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/dmaengine.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 <linux/platform_data/ata-pxa.h>
  35
  36 #define DRV_NAME        "pata_pxa"
  37 #define DRV_VERSION     "0.1"
  38
  39 struct pata_pxa_data {
  40         struct dma_chan         *dma_chan;
  41         dma_cookie_t            dma_cookie;
  42         struct completion       dma_done;
  43 };
  44
  45 /*
  46  * DMA interrupt handler.
  47  */
  48 static void pxa_ata_dma_irq(void *d)
  49 {
  50         struct pata_pxa_data *pd = d;
  51         enum dma_status status;
  52
  53         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
  54         if (status == DMA_ERROR || status == DMA_COMPLETE)
  55                 complete(&pd->dma_done);
  56 }
  57
  58 /*
  59  * Prepare taskfile for submission.
  60  */
  61 static void pxa_qc_prep(struct ata_queued_cmd *qc)
  62 {
  63         struct pata_pxa_data *pd = qc->ap->private_data;
  64         struct dma_async_tx_descriptor *tx;
  65         enum dma_transfer_direction dir;
  66
  67         if (!(qc->flags & ATA_QCFLAG_DMAMAP))
  68                 return;
  69
  70         dir = (qc->dma_dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
  71         tx = dmaengine_prep_slave_sg(pd->dma_chan, qc->sg, qc->n_elem, dir,
  72                                      DMA_PREP_INTERRUPT);
  73         if (!tx) {
  74                 ata_dev_err(qc->dev, "prep_slave_sg() failed\n");
  75                 return;
  76         }
  77         tx->callback = pxa_ata_dma_irq;
  78         tx->callback_param = pd;
  79         pd->dma_cookie = dmaengine_submit(tx);
  80 }
  81
  82 /*
  83  * Configure the DMA controller, load the DMA descriptors, but don't start the
  84  * DMA controller yet. Only issue the ATA command.
  85  */
  86 static void pxa_bmdma_setup(struct ata_queued_cmd *qc)
  87 {
  88         qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
  89 }
  90
  91 /*
  92  * Execute the DMA transfer.
  93  */
  94 static void pxa_bmdma_start(struct ata_queued_cmd *qc)
  95 {
  96         struct pata_pxa_data *pd = qc->ap->private_data;
  97         init_completion(&pd->dma_done);
  98         dma_async_issue_pending(pd->dma_chan);
  99 }
 100
 101 /*
 102  * Wait until the DMA transfer completes, then stop the DMA controller.
 103  */
 104 static void pxa_bmdma_stop(struct ata_queued_cmd *qc)
 105 {
 106         struct pata_pxa_data *pd = qc->ap->private_data;
 107         enum dma_status status;
 108
 109         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
 110         if (status != DMA_ERROR && status != DMA_COMPLETE &&
 111             wait_for_completion_timeout(&pd->dma_done, HZ))
 112                 ata_dev_err(qc->dev, "Timeout waiting for DMA completion!");
 113
 114         dmaengine_terminate_all(pd->dma_chan);
 115 }
 116
 117 /*
 118  * Read DMA status. The bmdma_stop() will take care of properly finishing the
 119  * DMA transfer so we always have DMA-complete interrupt here.
 120  */
 121 static unsigned char pxa_bmdma_status(struct ata_port *ap)
 122 {
 123         struct pata_pxa_data *pd = ap->private_data;
 124         unsigned char ret = ATA_DMA_INTR;
 125         struct dma_tx_state state;
 126         enum dma_status status;
 127
 128         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, &state);
 129         if (status != DMA_COMPLETE)
 130                 ret |= ATA_DMA_ERR;
 131
 132         return ret;
 133 }
 134
 135 /*
 136  * No IRQ register present so we do nothing.
 137  */
 138 static void pxa_irq_clear(struct ata_port *ap)
 139 {
 140 }
 141
 142 /*
 143  * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still
 144  * unclear why ATAPI has DMA issues.
