1 /* 2 * linux/arch/arm/mach-rpc/dma.c 3 * 4 * Copyright (C) 1998 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * DMA functions specific to RiscPC architecture 11 */ 12 #include <linux/mman.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/dma-mapping.h> 16 #include <linux/io.h> 17 18 #include <asm/page.h> 19 #include <asm/dma.h> 20 #include <asm/fiq.h> 21 #include <asm/irq.h> 22 #include <mach/hardware.h> 23 #include <asm/uaccess.h> 24 25 #include <asm/mach/dma.h> 26 #include <asm/hardware/iomd.h> 27 28 struct iomd_dma { 29 struct dma_struct dma; 30 unsigned int state; 31 unsigned long base; /* Controller base address */ 32 int irq; /* Controller IRQ */ 33 struct scatterlist cur_sg; /* Current controller buffer */ 34 dma_addr_t dma_addr; 35 unsigned int dma_len; 36 }; 37 38 #if 0 39 typedef enum { 40 dma_size_8 = 1, 41 dma_size_16 = 2, 42 dma_size_32 = 4, 43 dma_size_128 = 16 44 } dma_size_t; 45 #endif 46 47 #define TRANSFER_SIZE 2 48 49 #define CURA (0) 50 #define ENDA (IOMD_IO0ENDA - IOMD_IO0CURA) 51 #define CURB (IOMD_IO0CURB - IOMD_IO0CURA) 52 #define ENDB (IOMD_IO0ENDB - IOMD_IO0CURA) 53 #define CR (IOMD_IO0CR - IOMD_IO0CURA) 54 #define ST (IOMD_IO0ST - IOMD_IO0CURA) 55 56 static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma) 57 { 58 unsigned long end, offset, flags = 0; 59 60 if (idma->dma.sg) { 61 sg->dma_address = idma->dma_addr; 62 offset = sg->dma_address & ~PAGE_MASK; 63 64 end = offset + idma->dma_len; 65 66 if (end > PAGE_SIZE) 67 end = PAGE_SIZE; 68 69 if (offset + TRANSFER_SIZE >= end) 70 flags |= DMA_END_L; 71 72 sg->length = end - TRANSFER_SIZE; 73 74 idma->dma_len -= end - offset; 75 idma->dma_addr += end - offset; 76 77 if (idma->dma_len == 0) { 78 if (idma->dma.sgcount > 1) { 79 idma->dma.sg = sg_next(idma->dma.sg); 80 idma->dma_addr = idma->dma.sg->dma_address; 81 idma->dma_len = idma->dma.sg->length; 82 idma->dma.sgcount--; 83 } else { 84 idma->dma.sg = NULL; 85 flags |= DMA_END_S; 86 } 87 } 88 } else { 89 flags = DMA_END_S | DMA_END_L; 90 sg->dma_address = 0; 91 sg->length = 0; 92 } 93 94 sg->length |= flags; 95 } 96 97 static irqreturn_t iomd_dma_handle(int irq, void *dev_id) 98 { 99 struct iomd_dma *idma = dev_id; 100 unsigned long base = idma->base; 101 102 do { 103 unsigned int status; 104 105 status = iomd_readb(base + ST); 106 if (!(status & DMA_ST_INT)) 107 return IRQ_HANDLED; 108 109 if ((idma->state ^ status) & DMA_ST_AB) 110 iomd_get_next_sg(&idma->cur_sg, idma); 111 112 switch (status & (DMA_ST_OFL | DMA_ST_AB)) { 113 case DMA_ST_OFL: /* OIA */ 114 case DMA_ST_AB: /* .IB */ 115 iomd_writel(idma->cur_sg.dma_address, base + CURA); 116 iomd_writel(idma->cur_sg.length, base + ENDA); 117 idma->state = DMA_ST_AB; 118 break; 119 120 case DMA_ST_OFL | DMA_ST_AB: /* OIB */ 121 case 0: /* .IA */ 122 iomd_writel(idma->cur_sg.dma_address, base + CURB); 123 iomd_writel(idma->cur_sg.length, base + ENDB); 124 idma->state = 0; 125 break; 126 } 127 128 if (status & DMA_ST_OFL && 129 idma->cur_sg.length == (DMA_END_S|DMA_END_L)) 130 break; 131 } while (1); 132 133 idma->state = ~DMA_ST_AB; 134 disable_irq(irq); 135 136 return IRQ_HANDLED; 137 } 138 139 static int