ec/lenovo/h8/acpi: Add WWAN ACPI methods

Implement GWAN and SWAN for thinkpad_acpi kernel module.
Both methods allow power control of the WWAN module.

Change-Id: I5550c78e0d36884eca7a8d8ece19b64aaee44045
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/20986
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/ec/lenovo/h8/acpi/thinkpad.asl

@@ -18,6 +18,7 @@ Device (HKEY)
 {
 	/* Generated by ssdt.c */
 	External (\HBDC, IntObj)
+	External (\HWAN, IntObj)
 
 	Name (_HID, EisaId ("IBM0068"))
 
@@ -190,4 +191,41 @@ Device (HKEY)
 			/* FIXME: Store state at resume */
 		}
 	}
+
+	/*
+	 * Returns the current state:
+	 *  Bit 0: WWAN HW present
+	 *  Bit 1: WWAN radio enabled
+	 *  Bit 2: WWAN state at resume
+	 */
+	Method (GWAN, 0)
+	{
+		If (HWAN) {
+			Store(One, Local0)
+			If(\_SB.PCI0.LPCB.EC.WWEB)
+			{
+				Or(Local0, 2, Local0)
+			}
+			/* FIXME: Implement state at resume, for now Enabled */
+			Or(Local0, 4, Local0)
+			Return (Local0)
+		} Else {
+			Return (0)
+		}
+	}
+
+	/*
+	 * Set the current state:
+	 *  Bit 1: WWAN radio enabled
+	 *  Bit 2: WWAN state at resume
+	 */
+	Method (SWAN, 1)
+	{
+		If (HWAN) {
+			ShiftRight (And(Arg0, 2), 1, Local0)
+			Store (Local0, \_SB.PCI0.LPCB.EC.WWEB)
+
+			/* FIXME: Store state at resume */
+		}
+	}
 }

src/ec/lenovo/h8/ssdt.c

@@ -46,6 +46,7 @@ void h8_ssdt_generator(struct device *dev)
 
 	/* Used by thinkpad_acpi */
 	acpigen_write_name_byte("HBDC", h8_has_bdc(dev) ? ONE_OP : ZERO_OP);
+	acpigen_write_name_byte("HWAN", h8_has_wwan(dev) ? ONE_OP : ZERO_OP);
 
 	acpigen_pop_len(); /* Scope HKEY */
 }