Change in coreboot[master]: mb/google/brya/var/nereid: Add WLAN power sequence

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/63368 )

Change subject: mb/google/brya/var/nereid: Add WLAN power sequence
......................................................................

mb/google/brya/var/nereid: Add WLAN power sequence

There are currently two issues related to the WLAN power sequencing on
nereid:
- If the EN pin GPP_B11 is not high during cold boot, the SoC gets stuck
  in S3.
- During warm reboot, if we only assert RST without pulling the power
  low, then the kernel crashes.

As a workaround while we investigate these issues, we pull the EN high
in S5, then actively drive it low in bootblock and high in romstage to
make sure it goes low during warm reboot.

BUG=b:227694137, b:225261075
TEST=Cold boot succeeds, and there's no kernel crash during warm reboot.

Change-Id: I1ca46d9649eff3f96a0e77db594d87288b29a83a
Signed-off-by: Reka Norman 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63368
Tested-by: build bot (Jenkins) 
Reviewed-by: Kangheui Won 
Reviewed-by: Sam McNally 
---
M src/mainboard/google/brya/variants/nereid/gpio.c
1 file changed, 15 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Kangheui Won: Looks good to me, approved
  Sam McNally: Looks good to me, approved

diff --git a/src/mainboard/google/brya/variants/nereid/gpio.c b/src/mainboard/google/brya/variants/nereid/gpio.c
index f9ef8c9..f011e2f 100644
--- a/src/mainboard/google/brya/variants/nereid/gpio.c
+++ b/src/mainboard/google/brya/variants/nereid/gpio.c
@@ -41,6 +41,10 @@

/* Early pad configuration in bootblock */
 static const struct pad_config early_gpio_table[] = {
+	/* B11 : PMCALERT# ==> EN_PP3300_WLAN_X */
+	PAD_CFG_GPO(GPP_B11, 0, DEEP),
+	/* H20 : IMGCLKOUT1 ==> WLAN_PERST_L */
+	PAD_CFG_GPO(GPP_H20, 0, DEEP),
    /* A13 : GPP_A13 ==> GSC_SOC_INT_ODL */
    PAD_CFG_GPI_APIC(GPP_A13, NONE, PLTRST, LEVEL, INVERT),
    /* E12 : THC0_SPI1_IO1 ==> SOC_WP_OD */
@@ -57,6 +61,11 @@
    PAD_CFG_NF(GPP_H11, NONE, DEEP, NF2),
 };

+static const struct pad_config romstage_gpio_table[] = {
+	/* B11 : PMCALERT# ==> EN_PP3300_WLAN_X */
+	PAD_CFG_GPO(GPP_B11, 1, DEEP),
+};
+
 const struct pad_config *variant_gpio_override_table(size_t *num)
 {
    *num = ARRAY_SIZE(override_gpio_table);
@@ -68,3 +77,9 @@
    *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;
+}

3 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.