[PATCH 05/11] drm/vc4: Add support for feeding DSI encoders from the pixel valve.

Eric Anholt
2016-12-14T19:46:15Z

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>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 33 +++++++++++++++++++--------------
drivers/gpu/drm/vc4/vc4_regs.h | 2 ++
2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index a0fd3e66bc4b..cd070e0c79a6 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -349,38 +349,40 @@ 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));
@@ -436,17 +438,19 @@ 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),
@@ -455,7 +459,8 @@ 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 b3b297fba709..385405a2df05 100644
--- 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)

--
2.11.0