soc/intel/common/gpio: Add function to get GPIO index in group

The gpio_get_index_in_group function returns the index of the GPIO
within its own group

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I7f6b312bd1d0388ef799cd127c88b17bad6a3886
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51647
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/common/block/gpio/gpio.c

@@ -668,3 +668,13 @@ void gpio_pm_configure(const uint8_t *misccfg_pm_values, size_t num)
 		pcr_rmw8(comm->port, GPIO_MISCCFG,
 				misccfg_pm_mask, misccfg_pm_values[i]);
 }
+
+size_t gpio_get_index_in_group(gpio_t pad)
+{
+	const struct pad_community *comm;
+	size_t pin;
+
+	comm = gpio_get_community(pad);
+	pin = relative_pad_in_comm(comm, pad);
+	return gpio_within_group(comm, pin);
+}

src/soc/intel/common/block/include/intelblocks/gpio.h

@@ -235,5 +235,7 @@ void block_gpio_enable(struct device *dev);
  */
 bool gpio_routes_ioapic_irq(unsigned int irq);
 
+size_t gpio_get_index_in_group(gpio_t pad);
+
 #endif
 #endif /* _SOC_INTELBLOCKS_GPIO_H_ */