[PATCH v2 3/7] drm: rcar-du: lvsd: Add reset control

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Fri, Jan 20, 2023 at 10:50:05AM +0200, Tomi Valkeinen wrote:
> Reset LVDS using the reset control as CPG reset/release is required in
> the hardware manual sequence.
> 
> Based on a BSP patch from Koji Matsuoka <koji.matsuoka.xm at renesas.com>.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>
> ---
>  drivers/gpu/drm/rcar-du/Kconfig     |  1 +
>  drivers/gpu/drm/rcar-du/rcar_lvds.c | 19 ++++++++++++++++++-
>  2 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
> index a8f862c68b4f..151e400b996d 100644
> --- a/drivers/gpu/drm/rcar-du/Kconfig
> +++ b/drivers/gpu/drm/rcar-du/Kconfig
> @@ -43,6 +43,7 @@ config DRM_RCAR_LVDS
>  	select DRM_PANEL
>  	select OF_FLATTREE
>  	select OF_OVERLAY
> +	select RESET_CONTROLLER
>  
>  config DRM_RCAR_USE_MIPI_DSI
>  	bool "R-Car DU MIPI DSI Encoder Support"
> diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> index 8e1be51fbee6..668604616bfd 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> @@ -17,6 +17,7 @@
>  #include <linux/of_graph.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
>  #include <linux/sys_soc.h>
>  
> @@ -61,6 +62,7 @@ struct rcar_lvds_device_info {
>  struct rcar_lvds {
>  	struct device *dev;
>  	const struct rcar_lvds_device_info *info;
> +	struct reset_control *rstc;
>  
>  	struct drm_bridge bridge;
>  
> @@ -845,6 +847,10 @@ static int rcar_lvds_probe(struct platform_device *pdev)
>  	if (ret < 0)
>  		return ret;
>  
> +	lvds->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> +	if (IS_ERR(lvds->rstc))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(lvds->rstc),
> +				     "failed to get cpg reset\n");

Missing blank line.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

>  	pm_runtime_enable(&pdev->dev);
>  
>  	drm_bridge_add(&lvds->bridge);
> @@ -924,6 +930,8 @@ static int rcar_lvds_runtime_suspend(struct device *dev)
>  
>  	clk_disable_unprepare(lvds->clocks.mod);
>  
> +	reset_control_assert(lvds->rstc);
> +
>  	return 0;
>  }
>  
> @@ -932,11 +940,20 @@ static int rcar_lvds_runtime_resume(struct device *dev)
>  	struct rcar_lvds *lvds = dev_get_drvdata(dev);
>  	int ret;
>  
> +	ret = reset_control_deassert(lvds->rstc);
> +	if (ret)
> +		return ret;
> +
>  	ret = clk_prepare_enable(lvds->clocks.mod);
>  	if (ret < 0)
> -		return ret;
> +		goto err_reset_assert;
>  
>  	return 0;
> +
> +err_reset_assert:
> +	reset_control_assert(lvds->rstc);
> +
> +	return ret;
>  }
>  
>  static const struct dev_pm_ops rcar_lvds_pm_ops = {

-- 
Regards,

Laurent Pinchart