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 ---
drivers/gpio/gpio-uclass.c | 19 +++++++++++++++++++ include/asm-generic/gpio.h | 11 ++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-)
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) { diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index f81b51a..36a36c6 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_ */