 145  */
 146 static int pxa_check_atapi_dma(struct ata_queued_cmd *qc)
 147 {
 148         return -EOPNOTSUPP;
 149 }
 150
 151 static struct scsi_host_template pxa_ata_sht = {
 152         ATA_BMDMA_SHT(DRV_NAME),
 153 };
 154
 155 static struct ata_port_operations pxa_ata_port_ops = {
 156         .inherits               = &ata_bmdma_port_ops,
 157         .cable_detect           = ata_cable_40wire,
 158
 159         .bmdma_setup            = pxa_bmdma_setup,
 160         .bmdma_start            = pxa_bmdma_start,
 161         .bmdma_stop             = pxa_bmdma_stop,
 162         .bmdma_status           = pxa_bmdma_status,
 163
 164         .check_atapi_dma        = pxa_check_atapi_dma,
 165
 166         .sff_irq_clear          = pxa_irq_clear,
 167
 168         .qc_prep                = pxa_qc_prep,
 169 };
 170
 171 static int pxa_ata_probe(struct platform_device *pdev)
 172 {
 173         struct ata_host *host;
 174         struct ata_port *ap;
 175         struct pata_pxa_data *data;
 176         struct resource *cmd_res;
 177         struct resource *ctl_res;
 178         struct resource *dma_res;
 179         struct resource *irq_res;
 180         struct pata_pxa_pdata *pdata = dev_get_platdata(&pdev->dev);
 181         struct dma_slave_config config;
 182         int ret = 0;
 183
 184         /*
 185          * Resource validation, three resources are needed:
 186          *  - CMD port base address
 187          *  - CTL port base address
 188          *  - DMA port base address
 189          *  - IRQ pin
 190          */
 191         if (pdev->num_resources != 4) {
 192                 dev_err(&pdev->dev, "invalid number of resources\n");
 193                 return -EINVAL;
 194         }
 195
 196         /*
 197          * CMD port base address
 198          */
 199         cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 200         if (unlikely(cmd_res == NULL))
 201                 return -EINVAL;
 202
 203         /*
 204          * CTL port base address
 205          */
 206         ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 207         if (unlikely(ctl_res == NULL))
 208                 return -EINVAL;
 209
 210         /*
 211          * DMA port base address
 212          */
 213         dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 214         if (unlikely(dma_res == NULL))
 215                 return -EINVAL;
 216
 217         /*
 218          * IRQ pin
 219          */
 220         irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 221         if (unlikely(irq_res == NULL))
 222                 return -EINVAL;
 223
 224         /*
 225          * Allocate the host
 226          */
 227         host = ata_host_alloc(&pdev->dev, 1);
 228         if (!host)
 229                 return -ENOMEM;
 230
 231         ap              = host->ports[0];
 232         ap->ops         = &pxa_ata_port_ops;
 233         ap->pio_mask    = ATA_PIO4;
 234         ap->mwdma_mask  = ATA_MWDMA2;
 235
 236         ap->ioaddr.cmd_addr     = devm_ioremap(&pdev->dev, cmd_res->start,
 237                                                 resource_size(cmd_res));
 238         ap->ioaddr.ctl_addr     = devm_ioremap(&pdev->dev, ctl_res->start,
 239                                                 resource_size(ctl_res));
 240         ap->ioaddr.bmdma_addr   = devm_ioremap(&pdev->dev, dma_res->start,
 241                                                 resource_size(dma_res));
 242
 243         /*
 244          * Adjust register offsets
 245          */
 246         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 247         ap->ioaddr.data_addr    = ap->ioaddr.cmd_addr +
 248                                         (ATA_REG_DATA << pdata->reg_shift);
 249         ap->ioaddr.error_addr   = ap->ioaddr.cmd_addr +
 250                                         (ATA_REG_ERR << pdata->reg_shift);
 251         ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr +
 252                                         (ATA_REG_FEATURE << pdata->reg_shift);
 253         ap->ioaddr.nsect_addr   = ap->ioaddr.cmd_addr +
 254                                         (ATA_REG_NSECT << pdata->reg_shift);
 255         ap->ioaddr.lbal_addr    = ap->ioaddr.cmd_addr +
 256                                         (ATA_REG_LBAL << pdata->reg_shift);
 257         ap->ioaddr.lbam_addr    = ap->ioaddr.cmd_addr +
 258                                         (ATA_REG_LBAM << pdata->reg_shift);
 259         ap->ioaddr.lbah_addr    = ap->ioaddr.cmd_addr +
 260                                         (ATA_REG_LBAH << pdata->reg_shift);
 261         ap->ioaddr.device_addr  = ap->ioaddr.cmd_addr +
 262                                         (ATA_REG_DEVICE << pdata->reg_shift);
 263         ap->ioaddr.status_addr  = ap->ioaddr.cmd_addr +
 264                                         (ATA_REG_STATUS << pdata->reg_shift);
 265         ap->ioaddr.command_addr = ap->ioaddr.cmd_addr +
 266                                         (ATA_REG_CMD << pdata->reg_shift);
 267
 268         /*
 269          * Allocate and load driver's internal data structure
 270          */
 271         data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data),
 272                                                                 GFP_KERNEL);
 273         if (!data)
 274                 return -ENOMEM;
 275
 276         ap->private_data = data;
 277
 278         memset(&config, 0, sizeof(config));
 279         config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 280         config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 281         config.src_addr = dma_res->start;
 282         config.dst_addr = dma_res->start;
 283         config.src_maxburst = 32;
 284         config.dst_maxburst = 32;
 285
 286         /*
 287          * Request the DMA channel
 288          */
 289         data->dma_chan =
 290                 dma_request_slave_channel(&pdev->dev, "data");
 291         if (!data->dma_chan)
 292                 return -EBUSY;
 293         ret = dmaengine_slave_config(data->dma_chan, &config);
 294         if (ret < 0) {
 295                 dev_err(&pdev->dev, "dma configuration failed: %d\n", ret);
 296                 return ret;
 297         }
 298
 299         /*
 300          * Activate the ATA host
 301          */
 302         ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt,
 303                                 pdata->irq_flags, &pxa_ata_sht);
 304         if (ret)
 305                 dma_release_channel(data->dma_chan);
 306
 307         return ret;
 308 }
 309
 310 static int pxa_ata_remove(struct platform_device *pdev)
 311 {
 312         struct ata_host *host = platform_get_drvdata(pdev);
 313         struct pata_pxa_data *data = host->ports[0]->private_data;
 314
 315         dma_release_channel(data->dma_chan);
 316
 317         ata_host_detach(host);
 318
 319         return 0;
 320 }
 321
 322 static struct platform_driver pxa_ata_driver = {
 323         .probe          = pxa_ata_probe,
 324         .remove         = pxa_ata_remove,
 325         .driver         = {
 326                 .name           = DRV_NAME,
 327         },
 328 };
 329
 330 module_platform_driver(pxa_ata_driver);
 331
 332 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 333 MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU");
 334 MODULE_LICENSE("GPL");
 335 MODULE_VERSION(DRV_VERSION);
 336 MODULE_ALIAS("platform:" DRV_NAME);