taken into account. 322 * Assumes dma flip-flop is clear. 323 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7. 324 */ 325 static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count) 326 { 327 count--; 328 if (dmanr <= 3) { 329 dma_outb( count & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE ); 330 dma_outb( (count>>8) & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE ); 331 } else { 332 dma_outb( (count>>1) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE ); 333 dma_outb( (count>>9) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE ); 334 } 335 } 336 337 338 /* Get DMA residue count. After a DMA transfer, this 339 * should return zero. Reading this while a DMA transfer is 340 * still in progress will return unpredictable results. 341 * If called before the channel has been used, it may return 1. 342 * Otherwise, it returns the number of _bytes_ left to transfer. 343 * 344 * Assumes DMA flip-flop is clear. 345 */ 346 static __inline__ int get_dma_residue(unsigned int dmanr) 347 { 348 unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE 349 : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE; 350 351 /* using short to get 16-bit wrap around */ 352 unsigned short count; 353 354 count = 1 + dma_inb(io_port); 355 count += dma_inb(io_port) << 8; 356 357 return (dmanr<=3)? count : (count<<1); 358 } 359 360 361 /* These are in kernel/dma.c: */ 362 extern int request_dma(unsigned int dmanr, const char * device_id); /* reserve a DMA channel */ 363 extern void free_dma(unsigned int dmanr); /* release it again */ 364 #define KERNEL_HAVE_CHECK_DMA 365 extern int check_dma(unsigned int dmanr); 366 367 /* From PCI */ 368 369 #ifdef CONFIG_PCI 370 extern int isa_dma_bridge_buggy; 371 #else 372 #define isa_dma_bridge_buggy (0) 373 #endif 374 375 376 #endif /* _ASM_DMA_H */ 377