mb/google/dedede: Implement touchscreen power sequencing

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

Since the fast majority of dedede variants have a touchscreen option,
and those that do use the same GPIOs for enable/reset, set the GPIOs for
touchscreen operation in the baseboard and then override for the few (3)
variants that do not have a touchscreen.

BUG=b:121309055
TEST=tested with rest of patch train

Change-Id: Ib95e23545cc3e8589ddbd9e18cd0533bec9333e0
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/71187
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <felixsinger@posteo.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mainboard/google/dedede/variants/sasuke/gpio.c b/src/mainboard/google/dedede/variants/sasuke/gpio.c
index 8aa9f292e3..011b6e74ed 100644
--- a/src/mainboard/google/dedede/variants/sasuke/gpio.c
+++ b/src/mainboard/google/dedede/variants/sasuke/gpio.c
@@ -70,3 +70,17 @@ const struct pad_config *variant_override_gpio_table(size_t *num)
 	*num = ARRAY_SIZE(gpio_table);
 	return gpio_table;
 }
+
+static const struct pad_config romstage_gpio_table[] = {
+	/* no touchscreen present */
+	/* D5  : TOUCH_RESET_L */
+	PAD_NC(GPP_D5, NONE),
+	/* D6  : EN_PP3300_TOUCH_S0 */
+	PAD_NC(GPP_D6, NONE),
+};
+
+const struct pad_config *__weak variant_romstage_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(romstage_gpio_table);
+	return romstage_gpio_table;
+}