If a reset GPIO support is specified, request the GPIO and get the chip
out of reset at probe time.
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 ++++
drivers/i2c/muxes/i2c-mux-pca954x.c | 19 +++++++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
index cc7e7fd..34a3fb6 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 2880c38..e835304 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.
--
1.8.3.2
--
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