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_longerbeam@xxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Alexandre Courbot <gnurou@xxxxxxxxx>
Cc: linux-gpio@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
--
v2:
- Specify that reset signal to PCA953x chip is active low, in
binding doc.
- reorder includes in gpio-pca953x.c.
- remove dev_err() on devm_gpiod_get_optional() error return.
---
Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++
drivers/gpio/gpio-pca953x.c | 9 +++++++++
2 files changed, 13 insertions(+)
diff --git a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
index 08dd15f..e639357 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. This is an
+ active low signal to the PCA953x.
+
Example:
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index d5d72d8..d44232a 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -14,6 +14,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/platform_data/pca953x.h>
@@ -754,8 +755,16 @@ 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))
+ return PTR_ERR(reset_gpio);
}
chip->client = client;
--
2.7.4
--
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