From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Longerbeam Subject: [PATCH v2] gpio: pca953x: Add optional reset gpio control Date: Tue, 10 Jan 2017 11:29:51 -0800 Message-ID: <1484076591-20834-2-git-send-email-steve_longerbeam@mentor.com> References: <1484076591-20834-1-git-send-email-steve_longerbeam@mentor.com> Return-path: In-Reply-To: <1484076591-20834-1-git-send-email-steve_longerbeam@mentor.com> Sender: linux-kernel-owner@vger.kernel.org To: linus.walleij@linaro.org, gnurou@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Steve Longerbeam List-Id: devicetree@vger.kernel.org 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 Cc: Linus Walleij Cc: Alexandre Courbot Cc: linux-gpio@vger.kernel.org Cc: linux-kernel@vger.kernel.org -- 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. --- 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 08dd15f..e639357 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 d5d72d8..d44232a 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; -- 2.7.4