On Tuesday, April 03, 2012 7:45 AM, Rafal Prylowski wrote:
<snip>
> +static void ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
> +{
> + const struct platform_device *pdev = drv_data->pdev;
> + dma_cap_mask_t mask;
> + struct dma_slave_config conf;
> +
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_SLAVE, mask);
> +
> + /*
> + * Request two channels for IDE. Another possibility would be
> + * to request only one channel, and reprogram it's direction at
> + * start of new transfer.
> + */
> + drv_data->dma_rx_data.port = EP93XX_DMA_IDE;
> + drv_data->dma_rx_data.direction = DMA_FROM_DEVICE;
> + drv_data->dma_rx_data.name = "ep93xx-pata-rx";
> + drv_data->dma_rx_channel = dma_request_channel(mask,
> + ep93xx_pata_dma_filter, &drv_data->dma_rx_data);
> + if (!drv_data->dma_rx_channel)
> + return;
> +
> + drv_data->dma_tx_data.port = EP93XX_DMA_IDE;
> + drv_data->dma_tx_data.direction = DMA_TO_DEVICE;
> + drv_data->dma_tx_data.name = "ep93xx-pata-tx";
> + drv_data->dma_tx_channel = dma_request_channel(mask,
> + ep93xx_pata_dma_filter, &drv_data->dma_tx_data);
> + if (!drv_data->dma_tx_channel) {
> + dma_release_channel(drv_data->dma_rx_channel);
> + return;
> + }
> +
> + /* Configure receive channel direction and source address */
> + memset(&conf, 0, sizeof(conf));
> + conf.direction = DMA_FROM_DEVICE;
> + conf.src_addr = drv_data->udma_in_phys;
> + conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + if (dmaengine_slave_config(drv_data->dma_rx_channel, &conf)) {
> + dev_err(&pdev->dev, "failed to configure rx dma channel\n");
> + ep93xx_pata_release_dma(drv_data);
> + return;
> + }
> +
> + /* Configure transmit channel direction and destination address */
> + memset(&conf, 0, sizeof(conf));
> + conf.direction = DMA_TO_DEVICE;
> + conf.dst_addr = drv_data->udma_out_phys;
> + conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + if (dmaengine_slave_config(drv_data->dma_tx_channel, &conf)) {
> + dev_err(&pdev->dev, "failed to configure tx dma channel\n");
> + ep93xx_pata_release_dma(drv_data);
> + }
> +}
If the dma init fails does the driver fall back to pio mode correctly?
<snip>
> +static struct ata_port_operations ep93xx_pata_port_ops = {
> + .inherits = &ata_bmdma_port_ops,
> +
> + .qc_prep = ata_noop_qc_prep,
> +
> + .softreset = ep93xx_pata_softreset,
> + .hardreset = ATA_OP_NULL,
> +
> + .sff_dev_select = ep93xx_pata_dev_select,
> + .sff_set_devctl = ep93xx_pata_set_devctl,
> + .sff_check_status = ep93xx_pata_check_status,
> + .sff_check_altstatus = ep93xx_pata_check_altstatus,
> + .sff_tf_load = ep93xx_pata_tf_load,
> + .sff_tf_read = ep93xx_pata_tf_read,
> + .sff_exec_command = ep93xx_pata_exec_command,
> + .sff_data_xfer = ep93xx_pata_data_xfer,
> + .sff_drain_fifo = ep93xx_pata_drain_fifo,
> + .sff_irq_clear = ATA_OP_NULL,
> +
> + .set_piomode = ep93xx_pata_set_piomode,
> +
> + .bmdma_setup = ep93xx_pata_dma_setup,
> + .bmdma_start = ep93xx_pata_dma_start,
> + .bmdma_stop = ep93xx_pata_dma_stop,
> + .bmdma_status = ep93xx_pata_dma_status,
The bmdma ops pointers are still set if the dma init failed. Should they
be set to NULL?
