Change in coreboot[master]: google/gru: Re-enable 3V rail GPIO on Scarlet

[Julius Werner (Code Review)]

Hello Lin Huang, David Schneider, Philip Chen,

I'd like you to do a code review. Please visit

https://review.coreboot.org/21328

to review the following change.

Change subject: google/gru: Re-enable 3V rail GPIO on Scarlet
......................................................................

google/gru: Re-enable 3V rail GPIO on Scarlet

We've decided to move control for the 3.0V rail (technically 3.3V on
Scarlet, but who cares about millivolts) back to a GPIO on the AP for
Scarlet rev2. This patch adds the necessary code to enable it and make
ARM TF aware of its existence. Since the pin had previously not been
connected to anything, we shouldn't really need to guard this by board
ID... older Scarlets will just be twiddling an empty pin.

Change-Id: I6037aa486b50119f2c7b859b966cadc3686e3459
Signed-off-by: Julius Werner 
---
M src/mainboard/google/gru/board.h
M src/mainboard/google/gru/bootblock.c
M src/mainboard/google/gru/mainboard.c
3 files changed, 23 insertions(+), 34 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/28/21328/1

diff --git a/src/mainboard/google/gru/board.h b/src/mainboard/google/gru/board.h
index cc7581d..7237d46 100644
--- a/src/mainboard/google/gru/board.h
+++ b/src/mainboard/google/gru/board.h
@@ -30,7 +30,7 @@
 #define GPIO_EC_IRQ	GPIO(1, C, 2)
 #define GPIO_P15V_EN	dead_code_t(gpio_t, "PP1500 doesn't exist on Scarlet")
 #define GPIO_P18V_AUDIO_PWREN dead_code_t(gpio_t, "doesn't exist on Scarlet")
-#define GPIO_P30V_EN	dead_code_t(gpio_t, "PP3000 doesn't exist on Scarlet")
+#define GPIO_P30V_EN	GPIO(0, B, 1)
 #define GPIO_TP_RST_L	dead_code_t(gpio_t, "don't need TP_RST_L on Scarlet")
 #define GPIO_TPM_IRQ	GPIO(1, C, 1)
 #define GPIO_WP		GPIO(0, B, 5)
diff --git a/src/mainboard/google/gru/bootblock.c b/src/mainboard/google/gru/bootblock.c
index 01aa4bf..a3d3121 100644
--- a/src/mainboard/google/gru/bootblock.c
+++ b/src/mainboard/google/gru/bootblock.c
@@ -48,12 +48,10 @@
    if (IS_ENABLED(CONFIG_BOARD_GOOGLE_SCARLET))
    	write32(&rk3399_grf->io_vsel, RK_SETBITS(1 << 3));

-	if (!IS_ENABLED(CONFIG_BOARD_GOOGLE_SCARLET)) {
-		/* Enable rails powering GPIO blocks, among other things.
-		   These are EC-controlled on Scarlet and already on. */
-		gpio_output(GPIO_P15V_EN, 1);
-		gpio_output(GPIO_P30V_EN, 1);
-	}
+	/* Enable rails powering GPIO blocks, among other things. */
+	gpio_output(GPIO_P30V_EN, 1);
+	if (!IS_ENABLED(CONFIG_BOARD_GOOGLE_SCARLET))
+		gpio_output(GPIO_P15V_EN, 1);	/* Scarlet: EC-controlled */

#if IS_ENABLED(CONFIG_DRIVERS_UART)
    _Static_assert(CONFIG_CONSOLE_SERIAL_UART_ADDRESS == UART2_BASE,
diff --git a/src/mainboard/google/gru/mainboard.c b/src/mainboard/google/gru/mainboard.c
index df3df4f..38c2646 100644
--- a/src/mainboard/google/gru/mainboard.c
+++ b/src/mainboard/google/gru/mainboard.c
@@ -90,36 +90,27 @@
     * with highest voltage first.
     * Since register_bl31() appends to the front of the list, we need to
     * register them backwards, with 1.5V coming first.
+	 * 1.5V and 1.8V are EC-controlled on Scarlet, so we skip them.
     */
-	static struct bl31_gpio_param param_p15_en = {
-		.h = {
-			.type = PARAM_SUSPEND_GPIO,
-		},
-		.gpio = {
-			.polarity = BL31_GPIO_LEVEL_LOW,
-		},
-	};
-	param_p15_en.gpio.index = GPIO_P15V_EN.raw;
-	register_bl31_param(&param_p15_en.h);
+	if (!CONFIG_BOARD_GOOGLE_SCARLET) {
+		static struct bl31_gpio_param param_p15_en = {
+			.h = { .type = PARAM_SUSPEND_GPIO },
+			.gpio = { .polarity = BL31_GPIO_LEVEL_LOW },
+		};
+		param_p15_en.gpio.index = GPIO_P15V_EN.raw;
+		register_bl31_param(&param_p15_en.h);

-	static struct bl31_gpio_param param_p18_audio_en = {
-		.h = {
-			.type = PARAM_SUSPEND_GPIO,
-		},
-		.gpio = {
-			.polarity = BL31_GPIO_LEVEL_LOW,
-		},
-	};
-	param_p18_audio_en.gpio.index = GPIO_P18V_AUDIO_PWREN.raw;
-	register_bl31_param(&param_p18_audio_en.h);
+		static struct bl31_gpio_param param_p18_audio_en = {
+			.h = { .type = PARAM_SUSPEND_GPIO },
+			.gpio = { .polarity = BL31_GPIO_LEVEL_LOW },
+		};
+		param_p18_audio_en.gpio.index = GPIO_P18V_AUDIO_PWREN.raw;
+		register_bl31_param(&param_p18_audio_en.h);
+	}

static struct bl31_gpio_param param_p30_en = {
-		.h = {
-			.type = PARAM_SUSPEND_GPIO,
-		},
-		.gpio = {
-			.polarity = BL31_GPIO_LEVEL_LOW,
-		},
+		.h = { .type = PARAM_SUSPEND_GPIO },
+		.gpio = { .polarity = BL31_GPIO_LEVEL_LOW },
    };
    param_p30_en.gpio.index = GPIO_P30V_EN.raw;
    register_bl31_param(&param_p30_en.h);
@@ -354,8 +345,8 @@
    if (!IS_ENABLED(CONFIG_BOARD_GOOGLE_SCARLET)) {
    	configure_touchpad();		/* Scarlet: works differently */
    	setup_usb(1);			/* Scarlet: only one USB port */
-		register_gpio_suspend();	/* Scarlet: all EC-controlled */
    }
+	register_gpio_suspend();
    register_reset_to_bl31();
    register_poweroff_to_bl31();
    register_apio_suspend();