mb/lenovo/t*00/romstage: Switch to new hybrid driver

Get rid of old hybrid graphics driver and use the new one.

1. Disable IGD and PEG in early romstage.
 The PEG port will get disabled on devices that do not have a
 discrete GPU. The power savings are around ~1Watt.

 The disabled IGD does no longer waste GFX stolen memory.

2. Get rid of PCI driver
 The Nvidia GPU can be handled by the generic PCI driver and allows
 to use the ACPI _ROM generator for Switchable graphics.

3. Settings are stored in devicetree.
 One driver for all Lenovo hybrid graphics capable devices.

4. Add support for Thinker1 GPU power handling.
 Only boards that do use reference design 2012 are known to be
 supported. Needs test on boards that do you use reference design 2013.
 Should reduce idle power consumption when using IGD by ~5Watt.

Tested on Lenovo T430 without DGPU. PEG port is disabled.
Needs test on all devices.

Change-Id: Ibf18b75e8afe2568de8498b39a608dac8db3ba73
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/20794
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

3 files changed, 43 insertions, 0 deletions

diff --git a/src/mainboard/lenovo/t420/Kconfig b/src/mainboard/lenovo/t420/Kconfig
index 784d38a303..c0b475270f 100644
--- a/src/mainboard/lenovo/t420/Kconfig
+++ b/src/mainboard/lenovo/t420/Kconfig
@@ -22,6 +22,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select MAINBOARD_HAS_LPC_TPM
 	select MAINBOARD_HAS_LIBGFXINIT
 	select GFX_GMA_INTERNAL_IS_LVDS
+	select DRIVERS_LENOVO_HYBRID_GRAPHICS
 
 	# Workaround for EC/KBC IRQ1.
 	select SERIRQ_CONTINUOUS_MODE
diff --git a/src/mainboard/lenovo/t420/devicetree.cb b/src/mainboard/lenovo/t420/devicetree.cb
index deb62b7166..3b4e6ab9b5 100644
--- a/src/mainboard/lenovo/t420/devicetree.cb
+++ b/src/mainboard/lenovo/t420/devicetree.cb
@@ -162,6 +162,20 @@ chip northbridge/intel/sandybridge
 					register "eventd_enable" = "0xff"
 					register "evente_enable" = "0x0d"
 				end
+				chip drivers/lenovo/hybrid_graphics
+					device pnp ff.f on end # dummy
+
+					register "detect_gpio" = "21"
+
+					register "has_panel_hybrid_gpio" = "1"
+					register "panel_hybrid_gpio" = "52"
+					register "panel_integrated_lvl" = "1"
+
+					register "has_backlight_gpio" = "0"
+					register "has_dgpu_power_gpio" = "0"
+
+					register "has_thinker1" = "1"
+				end
 			end # LPC Controller
 			device pci 1f.2 on
 				subsystemid 0x17aa 0x21ce
diff --git a/src/mainboard/lenovo/t420/romstage.c b/src/mainboard/lenovo/t420/romstage.c
index 94b8d62504..9f178ea741 100644
--- a/src/mainboard/lenovo/t420/romstage.c
+++ b/src/mainboard/lenovo/t420/romstage.c
@@ -18,6 +18,33 @@
 #include <arch/io.h>
 #include <northbridge/intel/sandybridge/raminit_native.h>
 #include <southbridge/intel/bd82x6x/pch.h>
+#include <drivers/lenovo/hybrid_graphics/hybrid_graphics.h>
+#include <northbridge/intel/sandybridge/sandybridge.h>
+#include <device/device.h>
+#include <device/pci.h>
+
+static void hybrid_graphics_init(void)
+{
+	bool peg, igd;
+	u32 reg32;
+
+	early_hybrid_graphics(&igd, &peg);
+
+	/* Hide disabled devices */
+	reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
+	reg32 &= ~(DEVEN_PEG10 | DEVEN_IGD);
+
+	if (peg)
+		reg32 |= DEVEN_PEG10;
+
+	if (igd)
+		reg32 |= DEVEN_IGD;
+	else
+		/* Disable IGD VGA decode, no GTT or GFX stolen */
+		pci_write_config16(PCI_DEV(0, 0, 0), GGC, 2);
+
+	pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, reg32);
+}
 
 void pch_enable_lpc(void)
 {
@@ -65,6 +92,7 @@ void mainboard_get_spd(spd_raw_data *spd, bool id_only)
 
 void mainboard_early_init(int s3resume)
 {
+	hybrid_graphics_init();
 }
 
 void mainboard_config_superio(void)