> +
> + .cable_detect = ata_cable_unknown,
> + .port_start = ep93xx_pata_port_start,
> +};
> +
> +static int __devinit ep93xx_pata_probe(struct platform_device *pdev)
> +{
> + struct ep93xx_pata_data *drv_data;
> + struct ata_host *host;
> + struct ata_port *ap;
> + unsigned int irq;
> + struct resource *mem_res;
> + void __iomem *ide_base;
> + int err;
> +
> + err = ep93xx_ide_acquire_gpio(pdev);
> + if (err)
> + return err;
> +
> + /* INT[3] (IRQ_EP93XX_EXT3) line connected as pull down */
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + err = -ENXIO;
> + goto err_rel_gpio;
> + }
> +
> + mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem_res) {
> + err = -ENXIO;
> + goto err_rel_gpio;
> + }
> +
> + ide_base = devm_request_and_ioremap(&pdev->dev, mem_res);
> + if (!ide_base) {
> + err = -ENXIO;
> + goto err_rel_gpio;
> + }
> +
> + drv_data = devm_kzalloc(&pdev->dev, sizeof(*drv_data), GFP_KERNEL);
> + if (!drv_data) {
> + err = -ENXIO;
> + goto err_rel_gpio;
> + }
> +
> + platform_set_drvdata(pdev, drv_data);
> + drv_data->pdev = pdev;
> + drv_data->ide_base = ide_base;
> + drv_data->udma_in_phys = mem_res->start + IDEUDMADATAIN;
> + drv_data->udma_out_phys = mem_res->start + IDEUDMADATAOUT;
> + ep93xx_pata_dma_init(drv_data);
> +
> + /* allocate host */
> + host = ata_host_alloc(&pdev->dev, 1);
> + if (!host) {
> + err = -ENXIO;
> + goto err_rel_dma;
> + }
> +
> + ep93xx_pata_clear_regs(ide_base);
> +
> + host->n_ports = 1;
> + host->private_data = drv_data;
> +
> + ap = host->ports[0];
> + ap->dev = &pdev->dev;
> + ap->ops = &ep93xx_pata_port_ops;
> + ap->flags |= ATA_FLAG_SLAVE_POSS;
> + ap->pio_mask = ATA_PIO4;
> +
> + /*
> + * Maximum UDMA modes:
> + * EP931x rev.E0 - UDMA2
> + * EP931x rev.E1 - UDMA3
> + * EP931x rev.E2 - UDMA4
> + *
> + * MWDMA support was removed from EP931x rev.E2,
> + * so this driver supports only UDMA modes.
> + */
> + if (drv_data->dma_rx_channel && drv_data->dma_tx_channel) {
> + int chip_rev = ep93xx_chip_revision();
> +
> + if (chip_rev == EP93XX_CHIP_REV_E1)
> + ap->udma_mask = ATA_UDMA3;
> + else if (chip_rev == EP93XX_CHIP_REV_E2)
> + ap->udma_mask = ATA_UDMA4;
> + else
> + ap->udma_mask = ATA_UDMA2;
> + }
> +
> + /* defaults, pio 0 */
> + ep93xx_pata_enable_pio(ide_base, 0);
> +
> + dev_info(&pdev->dev, "version " DRV_VERSION "\n");
> +
> + /* activate host */
> + err = ata_host_activate(host, irq, ata_bmdma_interrupt, 0,
> + &ep93xx_pata_sht);
> + if (err == 0)
> + return 0;
> +
> +err_rel_dma:
> + ep93xx_pata_release_dma(drv_data);
> +err_rel_gpio:
> + ep93xx_ide_release_gpio(pdev);
> + return err;
> +}
There are only two m2m dma channels on the ep93xx. They could be already in
use by the spi driver. I just want to make sure that the ide driver will fall back to
pio mode if they are not available.
Regards,
Hartley
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