lynxpoint: provide gpio_is_native()

There's a need to determine if a specific gpio pin is
is set up to be a native function or not. Implement this.

Change-Id: I91d57a549e0f4fddc0b1849e5f74320fc839642c
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/59589
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/4324
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/southbridge/intel/lynxpoint/gpio.c b/src/southbridge/intel/lynxpoint/gpio.c
index 147a1c013b..c6d6a1522a 100644
--- a/src/southbridge/intel/lynxpoint/gpio.c
+++ b/src/southbridge/intel/lynxpoint/gpio.c
@@ -128,3 +128,22 @@ void set_gpio(int gpio_num, int value)
 	config |= value << bit;
 	outl(config, gpio_base + gpio_reg_offsets[index]);
 }
+
+int gpio_is_native(int gpio_num)
+{
+	static const int gpio_reg_offsets[] = {
+		GPIO_USE_SEL, GPIO_USE_SEL2, GPIO_USE_SEL3
+	};
+	u16 gpio_base = get_gpio_base();
+	int index, bit;
+	u32 config;
+
+	if (gpio_num > MAX_GPIO_NUMBER)
+		return 0; /* Just ignore wrong gpio numbers. */
+
+	index = gpio_num / 32;
+	bit = gpio_num % 32;
+
+	config = inl(gpio_base + gpio_reg_offsets[index]);
+	return !(config & (1 << bit));
+}