drm/tegra: Enable devfreq for the nvjpg client

Enable devfreq for the nvjpg client with userspace governor by default.

Bug 4074193

Signed-off-by: Johnny Liu <johnliu@nvidia.com>
Change-Id: Ic70651b5af4648808b188560e4c09da00c5dde55
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2895739
Reviewed-by: svcacv <svcacv@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/gpu/drm/tegra/nvjpg.c

@@ -5,6 +5,7 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/devfreq.h>
 #include <linux/host1x-next.h>
 #include <linux/iommu.h>
 #include <linux/module.h>
@@ -12,6 +13,7 @@
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
@@ -39,6 +41,8 @@ struct nvjpg {
 	struct host1x_channel *channel;
 	struct device *dev;
 	struct clk *clk;
+	struct devfreq *devfreq;
+	struct devfreq_dev_profile *devfreq_profile;
 
 	/* Platform configuration */
 	const struct nvjpg_config *config;
@@ -95,6 +99,91 @@ static int nvjpg_boot(struct nvjpg *nvjpg)
 	return 0;
 }
 
+static int nvjpg_devfreq_target(struct device *dev, unsigned long *freq, u32 flags)
+{
+	struct nvjpg *nvjpg = dev_get_drvdata(dev);
+	int err;
+
+	err = nvjpg_set_rate(nvjpg, *freq);
+	if (err < 0) {
+		dev_err(dev, "failed to set clock rate\n");
+		return err;
+	}
+
+	*freq = clk_get_rate(nvjpg->clk);
+
+	return 0;
+}
+
+static int nvjpg_devfreq_get_dev_status(struct device *dev, struct devfreq_dev_status *stat)
+{
+	struct nvjpg *nvjpg = dev_get_drvdata(dev);
+	struct host1x_client *client = &nvjpg->client.base;
+	unsigned long usage;
+
+	/* Update load information */
+	host1x_actmon_read_active_norm(client, &usage);
+	stat->total_time = 1;
+	stat->busy_time = usage;
+
+	/* Update device frequency */
+	stat->current_frequency = clk_get_rate(nvjpg->clk);
+
+	return 0;
+}
+
+static int nvjpg_devfreq_get_cur_freq(struct device *dev, unsigned long *freq)
+{
+	struct nvjpg *nvjpg = dev_get_drvdata(dev);
+
+	*freq = clk_get_rate(nvjpg->clk);
+
+	return 0;
+}
+
+static struct devfreq_dev_profile nvjpg_devfreq_profile = {
+	.target = nvjpg_devfreq_target,
+	.get_dev_status = nvjpg_devfreq_get_dev_status,
+	.get_cur_freq = nvjpg_devfreq_get_cur_freq,
+	.polling_ms = 100,
+};
+
+static int nvjpg_devfreq_init(struct nvjpg *nvjpg)
+{
+	unsigned long max_rate = clk_round_rate(nvjpg->clk, ULONG_MAX);
+	unsigned long min_rate = clk_round_rate(nvjpg->clk, 0);
+	unsigned long margin = clk_round_rate(nvjpg->clk, min_rate + 1) - min_rate;
+	unsigned long rate = min_rate;
+	struct devfreq *devfreq;
+
+	while (rate <= max_rate) {
+		dev_pm_opp_add(nvjpg->dev, rate, 0);
+		rate += margin;
+	}
+
+	devfreq = devm_devfreq_add_device(nvjpg->dev,
+					  &nvjpg_devfreq_profile,
+					  DEVFREQ_GOV_USERSPACE,
+					  NULL);
+	if (IS_ERR(devfreq))
+		return PTR_ERR(devfreq);
+
+	devfreq->suspend_freq = min_rate;
+	devfreq->resume_freq = min_rate;
+	nvjpg->devfreq = devfreq;
+
+	return 0;
+}
+
+static void nvjpg_devfreq_deinit(struct nvjpg *nvjpg)
+{
+	if (!nvjpg->devfreq)
+		return;
+
+	devm_devfreq_remove_device(nvjpg->dev, nvjpg->devfreq);
+	nvjpg->devfreq = NULL;
+}
+
 static int nvjpg_init(struct host1x_client *client)
 {
 	struct tegra_drm_client *drm = host1x_to_drm_client(client);
@@ -279,6 +368,8 @@ static __maybe_unused int nvjpg_runtime_resume(struct device *dev)
 	if (err < 0)
 		goto disable;
 
+	devfreq_resume_device(nvjpg->devfreq);
+
 	return 0;
 
 disable:
@@ -290,6 +381,8 @@ static __maybe_unused int nvjpg_runtime_suspend(struct device *dev)
 {
 	struct nvjpg *nvjpg = dev_get_drvdata(dev);
 
+	devfreq_suspend_device(nvjpg->devfreq);
+
 	host1x_channel_stop(nvjpg->channel);
 
 	clk_disable_unprepare(nvjpg->clk);
@@ -464,6 +557,12 @@ static int nvjpg_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	err = nvjpg_devfreq_init(nvjpg);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to init devfreq: %d\n", err);
+		return err;
+	}
+
 	pm_runtime_enable(dev);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_autosuspend_delay(dev, 500);
@@ -483,6 +582,8 @@ static int nvjpg_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
+	nvjpg_devfreq_deinit(nvjpg);
+
 	err = host1x_actmon_unregister(&nvjpg->client.base);
 	if (err < 0)
 		dev_info(&pdev->dev, "failed to unregister host1x actmon: %d\n",