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| author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2013-11-29 01:51:25 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-01-03 17:40:27 +0100 |
| commit | 12097957a9ed13135bfa4c4a9c649e5c9e5ac9ec (patch) | |
| tree | 16dada09190b1d71f91dfa1af701e3eeecf8bbcf | |
| parent | i2c: pca954x: Add device tree bindings documentation (diff) | |
| download | linux-12097957a9ed13135bfa4c4a9c649e5c9e5ac9ec.tar.xz linux-12097957a9ed13135bfa4c4a9c649e5c9e5ac9ec.zip | |
i2c: pca954x: Add reset GPIO support
If a reset GPIO support is specified, request the GPIO and get the chip
out of reset at probe time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 | ||||
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-pca954x.c | 19 |
2 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt index cc7e7fd92e31..34a3fb6f8488 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt @@ -13,6 +13,10 @@ Required Properties: - Standard I2C mux properties. See i2c-mux.txt in this directory. - I2C child bus nodes. See i2c-mux.txt in this directory. +Optional Properties: + + - reset-gpios: Reference to the GPIO connected to the reset input. + Example: diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 2880c38543de..e835304e7b5a 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -36,11 +36,13 @@ */ #include <linux/device.h> +#include <linux/gpio.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> #include <linux/i2c/pca954x.h> #include <linux/init.h> #include <linux/module.h> +#include <linux/of_gpio.h> #include <linux/slab.h> #define PCA954X_MAX_NCHANS 8 @@ -185,6 +187,7 @@ static int pca954x_probe(struct i2c_client *client, { struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent); struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev); + struct device_node *np = client->dev.of_node; int num, force, class; struct pca954x *data; int ret; @@ -198,6 +201,22 @@ static int pca954x_probe(struct i2c_client *client, i2c_set_clientdata(client, data); + if (IS_ENABLED(CONFIG_OF) && np) { + enum of_gpio_flags flags; + int gpio; + + /* Get the mux out of reset if a reset GPIO is specified. */ + gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags); + if (gpio_is_valid(gpio)) { + ret = devm_gpio_request_one(&client->dev, gpio, + flags & OF_GPIO_ACTIVE_LOW ? + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, + "pca954x reset"); + if (ret < 0) + return ret; + } + } + /* Write the mux register at addr to verify * that the mux is in fact present. This also * initializes the mux to disconnected state. |