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Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0010-spi-bcm2835-Support-pin-groups-other-than-7-11.patch')
-rw-r--r--target/linux/brcm2708/patches-4.19/950-0010-spi-bcm2835-Support-pin-groups-other-than-7-11.patch80
1 files changed, 80 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0010-spi-bcm2835-Support-pin-groups-other-than-7-11.patch b/target/linux/brcm2708/patches-4.19/950-0010-spi-bcm2835-Support-pin-groups-other-than-7-11.patch
new file mode 100644
index 0000000000..0517999883
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0010-spi-bcm2835-Support-pin-groups-other-than-7-11.patch
@@ -0,0 +1,80 @@
+From 61ca6adb1fc93622bb85acc18b6ce4f620c8c690 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Wed, 24 Jun 2015 14:10:44 +0100
+Subject: [PATCH] spi-bcm2835: Support pin groups other than 7-11
+
+The spi-bcm2835 driver automatically uses GPIO chip-selects due to
+some unreliability of the native ones. In doing so it chooses the
+same pins as the native chip-selects would use, but the existing
+code always uses pins 7 and 8, wherever the SPI function is mapped.
+
+Search the pinctrl group assigned to the driver for pins that
+correspond to native chip-selects, and use those for GPIO chip-
+selects.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/spi/spi-bcm2835.c | 45 ++++++++++++++++++++++++++++++++-------
+ 1 file changed, 37 insertions(+), 8 deletions(-)
+
+--- a/drivers/spi/spi-bcm2835.c
++++ b/drivers/spi/spi-bcm2835.c
+@@ -687,6 +687,8 @@ static int bcm2835_spi_setup(struct spi_
+ {
+ int err;
+ struct gpio_chip *chip;
++ struct device_node *pins;
++ u32 pingroup_index;
+ /*
+ * sanity checking the native-chipselects
+ */
+@@ -703,15 +705,42 @@ static int bcm2835_spi_setup(struct spi_
+ "setup: only two native chip-selects are supported\n");
+ return -EINVAL;
+ }
+- /* now translate native cs to GPIO */
+
+- /* get the gpio chip for the base */
+- chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
+- if (!chip)
+- return 0;
++ /* now translate native cs to GPIO */
++ /* first look for chip select pins in the devices pin groups */
++ for (pingroup_index = 0;
++ (pins = of_parse_phandle(spi->master->dev.of_node,
++ "pinctrl-0",
++ pingroup_index)) != 0;
++ pingroup_index++) {
++ u32 pin;
++ u32 pin_index;
++ for (pin_index = 0;
++ of_property_read_u32_index(pins,
++ "brcm,pins",
++ pin_index,
++ &pin) == 0;
++ pin_index++) {
++ if (((spi->chip_select == 0) &&
++ ((pin == 8) || (pin == 36) || (pin == 46))) ||
++ ((spi->chip_select == 1) &&
++ ((pin == 7) || (pin == 35)))) {
++ spi->cs_gpio = pin;
++ break;
++ }
++ }
++ of_node_put(pins);
++ }
++ /* if that fails, assume GPIOs 7-11 are used */
++ if (!gpio_is_valid(spi->cs_gpio) ) {
++ /* get the gpio chip for the base */
++ chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
++ if (!chip)
++ return 0;
+
+- /* and calculate the real CS */
+- spi->cs_gpio = chip->base + 8 - spi->chip_select;
++ /* and calculate the real CS */
++ spi->cs_gpio = chip->base + 8 - spi->chip_select;
++ }
+
+ /* and set up the "mode" and level */
+ dev_info(&spi->dev, "setting up native-CS%i as GPIO %i\n",