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authorAlexander Shiyan <shc_work@mail.ru>2019-01-19 07:52:01 +0300
committerJens Axboe <axboe@kernel.dk>2019-02-08 16:42:53 +0300
commitf3d5e4f18dba18d7c2303dda68b9dbcf5ccc05cd (patch)
tree325d873caee753bca9ee40555d84a5afcb64686c /drivers/ata/pata_of_platform.c
parent740c68a0cd42aab21ad9aaae092ff8a2215966b1 (diff)
downloadlinux-f3d5e4f18dba18d7c2303dda68b9dbcf5ccc05cd.tar.xz
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: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/ata/pata_of_platform.c')
-rw-r--r--drivers/ata/pata_of_platform.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
index 01161c1aef4d..7a0b1759e5f0 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[] = {