Add optional reset-gpios property. 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>
---
drivers/gpio/gpio-pca953x.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 5e3be32..475fa56 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -21,6 +21,7 @@
#include <asm/unaligned.h>
#include <linux/of_platform.h>
#include <linux/acpi.h>
+#include <linux/of_gpio.h>
#define PCA953X_INPUT 0
#define PCA953X_OUTPUT 1
@@ -111,6 +112,11 @@ struct pca953x_chip {
const char *const *names;
int chip_type;
unsigned long driver_data;
+
+#ifdef CONFIG_OF_GPIO
+ enum of_gpio_flags reset_gpio_flags;
+ int reset_gpio;
+#endif
};
static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
@@ -759,6 +765,28 @@ static int pca953x_probe(struct i2c_client *client,
} else {
chip->gpio_start = -1;
irq_base = 0;
+
+#ifdef CONFIG_OF_GPIO
+ /* see if we need to de-assert a reset pin */
+ ret = of_get_named_gpio_flags(client->dev.of_node,
+ "reset-gpios", 0,
+ &chip->reset_gpio_flags);
+ if (gpio_is_valid(ret)) {
+ chip->reset_gpio = ret;
+ ret = devm_gpio_request_one(&client->dev,
+ chip->reset_gpio,
+ GPIOF_DIR_OUT,
+ "pca953x_reset");
+ if (ret == 0) {
+ /* bring chip out of reset */
+ dev_info(&client->dev, "releasing reset\n");
+ gpio_set_value(chip->reset_gpio,
+ (chip->reset_gpio_flags ==
+ OF_GPIO_ACTIVE_LOW) ? 1 : 0);
+ }
+ } else if (ret == -EPROBE_DEFER)
+ return ret;
+#endif
}
chip->client = client;
--
1.9.1
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