On the SoC host controller, the pixel clock can be:
* standard: data is launched on the rising edge
* inverted: data is launched on the falling edge
Some panels may need the inverted option to be used so let's support
this DRM flag.
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
Hello, this change was tested on a Sama5d36 based custom board with a
panel not behaving correctly if the pixel clock was not inverted.
Cheers, Miquèl
.../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 25 +++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 58184cd6ab0b..cc5cf4c2faf7 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -68,7 +68,11 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
struct regmap *regmap = crtc->dc->hlcdc->regmap;
struct drm_display_mode *adj = &c->state->adjusted_mode;
+ struct drm_encoder *encoder = NULL, *en_iter;
+ struct drm_connector *connector = NULL;
struct atmel_hlcdc_crtc_state *state;
+ struct drm_device *ddev = c->dev;
+ struct drm_connector_list_iter iter;
unsigned long mode_rate;
struct videomode vm;
unsigned long prate;
@@ -76,6 +80,23 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
unsigned int cfg = 0;
int div, ret;
+ /* get encoder from crtc */
+ drm_for_each_encoder(en_iter, ddev) {
+ if (en_iter->crtc == c) {
+ encoder = en_iter;
+ break;
+ }
+ }
+
+ if (encoder) {
+ /* Get the connector from encoder */
+ drm_connector_list_iter_begin(ddev, &iter);
+ drm_for_each_connector_iter(connector, &iter)
+ if (connector->encoder == encoder)
+ break;
+ drm_connector_list_iter_end(&iter);
+ }
+
ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
if (ret)
return;
@@ -134,6 +155,10 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
cfg |= ATMEL_HLCDC_CLKDIV(div);
+ if (connector &&
+ connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
+ cfg |= ATMEL_HLCDC_CLKPOL;
+
regmap_update_bits(regmap, ATMEL_HLCDC_CFG(0), mask, cfg);
state = drm_crtc_state_to_atmel_hlcdc_crtc_state(c->state);
--
2.34.1
