[PATCH v2 3/7] drm/msm/mdp4: register the LVDS PLL as a clock provider

From: Dmitry Baryshkov
Date: Thu Feb 20 2025 - 06:15:51 EST


The LVDS/LCDC controller uses pixel clock coming from the multimedia
controller (mmcc) rather than using the PLL directly. Stop using LVDS
PLL directly and register it as a clock provider. Use lcdc_clk as a
pixel clock for the LCDC.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h | 2 +-
drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c | 8 +++++++-
drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c | 22 +++++++---------------
3 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
index 142ccb68b435263f91ba1ab27676e426d43e5d84..b8bdc3712c73b14f3547dce3439a895e3d10f193 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
@@ -207,6 +207,6 @@ static inline struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev)
}
#endif

-struct clk *mpd4_lvds_pll_init(struct drm_device *dev);
+int mpd4_lvds_pll_init(struct drm_device *dev);

#endif /* __MDP4_KMS_H__ */
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
index 8bbc7fb881d599e7d309cc61bda83697fecd253a..db93795916cdaa87ac8e61d3b44c2dadac10fd9e 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
@@ -381,7 +381,13 @@ struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev,
drm_encoder_helper_add(encoder, &mdp4_lcdc_encoder_helper_funcs);

/* TODO: do we need different pll in other cases? */
- mdp4_lcdc_encoder->lcdc_clk = mpd4_lvds_pll_init(dev);
+ ret = mpd4_lvds_pll_init(dev);
+ if (ret) {
+ DRM_DEV_ERROR(dev->dev, "failed to register LVDS PLL\n");
+ return ERR_PTR(ret);
+ }
+
+ mdp4_lcdc_encoder->lcdc_clk = devm_clk_get(dev->dev, "lcdc_clk");
if (IS_ERR(mdp4_lcdc_encoder->lcdc_clk)) {
DRM_DEV_ERROR(dev->dev, "failed to get lvds_clk\n");
return ERR_CAST(mdp4_lcdc_encoder->lcdc_clk);
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c
index ab8c0c187fb2cd05e26f5019244af15f1b2470c8..cbd154c72e44c848fa65fe01d848879b9f6735fb 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c
@@ -133,29 +133,21 @@ static struct clk_init_data pll_init = {
.num_parents = ARRAY_SIZE(mpd4_lvds_pll_parents),
};

-struct clk *mpd4_lvds_pll_init(struct drm_device *dev)
+int mpd4_lvds_pll_init(struct drm_device *dev)
{
struct mdp4_lvds_pll *lvds_pll;
- struct clk *clk;
int ret;

lvds_pll = devm_kzalloc(dev->dev, sizeof(*lvds_pll), GFP_KERNEL);
- if (!lvds_pll) {
- ret = -ENOMEM;
- goto fail;
- }
+ if (!lvds_pll)
+ return -ENOMEM;

lvds_pll->dev = dev;

lvds_pll->pll_hw.init = &pll_init;
- clk = devm_clk_register(dev->dev, &lvds_pll->pll_hw);
- if (IS_ERR(clk)) {
- ret = PTR_ERR(clk);
- goto fail;
- }
+ ret = devm_clk_hw_register(dev->dev, &lvds_pll->pll_hw);
+ if (ret)
+ return ret;

- return clk;
-
-fail:
- return ERR_PTR(ret);
+ return devm_of_clk_add_hw_provider(dev->dev, of_clk_hw_simple_get, &lvds_pll->pll_hw);
}

--
2.39.5