From 054ccdef8b2850be3aee8cbd49000e6d61f837b2 Mon Sep 17 00:00:00 2001 From: Steve Longerbeam Date: Tue, 10 Jan 2017 11:29:51 -0800 Subject: [PATCH] gpio: pca953x: Add optional reset gpio control Add optional reset-gpios pin control. If present, de-assert the specified reset gpio pin to bring the chip out of reset. v2: - Specify that reset signal to PCA953x chip is active low, in binding doc. - reorder includes in gpio-pca953x.c. - remove dev_err() on devm_gpiod_get_optional() error return. Cc: Alexandre Courbot Cc: linux-gpio@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Steve Longerbeam Reviewed-by: Andy Shevchenko Reviewed-by: Vladimir Zapolskiy Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++ drivers/gpio/gpio-pca953x.c | 9 +++++++++ 2 files changed, 13 insertions(+) diff --git a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt index 08dd15f89ba9..e63935710011 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. This is an + active low signal to the PCA953x. + Example: diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index d5d72d84b719..d44232aadb6c 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -754,8 +755,16 @@ static int pca953x_probe(struct i2c_client *client, invert = pdata->invert; chip->names = pdata->names; } else { + struct gpio_desc *reset_gpio; + chip->gpio_start = -1; irq_base = 0; + + /* See if we need to de-assert a reset pin */ + reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_LOW); + if (IS_ERR(reset_gpio)) + return PTR_ERR(reset_gpio); } chip->client = client; -- 2.25.1