mb/lenovo: Support dual graphics for xx20/xx30 ThinkPads

Add CMOS option that allows to use both integrated and discrete GPU.

Tested on ThinkPad W530.

Change-Id: I8842fef0fa1235eb91abf6b7e655ed4d8598adc7
Signed-off-by: Evgeny Zinoviev <me@ch1p.com>
Reviewed-on: https://review.coreboot.org/28393
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/lenovo/t420/cmos.layout

@@ -129,6 +129,7 @@ enumerations
 11    6     224M
 12    0     Integrated Only
 12    1     Discrete Only
+12    2     Dual Graphics
 13    0     Disable
 13    1     AC and battery
 13    2     AC only

src/mainboard/lenovo/t420/romstage.c

@@ -30,6 +30,9 @@ static void hybrid_graphics_init(void)
 
 	early_hybrid_graphics(&igd, &peg);
 
+	if (peg && igd)
+		return;
+
 	/* Hide disabled devices */
 	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
 	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);

src/mainboard/lenovo/t420s/cmos.layout

@@ -129,6 +129,7 @@ enumerations
 11    6     224M
 12    0     Integrated Only
 12    1     Discrete Only
+12    2     Dual Graphics
 13    0     Disable
 13    1     AC and battery
 13    2     AC only

src/mainboard/lenovo/t420s/romstage.c

@@ -32,6 +32,9 @@ static void hybrid_graphics_init(void)
 
 	early_hybrid_graphics(&igd, &peg);
 
+	if (peg && igd)
+		return;
+
 	/* Hide disabled devices */
 	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
 	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);

src/mainboard/lenovo/t430/cmos.layout

@@ -128,6 +128,7 @@ enumerations
 11    6     224M
 12    0     Integrated Only
 12    1     Discrete Only
+12    2     Dual Graphics
 13    0     Disable
 13    1     AC and battery
 13    2     AC only

src/mainboard/lenovo/t430/romstage.c

@@ -30,6 +30,9 @@ static void hybrid_graphics_init(void)
 
 	early_hybrid_graphics(&igd, &peg);
 
+	if (peg && igd)
+		return;
+
 	/* Hide disabled devices */
 	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
 	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);

src/mainboard/lenovo/t430s/cmos.default

@@ -13,4 +13,5 @@ fn_ctrl_swap=Disable
 sticky_fn=Disable
 trackpoint=Enable
 backlight=Both
+enable_dual_graphics=Disable
 usb_always_on=Disable

src/mainboard/lenovo/t430s/cmos.layout

@@ -76,7 +76,8 @@ entries
 
 # coreboot config options: northbridge
 432          3       e       11       gfx_uma_size
-#435         5       r       0        unused
+435          1       e       1        enable_dual_graphics
+#436         4       r       0        unused
 440          8       h       0        volume
 
 # SandyBridge MRC Scrambler Seed values

src/mainboard/lenovo/t430s/romstage.c

@@ -15,12 +15,14 @@
  * GNU General Public License for more details.
  */
 
+#include <option.h>
 #include <arch/byteorder.h>
 #include <arch/io.h>
 #include <device/pci_def.h>
 #include <console/console.h>
 #include <northbridge/intel/sandybridge/raminit_native.h>
 #include <southbridge/intel/bd82x6x/pch.h>
+#include <ec/lenovo/pmh7/pmh7.h>
 
 void pch_enable_lpc(void)
 {
@@ -64,6 +66,22 @@ void mainboard_get_spd(spd_raw_data *spd, bool id_only) {
 }
 
 void mainboard_early_init(int s3resume) {
+	u8 enable_peg;
+	if (get_option(&enable_peg, "enable_dual_graphics") != CB_SUCCESS)
+		enable_peg = 0;
+
+	bool power_en = pmh7_dgpu_power_state();
+
+	if (enable_peg != power_en)
+		pmh7_dgpu_power_enable(!power_en);
+
+	if (!enable_peg) {
+		// Hide disabled dGPU device
+		u32 reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
+		reg32 &= ~DEVEN_PEG10;
+
+		pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, reg32);
+	}
 }
 
 void mainboard_config_superio(void)

src/mainboard/lenovo/t520/romstage.c

@@ -42,6 +42,9 @@ static void hybrid_graphics_init(void)
 
 	early_hybrid_graphics(&igd, &peg);
 
+	if (peg && igd)
+		return;
+
 	/* Hide disabled devices */
 	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
 	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);

src/mainboard/lenovo/t530/cmos.layout

@@ -129,6 +129,7 @@ enumerations
 11    6     224M
 12    0     Integrated Only
 12    1     Discrete Only
+12    2     Dual Graphics
 13    0     Disable
 13    1     AC and battery
 13    2     AC only

src/mainboard/lenovo/t530/romstage.c

@@ -34,6 +34,9 @@ static void hybrid_graphics_init(void)
 
 	early_hybrid_graphics(&igd, &peg);
 
+	if (peg && igd)
+		return;
+
 	/* Hide disabled devices */
 	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
 	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);