soc/intel/cannonlake: Add ASL function for setting pad mode

Add a function in gpio ASL library to set pad mode.

BUG=b:123350329

Change-Id: I6c683f27ddffc3132001706d1694c71bb5664577
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/c/31444
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/cannonlake/acpi/gpio_op.asl

@@ -72,3 +72,25 @@ Method (CTXS, 1, Serialized)
 	}
 	And (Not (GPIOTXSTATE_MASK), VAL0, VAL0)
 }
+
+/*
+ * Set Pad mode
+ * Arg0 - GPIO Number
+ * Arg1 - Pad mode
+ *     0 = GPIO control pad
+ *     1 = Native Function 1
+ *     2 = Native Function 2
+ *     3 = Native Function 3
+ */
+Method (GPMO, 2, Serialized)
+{
+	OperationRegion (PREG, SystemMemory, GADD (Arg0), 4)
+	Field (PREG, AnyAcc, NoLock, Preserve)
+	{
+		VAL0, 32
+	}
+	Store (VAL0, Local0)
+	And (Not (GPIOPADMODE_MASK), Local0, Local0)
+	And (ShiftLeft (Arg1, GPIOPADMODE_SHIFT, Arg1), GPIOPADMODE_MASK, Arg1)
+	Or (Local0, Arg1, VAL0)
+}

src/soc/intel/cannonlake/include/soc/gpio_defs.h

@@ -253,4 +253,6 @@
 #define GPIORXSTATE_MASK			0x1
 #define GPIORXSTATE_SHIFT			1
 #define GPIOTXSTATE_MASK			0x1
+#define GPIOPADMODE_MASK			0xC00
+#define GPIOPADMODE_SHIFT			10
 #endif

src/soc/intel/cannonlake/include/soc/gpio_defs_cnp_h.h

@@ -327,4 +327,6 @@
 #define GPIORXSTATE_MASK			0x1
 #define GPIORXSTATE_SHIFT			1
 #define GPIOTXSTATE_MASK			0x1
+#define GPIOPADMODE_MASK			0xC00
+#define GPIOPADMODE_SHIFT			10
 #endif