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 <steve_longerb...@mentor.com>
Cc: Linus Walleij <linus.wall...@linaro.org>
Cc: Alexandre Courbot <gnu...@gmail.com>
Cc: linux-g...@vger.kernel.org
Cc: linux-ker...@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 <linux/of_platform.h>
#include <linux/acpi.h>
#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
#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
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