drm/vc4: Add support for feeding DSI encoders from the pixel valve.

We have to set a different pixel format, which tells the hardware to
use the pix_width field that's fed in sideband from the DSI encoder to
divide the "pixel" clock.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161214194621.16499-6-eric@anholt.net

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 75b708b36890591caaa0b2612d9c8617f942d82f..63239b5b5092b7d73619cd77fd6fcd425ad9a6bf 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -348,38 +348,40 @@ static u32 vc4_get_fifo_full_level(u32 format)
 }
 
 /*
- * 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 time, 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 pixel_rep = (mode->flags & DRM_MODE_FLAG_DBLCLK) ? 2 : 1;
-       u32 format = PV_CONTROL_FORMAT_24;
+       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 = false;
-       int clock_select = vc4_get_clock_select(crtc);
 
        if (debug_dump_regs) {
                DRM_INFO("CRTC %d regs before:\n", drm_crtc_index(crtc));
@@ -435,17 +437,19 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
                 */
                CRTC_WRITE(PV_V_CONTROL,
                           PV_VCONTROL_CONTINUOUS |
+                          (is_dsi ? PV_VCONTROL_DSI : 0) |
                           PV_VCONTROL_INTERLACE |
                           VC4_SET_FIELD(mode->htotal * pixel_rep / 2,
                                         PV_VCONTROL_ODD_DELAY));
                CRTC_WRITE(PV_VSYNCD_EVEN, 0);
        } else {
-               CRTC_WRITE(PV_V_CONTROL, PV_VCONTROL_CONTINUOUS);
+               CRTC_WRITE(PV_V_CONTROL,
+                          PV_VCONTROL_CONTINUOUS |
+                          (is_dsi ? PV_VCONTROL_DSI : 0));
        }
 
        CRTC_WRITE(PV_HACT_ACT, mode->hdisplay * pixel_rep);
 
-
        CRTC_WRITE(PV_CONTROL,
                   VC4_SET_FIELD(format, PV_CONTROL_FORMAT) |
                   VC4_SET_FIELD(vc4_get_fifo_full_level(format),
@@ -454,7 +458,8 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
                   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);
 

diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index b3b297fba7097bc495fa8916292c547925720199..385405a2df05eb3dd86d4f687aa8205331bec3cc 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -190,6 +190,8 @@
 # define PV_VCONTROL_ODD_DELAY_SHIFT           6
 # define PV_VCONTROL_ODD_FIRST                 BIT(5)
 # 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)