Re: [PATCH] drm/komeda: Adds power management support

[Sean Paul]

On Mon, Sep 23, 2019 at 01:59:25AM +0000, Lowry Li (Arm Technology China) wrote:
> From: "Lowry Li (Arm Technology China)" <Lowry.Li@xxxxxxx>
> 
> Adds system power management support in KMS kernel driver.
> 
> Depends on:
> https://patchwork.freedesktop.org/series/62377/
> 
> Changes since v1:
> Since we have unified mclk/pclk/pipeline->aclk to one mclk, which will
> be turned on/off when crtc atomic enable/disable, removed runtime power
> management.
> Removes run time get/put related flow.
> Adds to disable the aclk when register access finished.
> 
> Changes since v2:
> Rebases to the drm-misc-next branch.
> 
> Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@xxxxxxx>
> ---
>  .../gpu/drm/arm/display/komeda/komeda_crtc.c  |  1 -
>  .../gpu/drm/arm/display/komeda/komeda_dev.c   | 65 +++++++++++++++++--
>  .../gpu/drm/arm/display/komeda/komeda_dev.h   |  3 +
>  .../gpu/drm/arm/display/komeda/komeda_drv.c   | 30 ++++++++-
>  4 files changed, 91 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> index 38d5cb20e908..b47c0dabd0d1 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> @@ -5,7 +5,6 @@
>   *
>   */
>  #include <linux/clk.h>
> -#include <linux/pm_runtime.h>
>  #include <linux/spinlock.h>
>  
>  #include <drm/drm_atomic.h>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> index bee4633cdd9f..8a03324f02a5 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> @@ -258,7 +258,7 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
>  			  product->product_id,
>  			  MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id));
>  		err = -ENODEV;
> -		goto err_cleanup;
> +		goto disable_clk;
>  	}
>  
>  	DRM_INFO("Found ARM Mali-D%x version r%dp%d\n",
> @@ -271,19 +271,19 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
>  	err = mdev->funcs->enum_resources(mdev);
>  	if (err) {
>  		DRM_ERROR("enumerate display resource failed.\n");
> -		goto err_cleanup;
> +		goto disable_clk;
>  	}
>  
>  	err = komeda_parse_dt(dev, mdev);
>  	if (err) {
>  		DRM_ERROR("parse device tree failed.\n");
> -		goto err_cleanup;
> +		goto disable_clk;
>  	}
>  
>  	err = komeda_assemble_pipelines(mdev);
>  	if (err) {
>  		DRM_ERROR("assemble display pipelines failed.\n");
> -		goto err_cleanup;
> +		goto disable_clk;
>  	}
>  
>  	dev->dma_parms = &mdev->dma_parms;
> @@ -296,11 +296,14 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
>  	if (mdev->iommu && mdev->funcs->connect_iommu) {
>  		err = mdev->funcs->connect_iommu(mdev);
>  		if (err) {
> +			DRM_ERROR("connect iommu failed.\n");
>  			mdev->iommu = NULL;
> -			goto err_cleanup;
> +			goto disable_clk;
>  		}
>  	}
>  
> +	clk_disable_unprepare(mdev->aclk);
> +
>  	err = sysfs_create_group(&dev->kobj, &komeda_sysfs_attr_group);
>  	if (err) {
>  		DRM_ERROR("create sysfs group failed.\n");
> @@ -313,6 +316,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
>  
>  	return mdev;
>  
> +disable_clk:
> +	clk_disable_unprepare(mdev->aclk);
>  err_cleanup:
>  	komeda_dev_destroy(mdev);
>  	return ERR_PTR(err);
> @@ -330,8 +335,12 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
>  	debugfs_remove_recursive(mdev->debugfs_root);
>  #endif
>  
> +	if (mdev->aclk)
> +		clk_prepare_enable(mdev->aclk);
> +
>  	if (mdev->iommu && mdev->funcs->disconnect_iommu)
> -		mdev->funcs->disconnect_iommu(mdev);
