drivers/ata/pata_pxa.c

   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 = pdev->dev.platform_data;
 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 = dev_get_drvdata(&pdev->dev);
 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);