root/drivers/ata/pata_pxa.c

DEFINITIONS

1. pxa_ata_dma_irq
2. pxa_qc_prep
3. pxa_bmdma_setup
4. pxa_bmdma_start
5. pxa_bmdma_stop
6. pxa_bmdma_status
7. pxa_irq_clear
8. pxa_check_atapi_dma
9. pxa_ata_probe
10. pxa_ata_remove

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Generic PXA PATA driver
   4  *
   5  * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
   6  */
   7 
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/blkdev.h>
  11 #include <linux/ata.h>
  12 #include <linux/libata.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/slab.h>
  16 #include <linux/completion.h>
  17 
  18 #include <scsi/scsi_host.h>
  19 
  20 #include <linux/platform_data/ata-pxa.h>
  21 
  22 #define DRV_NAME        "pata_pxa"
  23 #define DRV_VERSION     "0.1"
  24 
  25 struct pata_pxa_data {
  26         struct dma_chan         *dma_chan;
  27         dma_cookie_t            dma_cookie;
  28         struct completion       dma_done;
  29 };
  30 
  31 /*
  32  * DMA interrupt handler.
  33  */
  34 static void pxa_ata_dma_irq(void *d)
  35 {
  36         struct pata_pxa_data *pd = d;
  37         enum dma_status status;
  38 
  39         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
  40         if (status == DMA_ERROR || status == DMA_COMPLETE)
  41                 complete(&pd->dma_done);
  42 }
  43 
  44 /*
  45  * Prepare taskfile for submission.
  46  */
  47 static void pxa_qc_prep(struct ata_queued_cmd *qc)
  48 {
  49         struct pata_pxa_data *pd = qc->ap->private_data;
  50         struct dma_async_tx_descriptor *tx;
  51         enum dma_transfer_direction dir;
  52 
  53         if (!(qc->flags & ATA_QCFLAG_DMAMAP))
  54                 return;
  55 
  56         dir = (qc->dma_dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
  57         tx = dmaengine_prep_slave_sg(pd->dma_chan, qc->sg, qc->n_elem, dir,
  58                                      DMA_PREP_INTERRUPT);
  59         if (!tx) {
  60                 ata_dev_err(qc->dev, "prep_slave_sg() failed\n");
  61                 return;
  62         }
  63         tx->callback = pxa_ata_dma_irq;
  64         tx->callback_param = pd;
  65         pd->dma_cookie = dmaengine_submit(tx);
  66 }
  67 
  68 /*
  69  * Configure the DMA controller, load the DMA descriptors, but don't start the
  70  * DMA controller yet. Only issue the ATA command.
  71  */
  72 static void pxa_bmdma_setup(struct ata_queued_cmd *qc)
  73 {
  74         qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
  75 }
  76 
  77 /*
  78  * Execute the DMA transfer.
  79  */
  80 static void pxa_bmdma_start(struct ata_queued_cmd *qc)
  81 {
  82         struct pata_pxa_data *pd = qc->ap->private_data;
  83         init_completion(&pd->dma_done);
  84         dma_async_issue_pending(pd->dma_chan);
  85 }
  86 
  87 /*
  88  * Wait until the DMA transfer completes, then stop the DMA controller.
  89  */
  90 static void pxa_bmdma_stop(struct ata_queued_cmd *qc)
  91 {
  92         struct pata_pxa_data *pd = qc->ap->private_data;
  93         enum dma_status status;
  94 
  95         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
  96         if (status != DMA_ERROR && status != DMA_COMPLETE &&
  97             wait_for_completion_timeout(&pd->dma_done, HZ))
  98                 ata_dev_err(qc->dev, "Timeout waiting for DMA completion!");
  99 
 100         dmaengine_terminate_all(pd->dma_chan);
 101 }
 102 
 103 /*
 104  * Read DMA status. The bmdma_stop() will take care of properly finishing the
 105  * DMA transfer so we always have DMA-complete interrupt here.
