From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:33628 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753367AbcL2W2N (ORCPT ); Thu, 29 Dec 2016 17:28:13 -0500 From: Steve Longerbeam To: shawnguo@kernel.org, kernel@pengutronix.de, fabio.estevam@nxp.com, robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, linus.walleij@linaro.org, gnurou@gmail.com, mchehab@kernel.org, gregkh@linuxfoundation.org, p.zabel@pengutronix.de Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, Steve Longerbeam Subject: [PATCH 10/20] gpio: pca953x: Add optional reset gpio control Date: Thu, 29 Dec 2016 14:27:25 -0800 Message-Id: <1483050455-10683-11-git-send-email-steve_longerbeam@mentor.com> In-Reply-To: <1483050455-10683-1-git-send-email-steve_longerbeam@mentor.com> References: <1483050455-10683-1-git-send-email-steve_longerbeam@mentor.com> Sender: linux-media-owner@vger.kernel.org List-ID: 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: - 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 #include #include +#include #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