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/init.h> 24 #include <linux/blkdev.h> 25 #include <linux/ata.h> 26 #include <linux/libata.h> 27 #include <linux/platform_device.h> 28 #include <linux/gpio.h> 29 #include <linux/slab.h> 30 #include <linux/completion.h> 31 32 #include <scsi/scsi_host.h> 33 34 #include <mach/pxa2xx-regs.h> 35 #include <linux/platform_data/ata-pxa.h> 36 #include <mach/dma.h> 37 38 #define DRV_NAME "pata_pxa" 39 #define DRV_VERSION "0.1" 40 41 struct pata_pxa_data { 42 uint32_t dma_channel; 43 struct pxa_dma_desc *dma_desc; 44 dma_addr_t dma_desc_addr; 45 uint32_t dma_desc_id; 46 47 /* DMA IO physical address */ 48 uint32_t dma_io_addr; 49 /* PXA DREQ<0:2> pin selector */ 50 uint32_t dma_dreq; 51 /* DMA DCSR register value */ 52 uint32_t dma_dcsr; 53 54 struct completion dma_done; 55 }; 56 57 /* 58 * Setup the DMA descriptors. The size is transfer capped at 4k per descriptor, 59 * if the transfer is longer, it is split into multiple chained descriptors. 60 */ 61 static void pxa_load_dmac(struct scatterlist *sg, struct ata_queued_cmd *qc) 62 { 63 struct pata_pxa_data *pd = qc->ap->private_data; 64 65 uint32_t cpu_len, seg_len; 66 dma_addr_t cpu_addr; 67 68 cpu_addr = sg_dma_address(sg); 69 cpu_len = sg_dma_len(sg); 70 71 do { 72 seg_len = (cpu_len > 0x1000) ? 0x1000 : cpu_len; 73 74 pd->dma_desc[pd->dma_desc_id].ddadr = pd->dma_desc_addr + 75 ((pd->dma_desc_id + 1) * sizeof(struct pxa_dma_desc)); 76 77 pd->dma_desc[pd->dma_desc_id].dcmd = DCMD_BURST32 | 78 DCMD_WIDTH2 | (DCMD_LENGTH & seg_len); 79 80 if (qc->tf.flags & ATA_TFLAG_WRITE) { 81 pd->dma_desc[pd->dma_desc_id].dsadr = cpu_addr; 82 pd->dma_desc[pd->dma_desc_id].dtadr = pd->dma_io_addr; 83 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCSRCADDR | 84 DCMD_FLOWTRG; 85 } else { 86 pd->dma_desc[pd->dma_desc_id].dsadr = pd->dma_io_addr; 87 pd->dma_desc[pd->dma_desc_id].dtadr = cpu_addr; 88 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCTRGADDR | 89 DCMD_FLOWSRC; 90 } 91 92 cpu_len -= seg_len; 93 cpu_addr += seg_len; 94 pd->dma_desc_id++; 95 96 } while (cpu_len); 97 98 /* Should not happen */ 99 if (seg_len & 0x1f) 100 DALGN |= (1 << pd->dma_dreq); 101 } 102 103 /* 104 * Prepare taskfile for submission. 105 */ 106 static void pxa_qc_prep(struct ata_queued_cmd *qc) 107 { 108 struct pata_pxa_data *pd = qc->ap->private_data; 109 int si = 0; 110 struct scatterlist *sg; 111 112 if (!(qc->flags & ATA_QCFLAG_DMAMAP)) 113 return; 114 115 pd->dma_desc_id = 0; 116 117 DCSR(pd->dma_channel) = 0; 118 DALGN &= ~(1 << pd->dma_dreq); 119 120 for_each_sg(qc->sg, sg, qc->n_elem, si) 121 pxa_load_dmac(sg, qc); 122 123 pd->dma_desc[pd->dma_desc_id - 1].ddadr = DDADR_STOP; 124 125 /* Fire IRQ only at the end of last block */ 126 pd->dma_desc[pd->dma_desc_id - 1].dcmd |= DCMD_ENDIRQEN; 127 128 DDADR(pd->dma_channel) = pd->dma_desc_addr; 129 DRCMR(pd->dma_dreq) = DRCMR_MAPVLD | pd->dma_channel; 130 131 } 132 133 /* 134 * Configure the DMA controller, load the DMA descriptors, but don't start the 135 * DMA controller yet. Only issue the ATA command. 136 */ 137 static void pxa_bmdma_setup(struct ata_queued_cmd *qc) 138 { 139 qc->ap->ops->sff_exec_command(qc->ap, &qc->tf); 140 } 141 142 /* 143 * Execute the DMA transfer. 