openwrtv4/target/linux/brcm2708/patches-4.4/0440-drm-vc4-Add-support-for-feeding-DSI-encoders-from-th.patch

From d41850b2bd8ad77636e344c5fed1ebda0d77a9bc Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 10 Feb 2016 16:17:29 -0800
Subject: [PATCH] drm/vc4: Add support for feeding DSI encoders from the pixel
 valve.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 30 +++++++++++++++++-------------
 drivers/gpu/drm/vc4/vc4_regs.h |  2 ++
 2 files changed, 19 insertions(+), 13 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -210,38 +210,40 @@ static u32 vc4_get_fifo_full_level(u32 f
 }
 
 /*
- * Returns the clock select bit for the connector attached to the
- * CRTC.
+ * Returns the encoder attached to the CRTC.
+ *
+ * VC4 can only scan out to one encoder at a type, while the DRM core
+ * allows drivers to push pixels to more than one encoder from the
+ * same CRTC.
  */
-static int vc4_get_clock_select(struct drm_crtc *crtc)
+static struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc)
 {
 	struct drm_connector *connector;
 
 	drm_for_each_connector(connector, crtc->dev) {
 		if (connector->state->crtc == crtc) {
-			struct drm_encoder *encoder = connector->encoder;
-			struct vc4_encoder *vc4_encoder =
-				to_vc4_encoder(encoder);
-
-			return vc4_encoder->clock_select;
+			return connector->encoder;
 		}
 	}
 
-	return -1;
+	return NULL;
 }
 
 static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc);
+	struct vc4_encoder *vc4_encoder = to_vc4_encoder(encoder);
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 	struct drm_crtc_state *state = crtc->state;
 	struct drm_display_mode *mode = &state->adjusted_mode;
 	bool interlace = mode->flags & DRM_MODE_FLAG_INTERLACE;
 	u32 vactive = (mode->vdisplay >> (interlace ? 1 : 0));
-	u32 format = PV_CONTROL_FORMAT_24;
-	bool debug_dump_regs = false;
-	int clock_select = vc4_get_clock_select(crtc);
+	bool is_dsi = (vc4_encoder->type == VC4_ENCODER_TYPE_DSI0 ||
+		       vc4_encoder->type == VC4_ENCODER_TYPE_DSI1);
+	u32 format = is_dsi ? PV_CONTROL_FORMAT_DSIV_24 : PV_CONTROL_FORMAT_24;
+	bool debug_dump_regs = true;
 
 	if (debug_dump_regs) {
 		DRM_INFO("CRTC %d regs before:\n", drm_crtc_index(crtc));
@@ -289,6 +291,7 @@ static void vc4_crtc_mode_set_nofb(struc
 
 	CRTC_WRITE(PV_V_CONTROL,
 		   PV_VCONTROL_CONTINUOUS |
+		   (is_dsi ? PV_VCONTROL_DSI : 0) |
 		   (interlace ? PV_VCONTROL_INTERLACE : 0));
 
 	CRTC_WRITE(PV_CONTROL,
@@ -298,7 +301,8 @@ static void vc4_crtc_mode_set_nofb(struc
 		   PV_CONTROL_CLR_AT_START |
 		   PV_CONTROL_TRIGGER_UNDERFLOW |
 		   PV_CONTROL_WAIT_HSTART |
-		   VC4_SET_FIELD(clock_select, PV_CONTROL_CLK_SELECT) |
+		   VC4_SET_FIELD(vc4_encoder->clock_select,
+				 PV_CONTROL_CLK_SELECT) |
 		   PV_CONTROL_FIFO_CLR |
 		   PV_CONTROL_EN);
 
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -184,6 +184,8 @@
 
 #define PV_V_CONTROL				0x04
 # define PV_VCONTROL_INTERLACE			BIT(4)
+# define PV_VCONTROL_DSI			BIT(3)
+# define PV_VCONTROL_COMMAND			BIT(2)
 # define PV_VCONTROL_CONTINUOUS			BIT(1)
 # define PV_VCONTROL_VIDEN			BIT(0)