gpio: Report errors when GPIOs cannot be read
Some controllers do not allow the output value to be read. Detect this and
report the error in that case.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/gpio.c b/cmd/gpio.c
index 693998e..ecdc453 100644
--- a/cmd/gpio.c
+++ b/cmd/gpio.c
@@ -119,7 +119,7 @@
{
unsigned int gpio;
enum gpio_cmd sub_cmd;
- ulong value;
+ int value;
const char *str_cmd, *str_gpio = NULL;
int ret;
#ifdef CONFIG_DM_GPIO
@@ -197,15 +197,35 @@
value = gpio_get_value(gpio);
} else {
switch (sub_cmd) {
- case GPIO_SET: value = 1; break;
- case GPIO_CLEAR: value = 0; break;
- case GPIO_TOGGLE: value = !gpio_get_value(gpio); break;
- default: goto show_usage;
+ case GPIO_SET:
+ value = 1;
+ break;
+ case GPIO_CLEAR:
+ value = 0;
+ break;
+ case GPIO_TOGGLE:
+ value = gpio_get_value(gpio);
+ if (!IS_ERR_VALUE(value))
+ value = !value;
+ break;
+ default:
+ goto show_usage;
}
gpio_direction_output(gpio, value);
}
- printf("gpio: pin %s (gpio %i) value is %lu\n",
- str_gpio, gpio, value);
+ printf("gpio: pin %s (gpio %i) value is ", str_gpio, gpio);
+ if (IS_ERR_VALUE(value))
+ printf("unknown (ret=%d)\n", value);
+ else
+ printf("%d\n", value);
+ if (sub_cmd != GPIO_INPUT && !IS_ERR_VALUE(value)) {
+ int nval = gpio_get_value(gpio);
+
+ if (IS_ERR_VALUE(nval))
+ printf(" Warning: no access to GPIO output value\n");
+ else if (nval != value)
+ printf(" Warning: value of pin is still %d\n", nval);
+ }
if (ret != -EBUSY)
gpio_free(gpio);