 106  */
 107 static unsigned char pxa_bmdma_status(struct ata_port *ap)
 108 {
 109         struct pata_pxa_data *pd = ap->private_data;
 110         unsigned char ret = ATA_DMA_INTR;
 111         struct dma_tx_state state;
 112         enum dma_status status;
 113 
 114         status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, &state);
 115         if (status != DMA_COMPLETE)
 116                 ret |= ATA_DMA_ERR;
 117 
 118         return ret;
 119 }
 120 
 121 /*
 122  * No IRQ register present so we do nothing.
 123  */
 124 static void pxa_irq_clear(struct ata_port *ap)
 125 {
 126 }
 127 
 128 /*
 129  * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still
 130  * unclear why ATAPI has DMA issues.
 131  */
 132 static int pxa_check_atapi_dma(struct ata_queued_cmd *qc)
 133 {
 134         return -EOPNOTSUPP;
 135 }
 136 
 137 static struct scsi_host_template pxa_ata_sht = {
 138         ATA_BMDMA_SHT(DRV_NAME),
 139 };
 140 
 141 static struct ata_port_operations pxa_ata_port_ops = {
 142         .inherits               = &ata_bmdma_port_ops,
 143         .cable_detect           = ata_cable_40wire,
 144 
 145         .bmdma_setup            = pxa_bmdma_setup,
 146         .bmdma_start            = pxa_bmdma_start,
 147         .bmdma_stop             = pxa_bmdma_stop,
 148         .bmdma_status           = pxa_bmdma_status,
 149 
 150         .check_atapi_dma        = pxa_check_atapi_dma,
 151 
 152         .sff_irq_clear          = pxa_irq_clear,
 153 
 154         .qc_prep                = pxa_qc_prep,
 155 };
 156 
 157 static int pxa_ata_probe(struct platform_device *pdev)
 158 {
 159         struct ata_host *host;
 160         struct ata_port *ap;
 161         struct pata_pxa_data *data;
 162         struct resource *cmd_res;
 163         struct resource *ctl_res;
 164         struct resource *dma_res;
 165         struct resource *irq_res;
 166         struct pata_pxa_pdata *pdata = dev_get_platdata(&pdev->dev);
 167         struct dma_slave_config config;
 168         int ret = 0;
 169 
 170         /*
 171          * Resource validation, three resources are needed:
 172          *  - CMD port base address
 173          *  - CTL port base address
 174          *  - DMA port base address
 175          *  - IRQ pin
 176          */
 177         if (pdev->num_resources != 4) {
 178                 dev_err(&pdev->dev, "invalid number of resources\n");
 179                 return -EINVAL;
 180         }
 181 
 182         /*
 183          * CMD port base address
 184          */
 185         cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 186         if (unlikely(cmd_res == NULL))
 187                 return -EINVAL;
 188 
 189         /*
 190          * CTL port base address
 191          */
 192         ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 193         if (unlikely(ctl_res == NULL))
 194                 return -EINVAL;
 195 
 196         /*
 197          * DMA port base address
 198          */
 199         dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 200         if (unlikely(dma_res == NULL))
 201                 return -EINVAL;
 202 
 203         /*
 204          * IRQ pin
 205          */
 206         irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 207         if (unlikely(irq_res == NULL))
 208                 return -EINVAL;
 209 
 210         /*
 211          * Allocate the host
 212          */
 213         host = ata_host_alloc(&pdev->dev, 1);
 214         if (!host)
 215                 return -ENOMEM;
 216 
 217         ap              = host->ports[0];
 218         ap->ops         = &pxa_ata_port_ops;
 219         ap->pio_mask    = ATA_PIO4;
 220         ap->mwdma_mask  = ATA_MWDMA2;
 221 
 222         ap->ioaddr.cmd_addr     = devm_ioremap(&pdev->dev, cmd_res->start,
 223                                                 resource_size(cmd_res));
 224         ap->ioaddr.ctl_addr     = devm_ioremap(&pdev->dev, ctl_res->start,
 225                                                 resource_size(ctl_res));
 226         ap->ioaddr.bmdma_addr   = devm_ioremap(&pdev->dev, dma_res->start,
