kernel/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/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);