mb/google/poppy/variant/nami - Ensure power cycle of FPMCU on startup

Add functionality to ensure that the FPMCU is power cycled long enough
on boot to ensure proper reset.

This solution relies solely on coreboot to sequence the power and reset
signals appropriately (150ms on boot).

-Confirmed power is off for 150ms on boot.
-Confirmed RCC_CSR of FPMCU indicates power cycle occurred.
-Confirmed reset is de-asserted approx 3ms after power application
(target >2.5ms)


BUG=b:245954151
TEST=Confirmed FPMCU is still functional on Nami and timings are
as expected.

Change-Id: I0a23bda96bc2ea90be81a2310605f75c55c0a839
Signed-off-by: Tarun Tuli <taruntuli@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73212
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Shelley Chen <shchen@google.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

2 files changed, 73 insertions, 4 deletions

diff --git a/src/mainboard/google/poppy/variants/nami/gpio.c b/src/mainboard/google/poppy/variants/nami/gpio.c
index 68f0f5b0d7..58c02b8a98 100644
--- a/src/mainboard/google/poppy/variants/nami/gpio.c
+++ b/src/mainboard/google/poppy/variants/nami/gpio.c
@@ -404,7 +404,7 @@ static const struct pad_config fpmcu_gpio_table[] = {
 	/* B1  : CORE_VID1 ==> FPMCU_INT_L */
 	PAD_CFG_GPI_SCI(GPP_B1, UP_20K, DEEP, EDGE_SINGLE, INVERT),
 	/* B11 : EXT_PWR_GATE# ==> PCH_FP_PWR_EN */
-	PAD_CFG_GPO(GPP_B11, 1, DEEP),
+	PAD_CFG_GPO(GPP_B11, 0, DEEP),
 	/* B19 : GSPI1_CS# ==> PCH_SPI_FP_CS# */
 	PAD_CFG_NF(GPP_B19, NONE, DEEP, NF1),
 	/* B20 : GSPI1_CLK ==> PCH_SPI_FP_CLK */
@@ -416,13 +416,47 @@ static const struct pad_config fpmcu_gpio_table[] = {
 	/* C3  : SML0CLK ==> TOUCHSCREEN_DIS# */
 	PAD_CFG_GPO(GPP_C3, 0, DEEP),
 	/* C9  : UART0_TXD ==> FP_RST_ODL */
-	PAD_CFG_GPO(GPP_C9, 1, DEEP),
+	PAD_CFG_GPO(GPP_C9, 0, DEEP),
 	/* D5  : ISH_I2C0_SDA ==> FPMCU_BOOT0 */
 	PAD_CFG_GPO(GPP_D5, 0, DEEP),
 	/* D17 : DMIC_CLK1 ==> NC */
 	PAD_NC(GPP_D17, NONE),
 };
 
+const struct pad_config *variant_romstage_sku_gpio_table(size_t *num)
+{
+	uint32_t sku_id = variant_board_sku();
+	const struct pad_config *board_gpio_tables;
+
+	switch (sku_id) {
+	case SKU_0_EKKO:
+	case SKU_1_EKKO:
+	case SKU_2_EKKO:
+	case SKU_3_EKKO:
+	case SKU_4_EKKO:
+	case SKU_5_EKKO:
+	case SKU_6_EKKO:
+	case SKU_7_EKKO:
+	case SKU_0_BARD:
+	case SKU_1_BARD:
+	case SKU_2_BARD:
+	case SKU_3_BARD:
+	case SKU_4_BARD:
+	case SKU_5_BARD:
+	case SKU_6_BARD:
+	case SKU_7_BARD:
+		*num = ARRAY_SIZE(fpmcu_gpio_table);
+		board_gpio_tables = fpmcu_gpio_table;
+		break;
+	default:
+		/* Initialized in variant_sku_gpio_table */
+		*num = 0;
+		board_gpio_tables = NULL;
+		break;
+	}
+	return board_gpio_tables;
+}
+
 const struct pad_config *variant_sku_gpio_table(size_t *num)
 {
 	uint32_t sku_id = variant_board_sku();
@@ -468,8 +502,8 @@ const struct pad_config *variant_sku_gpio_table(size_t *num)
 	case SKU_5_BARD:
 	case SKU_6_BARD:
 	case SKU_7_BARD:
-		*num = ARRAY_SIZE(fpmcu_gpio_table);
-		board_gpio_tables = fpmcu_gpio_table;
+		*num = 0;
+		board_gpio_tables = NULL;
 		break;
 	default:
 		*num = ARRAY_SIZE(nami_default_sku_gpio_table);
diff --git a/src/mainboard/google/poppy/variants/nami/mainboard.c b/src/mainboard/google/poppy/variants/nami/mainboard.c
index b703d40fc3..a4634fc6e5 100644
--- a/src/mainboard/google/poppy/variants/nami/mainboard.c
+++ b/src/mainboard/google/poppy/variants/nami/mainboard.c
@@ -15,6 +15,8 @@
 #include <soc/ramstage.h>
 #include <string.h>
 #include <variant/sku.h>
+#include <gpio.h>
+#include <delay.h>
 
 #define PL2_I7_SKU	44
 #define PL2_DEFAULT	29
@@ -299,3 +301,36 @@ void variant_devtree_update(void)
 				sku_overwrite_mapping[oem_index].dc_loadline[i];
 	}
 }
+
+void variant_final(void)
+{
+	uint32_t sku_id = variant_board_sku();
+
+	switch (sku_id) {
+	case SKU_0_BARD:
+	case SKU_1_BARD:
+	case SKU_2_BARD:
+	case SKU_3_BARD:
+	case SKU_4_BARD:
+	case SKU_5_BARD:
+	case SKU_6_BARD:
+	case SKU_7_BARD:
+	case SKU_0_EKKO:
+	case SKU_1_EKKO:
+	case SKU_2_EKKO:
+	case SKU_3_EKKO:
+	case SKU_4_EKKO:
+	case SKU_5_EKKO:
+	case SKU_6_EKKO:
+	case SKU_7_EKKO:
+		/* Enable FPMCU late in the boot process to achieve
+		 * ~150ms of power off time in total.
+		 */
+		gpio_output(GPP_B11, 1);	/* PCH_FP_PWR_EN */
+		mdelay(3);
+		gpio_output(GPP_C9, 1);		/* FP_RST_ODL */
+		break;
+	default:
+		break;
+	}
+}