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authorSimon Glass <sjg@chromium.org>2014-11-10 18:00:21 -0700
committerSimon Glass <sjg@chromium.org>2014-11-21 07:24:11 +0100
commite5901c94e32b3533c35511d1acfb7f1587e324ee (patch)
tree6dc5d86c7f55b0ac45e60bb3b019ceec02db59ec /drivers
parent469a579df2907a421afec06e37d50e61b7d80227 (diff)
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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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-uclass.c19
1 files changed, 19 insertions, 0 deletions
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 @@ int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize)
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)
{