[PATCH v3 1/3] drm/rockchip: lvds: move pclk preparation in with clk_get

From: Heiko Stuebner
Date: Tue Mar 04 2025 - 07:45:00 EST


From: Heiko Stuebner <heiko.stuebner@xxxxxxxxx>

The LVDS block needs a separate pclk only on some socs, so currently
requests and prepares it in the soc-specific probe function, but common
code is required to unprepare it in the error path or on driver remove.

While this works because clk_unprepare just does nothing if clk is NULL,
this mismatch of who is responsible still is not very nice.
The clock-framework already has a helper for clk-get-and-prepare even
with devres support in devm_clk_get_prepared().

This will get and prepare the clock and also unprepare it on driver
removal, saving the driver from having to handle it "manually".

Reviewed-by: Quentin Schulz <quentin.schulz@xxxxxxxxx>
Reviewed-by: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxx>
---
drivers/gpu/drm/rockchip/rockchip_lvds.c | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c
index 385cf6881504..ecfae8d5da89 100644
--- a/drivers/gpu/drm/rockchip/rockchip_lvds.c
+++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c
@@ -448,15 +448,13 @@ struct drm_encoder_helper_funcs px30_lvds_encoder_helper_funcs = {
static int rk3288_lvds_probe(struct platform_device *pdev,
struct rockchip_lvds *lvds)
{
- int ret;
-
lvds->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(lvds->regs))
return PTR_ERR(lvds->regs);

- lvds->pclk = devm_clk_get(lvds->dev, "pclk_lvds");
+ lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk_lvds");
if (IS_ERR(lvds->pclk)) {
- DRM_DEV_ERROR(lvds->dev, "could not get pclk_lvds\n");
+ DRM_DEV_ERROR(lvds->dev, "could not get or prepare pclk_lvds\n");
return PTR_ERR(lvds->pclk);
}

@@ -480,12 +478,6 @@ static int rk3288_lvds_probe(struct platform_device *pdev,
}
}

- ret = clk_prepare(lvds->pclk);
- if (ret < 0) {
- DRM_DEV_ERROR(lvds->dev, "failed to prepare pclk_lvds\n");
- return ret;
- }
-
return 0;
}

@@ -728,20 +720,15 @@ static int rockchip_lvds_probe(struct platform_device *pdev)
dev_set_drvdata(dev, lvds);

ret = component_add(&pdev->dev, &rockchip_lvds_component_ops);
- if (ret < 0) {
+ if (ret < 0)
DRM_DEV_ERROR(dev, "failed to add component\n");
- clk_unprepare(lvds->pclk);
- }

return ret;
}

static void rockchip_lvds_remove(struct platform_device *pdev)
{
- struct rockchip_lvds *lvds = platform_get_drvdata(pdev);
-
component_del(&pdev->dev, &rockchip_lvds_component_ops);
- clk_unprepare(lvds->pclk);
}

struct platform_driver rockchip_lvds_driver = {
--
2.47.2