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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2013-11-29 01:51:25 +0100
committerWolfram Sang <wsa@the-dreams.de>2014-01-03 17:40:27 +0100
commit12097957a9ed13135bfa4c4a9c649e5c9e5ac9ec (patch)
tree16dada09190b1d71f91dfa1af701e3eeecf8bbcf /drivers/i2c/muxes
parent4215138e08489f2c1670c9118da2e62fcab2ffc6 (diff)
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>
Diffstat (limited to 'drivers/i2c/muxes')
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c19
1 files changed, 19 insertions, 0 deletions
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.