> +		if (mdev->funcs->disconnect_iommu(mdev))
> +			DRM_ERROR("disconnect iommu failed.\n");
>  	mdev->iommu = NULL;
>  
>  	for (i = 0; i < mdev->n_pipelines; i++) {
> @@ -359,3 +368,47 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
>  
>  	devm_kfree(dev, mdev);
>  }
> +
> +int komeda_dev_resume(struct komeda_dev *mdev)
> +{
> +	int ret = 0;
> +
> +	clk_prepare_enable(mdev->aclk);
> +
> +	if (mdev->iommu && mdev->funcs->connect_iommu) {
> +		ret = mdev->funcs->connect_iommu(mdev);
> +		if (ret < 0) {
> +			DRM_ERROR("connect iommu failed.\n");
> +			goto disable_clk;
> +		}
> +	}
> +
> +	ret = mdev->funcs->enable_irq(mdev);
> +
> +disable_clk:
> +	clk_disable_unprepare(mdev->aclk);
> +
> +	return ret;
> +}
> +
> +int komeda_dev_suspend(struct komeda_dev *mdev)
> +{
> +	int ret = 0;
> +
> +	clk_prepare_enable(mdev->aclk);
> +
> +	if (mdev->iommu && mdev->funcs->disconnect_iommu) {
> +		ret = mdev->funcs->disconnect_iommu(mdev);
> +		if (ret < 0) {
> +			DRM_ERROR("disconnect iommu failed.\n");
> +			goto disable_clk;
> +		}
> +	}
> +
> +	ret = mdev->funcs->disable_irq(mdev);
> +
> +disable_clk:
> +	clk_disable_unprepare(mdev->aclk);
> +
> +	return ret;
> +}
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index 8acf8c0601cc..414200233b64 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -224,4 +224,7 @@ void komeda_print_events(struct komeda_events *evts);
>  static inline void komeda_print_events(struct komeda_events *evts) {}
>  #endif
>  
> +int komeda_dev_resume(struct komeda_dev *mdev);
> +int komeda_dev_suspend(struct komeda_dev *mdev);
> +
>  #endif /*_KOMEDA_DEV_H_*/
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> index 69ace6f9055d..d6c2222c5d33 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> @@ -8,6 +8,7 @@
>  #include <linux/kernel.h>
>  #include <linux/platform_device.h>
>  #include <linux/component.h>
> +#include <linux/pm_runtime.h>
>  #include <drm/drm_of.h>
>  #include "komeda_dev.h"
>  #include "komeda_kms.h"
> @@ -136,13 +137,40 @@ static const struct of_device_id komeda_of_match[] = {
>  
>  MODULE_DEVICE_TABLE(of, komeda_of_match);
>  
> +static int __maybe_unused komeda_pm_suspend(struct device *dev)
> +{
> +	struct komeda_drv *mdrv = dev_get_drvdata(dev);
> +	struct drm_device *drm = &mdrv->kms->base;
> +	int res;
> +
> +	res = drm_mode_config_helper_suspend(drm);

Just noticed this while prepping the -misc pull request.

You should use the atomic helpers instead, drm_atomic_helper_suspend and
drm_atomic_helper_resume.

> +
> +	komeda_dev_suspend(mdrv->mdev);
> +
> +	return res;
> +}
> +
> +static int __maybe_unused komeda_pm_resume(struct device *dev)
> +{
> +	struct komeda_drv *mdrv = dev_get_drvdata(dev);
> +	struct drm_device *drm = &mdrv->kms->base;
> +
> +	komeda_dev_resume(mdrv->mdev);
> +
> +	return drm_mode_config_helper_resume(drm);
> +}
> +
> +static const struct dev_pm_ops komeda_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(komeda_pm_suspend, komeda_pm_resume)
> +};
> +
>  static struct platform_driver komeda_platform_driver = {
>  	.probe	= komeda_platform_probe,
>  	.remove	= komeda_platform_remove,
>  	.driver	= {
>  		.name = "komeda",
>  		.of_match_table	= komeda_of_match,
> -		.pm = NULL,
> +		.pm = &komeda_pm_ops,
>  	},
>  };
>  
> -- 
> 2.17.1
> 
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-- 
Sean Paul, Software Engineer, Google / Chromium OS