144 */ 145 static void pxa_bmdma_start(struct ata_queued_cmd *qc) 146 { 147 struct pata_pxa_data *pd = qc->ap->private_data; 148 init_completion(&pd->dma_done); 149 DCSR(pd->dma_channel) = DCSR_RUN; 150 } 151 152 /* 153 * Wait until the DMA transfer completes, then stop the DMA controller. 154 */ 155 static void pxa_bmdma_stop(struct ata_queued_cmd *qc) 156 { 157 struct pata_pxa_data *pd = qc->ap->private_data; 158 159 if ((DCSR(pd->dma_channel) & DCSR_RUN) && 160 wait_for_completion_timeout(&pd->dma_done, HZ)) 161 dev_err(qc->ap->dev, "Timeout waiting for DMA completion!"); 162 163 DCSR(pd->dma_channel) = 0; 164 } 165 166 /* 167 * Read DMA status. The bmdma_stop() will take care of properly finishing the 168 * DMA transfer so we always have DMA-complete interrupt here. 169 */ 170 static unsigned char pxa_bmdma_status(struct ata_port *ap) 171 { 172 struct pata_pxa_data *pd = ap->private_data; 173 unsigned char ret = ATA_DMA_INTR; 174 175 if (pd->dma_dcsr & DCSR_BUSERR) 176 ret |= ATA_DMA_ERR; 177 178 return ret; 179 } 180 181 /* 182 * No IRQ register present so we do nothing. 183 */ 184 static void pxa_irq_clear(struct ata_port *ap) 185 { 186 } 187 188 /* 189 * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still 190 * unclear why ATAPI has DMA issues. 191 */ 192 static int pxa_check_atapi_dma(struct ata_queued_cmd *qc) 193 { 194 return -EOPNOTSUPP; 195 } 196 197 static struct scsi_host_template pxa_ata_sht = { 198 ATA_BMDMA_SHT(DRV_NAME), 199 }; 200 201 static struct ata_port_operations pxa_ata_port_ops = { 202 .inherits = &ata_bmdma_port_ops, 203 .cable_detect = ata_cable_40wire, 204 205 .bmdma_setup = pxa_bmdma_setup, 206 .bmdma_start = pxa_bmdma_start, 207 .bmdma_stop = pxa_bmdma_stop, 208 .bmdma_status = pxa_bmdma_status, 209 210 .check_atapi_dma = pxa_check_atapi_dma, 211 212 .sff_irq_clear = pxa_irq_clear, 213 214 .qc_prep = pxa_qc_prep, 215 }; 216 217 /* 218 * DMA interrupt handler. 219 */ 220 static void pxa_ata_dma_irq(int dma, void *port) 221 { 222 struct ata_port *ap = port; 223 struct pata_pxa_data *pd = ap->private_data; 224 225 pd->dma_dcsr = DCSR(dma); 226 DCSR(dma) = pd->dma_dcsr; 227 228 if (pd->dma_dcsr & DCSR_STOPSTATE) 229 complete(&pd->dma_done); 230 } 231 232 static int pxa_ata_probe(struct platform_device *pdev) 233 { 234 struct ata_host *host; 235 struct ata_port *ap; 236 struct pata_pxa_data *data; 237 struct resource *cmd_res; 238 struct resource *ctl_res; 239 struct resource *dma_res; 240 struct resource *irq_res; 241 struct pata_pxa_pdata *pdata = dev_get_platdata(&pdev->dev); 242 int ret = 0; 243 244 /* 245 * Resource validation, three resources are needed: 246 * - CMD port base address 247 * - CTL port base address 248 * - DMA port base address 249 * - IRQ pin 250 */ 251 if (pdev->num_resources != 4) { 252 dev_err(&pdev->dev, "invalid number of resources\n"); 253 return -EINVAL; 254 } 255 256 /* 257 * CMD port base address 258 */ 259 cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 260 if (unlikely(cmd_res == NULL)) 261 return -EINVAL; 262 263 /* 264 * CTL port base address 265 */ 266 ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 267 if (unlikely(ctl_res == NULL)) 268 return -EINVAL; 269 270 /* 271 * DMA port base address 272 */ 273 dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0); 274 if (unlikely(dma_res == NULL)) 275 return -EINVAL; 276 277 /* 278 * IRQ pin 279 */ 280 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 281 if (unlikely(irq_res == NULL)) 282 return -EINVAL; 283 284 /* 285 * Allocate the host 286 */ 287 host = ata_host_alloc(&pdev->dev, 1); 288 if (!host) 289 return -ENOMEM; 290 291 ap = host->ports[0]; 292 ap->ops = &pxa_ata_port_ops; 293 ap->pio_mask = ATA_PIO4; 294 ap->mwdma_mask = ATA_MWDMA2; 295 296 ap->ioaddr.cmd_addr = devm_ioremap(&pdev->dev, cmd_res->start, 297 resource_size(cmd_res)); 298 ap->ioaddr.ctl_addr = devm_ioremap(&pdev->dev, ctl_res->start, 299 resource_size(ctl_res)); 300 ap->ioaddr.bmdma_addr = devm_ioremap(&pdev->dev, dma_res->start, 301 resource_size(dma_res)); 302 303 /* 304 * Adjust register offsets 305 */ 306 ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr; 307 ap->ioaddr.data_addr = ap->ioaddr.cmd_addr + 308 (ATA_REG_DATA << pdata->reg_shift); 309 ap->ioaddr.error_addr = ap->ioaddr.cmd_addr + 310 (ATA_REG_ERR << pdata->reg_shift); 311 ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr + 312 (ATA_REG_FEATURE << pdata->reg_shift); 313 ap->ioaddr.nsect_addr = ap->ioaddr.cmd_addr + 314 (ATA_REG_NSECT << pdata->reg_shift); 315 ap->ioaddr.lbal_addr = ap->ioaddr.cmd_addr + 316 (ATA_REG_LBAL << pdata->reg_shift); 317 ap->ioaddr.lbam_addr = ap->ioaddr.cmd_addr + 318 (ATA_REG_LBAM << pdata->reg_shift); 319 ap->ioaddr.lbah_addr = ap->ioaddr.cmd_addr + 320 (ATA_REG_LBAH << pdata->reg_shift); 321 ap->ioaddr.device_addr = ap->ioaddr.cmd_addr + 322 (ATA_REG_DEVICE << pdata->reg_shift); 323 ap->ioaddr.status_addr = ap->ioaddr.cmd_addr + 324 (ATA_REG_STATUS << pdata->reg_shift); 325 ap->ioaddr.command_addr = ap->ioaddr.cmd_addr + 326 (ATA_REG_CMD << pdata->reg_shift); 327 328 /* 329 * Allocate and load driver's internal data structure 330 */ 331 data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data), 332 GFP_KERNEL); 333 if (!data) 334 return -ENOMEM; 335 336 ap->private_data = data; 337 data->dma_dreq = pdata->dma_dreq; 338 data->dma_io_addr = dma_res->start; 339 340 /* 341 * Allocate space for the DMA descriptors 342 */ 343 data->dma_desc = dmam_alloc_coherent(&pdev->dev, PAGE_SIZE, 344 &data->dma_desc_addr, GFP_KERNEL); 345 if (!data->dma_desc) 346 return -EINVAL; 347 348 /* 349 * Request the DMA channel 350 */ 351 data->dma_channel = pxa_request_dma(DRV_NAME, DMA_PRIO_LOW, 352 pxa_ata_dma_irq, ap); 353 if (data->dma_channel < 0) 354 return -EBUSY; 355 356 /* 357 * Stop and clear the DMA channel 358 */ 359 DCSR(data->dma_channel) = 0; 360 361 /* 362 * Activate the ATA host 363 */ 364 ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt, 365 pdata->irq_flags, &pxa_ata_sht); 366 if (ret) 367 pxa_free_dma(data->dma_channel); 368 369 return ret; 370 } 371 372 static int pxa_ata_remove(struct platform_device *pdev) 373 { 374 struct ata_host *host = platform_get_drvdata(pdev); 375 struct pata_pxa_data *data = host->ports[0]->private_data; 376 377 pxa_free_dma(data->dma_channel); 378 379 ata_host_detach(host); 380 381 return 0; 382 } 383 384 static struct platform_driver pxa_ata_driver = { 385 .probe = pxa_ata_probe, 386 .remove = pxa_ata_remove, 387 .driver = { 388 .name = DRV_NAME, 389 .owner = THIS_MODULE, 390 }, 391 }; 392 393 module_platform_driver(pxa_ata_driver); 394 395 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 396 MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU"); 397 MODULE_LICENSE("GPL"); 398 MODULE_VERSION(DRV_VERSION); 399 MODULE_ALIAS("platform:" DRV_NAME); 400