dm: gpio: Add a function to read an ID from a list of GPIOs
For board IDs a common approach is to set aside several GPIOs for use in
determining the board ID. This can provide information about board features
and the revision.
Add a function that turns a list of GPIOs into an integer by assigning
each GPIO to a single bit.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 45e9a5a..255700a 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -390,6 +390,25 @@
return 0;
}
+/*
+ * get a number comprised of multiple GPIO values. gpio_num_array points to
+ * the array of gpio pin numbers to scan, terminated by -1.
+ */
+unsigned gpio_get_values_as_int(const int *gpio_num_array)
+{
+ int gpio;
+ unsigned bitmask = 1;
+ unsigned vector = 0;
+
+ while (bitmask &&
+ ((gpio = *gpio_num_array++) != -1)) {
+ if (gpio_get_value(gpio))
+ vector |= bitmask;
+ bitmask <<= 1;
+ }
+ return vector;
+}
+
/* We need to renumber the GPIOs when any driver is probed/removed */
static int gpio_renumber(struct udevice *removed_dev)
{