soc/rockchip: split edp_enable() function

To avoid garbage display in firmware on warm reset, we need
to enable eDP display in depthcharge instead when the framebuffer is
cleared.
Therefore limit edp_enable() in coreboot to just configure eDP,
and leave enabling the display to depthcharge.

CQ-DEPEND=CL:402071
BUG=chrome-os-partner:58675
BRANCH=none
TEST=Boot from kevin, and display work

Change-Id: I9d937ead33ebba58e33e02fd73b80d6e11bb69aa
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 38b0d18c3fae37dfccb18fe809f763b98703167c
Original-Change-Id: Ibbc283a5892b98f4922f02fd67465fe2e1d01b71
Original-Signed-off-by: Lin Huang <hl@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/402095
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/17207
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/rockchip/common/edp.c

@@ -921,10 +921,7 @@ static int rk_edp_config_video(struct rk_edp *edp)
 	/* Disable video mute */
 	clrbits_le32(&edp->regs->video_ctl_1, VIDEO_MUTE);
 
-	/* Enable video at next frame */
+	return 0;
-	setbits_le32(&edp->regs->video_ctl_1, VIDEO_EN);
-
-	return rk_edp_is_video_stream_on(edp);
 }
 
 static void rockchip_edp_force_hpd(struct rk_edp *edp)
@@ -985,7 +982,7 @@ int rk_edp_get_edid(struct edid *edid)
 	return retval;
 }
 
-int rk_edp_enable(void)
+int rk_edp_prepare(void)
 {
 	int ret = 0;
 
@@ -1002,6 +999,14 @@ int rk_edp_enable(void)
 	return ret;
 }
 
+int rk_edp_enable(void)
+{
+	/* Enable video at next frame */
+	setbits_le32(&rk_edp.regs->video_ctl_1, VIDEO_EN);
+
+	return rk_edp_is_video_stream_on(&rk_edp);
+}
+
 void rk_edp_init(void)
 {
 	rk_edp.regs = (struct rk_edp_regs *)EDP_BASE;

src/soc/rockchip/common/include/soc/edp.h

@@ -651,6 +651,7 @@ struct rk_edp {
 	u8 train_set[4];
 };
 
+int rk_edp_prepare(void);
 int rk_edp_enable(void);
 void rk_edp_init(void);
 int rk_edp_get_edid(struct edid *edid);

src/soc/rockchip/rk3288/display.c

@@ -128,6 +128,10 @@ void rk_display_init(device_t dev, u32 lcdbase,
 
 	case VOP_MODE_EDP:
 	default:
+		if (rk_edp_prepare()) {
+			printk(BIOS_WARNING, "edp prepare err\n");
+			return;
+		}
 		if (rk_edp_enable()) {
 			printk(BIOS_WARNING, "edp enable err\n");
 			return;

src/soc/rockchip/rk3399/display.c

@@ -99,8 +99,9 @@ void rk_display_init(device_t dev)
 		return;
 	case VOP_MODE_EDP:
 	default:
-		if (rk_edp_enable()) {
+		/* will enable edp in depthcharge */
-			printk(BIOS_WARNING, "edp enable error\n");
+		if (rk_edp_prepare()) {
+			printk(BIOS_WARNING, "edp prepare error\n");
 			return;
 		}
 		mainboard_power_on_backlight();