iomd_request_dma(unsigned int chan, dma_t *dma) 140 { 141 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); 142 143 return request_irq(idma->irq, iomd_dma_handle, 144 IRQF_DISABLED, idma->dma.device_id, idma); 145 } 146 147 static void iomd_free_dma(unsigned int chan, dma_t *dma) 148 { 149 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); 150 151 free_irq(idma->irq, idma); 152 } 153 154 static void iomd_enable_dma(unsigned int chan, dma_t *dma) 155 { 156 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); 157 unsigned long dma_base = idma->base; 158 unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E; 159 160 if (idma->dma.invalid) { 161 idma->dma.invalid = 0; 162 163 /* 164 * Cope with ISA-style drivers which expect cache 165 * coherence. 166 */ 167 if (!idma->dma.sg) { 168 idma->dma.sg = &idma->dma.buf; 169 idma->dma.sgcount = 1; 170 idma->dma.buf.length = idma->dma.count; 171 idma->dma.buf.dma_address = dma_map_single(NULL, 172 idma->dma.addr, idma->dma.count, 173 idma->dma.dma_mode == DMA_MODE_READ ? 174 DMA_FROM_DEVICE : DMA_TO_DEVICE); 175 } 176 177 iomd_writeb(DMA_CR_C, dma_base + CR); 178 idma->state = DMA_ST_AB; 179 } 180 181 if (idma->dma.dma_mode == DMA_MODE_READ) 182 ctrl |= DMA_CR_D; 183 184 iomd_writeb(ctrl, dma_base + CR); 185 enable_irq(idma->irq); 186 } 187 188 static void iomd_disable_dma(unsigned int chan, dma_t *dma) 189 { 190 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); 191 unsigned long dma_base = idma->base; 192 unsigned long flags; 193 194 local_irq_save(flags); 195 if (idma->state != ~DMA_ST_AB) 196 disable_irq(idma->irq); 197 iomd_writeb(0, dma_base + CR); 198 local_irq_restore(flags); 199 } 200 201 static int iomd_set_dma_speed(unsigned int chan, dma_t *dma, int cycle) 202 { 203 int tcr, speed; 204 205 if (cycle < 188) 206 speed = 3; 207 else if (cycle <= 250) 208 speed = 2; 209 else if (cycle < 438) 210 speed = 1; 211 else 212 speed = 0; 213 214 tcr = iomd_readb(IOMD_DMATCR); 215 speed &= 3; 216 217 switch (chan) { 218 case DMA_0: 219 tcr = (tcr & ~0x03) | speed; 220 break; 221 222 case DMA_1: 223 tcr = (tcr & ~0x0c) | (speed << 2); 224 break; 225 226 case DMA_2: 227 tcr = (tcr & ~0x30) | (speed << 4); 228 break; 229 230 case DMA_3: 231 tcr = (tcr & ~0xc0) | (speed << 6); 232 break; 233 234 default: 235 break; 236 } 237 238 iomd_writeb(tcr, IOMD_DMATCR); 239 240 return speed; 241 } 242 243 static struct dma_ops iomd_dma_ops = { 244 .type = "IOMD", 245 .request = iomd_request_dma, 246 .free = iomd_free_dma, 247 .enable = iomd_enable_dma, 248 .disable = iomd_disable_dma, 249 .setspeed = iomd_set_dma_speed, 250 }; 251 252 static struct fiq_handler fh = { 253 .name = "floppydma" 254 }; 255 256 struct floppy_dma { 257 struct dma_struct dma; 258 unsigned int fiq; 259 }; 260 261 static void floppy_enable_dma(unsigned int chan, dma_t *dma) 262 { 263 struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); 264 void *fiqhandler_start; 265 unsigned int fiqhandler_length; 266 struct pt_regs regs; 267 268 if (fdma->dma.sg) 269 BUG(); 270 271 if (fdma->dma.dma_mode == DMA_MODE_READ) { 272 extern unsigned char floppy_fiqin_start, floppy_fiqin_end; 273 