mb/google/geralt: Pass GPIOs to allow backlight control in payloads

There are two ways to control backlight in geralt:
1. MIPI/eDP panel => control backlight via the GPIOs.
   (`backlight chip enable` and `PWM dimming control`)
2. eDP OLED panel => enable backlight via `backlight chip enable` and
   control dimming over AUX.

For MIPI/eDP panels(#1), both "backlight enable" and "PWM control" GPIOs
will be passed from coreboot. For eDP OLED panel(#2), only the
"backlight enable" GPIO will be passed. If depthcharge successfully gets
the GPIOs, it will use them to control backlight.

BUG=b:244208960
TEST=test firmware display pass for eDP and MIPI panels on MT8188 EVB

Change-Id: I866fa219722241008e2b0d566b29edf2f6d9321f
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70744
Reviewed-by: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/geralt/panel_geralt.c b/src/mainboard/google/geralt/panel_geralt.c
index d37d68a..dfcd721 100644
--- a/src/mainboard/google/geralt/panel_geralt.c
+++ b/src/mainboard/google/geralt/panel_geralt.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <boardid.h>
+#include <boot/coreboot_tables.h>
 #include <gpio.h>
 #include <soc/gpio_common.h>
 #include <string.h>
@@ -35,12 +36,14 @@
 		.power_on = power_on_mipi_boe_nv110c9m_l60,
 		.configure_panel_backlight = configure_mipi_pwm_backlight,
 		.disp_path = DISP_PATH_MIPI,
+		.pwm_ctrl_gpio = true,
 	},
 	[11] = {
 		.name = "MUTTO_B152731E1",
 		.power_on = power_on_edp_mutto_b152731e1,
 		.configure_panel_backlight = configure_edp_aux_backlight,
 		.disp_path = DISP_PATH_EDP,
+		.pwm_ctrl_gpio = false,
 	},
 };
 
@@ -51,3 +54,32 @@
 
 	return &panels[panel_id];
 }
+
+void fill_lp_backlight_gpios(struct lb_gpios *gpios)
+{
+	struct panel_description *panel = get_active_panel();
+	if (!panel || panel->disp_path == DISP_PATH_NONE)
+		return;
+
+	struct lb_gpio mipi_pwm_gpios[] = {
+		{GPIO_MIPI_PANEL_BL_PWM.id, ACTIVE_HIGH, -1, "PWM control"},
+	};
+
+	struct lb_gpio edp_pwm_gpios[] = {
+		{GPIO_EDP_BL_PWM_1V8.id, ACTIVE_HIGH, -1, "PWM control"},
+	};
+
+	if (panel->pwm_ctrl_gpio) {
+		/* PWM control for typical eDP and MIPI panels */
+		if (panel->disp_path == DISP_PATH_MIPI)
+			lb_add_gpios(gpios, mipi_pwm_gpios, ARRAY_SIZE(mipi_pwm_gpios));
+		else
+			lb_add_gpios(gpios, edp_pwm_gpios, ARRAY_SIZE(edp_pwm_gpios));
+	}
+
+	struct lb_gpio backlight_gpios[] = {
+		{GPIO_AP_DISP_BKLTEN.id, ACTIVE_HIGH, -1, "backlight enable"},
+	};
+
+	lb_add_gpios(gpios, backlight_gpios, ARRAY_SIZE(backlight_gpios));
+}