Commit d01cb045 authored by Miquel Raynal's avatar Miquel Raynal Committed by Boris Brezillon
Browse files

drm: atmel-hlcdc: Support inverting the pixel clock polarity 



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: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230609144843.851327-1-miquel.raynal@bootlin.com
parent 2da20c92

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c

+25 −0
Original line number Diff line number Diff line
@@ -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);