Commit ffcde9e4 authored by Matthias Schiffer's avatar Matthias Schiffer Committed by Dmitry Baryshkov
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drm: fsl-dcu: enable PIXCLK on LS1021A 



The PIXCLK needs to be enabled in SCFG before accessing certain DCU
registers, or the access will hang. For simplicity, the PIXCLK is enabled
unconditionally, resulting in increased power consumption.

Signed-off-by: default avatarMatthias Schiffer <matthias.schiffer@tq-group.com>
Signed-off-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Fixes: 109eee2f ("drm/layerscape: Add Freescale DCU DRM driver")
Acked-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240926055552.1632448-2-alexander.stein@ew.tq-group.com


Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
parent 5b7abfb2

drivers/gpu/drm/fsl-dcu/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ config DRM_FSL_DCU 
	select DRM_PANEL

	select REGMAP_MMIO

	select VIDEOMODE_HELPERS

	select MFD_SYSCON if SOC_LS1021A

	help

	  Choose this option if you have an Freescale DCU chipset.

	  If M is selected the module will be called fsl-dcu-drm.

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c

+15 −0
Original line number Diff line number Diff line
@@ -101,12 +101,27 @@ static void fsl_dcu_irq_uninstall(struct drm_device *dev) 
static int fsl_dcu_load(struct drm_device *dev, unsigned long flags)

{

	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;

	struct regmap *scfg;

	int ret;



	ret = fsl_dcu_drm_modeset_init(fsl_dev);

	if (ret < 0)

		return dev_err_probe(dev->dev, ret, "failed to initialize mode setting\n");



	scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");

	if (PTR_ERR(scfg) != -ENODEV) {

		/*

		 * For simplicity, enable the PIXCLK unconditionally,

		 * resulting in increased power consumption. Disabling

		 * the clock in PM or on unload could be implemented as

		 * a future improvement.

		 */

		ret = regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,

					 SCFG_PIXCLKCR_PXCEN);

		if (ret < 0)

			return dev_err_probe(dev->dev, ret, "failed to enable pixclk\n");

	}



	ret = drm_vblank_init(dev, dev->mode_config.num_crtc);

	if (ret < 0) {

		dev_err(dev->dev, "failed to initialize vblank\n");

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h

+3 −0
Original line number Diff line number Diff line
@@ -160,6 +160,9 @@ 
#define FSL_DCU_ARGB4444		12

#define FSL_DCU_YUV422			14



#define SCFG_PIXCLKCR			0x28

#define SCFG_PIXCLKCR_PXCEN		BIT(31)



#define VF610_LAYER_REG_NUM		9

#define LS1021A_LAYER_REG_NUM		10