In some cases, the system bus can be configured for 16-bit mode, in this case using read/write functions for 32-bit values results in two cycles of 16 bits each, which is wrong. This patch adds the devicetree flag to switch the driver to use 16-bit mode for I/O transfers. Signed-off-by: Alexander Shiyan <shc_work@xxxxxxx> --- drivers/ata/pata_of_platform.c | 6 +++++- drivers/ata/pata_platform.c | 22 ++++++++++++---------- include/linux/ata_platform.h | 3 ++- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c index 01161c1..7a0b175 100644 --- a/drivers/ata/pata_of_platform.c +++ b/drivers/ata/pata_of_platform.c @@ -32,6 +32,7 @@ static int pata_of_platform_probe(struct platform_device *ofdev) unsigned int reg_shift = 0; int pio_mode = 0; int pio_mask; + bool use16bit; ret = of_address_to_resource(dn, 0, &io_res); if (ret) { @@ -60,11 +61,14 @@ static int pata_of_platform_probe(struct platform_device *ofdev) dev_info(&ofdev->dev, "pio-mode unspecified, assuming PIO0\n"); } + use16bit = of_property_read_bool(dn, "ata-generic,use16bit"); + pio_mask = 1 << pio_mode; pio_mask |= (1 << pio_mode) - 1; return __pata_platform_probe(&ofdev->dev, &io_res, &ctl_res, irq_res, - reg_shift, pio_mask, &pata_platform_sht); + reg_shift, pio_mask, &pata_platform_sht, + use16bit); } static const struct of_device_id pata_of_platform_match[] = { diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c index d6f8f54..31cd0f3 100644 --- a/drivers/ata/pata_platform.c +++ b/drivers/ata/pata_platform.c @@ -47,13 +47,6 @@ static struct scsi_host_template pata_platform_sht = { ATA_PIO_SHT(DRV_NAME), }; -static struct ata_port_operations pata_platform_port_ops = { - .inherits = &ata_sff_port_ops, - .sff_data_xfer = ata_sff_data_xfer32, - .cable_detect = ata_cable_unknown, - .set_mode = pata_platform_set_mode, -}; - static void pata_platform_setup_port(struct ata_ioports *ioaddr, unsigned int shift) { @@ -79,6 +72,7 @@ static void pata_platform_setup_port(struct ata_ioports *ioaddr, * @ioport_shift: I/O port shift * @__pio_mask: PIO mask * @sht: scsi_host_template to use when registering + * @use16bit: Flag to indicate 16-bit IO instead of 32-bit * * Register a platform bus IDE interface. Such interfaces are PIO and we * assume do not support IRQ sharing. @@ -101,7 +95,7 @@ static void pata_platform_setup_port(struct ata_ioports *ioaddr, int __pata_platform_probe(struct device *dev, struct resource *io_res, struct resource *ctl_res, struct resource *irq_res, unsigned int ioport_shift, int __pio_mask, - struct scsi_host_template *sht) + struct scsi_host_template *sht, bool use16bit) { struct ata_host *host; struct ata_port *ap; @@ -131,7 +125,15 @@ int __pata_platform_probe(struct device *dev, struct resource *io_res, return -ENOMEM; ap = host->ports[0]; - ap->ops = &pata_platform_port_ops; + ap->ops = devm_kzalloc(dev, sizeof(*ap->ops), GFP_KERNEL); + ap->ops->inherits = &ata_sff_port_ops; + ap->ops->cable_detect = ata_cable_unknown; + ap->ops->set_mode = pata_platform_set_mode; + if (use16bit) + ap->ops->sff_data_xfer = ata_sff_data_xfer; + else + ap->ops->sff_data_xfer = ata_sff_data_xfer32; + ap->pio_mask = __pio_mask; ap->flags |= ATA_FLAG_SLAVE_POSS; @@ -218,7 +220,7 @@ static int pata_platform_probe(struct platform_device *pdev) return __pata_platform_probe(&pdev->dev, io_res, ctl_res, irq_res, pp_info ? pp_info->ioport_shift : 0, - pio_mask, &pata_platform_sht); + pio_mask, &pata_platform_sht, false); } static struct platform_driver pata_platform_driver = { diff --git a/include/linux/ata_platform.h b/include/linux/ata_platform.h index ff21202..9cafec9 100644 --- a/include/linux/ata_platform.h +++ b/include/linux/ata_platform.h @@ -19,7 +19,8 @@ extern int __pata_platform_probe(struct device *dev, struct resource *irq_res, unsigned int ioport_shift, int __pio_mask, - struct scsi_host_template *sht); + struct scsi_host_template *sht, + bool use16bit); /* * Marvell SATA private data -- 2.10.2