From dff0109496846fd9787b6cdc0941217ecdf0ae28 Mon Sep 17 00:00:00 2001
From: Anatolij Gustschin <agust@denx.de>
Date: Thu, 20 Jan 2011 07:53:06 +0000
Subject: [PATCH] SPI: mxc_spi: fix swapping bug and add missing swapping in
unaligned rx case
We need to shift only one time in each cycle in the swapping loop
for unaligned tx case. Currently two byte shift operations are
performed in each loop cycle causing zero gaps in the transmited
data, so not all data scheduled for transmition is actually
transmited.
The proper swapping in unaligned rx case is missing, so add it
as we need to put the received data into the rx buffer in the
correct byte order.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Tested-by: Stefano Babic <sbabic@denx.de>
---
drivers/spi/mxc_spi.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 567071457d0..dadf228844d 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -372,9 +372,8 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
/* Buffer is not 32-bit aligned */
if ((unsigned long)dout & 0x03) {
data = 0;
- for (i = 0; i < 4; i++, data <<= 8) {
+ for (i = 0; i < 4; i++)
data = (data << 8) | (*dout++ & 0xFF);
- }
} else {
data = *(u32 *)dout;
data = cpu_to_be32(data);
@@ -405,11 +404,11 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
if (bitlen % 32) {
data = reg_read(mxcs->base + MXC_CSPIRXDATA);
cnt = (bitlen % 32) / 8;
+ data = cpu_to_be32(data) >> ((sizeof(data) - cnt) * 8);
debug("SPI Rx unaligned: 0x%x\n", data);
if (din) {
- for (i = 0; i < cnt; i++, data >>= 8) {
- *din++ = data & 0xFF;
- }
+ memcpy(din, &data, cnt);
+ din += cnt;
}
nbytes -= cnt;
}
--
GitLab