fiqhandler_start = &floppy_fiqin_start; 274 fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start; 275 } else { 276 extern unsigned char floppy_fiqout_start, floppy_fiqout_end; 277 fiqhandler_start = &floppy_fiqout_start; 278 fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start; 279 } 280 281 regs.ARM_r9 = fdma->dma.count; 282 regs.ARM_r10 = (unsigned long)fdma->dma.addr; 283 regs.ARM_fp = (unsigned long)FLOPPYDMA_BASE; 284 285 if (claim_fiq(&fh)) { 286 printk("floppydma: couldn't claim FIQ.\n"); 287 return; 288 } 289 290 set_fiq_handler(fiqhandler_start, fiqhandler_length); 291 set_fiq_regs(®s); 292 enable_fiq(fdma->fiq); 293 } 294 295 static void floppy_disable_dma(unsigned int chan, dma_t *dma) 296 { 297 struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); 298 disable_fiq(fdma->fiq); 299 release_fiq(&fh); 300 } 301 302 static int floppy_get_residue(unsigned int chan, dma_t *dma) 303 { 304 struct pt_regs regs; 305 get_fiq_regs(®s); 306 return regs.ARM_r9; 307 } 308 309 static struct dma_ops floppy_dma_ops = { 310 .type = "FIQDMA", 311 .enable = floppy_enable_dma, 312 .disable = floppy_disable_dma, 313 .residue = floppy_get_residue, 314 }; 315 316 /* 317 * This is virtual DMA - we don't need anything here. 318 */ 319 static void sound_enable_disable_dma(unsigned int chan, dma_t *dma) 320 { 321 } 322 323 static struct dma_ops sound_dma_ops = { 324 .type = "VIRTUAL", 325 .enable = sound_enable_disable_dma, 326 .disable = sound_enable_disable_dma, 327 }; 328 329 static struct iomd_dma iomd_dma[6]; 330 331 static struct floppy_dma floppy_dma = { 332 .dma = { 333 .d_ops = &floppy_dma_ops, 334 }, 335 .fiq = FIQ_FLOPPYDATA, 336 }; 337 338 static dma_t sound_dma = { 339 .d_ops = &sound_dma_ops, 340 }; 341 342 static int __init rpc_dma_init(void) 343 { 344 unsigned int i; 345 int ret; 346 347 iomd_writeb(0, IOMD_IO0CR); 348 iomd_writeb(0, IOMD_IO1CR); 349 iomd_writeb(0, IOMD_IO2CR); 350 iomd_writeb(0, IOMD_IO3CR); 351 352 iomd_writeb(0xa0, IOMD_DMATCR); 353 354 /* 355 * Setup DMA channels 2,3 to be for podules 356 * and channels 0,1 for internal devices 357 */ 358 iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT); 359 360 iomd_dma[DMA_0].base = IOMD_IO0CURA; 361 iomd_dma[DMA_0].irq = IRQ_DMA0; 362 iomd_dma[DMA_1].base = IOMD_IO1CURA; 363 iomd_dma[DMA_1].irq = IRQ_DMA1; 364 iomd_dma[DMA_2].base = IOMD_IO2CURA; 365 iomd_dma[DMA_2].irq = IRQ_DMA2; 366 iomd_dma[DMA_3].base = IOMD_IO3CURA; 367 iomd_dma[DMA_3].irq = IRQ_DMA3; 368 iomd_dma[DMA_S0].base = IOMD_SD0CURA; 369 iomd_dma[DMA_S0].irq = IRQ_DMAS0; 370 iomd_dma[DMA_S1].base = IOMD_SD1CURA; 371 iomd_dma[DMA_S1].irq = IRQ_DMAS1; 372 373 for (i = DMA_0; i <= DMA_S1; i++) { 374 iomd_dma[i].dma.d_ops = &iomd_dma_ops; 375 376 ret = isa_dma_add(i, &iomd_dma[i].dma); 377 if (ret) 378 printk("IOMDDMA%u: unable to register: %d\n", i, ret); 379 } 380 381 ret = isa_dma_add(DMA_VIRTUAL_FLOPPY, &floppy_dma.dma); 382 if (ret) 383 printk("IOMDFLOPPY: unable to register: %d\n", ret); 384 ret = isa_dma_add(DMA_VIRTUAL_SOUND, &sound_dma); 385 if (ret) 386 printk("IOMDSOUND: unable to register: %d\n", ret); 387 return 0; 388 } 389 core_initcall(rpc_dma_init); 390