Magf - has uploaded this change for review.
mb/google/kukui: fix damu touchscreen reset sequence
Damu touchscreen is a typical hid-over-i2c device and its reset pin
has a sequence requirement (T5) > 500us. Kernel hid-over-i2c driver
has no interface to support a reset pin, so current implementation
will be using a default pull down pin and rely on kernel to pull
it to high to make it exit reset. But when warm reboot, because
kernel will not pull it low, if we want a reset, we can pull it low
and rely on kernel to release it to get a valid reset > 500us.
BUG=b:159688118
BRANCH=kukui
TEST=build and boot damu device, when warm reboot, we can get a
valid reset sequence which is greater than 500us.
Change-Id: I069f5ef3e9477410d5349e5a702a4fbc14c201ed
Signed-off-by: Paul Ma <magf@bitland.crop-partner.google.com>
---
M src/mainboard/google/kukui/chromeos.c
M src/mainboard/google/kukui/gpio.h
2 files changed, 4 insertions(+), 0 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/19/43319/1
diff --git a/src/mainboard/google/kukui/chromeos.c b/src/mainboard/google/kukui/chromeos.c
index c5810d1..755a386 100644
--- a/src/mainboard/google/kukui/chromeos.c
+++ b/src/mainboard/google/kukui/chromeos.c
@@ -15,6 +15,9 @@
gpio_input_pullup(CR50_IRQ);
gpio_output(GPIO_RESET, 0);
gpio_output(GPIO_EN_SPK_AMP, 0);
+
+ if (CONFIG(BOARD_GOOGLE_DAMU))
+ gpio_output(GPIO_TOUCH_RST, 0);
}
void fill_lb_gpios(struct lb_gpios *gpios)
diff --git a/src/mainboard/google/kukui/gpio.h b/src/mainboard/google/kukui/gpio.h
index c71fe3e..e0329ce 100644
--- a/src/mainboard/google/kukui/gpio.h
+++ b/src/mainboard/google/kukui/gpio.h
@@ -11,6 +11,7 @@
#define CR50_IRQ GPIO(PERIPHERAL_EN3)
#define GPIO_RESET GPIO(PERIPHERAL_EN8)
#define GPIO_EN_SPK_AMP GPIO(PERIPHERAL_EN12)
+#define GPIO_TOUCH_RST GPIO(ANT_SEL1)
void setup_chromeos_gpios(void);
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