summaryrefslogtreecommitdiff
path: root/target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch')
-rw-r--r--target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch31
1 files changed, 31 insertions, 0 deletions
diff --git a/target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch b/target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch
new file mode 100644
index 0000000..393ffa5
--- /dev/null
+++ b/target/linux/ar71xx/patches-3.8/002-spi-ath79-add-missing-HIGH-LOW-SCK-transition.patch
@@ -0,0 +1,31 @@
+From c7c943b1e3813ff5764ee6417a14530cb7cd6f57 Mon Sep 17 00:00:00 2001
+From: Gabor Juhos <juhosg@openwrt.org>
+Date: Thu, 27 Dec 2012 10:42:25 +0100
+Subject: [PATCH] spi/ath79: add missing HIGH->LOW SCK transition
+
+commit 72611db0eef21f4456d79ba302af4b34ea384f30 upstream.
+
+The 'ath79_spi_txrx_mode0' function does not
+set the SCK signal to LOW at the end of a word
+transfer. This causes communications errors with
+certain devices (e.g. the PCF2123 RTC chip).
+
+The patch ensures that the SCK signal will be LOW.
+
+Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
+Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
+---
+ drivers/spi/spi-ath79.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/drivers/spi/spi-ath79.c
++++ b/drivers/spi/spi-ath79.c
+@@ -200,6 +200,8 @@ static u32 ath79_spi_txrx_mode0(struct s
+ ath79_spi_delay(sp, nsecs);
+ ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
+ ath79_spi_delay(sp, nsecs);
++ if (bits == 1)
++ ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
+
+ word <<= 1;
+ }