1 /* 2 * Generic PXA PATA driver 3 * 4 * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com> 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 as published by 8 * the Free Software Foundation; either version 2, or (at your option) 9 * any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; see the file COPYING. If not, write to 18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/blkdev.h> 24 #include <linux/ata.h> 25 #include <linux/libata.h> 26 #include <linux/platform_device.h> 27 #include <linux/gpio.h> 28 #include <linux/slab.h> 29 #include <linux/completion.h> 30 31 #include <scsi/scsi_host.h> 32 33 #include <mach/pxa2xx-regs.h> 34 #include <linux/platform_data/ata-pxa.h> 35 #include <mach/dma.h> 36 37 #define DRV_NAME "pata_pxa" 38 #define DRV_VERSION "0.1" 39 40 struct pata_pxa_data { 41 uint32_t dma_channel; 42 struct pxa_dma_desc *dma_desc; 43 dma_addr_t dma_desc_addr; 44 uint32_t dma_desc_id; 45 46 /* DMA IO physical address */ 47 uint32_t dma_io_addr; 48 /* PXA DREQ<0:2> pin selector */ 49 uint32_t dma_dreq; 50 /* DMA DCSR register value */ 51 uint32_t dma_dcsr; 52 53 struct completion dma_done; 54 }; 55 56 /* 57 * Setup the DMA descriptors. The size is transfer capped at 4k per descriptor, 58 * if the transfer is longer, it is split into multiple chained descriptors. 59 */ 60 static void pxa_load_dmac(struct scatterlist *sg, struct ata_queued_cmd *qc) 61 { 62 struct pata_pxa_data *pd = qc->ap->private_data; 63 64 uint32_t cpu_len, seg_len; 65 dma_addr_t cpu_addr; 66 67 cpu_addr = sg_dma_address(sg); 68 cpu_len = sg_dma_len(sg); 69 70 do { 71 seg_len = (cpu_len > 0x1000) ? 0x1000 : cpu_len; 72 73 pd->dma_desc[pd->dma_desc_id].ddadr = pd->dma_desc_addr + 74 ((pd->dma_desc_id + 1) * sizeof(struct pxa_dma_desc)); 75 76 pd->dma_desc[pd->dma_desc_id].dcmd = DCMD_BURST32 | 77 DCMD_WIDTH2 | (DCMD_LENGTH & seg_len); 78 79 if (qc->tf.flags & ATA_TFLAG_WRITE) { 80 pd->dma_desc[pd->dma_desc_id].dsadr = cpu_addr; 81 pd->dma_desc[pd->dma_desc_id].dtadr = pd->dma_io_addr; 82 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCSRCADDR | 83 DCMD_FLOWTRG; 84 } else { 85 pd->dma_desc[pd->dma_desc_id].dsadr = pd->dma_io_addr; 86 pd->dma_desc[pd->dma_desc_id].dtadr = cpu_addr; 87 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCTRGADDR | 88 DCMD_FLOWSRC; 89 } 90 91 cpu_len -= seg_len; 92 cpu_addr += seg_len; 93 pd->dma_desc_id++; 94 95 } while (cpu_len); 96 97 /* Should not happen */ 98 if (seg_len & 0x1f) 99 DALGN |= (1 << pd->dma_dreq); 100 } 101 102 /* 103 * Prepare taskfile for submission. 104 */ 105 static void pxa_qc_prep(struct ata_queued_cmd *qc) 106 { 107 struct pata_pxa_data *pd = qc->ap->private_data; 108 int si = 0; 109 struct scatterlist *sg; 110 111 if (!(qc->flags & ATA_QCFLAG_DMAMAP)) 112 return; 113 114 pd->dma_desc_id = 0; 115 116 DCSR(pd->dma_channel) = 0; 117 DALGN &= ~(1 << pd->dma_dreq); 118 119 for_each_sg(qc->sg, sg, qc->n_elem, si) 120 pxa_load_dmac(sg, qc); 121 122 pd->dma_desc[pd->dma_desc_id - 1].ddadr = DDADR_STOP; 123 124 /* Fire IRQ only at the end of last block */ 125 pd->dma_desc[pd->dma_desc_id - 1].dcmd |= DCMD_ENDIRQEN; 126 127 DDADR(pd->dma_channel) = pd->dma_desc_addr; 128 DRCMR(pd->dma_dreq) = DRCMR_MAPVLD | pd->dma_channel; 129 130 } 131 132 /* 133 * Configure the DMA controller, load the DMA descriptors, but don't start the 134 * DMA controller yet. Only issue the ATA command. 