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-kernel@vger.kernel.org
---
 Documentation/devicetree/bindings/gpio/gpio-pca953x.txt |  4 ++++
 drivers/gpio/gpio-pca953x.c                             | 11 +++++++++++
 2 files changed, 15 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..ca2ddea 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
@@ -754,8 +755,18 @@ static int pca953x_probe(struct i2c_client *client,
                invert = pdata->invert;
                chip->names = pdata->names;
        } else {
+               struct gpio_desc *reset_gpio;
+
                chip->gpio_start = -1;
                irq_base = 0;
+
+               /* see if we need to de-assert a reset pin */
+               reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+                                                    GPIOD_OUT_LOW);
+               if (IS_ERR(reset_gpio)) {
+                       dev_err(&client->dev, "request for reset pin failed\n");
+                       return PTR_ERR(reset_gpio);
+               }
        }
 
        chip->client = client;
-- 
2.7.4

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