diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0012-spi-bcm2835-Support-pin-groups-other-than-7-11.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0012-spi-bcm2835-Support-pin-groups-other-than-7-11.patch | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0012-spi-bcm2835-Support-pin-groups-other-than-7-11.patch b/target/linux/brcm2708/patches-4.4/0012-spi-bcm2835-Support-pin-groups-other-than-7-11.patch new file mode 100644 index 0000000000..73e27817b3 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0012-spi-bcm2835-Support-pin-groups-other-than-7-11.patch @@ -0,0 +1,80 @@ +From bc9d2c297e886dfcc340414a61de970942ad7319 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Wed, 24 Jun 2015 14:10:44 +0100 +Subject: [PATCH 012/127] 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 +@@ -688,6 +688,8 @@ 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 + */ +@@ -704,15 +706,42 @@ 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", |