From f2c259cf2a16714bd2695507b9241080de660e05 Mon Sep 17 00:00:00 2001
From: Jitao Shi <jitao.shi@mediatek.com>
Date: Thu, 3 Jun 2021 13:51:29 +0800
Subject: [PATCH] mb/google/cherry: enable display support

To enable display, we have to:
1. Configure panel power and backlight
2. Configure eDP driver

BUG=b:189985956

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Change-Id: Ida6c157a6a3bd904d3fa3dd2001385ced34f7711
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55574
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
 src/mainboard/google/cherry/mainboard.c | 68 +++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/src/mainboard/google/cherry/mainboard.c b/src/mainboard/google/cherry/mainboard.c
index 04f4293308..a454adfd8a 100644
--- a/src/mainboard/google/cherry/mainboard.c
+++ b/src/mainboard/google/cherry/mainboard.c
@@ -6,10 +6,15 @@
 #include <delay.h>
 #include <device/device.h>
 #include <device/mmio.h>
+#include <edid.h>
+#include <framebuffer_info.h>
 #include <gpio.h>
+#include <soc/ddp.h>
+#include <soc/dptx.h>
 #include <soc/gpio.h>
 #include <soc/i2c.h>
 #include <soc/mt6360.h>
+#include <soc/mtcmos.h>
 #include <soc/regulator.h>
 #include <soc/spm.h>
 #include <soc/usb.h>
@@ -18,6 +23,12 @@
 
 #include <arm-trusted-firmware/include/export/plat/mediatek/common/plat_params_exp.h>
 
+/* GPIO to schematics names */
+#define GPIO_AP_EDP_BKLTEN GPIO(DGI_D5)
+#define GPIO_BL_PWM_1V8 GPIO(DISP_PWM0)
+#define GPIO_EDP_HPD_1V8 GPIO(GPIO_07)
+#define GPIO_EN_PP3300_DISP_X GPIO(I2SO1_D2)
+
 DEFINE_BITFIELD(MSDC0_DRV, 29, 0)
 DEFINE_BITFIELD(MSDC1_DRV, 17, 0)
 DEFINE_BITFIELD(MSDC1_GPIO_MODE0_0, 26, 24)
@@ -119,8 +130,65 @@ static void configure_sdcard(void)
 	mt6360_ldo_enable(MT6360_LDO5, 1);
 }
 
+/* Set up backlight control pins as output pin and power-off by default */
+static void configure_panel_backlight(void)
+{
+	gpio_output(GPIO_AP_EDP_BKLTEN, 0);
+	gpio_output(GPIO_BL_PWM_1V8, 0);
+}
+
+static void power_on_panel(void)
+{
+	/* Default power sequence for most panels. */
+	gpio_set_pull(GPIO_EDP_HPD_1V8, GPIO_PULL_ENABLE, GPIO_PULL_UP);
+	gpio_set_mode(GPIO_EDP_HPD_1V8, 2);
+	gpio_output(GPIO_EN_PP3300_DISP_X, 1);
+}
+
+static bool configure_display(void)
+{
+	struct edid edid;
+	struct fb_info *info;
+	const char *name;
+
+	printk(BIOS_INFO, "%s: Starting display initialization\n", __func__);
+
+	mtcmos_display_power_on();
+	mtcmos_protect_display_bus();
+	configure_panel_backlight();
+	power_on_panel();
+
+	mtk_ddp_init();
+	mdelay(200);
+
+	if (mtk_edp_init(&edid) < 0) {
+		printk(BIOS_ERR, "%s: Failed to initialize eDP\n", __func__);
+		return false;
+	}
+	name = edid.ascii_string;
+	if (name[0] == '\0')
+		name = "unknown name";
+	printk(BIOS_INFO, "%s: '%s %s' %dx%d@%dHz\n", __func__,
+	       edid.manufacturer_name, name, edid.mode.ha, edid.mode.va,
+	       edid.mode.refresh);
+
+	edid_set_framebuffer_bits_per_pixel(&edid, 32, 0);
+
+	mtk_ddp_mode_set(&edid);
+	info = fb_new_framebuffer_info_from_edid(&edid, (uintptr_t)0);
+	if (info)
+		fb_set_orientation(info, LB_FB_ORIENTATION_NORMAL);
+
+	return true;
+}
+
 static void mainboard_init(struct device *dev)
 {
+	if (display_init_required())
+		configure_display();
+	else
+		printk(BIOS_INFO, "%s: Skipped display initialization\n", __func__);
+
 	configure_emmc();
 	configure_sdcard();
 	setup_usb_host();