[M] Change in coreboot[master]: mb/google/poppy/variant/nami - Ensure power cycle of FPMCU on startup

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/73212 )

Change subject: mb/google/poppy/variant/nami - Ensure power cycle of FPMCU on startup
......................................................................

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 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73212
Tested-by: build bot (Jenkins) 
Reviewed-by: Subrata Banik 
Reviewed-by: Shelley Chen 
Reviewed-by: Eric Lai 
---
M src/mainboard/google/poppy/variants/nami/gpio.c
M src/mainboard/google/poppy/variants/nami/mainboard.c
2 files changed, 104 insertions(+), 4 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Shelley Chen: Looks good to me, approved
  Subrata Banik: Looks good to me, approved
  Eric Lai: Looks good to me, approved

diff --git a/src/mainboard/google/poppy/variants/nami/gpio.c b/src/mainboard/google/poppy/variants/nami/gpio.c
index 68f0f5b..58c02b8 100644
--- a/src/mainboard/google/poppy/variants/nami/gpio.c
+++ b/src/mainboard/google/poppy/variants/nami/gpio.c
@@ -404,7 +404,7 @@
    /* 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 @@
    /* 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 @@
    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 b703d40..a4634fc 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 @@
    			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;
+	}
+}