The DT bindings for the pca953x family has an optional reset-gpios property. If present, ensure that the device is taken out of reset before attempting to read from it.
Signed-off-by: Rasmus Villemoes rasmus.villemoes@prevas.dk --- drivers/gpio/pca953x_gpio.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/gpio/pca953x_gpio.c b/drivers/gpio/pca953x_gpio.c index b0c66d18317..24b0732f89a 100644 --- a/drivers/gpio/pca953x_gpio.c +++ b/drivers/gpio/pca953x_gpio.c @@ -306,6 +306,7 @@ static int pca953x_probe(struct udevice *dev) struct pca953x_info *info = dev_get_plat(dev); struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); char name[32], label[8], *str; + struct gpio_desc reset; int addr; ulong driver_data; int ret; @@ -321,6 +322,13 @@ static int pca953x_probe(struct udevice *dev)
driver_data = dev_get_driver_data(dev);
+ /* If a reset-gpios property is present, take the device out of reset. */ + ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT); + if (ret && ret != -ENOENT) { + dev_err(dev, "requesting reset-gpios failed: %d\n", ret); + return ret; + } + info->gpio_count = driver_data & PCA_GPIO_MASK; if (info->gpio_count > MAX_BANK * BANK_SZ) { dev_err(dev, "Max support %d pins now\n", MAX_BANK * BANK_SZ);