[PATCH 10/20] gpio: pca953x: Add optional reset gpio control
From: slongerbeam@gmail.com (Steve Longerbeam)
Date: 2016-12-29 22:31:56
Also in:
linux-devicetree, linux-gpio, linux-media, lkml
Subsystem:
gpio subsystem, open firmware and flattened device tree bindings, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Add optional reset-gpios pin control. If present, de-assert the specified reset gpio pin to bring the chip out of reset. Signed-off-by: Steve Longerbeam <redacted> Cc: Linus Walleij <redacted> Cc: Alexandre Courbot <redacted> Cc: linux-gpio at vger.kernel.org Cc: linux-kernel at vger.kernel.org --- v2: - documented optional reset-gpios property in Documentation/devicetree/bindings/gpio/gpio-pca953x.txt. --- Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++ drivers/gpio/gpio-pca953x.c | 17 +++++++++++++++++ 2 files changed, 21 insertions(+)
diff --git a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
index 08dd15f..da54f4c 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt@@ -29,6 +29,10 @@ Required properties: onsemi,pca9654 exar,xra1202 +Optional properties: + - reset-gpios: GPIO specification for the RESET input + + Example:
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index d5d72d8..d1c0bd5 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c@@ -22,6 +22,7 @@ #include <linux/of_platform.h> #include <linux/acpi.h> #include <linux/regulator/consumer.h> +#include <linux/gpio/consumer.h> #define PCA953X_INPUT 0 #define PCA953X_OUTPUT 1
@@ -133,6 +134,7 @@ struct pca953x_chip { const char *const *names; unsigned long driver_data; struct regulator *regulator; + struct gpio_desc *reset_gpio; const struct pca953x_reg_config *regs;
@@ -756,6 +758,21 @@ static int pca953x_probe(struct i2c_client *client, } else { chip->gpio_start = -1; irq_base = 0; + + /* see if we need to de-assert a reset pin */ + chip->reset_gpio = devm_gpiod_get_optional(&client->dev, + "reset", + GPIOD_OUT_LOW); + if (IS_ERR(chip->reset_gpio)) { + dev_err(&client->dev, "request for reset pin failed\n"); + return PTR_ERR(chip->reset_gpio); + } + + if (chip->reset_gpio) { + /* bring chip out of reset */ + dev_info(&client->dev, "releasing reset\n"); + gpiod_set_value(chip->reset_gpio, 0); + } } chip->client = client;
--
2.7.4