135 */ 136 static void pxa_bmdma_setup(struct ata_queued_cmd *qc) 137 { 138 qc->ap->ops->sff_exec_command(qc->ap, &qc->tf); 139 } 140 141 /* 142 * Execute the DMA transfer. 143 */ 144 static void pxa_bmdma_start(struct ata_queued_cmd *qc) 145 { 146 struct pata_pxa_data *pd = qc->ap->private_data; 147 init_completion(&pd->dma_done); 148 DCSR(pd->dma_channel) = DCSR_RUN; 149 } 150 151 /* 152 * Wait until the DMA transfer completes, then stop the DMA controller. 153 */ 154 static void pxa_bmdma_stop(struct ata_queued_cmd *qc) 155 { 156 struct pata_pxa_data *pd = qc->ap->private_data; 157 158 if ((DCSR(pd->dma_channel) & DCSR_RUN) && 159 wait_for_completion_timeout(&pd->dma_done, HZ)) 160 dev_err(qc->ap->dev, "Timeout waiting for DMA completion!"); 161 162 DCSR(pd->dma_channel) = 0; 163 } 164 165 /* 166 * Read DMA status. The bmdma_stop() will take care of properly finishing the 167 * DMA transfer so we always have DMA-complete interrupt here. 168 */ 169 static unsigned char pxa_bmdma_status(struct ata_port *ap) 170 { 171 struct pata_pxa_data *pd = ap->private_data; 172 unsigned char ret = ATA_DMA_INTR; 173 174 if (pd->dma_dcsr & DCSR_BUSERR) 175 ret |= ATA_DMA_ERR; 176 177 return ret; 178 } 179 180 /* 181 * No IRQ register present so we do nothing. 182 */ 183 static void pxa_irq_clear(struct ata_port *ap) 184 { 185 } 186 187 /* 188 * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still 189 * unclear why ATAPI has DMA issues. 190 */ 191 static int pxa_check_atapi_dma(struct ata_queued_cmd *qc) 192 { 193 return -EOPNOTSUPP; 194 } 195 196 static struct scsi_host_template pxa_ata_sht = { 197 ATA_BMDMA_SHT(DRV_NAME), 198 }; 199 200 static struct ata_port_operations pxa_ata_port_ops = { 201 .inherits = &ata_bmdma_port_ops, 202 .cable_detect = ata_cable_40wire, 203 204 .bmdma_setup = pxa_bmdma_setup, 205 .bmdma_start = pxa_bmdma_start, 206 .bmdma_stop = pxa_bmdma_stop, 207 .bmdma_status = pxa_bmdma_status, 208 209 .check_atapi_dma = pxa_check_atapi_dma, 210 211 .sff_irq_clear = pxa_irq_clear, 212 213 .qc_prep = pxa_qc_prep, 214 }; 215 216 /* 217 * DMA interrupt handler. 218 */ 219 static void pxa_ata_dma_irq(int dma, void *port) 220 { 221 struct ata_port *ap = port; 222 struct pata_pxa_data *pd = ap->private_data; 223 224 pd->dma_dcsr = DCSR(dma); 225 DCSR(dma) = pd->dma_dcsr; 226 227 if (pd->dma_dcsr & DCSR_STOPSTATE) 228 complete(&pd->dma_done); 229 } 230 231 static int pxa_ata_probe(struct platform_device *pdev) 232 { 233 struct ata_host *host; 234 struct ata_port *ap; 235 struct pata_pxa_data *data; 236 struct resource *cmd_res; 237 struct resource *ctl_res; 238 struct resource *dma_res; 239 struct resource *irq_res; 240 struct pata_pxa_pdata *pdata = dev_get_platdata(&pdev->dev); 241 int ret = 0; 242 243 /* 244 * Resource validation, three resources are needed: 245 * - CMD port base address 246 * - CTL port base address 247 * - DMA port base address 248 * - IRQ pin 249 */ 250 if (pdev->num_resources != 4) { 251 dev_err(&pdev->dev, "invalid number of resources\n"); 252 return -EINVAL; 253 } 254 255 /* 256 * CMD port base address 257 */ 258 cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 259 if (unlikely(cmd_res == NULL)) 260 return -EINVAL; 261 262 /* 263 * CTL port base address 264 */ 265 ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 266 if (unlikely(ctl_res == NULL)) 267 return -EINVAL; 268 269 /* 270 * DMA port base address 271 */ 272 dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0); 273 if (unlikely(dma_res == NULL)) 274 return -EINVAL; 275 276 /* 277 * IRQ pin 278 */ 279 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 280 if (unlikely(irq_res == NULL)) 281 return -EINVAL; 282 283 /* 284 * Allocate the host 285 */ 286 host = ata_host_alloc(&pdev->dev, 1); 287 if (!host) 288 return -ENOMEM; 289 290 ap = host->ports[0]; 291 ap->ops = &pxa_ata_port_ops; 292 ap->pio_mask = ATA_PIO4; 293 ap->mwdma_mask = ATA_MWDMA2; 294 295 ap->ioaddr.cmd_addr = devm_ioremap(&pdev->dev, cmd_res->start, 296 resource_size(cmd_res)); 297 ap->ioaddr.ctl_addr = devm_ioremap(&pdev->dev, ctl_res->start, 298 resource_size(ctl_res)); 299 ap->ioaddr.bmdma_addr = devm_ioremap(&pdev->dev, dma_res->start, 300 resource_size(dma_res)); 301 302 /* 303 * Adjust register offsets 304 */ 305 ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr; 306 ap->ioaddr.data_addr = ap->ioaddr.cmd_addr + 307 (ATA_REG_DATA << pdata->reg_shift); 308 ap->ioaddr.error_addr = ap->ioaddr.cmd_addr + 309 (ATA_REG_ERR << pdata->reg_shift); 310 ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr + 311 (ATA_REG_FEATURE << pdata->reg_shift); 312 ap->ioaddr.nsect_addr = ap->ioaddr.cmd_addr + 313 (ATA_REG_NSECT << pdata->reg_shift); 314 ap->ioaddr.lbal_addr = ap->ioaddr.cmd_addr + 315 (ATA_REG_LBAL << pdata->reg_shift); 316 ap->ioaddr.lbam_addr = ap->ioaddr.cmd_addr + 317 (ATA_REG_LBAM << pdata->reg_shift); 318 ap->ioaddr.lbah_addr = ap->ioaddr.cmd_addr + 319 (ATA_REG_LBAH << pdata->reg_shift); 320 ap->ioaddr.device_addr = ap->ioaddr.cmd_addr + 321 (ATA_REG_DEVICE << pdata->reg_shift); 322 ap->ioaddr.status_addr = ap->ioaddr.cmd_addr + 323 (ATA_REG_STATUS << pdata->reg_shift); 324 ap->ioaddr.command_addr = ap->ioaddr.cmd_addr + 325 (ATA_REG_CMD << pdata->reg_shift); 326 327 /* 328 * Allocate and load driver's internal data structure 329 */ 330 data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data), 331 GFP_KERNEL); 332 if (!data) 333 return -ENOMEM; 334 335 ap->private_data = data; 336 data->dma_dreq = pdata->dma_dreq; 337 data->dma_io_addr = dma_res->start; 338 339 /* 340 * Allocate space for the DMA descriptors 341 */ 342 data->dma_desc = dmam_alloc_coherent(&pdev->dev, PAGE_SIZE, 343 &data->dma_desc_addr, GFP_KERNEL); 344 if (!data->dma_desc) 345 return -EINVAL; 346 347 /* 348 * Request the DMA channel 349 */ 350 data->dma_channel = pxa_request_dma(DRV_NAME, DMA_PRIO_LOW, 351 pxa_ata_dma_irq, ap); 352 if (data->dma_channel < 0) 353 return -EBUSY; 354 355 /* 356 * Stop and clear the DMA channel 357 */ 358 DCSR(data->dma_channel) = 0; 359 360 /* 361 * Activate the ATA host 362 */ 363 ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt, 364 pdata->irq_flags, &pxa_ata_sht); 365 if (ret) 366 pxa_free_dma(data->dma_channel); 367 368 return ret; 369 } 370 371 static int pxa_ata_remove(struct platform_device *pdev) 372 { 373 struct ata_host *host = platform_get_drvdata(pdev); 374 struct pata_pxa_data *data = host->ports[0]->private_data; 375 376 pxa_free_dma(data->dma_channel); 377 378 ata_host_detach(host); 379 380 return 0; 381 } 382 383 static struct platform_driver pxa_ata_driver = { 384 .probe = pxa_ata_probe, 385 .remove = pxa_ata_remove, 386 .driver = { 387 .name = DRV_NAME, 388 }, 389 }; 390 391 module_platform_driver(pxa_ata_driver); 392 393 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 394 MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU"); 395 MODULE_LICENSE("GPL"); 396 MODULE_VERSION(DRV_VERSION); 397 MODULE_ALIAS("platform:" DRV_NAME); 398