summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
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
parent469a579df2907a421afec06e37d50e61b7d80227 (diff)
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>
-rw-r--r--drivers/gpio/gpio-uclass.c19
-rw-r--r--include/asm-generic/gpio.h11
2 files changed, 29 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 45e9a5ad227..255700ab18d 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)
{
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index f81b51aa301..36a36c64b8a 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -257,6 +257,15 @@ const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
int gpio_lookup_name(const char *name, struct udevice **devp,
unsigned int *offsetp, unsigned int *gpiop);
-int name_to_gpio(const char *name);
+/**
+ * get_gpios() - Turn the values of a list of GPIOs into an integer
+ *
+ * This puts the value of the first GPIO into bit 0, the second into bit 1,
+ * etc. then returns the resulting integer.
+ *
+ * @gpio_list: List of GPIOs to collect
+ * @return resulting integer value
+ */
+unsigned gpio_get_values_as_int(const int *gpio_list);
#endif /* _ASM_GENERIC_GPIO_H_ */