[PATCH] pata-rb532-cf: read/write data in 4-byte blocks

[Phil Sutter <n0-1@xxxxxxxxxxx>]

* rename the offset definition to avoid abiguity with the standard ATA
  IO address
* read and write four bytes at once like the original driver does
* use writesl() and readsl() which implicitly iterate over the data

This patch assumes buflen to be a multiple of four, which is true for
ATA devices. ATAPI support is not known, though unlikely, as the
original driver always transfers 512 Bytes at once.

Signed-off-by: Phil Sutter <n0-1@xxxxxxxxxxx>
Acked-by: Sergei Shtyltov <sshtylyov@xxxxxxxxxxxxx>
---
 drivers/ata/pata_rb532_cf.c |   20 +++++++++-----------
 1 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/ata/pata_rb532_cf.c b/drivers/ata/pata_rb532_cf.c
index 7b11f40..b919012 100644
--- a/drivers/ata/pata_rb532_cf.c
+++ b/drivers/ata/pata_rb532_cf.c
@@ -43,7 +43,8 @@
 #define RB500_CF_REG_BASE	0x0800
 #define RB500_CF_REG_ERR	0x080D
 #define RB500_CF_REG_CTRL	0x080E
-#define RB500_CF_REG_DATA	0x0C00
+/* 32bit buffered data register offset */
+#define RB500_CF_REG_DBUF32	0x0C00
 
 struct rb532_cf_info {
 	void __iomem	*iobase;
@@ -74,19 +75,16 @@ static void rb532_pata_exec_command(struct ata_port *ap,
 	rb532_pata_finish_io(ap);
 }
 
-static void rb532_pata_data_xfer(struct ata_device *adev, unsigned char *buf,
-				unsigned int buflen, int write_data)
+static void rb532_pata_data_xfer(struct ata_device *adev,
+		unsigned char *buf, unsigned int buflen, int write_data)
 {
 	struct ata_port *ap = adev->link->ap;
 	void __iomem *ioaddr = ap->ioaddr.data_addr;
 
-	if (write_data) {
-		for (; buflen > 0; buflen--, buf++)
-			writeb(*buf, ioaddr);
-	} else {
-		for (; buflen > 0; buflen--, buf++)
-			*buf = readb(ioaddr);
-	}
+	if (write_data)
+		writesl(ioaddr, buf, buflen / sizeof(u32));
+	else
+		readsl(ioaddr, buf, buflen / sizeof(u32));
 
 	rb532_pata_finish_io(adev->link->ap);
 }
@@ -156,7 +154,7 @@ static void rb532_pata_setup_ports(struct ata_host *ah)
 
 	ata_sff_std_ports(&ap->ioaddr);
 
-	ap->ioaddr.data_addr	= info->iobase + RB500_CF_REG_DATA;
+	ap->ioaddr.data_addr	= info->iobase + RB500_CF_REG_DBUF32;
 	ap->ioaddr.error_addr	= info->iobase + RB500_CF_REG_ERR;
 }
 
-- 
1.5.6.4

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