[S] Change in coreboot[main]: mb/google/nissa/var/craaskov: Implement touchscreen power sequencing

[Rex Chou (Code Review)]

Rex Chou has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/79764?usp=email )

Change subject: mb/google/nissa/var/craaskov: Implement touchscreen power sequencing
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mb/google/nissa/var/craaskov: Implement touchscreen power sequencing

For brya variants with a touchscreen, drive the enable GPIO high
starting in romstage while holding in reset, then disable the reset
GPIO in ramstage (done in the baseboard). This will allow coreboot
to detect the presence of i2c touchscreens during ACPI SSDT generation
(implemented in a subsequent commit).

BUG=b:317746281
TEST=emerge-nissa coreboot chromeos-bootimage

Change-Id: I85f2bee58582c0f56331d20a2984a3079c967be4
Signed-off-by: rex_chou

Change-Id: I3ca2e2d12a86eaae9e37870a2541c0287e354690
---
M src/mainboard/google/brya/variants/craaskov/gpio.c
1 file changed, 14 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/64/79764/1

diff --git a/src/mainboard/google/brya/variants/craaskov/gpio.c b/src/mainboard/google/brya/variants/craaskov/gpio.c
index 8b1446d..0d280ce 100644
--- a/src/mainboard/google/brya/variants/craaskov/gpio.c
+++ b/src/mainboard/google/brya/variants/craaskov/gpio.c
@@ -63,6 +63,14 @@
    PAD_CFG_NF(GPP_H11, NONE, DEEP, NF2),
 };

+static const struct pad_config romstage_gpio_table[] = {
+	/* Enable touchscreen, hold in reset */
+	/* C0  : SMBCLK ==> EN_PP3300_TCHSCR */
+	PAD_CFG_GPO(GPP_C0, 1, DEEP),
+	/* C1  : SMBDATA ==> USI_RST_L */
+	PAD_CFG_GPO(GPP_C1, 0, DEEP),
+};
+
 const struct pad_config *variant_gpio_override_table(size_t *num)
 {
    *num = ARRAY_SIZE(override_gpio_table);
@@ -74,3 +82,9 @@
    *num = ARRAY_SIZE(early_gpio_table);
    return early_gpio_table;
 }
+
+const struct pad_config *variant_romstage_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(romstage_gpio_table);
+	return romstage_gpio_table;
+}