Commit f3d5e4f1 authored by Alexander Shiyan's avatar Alexander Shiyan Committed by Jens Axboe
Browse files

ata: pata_of_platform: Allow to use 16-bit wide data transfer 



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.

Acked-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 740c68a0

drivers/ata/pata_of_platform.c

+5 −1
Original line number Diff line number Diff line
@@ -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[] = {

drivers/ata/pata_platform.c

+12 −10
Original line number Diff line number Diff line
@@ -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 = {

include/linux/ata_platform.h

+2 −1
Original line number Diff line number Diff line
@@ -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

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