From 7ebc194d0fd4bb0fc8c7aca4b500b5b24e733267 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Mon, 7 Aug 2017 09:41:50 -0300 Subject: [PATCH] gpio: 74x164: Introduce 'enable-gpios' property 74HC595 has an /OE (output enable) pin that can be controlled by a GPIO. Introduce an optional property called 'enable-gpios' that allows controlling the /OE pin. Signed-off-by: Fabio Estevam Acked-by: Rob Herring Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/gpio-74x164.txt | 3 +++ drivers/gpio/gpio-74x164.c | 10 ++++++++++ 2 files changed, 13 insertions(+) diff --git a/Documentation/devicetree/bindings/gpio/gpio-74x164.txt b/Documentation/devicetree/bindings/gpio/gpio-74x164.txt index ce1b223..2a97553 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-74x164.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-74x164.txt @@ -12,6 +12,9 @@ Required properties: 1 = active low - registers-number: Number of daisy-chained shift registers +Optional properties: +- enable-gpios: GPIO connected to the OE (Output Enable) pin. + Example: gpio5: gpio5@0 { diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c index a6607fa..6b535ec 100644 --- a/drivers/gpio/gpio-74x164.c +++ b/drivers/gpio/gpio-74x164.c @@ -9,6 +9,7 @@ * published by the Free Software Foundation. */ +#include #include #include #include @@ -31,6 +32,7 @@ struct gen_74x164_chip { * numbering, store the bytes in reverse order. */ u8 buffer[0]; + struct gpio_desc *gpiod_oe; }; static int __gen_74x164_write_config(struct gen_74x164_chip *chip) @@ -126,6 +128,13 @@ static int gen_74x164_probe(struct spi_device *spi) if (!chip) return -ENOMEM; + chip->gpiod_oe = devm_gpiod_get_optional(&spi->dev, "enable", + GPIOD_OUT_LOW); + if (IS_ERR(chip->gpiod_oe)) + return PTR_ERR(chip->gpiod_oe); + + gpiod_set_value_cansleep(chip->gpiod_oe, 1); + spi_set_drvdata(spi, chip); chip->gpio_chip.label = spi->modalias; @@ -164,6 +173,7 @@ static int gen_74x164_remove(struct spi_device *spi) { struct gen_74x164_chip *chip = spi_get_drvdata(spi); + gpiod_set_value_cansleep(chip->gpiod_oe, 0); gpiochip_remove(&chip->gpio_chip); mutex_destroy(&chip->lock); -- 2.7.4