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-rw-r--r--target/linux/brcm2708/patches-4.4/0421-spi-bcm2835-Disable-forced-software-CS.patch46
1 files changed, 46 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0421-spi-bcm2835-Disable-forced-software-CS.patch b/target/linux/brcm2708/patches-4.4/0421-spi-bcm2835-Disable-forced-software-CS.patch
new file mode 100644
index 0000000000..1e407630ab
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0421-spi-bcm2835-Disable-forced-software-CS.patch
@@ -0,0 +1,46 @@
+From e95bf039347d97f57e7045d7cd2d1f7e4daed1c6 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Fri, 1 Jul 2016 22:09:24 +0100
+Subject: [PATCH 421/423] spi-bcm2835: Disable forced software CS
+
+Select software CS in bcm2708_common.dtsi, and disable the automatic
+conversion in the driver to allow hardware CS to be re-enabled with an
+overlay.
+
+See: https://github.com/raspberrypi/linux/issues/1547
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ arch/arm/boot/dts/bcm2708_common.dtsi | 2 +-
+ drivers/spi/spi-bcm2835.c | 2 ++
+ 2 files changed, 3 insertions(+), 1 deletion(-)
+
+--- a/arch/arm/boot/dts/bcm2708_common.dtsi
++++ b/arch/arm/boot/dts/bcm2708_common.dtsi
+@@ -183,7 +183,7 @@
+ * add more gpios if necessary as <&gpio 6 1>
+ * (but do not forget to make them output!)
+ */
+- cs-gpios = <0>, <0>;
++ cs-gpios = <&gpio 8 1>, <&gpio 7 1>;
+ };
+
+ i2c0: i2c@7e205000 {
+--- a/drivers/spi/spi-bcm2835.c
++++ b/drivers/spi/spi-bcm2835.c
+@@ -707,6 +707,7 @@ static int bcm2835_spi_setup(struct spi_
+ return -EINVAL;
+ }
+
++#if 0
+ /* now translate native cs to GPIO */
+ /* first look for chip select pins in the devices pin groups */
+ for (pingroup_index = 0;
+@@ -761,6 +762,7 @@ static int bcm2835_spi_setup(struct spi_
+ * so we are setting it here explicitly
+ */
+ gpio_set_value(spi->cs_gpio, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
++#endif
+
+ return 0;
+ }