From 33ec8951f887ab2beb1340d44f7de2a5da57da8a Mon Sep 17 00:00:00 2001 From: juhosg Date: Fri, 10 Feb 2012 11:53:56 +0000 Subject: ar71xx: add preliminary support for 3.3 git-svn-id: svn://svn.openwrt.org/openwrt/trunk@30410 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- ...1-spi-ath79-add-delay-between-SCK-changes.patch | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 target/linux/ar71xx/patches-3.3/201-spi-ath79-add-delay-between-SCK-changes.patch (limited to 'target/linux/ar71xx/patches-3.3/201-spi-ath79-add-delay-between-SCK-changes.patch') diff --git a/target/linux/ar71xx/patches-3.3/201-spi-ath79-add-delay-between-SCK-changes.patch b/target/linux/ar71xx/patches-3.3/201-spi-ath79-add-delay-between-SCK-changes.patch new file mode 100644 index 000000000..c2681f9a5 --- /dev/null +++ b/target/linux/ar71xx/patches-3.3/201-spi-ath79-add-delay-between-SCK-changes.patch @@ -0,0 +1,42 @@ +From 48b7e765e6e097d20d809fadd17a4355d26ad6d5 Mon Sep 17 00:00:00 2001 +From: Gabor Juhos +Date: Wed, 11 Jan 2012 20:06:35 +0100 +Subject: [PATCH 1/7] spi/ath79: add delay between SCK changes + +The driver uses the "as fast as it can" approach +to drive the SCK signal. However this does not +work with certain low speed SPI chips (e.g. the +PCF2123 RTC chip). Add per-bit slowdowns in order +to be able to use the driver with such chips as +well. + +Signed-off-by: Gabor Juhos +--- + drivers/spi/spi-ath79.c | 8 ++++++++ + 1 files changed, 8 insertions(+), 0 deletions(-) + +--- a/drivers/spi/spi-ath79.c ++++ b/drivers/spi/spi-ath79.c +@@ -52,6 +52,12 @@ static inline struct ath79_spi *ath79_sp + return spi_master_get_devdata(spi->master); + } + ++static inline void ath79_spi_delay(unsigned nsecs) ++{ ++ if (nsecs) ++ ndelay(nsecs); ++} ++ + static void ath79_spi_chipselect(struct spi_device *spi, int is_active) + { + struct ath79_spi *sp = ath79_spidev_to_sp(spi); +@@ -184,7 +190,9 @@ static u32 ath79_spi_txrx_mode0(struct s + + /* setup MSB (to slave) on trailing edge */ + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out); ++ ath79_spi_delay(nsecs); + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK); ++ ath79_spi_delay(nsecs); + + word <<= 1; + } -- cgit v1.2.3