Thread (7 messages) read the whole thread 7 messages, 2 authors, 2025-02-28

Re: [PATCH 1/2] drm/rockchip: lvds: move pclk preparation in with clk_get

From: Quentin Schulz <hidden>
Date: 2025-02-28 17:19:57
Also in: dri-devel, linux-rockchip, lkml

Hi Heiko,

On 2/28/25 5:57 PM, Heiko Stuebner wrote:
From: Heiko Stuebner <redacted>

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".

Signed-off-by: Heiko Stuebner <redacted>
Reviewed-by: Quentin Schulz <redacted>

Small nitpick below.
quoted hunk ↗ jump to hunk
---
  drivers/gpu/drm/rockchip/rockchip_lvds.c | 17 ++---------------
  1 file changed, 2 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c
index 385cf6881504..c19b7b1f6cb5 100644
--- a/drivers/gpu/drm/rockchip/rockchip_lvds.c
+++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c
@@ -448,13 +448,11 @@ 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");
Should we say

Could not get or prepare pclk_lvds\n

instead?

Thanks!
Quentin
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