drm/komeda: Adds power management support

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@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190923015908.26627-1-lowry.li@arm.com

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>

drivers/gpu/drm/arm/display/komeda/komeda_dev.c

@@ -228,7 +228,7 @@ 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",
@@ -241,19 +241,19 @@ 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;
@@ -266,11 +266,14 @@ 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");
@@ -283,6 +286,8 @@ 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);
@@ -300,8 +305,12 @@ 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++) {
@@ -329,3 +338,47 @@ 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;
+}

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_*/

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);
+
+	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,
 	},
 };