[PATCH] drm/stm: add sleep power management

[Philippe CORNU]

(+ Benjamin)

Dear Yannick,
Many thanks for your patch.
Acked-by: Philippe Cornu <philippe.cornu at st.com>

Dear Benjamin,
May I ask you please to merge this patch + "drm/stm: dw_mipi_dsi-stm: 
add sleep power management" on drm-misc, if you agree of course and when 
you think it is the right time (next week?)
Big thanks,

Philippe :-)


On 3/21/19 9:15 AM, Yannick Fertré wrote:
> Implements system sleep power management ops.
> 
> Signed-off-by: Yannick Fertré <yannick.fertre at st.com>
> ---
>   drivers/gpu/drm/stm/drv.c  | 35 +++++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/stm/ltdc.c | 24 ++++++++++++++++++++++++
>   drivers/gpu/drm/stm/ltdc.h |  3 +++
>   3 files changed, 62 insertions(+)
> 
> diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
> index 0a7f933..5834ef5 100644
> --- a/drivers/gpu/drm/stm/drv.c
> +++ b/drivers/gpu/drm/stm/drv.c
> @@ -129,6 +129,40 @@ static void drv_unload(struct drm_device *ddev)
>   	drm_mode_config_cleanup(ddev);
>   }
>   
> +static __maybe_unused int drv_suspend(struct device *dev)
> +{
> +	struct drm_device *ddev = dev_get_drvdata(dev);
> +	struct ltdc_device *ldev = ddev->dev_private;
> +	struct drm_atomic_state *state;
> +
> +	drm_kms_helper_poll_disable(ddev);
> +	state = drm_atomic_helper_suspend(ddev);
> +	if (IS_ERR(state)) {
> +		drm_kms_helper_poll_enable(ddev);
> +		return PTR_ERR(state);
> +	}
> +	ldev->suspend_state = state;
> +	ltdc_suspend(ddev);
> +
> +	return 0;
> +}
> +
> +static __maybe_unused int drv_resume(struct device *dev)
> +{
> +	struct drm_device *ddev = dev_get_drvdata(dev);
> +	struct ltdc_device *ldev = ddev->dev_private;
> +
> +	ltdc_resume(ddev);
> +	drm_atomic_helper_resume(ddev, ldev->suspend_state);
> +	drm_kms_helper_poll_enable(ddev);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops drv_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(drv_suspend, drv_resume)
> +};
> +
>   static int stm_drm_platform_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
> @@ -186,6 +220,7 @@ static struct platform_driver stm_drm_platform_driver = {
>   	.driver = {
>   		.name = "stm32-display",
>   		.of_match_table = drv_dt_ids,
> +		.pm = &drv_pm_ops,
>   	},
>   };
>   
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index b1741a9..32fd6a3 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -1062,6 +1062,30 @@ static int ltdc_get_caps(struct drm_device *ddev)
>   	return 0;
>   }
>   
> +void ltdc_suspend(struct drm_device *ddev)
> +{
> +	struct ltdc_device *ldev = ddev->dev_private;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +	clk_disable_unprepare(ldev->pixel_clk);
> +}
> +
> +int ltdc_resume(struct drm_device *ddev)
> +{
> +	struct ltdc_device *ldev = ddev->dev_private;
> +	int ret;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	ret = clk_prepare_enable(ldev->pixel_clk);
> +	if (ret) {
> +		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   int ltdc_load(struct drm_device *ddev)
>   {
>   	struct platform_device *pdev = to_platform_device(ddev->dev);
> diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
> index e46f477..a1ad0ae 100644
> --- a/drivers/gpu/drm/stm/ltdc.h
> +++ b/drivers/gpu/drm/stm/ltdc.h
> @@ -36,6 +36,7 @@ struct ltdc_device {
>   	u32 error_status;
>   	u32 irq_status;
>   	struct fps_info plane_fpsi[LTDC_MAX_LAYER];
> +	struct drm_atomic_state *suspend_state;
>   };
>   
>   bool ltdc_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
> @@ -45,5 +46,7 @@ bool ltdc_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
>   
>   int ltdc_load(struct drm_device *ddev);
>   void ltdc_unload(struct drm_device *ddev);
> +void ltdc_suspend(struct drm_device *ddev);
> +int ltdc_resume(struct drm_device *ddev);
>   
>   #endif
>