mb/google/volteer: Separate power resource for VCM

The camera privacy LED blinks during the boot and this gives a wrong
impression to the users that the camera is being used during the power
up. The blink happens when the camera module is probed and a series of
kernel patches and coreboot patches are being submitted to resolve the
issue.

The kernel patches are submitted to the chromium gerrit.

https://chromium-review.googlesource.com/2403386
https://chromium-review.googlesource.com/2403387
https://chromium-review.googlesource.com/2403385
https://chromium-review.googlesource.com/2403384
https://chromium-review.googlesource.com/2403383
https://chromium-review.googlesource.com/2403382
https://chromium-review.googlesource.com/2403381
https://chromium-review.googlesource.com/2403380

This is to separate the power resource for the VCM so that it can be
controlled by the driver and suppress the LED turn on.

BUG=b:169049942
BRANCH=none
TEST=Build and boot volteer board. Monitor camera privacy LED
and check if it blinks. It should not blink.

Signed-off-by: Daniel Kang <daniel.h.kang@intel.com>
Change-Id: Id51c98e42c5f20e231d8096c9d2d98deebc7c968
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45159
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@google.com>

src/mainboard/google/volteer/variants/baseboard/include/baseboard/acpi/mipi_camera.asl

@@ -146,12 +146,12 @@ Scope (\_SB.PCI0.IPU0)
 
 Scope (\_SB.PCI0.I2C3)
 {
+	/* Reference counter to track power control by RCAM and VCM */
+	Name (REFC, 0)
 	PowerResource (RCPR, 0x00, 0x0000)
 	{
-		Name (STA, Zero)
+		Name (STA, 0)
 		Method (_ON, 0, Serialized)  /* Rear camera_ON_: Power On */
-		{
-			If ((STA == Zero))
 		{
 			/* Enable IMG_CLK */
 			MCON(3,1) /* Clock 3, 19.2MHz */
@@ -166,10 +166,15 @@ Scope (\_SB.PCI0.I2C3)
 			/* Pull SNRPWR_EN high */
 			STXS(GPP_H14)
 
+			If (REFC == 0)
+			{
 				/* Pull PWREN high */
 				STXS(GPP_H20)
+			}
 			Sleep(2) /* reset pulse width */
 
+			REFC++
+
 			/* Pull RST high */
 #if CONFIG(BOARD_GOOGLE_VOLTEER)
 			STXS(GPP_F15)
@@ -178,12 +183,9 @@ Scope (\_SB.PCI0.I2C3)
 #endif
 			Sleep(1) /* t2 */
 
-				Store(1,STA)
+			STA = 1
-			}
 		}
 		Method (_OFF, 0, Serialized)  /* Rear camera _OFF: Power Off */
-		{
-			If ((STA == One))
 		{
 			/* Disable IMG_CLK */
 			Sleep(1) /* t0+t1 */
@@ -196,14 +198,17 @@ Scope (\_SB.PCI0.I2C3)
 			CTXS(GPP_D4)
 #endif
 
+			If (REFC == 1)
+			{
 				/* Pull PWREN low */
 				CTXS(GPP_H20)
+			}
+			REFC--
 
 			/* Pull SNRPWR_EN low */
 			CTXS(GPP_H14)
 
-				Store(0,STA)
+			STA = 0
-			}
 		}
 		Method (_STA, 0, NotSerialized)  /* _STA: Status */
 		{
@@ -339,6 +344,35 @@ Scope (\_SB.PCI0.I2C3)
 		})
 	}
 
+	PowerResource (VCPR, 0x00, 0x0000)
+	{
+		Name (STA, 0)
+		Method (_ON, 0, Serialized)  /* VCPR_ON_: VCM Power On */
+		{
+			If (REFC == 0)
+			{
+				/* Pull PWREN high */
+				STXS(GPP_H20)
+			}
+			REFC++
+			STA = 1
+		}
+		Method (_OFF, 0, Serialized)  /* VCPR_OFF: VCM Power Off */
+		{
+			If (REFC == 1)
+			{
+				/* Pull PWREN low */
+				CTXS(GPP_H20)
+			}
+			REFC--
+			STA = 0
+		}
+		Method (_STA, 0, NotSerialized)  /* _STA: Status */
+		{
+			Return (STA)
+		}
+	}
+
 	Device (VCM0)
 	{
 		Name (_HID, "PRP0001")  /* _HID: Hardware ID */
@@ -361,11 +395,11 @@ Scope (\_SB.PCI0.I2C3)
 		})
 		Name (_PR0, Package (0x01)  /* _PR0: Power Resources for D0 */
 		{
-			RCPR
+			VCPR
 		})
 		Name (_PR3, Package (0x01)  /* _PR3: Power Resources for D3hot */
 		{
-			RCPR
+			VCPR
 		})
 		Name (_DSD, Package (0x02)  /* _DSD: Device-Specific Data */
 		{
@@ -455,12 +489,12 @@ Scope (\_SB.PCI0.I2C3)
 
 Scope (\_SB.PCI0.I2C2)
 {
+	Name (STA, Zero)
 	PowerResource (FCPR, 0x00, 0x0000)
 	{
-		Name (STA, Zero)
 		Method (_ON, 0, Serialized)  /* Front camera_ON_: Power On */
 		{
-			If ((STA == Zero))
+			If (STA == 0)
 			{
 				/* Enable IMG_CLK */
 				MCON(2,1) /* Clock 2, 19.2MHz */
@@ -479,12 +513,12 @@ Scope (\_SB.PCI0.I2C2)
 				STXS(GPP_D4)
 				Sleep(1) /* t2 */
 
-				Store(1,STA)
+				STA = 1
 			}
 		}
 		Method (_OFF, 0, Serialized)  /* Front camera_OFF_: Power Off */
 		{
-			If ((STA == One))
+			If (STA == 1)
 			{
 				/* Disable IMG_CLK */
 				Sleep(1) /* t0+t1 */
@@ -499,7 +533,7 @@ Scope (\_SB.PCI0.I2C2)
 				/* Pull SNRPWR_EN low */
 				CTXS(GPP_D18)
 
-				Store(0,STA)
+				STA = 0
 			}
 		}
 		Method (_STA, 0, NotSerialized)  /* _STA: Status */