 227                                                 resource_size(dma_res));
 228 
 229         /*
 230          * Adjust register offsets
 231          */
 232         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 233         ap->ioaddr.data_addr    = ap->ioaddr.cmd_addr +
 234                                         (ATA_REG_DATA << pdata->reg_shift);
 235         ap->ioaddr.error_addr   = ap->ioaddr.cmd_addr +
 236                                         (ATA_REG_ERR << pdata->reg_shift);
 237         ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr +
 238                                         (ATA_REG_FEATURE << pdata->reg_shift);
 239         ap->ioaddr.nsect_addr   = ap->ioaddr.cmd_addr +
 240                                         (ATA_REG_NSECT << pdata->reg_shift);
 241         ap->ioaddr.lbal_addr    = ap->ioaddr.cmd_addr +
 242                                         (ATA_REG_LBAL << pdata->reg_shift);
 243         ap->ioaddr.lbam_addr    = ap->ioaddr.cmd_addr +
 244                                         (ATA_REG_LBAM << pdata->reg_shift);
 245         ap->ioaddr.lbah_addr    = ap->ioaddr.cmd_addr +
 246                                         (ATA_REG_LBAH << pdata->reg_shift);
 247         ap->ioaddr.device_addr  = ap->ioaddr.cmd_addr +
 248                                         (ATA_REG_DEVICE << pdata->reg_shift);
 249         ap->ioaddr.status_addr  = ap->ioaddr.cmd_addr +
 250                                         (ATA_REG_STATUS << pdata->reg_shift);
 251         ap->ioaddr.command_addr = ap->ioaddr.cmd_addr +
 252                                         (ATA_REG_CMD << pdata->reg_shift);
 253 
 254         /*
 255          * Allocate and load driver's internal data structure
 256          */
 257         data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data),
 258                                                                 GFP_KERNEL);
 259         if (!data)
 260                 return -ENOMEM;
 261 
 262         ap->private_data = data;
 263 
 264         memset(&config, 0, sizeof(config));
 265         config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 266         config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 267         config.src_addr = dma_res->start;
 268         config.dst_addr = dma_res->start;
 269         config.src_maxburst = 32;
 270         config.dst_maxburst = 32;
 271 
 272         /*
 273          * Request the DMA channel
 274          */
 275         data->dma_chan =
 276                 dma_request_slave_channel(&pdev->dev, "data");
 277         if (!data->dma_chan)
 278                 return -EBUSY;
 279         ret = dmaengine_slave_config(data->dma_chan, &config);
 280         if (ret < 0) {
 281                 dev_err(&pdev->dev, "dma configuration failed: %d\n", ret);
 282                 return ret;
 283         }
 284 
 285         /*
 286          * Activate the ATA host
 287          */
 288         ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt,
 289                                 pdata->irq_flags, &pxa_ata_sht);
 290         if (ret)
 291                 dma_release_channel(data->dma_chan);
 292 
 293         return ret;
 294 }
 295 
 296 static int pxa_ata_remove(struct platform_device *pdev)
 297 {
 298         struct ata_host *host = platform_get_drvdata(pdev);
 299         struct pata_pxa_data *data = host->ports[0]->private_data;
 300 
 301         dma_release_channel(data->dma_chan);
 302 
 303         ata_host_detach(host);
 304 
 305         return 0;
 306 }
 307 
 308 static struct platform_driver pxa_ata_driver = {
 309         .probe          = pxa_ata_probe,
 310         .remove         = pxa_ata_remove,
 311         .driver         = {
 312                 .name           = DRV_NAME,
 313         },
 314 };
 315 
 316 module_platform_driver(pxa_ata_driver);
 317 
 318 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 319 MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU");
 320 MODULE_LICENSE("GPL");
 321 MODULE_VERSION(DRV_VERSION);
 322 MODULE_ALIAS("platform:" DRV_NAME);