[S] Change in coreboot[master]: mb/google/kahlee: Implement touchscreen power sequencing

[Matt DeVillier (Code Review)]

Attention is currently required from: Jason Nien, Martin Roth.

Matt DeVillier has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/69547 )

Change subject: mb/google/kahlee: Implement touchscreen power sequencing
......................................................................

mb/google/kahlee: Implement touchscreen power sequencing

As all variants have a touchscreen option, in baseboard table set the
enable GPIO high and hold in reset during romstage, then release reset
in ramstage. This will allow the touchscreen to make use of the runtime
I2C detect feature (enabled in a subsequent commit) so that an ACPI
device entry is created only for the touchscreen actually present.

This mirrors similar changes made for skyrim, guybrush, and zork.

TEST=tested with rest of patch train

Change-Id: Id235815904dfc093549a1ed529e19974010977c7
Signed-off-by: Matt DeVillier 
---
M src/mainboard/google/kahlee/variants/baseboard/gpio.c
1 file changed, 25 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/47/69547/1

diff --git a/src/mainboard/google/kahlee/variants/baseboard/gpio.c b/src/mainboard/google/kahlee/variants/baseboard/gpio.c
index d421e7d..8f22835 100644
--- a/src/mainboard/google/kahlee/variants/baseboard/gpio.c
+++ b/src/mainboard/google/kahlee/variants/baseboard/gpio.c
@@ -69,6 +69,11 @@
 };

static const struct soc_amd_gpio gpio_set_stage_rom[] = {
+	/* Enable touchscreen, hold in reset */
+	/* GPIO_76 - EN_PP3300_TOUCHSCREEN */
+	PAD_GPO(GPIO_76, HIGH),
+	/* GPIO_85 - TOUCHSCREEN_RST (Active High) */
+	PAD_GPO(GPIO_85, HIGH),
    /* GPIO_133 - APU_EDP_BKLTEN_L (backlight - Active LOW) */
    PAD_GPO(GPIO_133, HIGH),
 };