[PATCH] devfreq: Register devfreq as a cooling device

[Daniel Lezcano <daniel.lezcano@linaro.org>]

Currently the default behavior is to manually having the devfreq
backend to register themselves as a devfreq cooling device.

There are no so many and actually it makes more sense to register the
devfreq device when adding it.

Consequently, every devfreq becomes a cooling device like cpufreq is.

Having a devfreq being registered as a cooling device can not mitigate
a thermal zone if it is not bound to this one. Thus, the current
configurations are not impacted by this change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/devfreq/devfreq.c                   |  8 ++++++++
 drivers/gpu/drm/lima/lima_devfreq.c         | 13 -------------
 drivers/gpu/drm/lima/lima_devfreq.h         |  2 --
 drivers/gpu/drm/msm/msm_gpu.c               | 11 -----------
 drivers/gpu/drm/msm/msm_gpu.h               |  2 --
 drivers/gpu/drm/panfrost/panfrost_devfreq.c | 13 -------------
 include/linux/devfreq.h                     |  3 +++
 7 files changed, 11 insertions(+), 41 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b6d63f02d293..19149b31b000 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -11,6 +11,7 @@
 #include <linux/kmod.h>
 #include <linux/sched.h>
 #include <linux/debugfs.h>
+#include <linux/devfreq_cooling.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -26,6 +27,7 @@
 #include <linux/hrtimer.h>
 #include <linux/of.h>
 #include <linux/pm_qos.h>
+#include <linux/thermal.h>
 #include <linux/units.h>
 #include "governor.h"
 
@@ -935,6 +937,10 @@ struct devfreq *devfreq_add_device(struct device *dev,
 
 	mutex_unlock(&devfreq_list_lock);
 
+	devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
+	if (IS_ERR(devfreq->cdev))
+		dev_info(dev, "Failed to register devfreq cooling device\n");
+
 	return devfreq;
 
 err_init:
@@ -960,6 +966,8 @@ int devfreq_remove_device(struct devfreq *devfreq)
 	if (!devfreq)
 		return -EINVAL;
 
+	thermal_cooling_device_unregister(devfreq->cdev);
+
 	if (devfreq->governor) {
 		devfreq->governor->event_handler(devfreq,
 						 DEVFREQ_GOV_STOP, NULL);
diff --git a/drivers/gpu/drm/lima/lima_devfreq.c b/drivers/gpu/drm/lima/lima_devfreq.c
index 5686ad4aaf7c..a696eff1642c 100644
--- a/drivers/gpu/drm/lima/lima_devfreq.c
+++ b/drivers/gpu/drm/lima/lima_devfreq.c
@@ -7,7 +7,6 @@
  */
 #include <linux/clk.h>
 #include <linux/devfreq.h>
-#include <linux/devfreq_cooling.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
@@ -90,11 +89,6 @@ void lima_devfreq_fini(struct lima_device *ldev)
 {
 	struct lima_devfreq *devfreq = &ldev->devfreq;
 
-	if (devfreq->cooling) {
-		devfreq_cooling_unregister(devfreq->cooling);
-		devfreq->cooling = NULL;
-	}
-
 	if (devfreq->devfreq) {
 		devm_devfreq_remove_device(ldev->dev, devfreq->devfreq);
 		devfreq->devfreq = NULL;
@@ -110,7 +104,6 @@ void lima_devfreq_fini(struct lima_device *ldev)
 
 int lima_devfreq_init(struct lima_device *ldev)
 {
-	struct thermal_cooling_device *cooling;
 	struct device *dev = ldev->dev;
 	struct opp_table *opp_table;
 	struct devfreq *devfreq;
@@ -173,12 +166,6 @@ int lima_devfreq_init(struct lima_device *ldev)
 
 	ldevfreq->devfreq = devfreq;
 
-	cooling = of_devfreq_cooling_register(dev->of_node, devfreq);
-	if (IS_ERR(cooling))
-		dev_info(dev, "Failed to register cooling device\n");
-	else
-		ldevfreq->cooling = cooling;
-
 	return 0;
 
 err_fini:
diff --git a/drivers/gpu/drm/lima/lima_devfreq.h b/drivers/gpu/drm/lima/lima_devfreq.h
index 2d9b3008ce77..c43a2069e5d3 100644
--- a/drivers/gpu/drm/lima/lima_devfreq.h
+++ b/drivers/gpu/drm/lima/lima_devfreq.h
@@ -9,7 +9,6 @@
 
 struct devfreq;
 struct opp_table;
-struct thermal_cooling_device;
 
 struct lima_device;
 
@@ -17,7 +16,6 @@ struct lima_devfreq {
 	struct devfreq *devfreq;
 	struct opp_table *clkname_opp_table;
 	struct opp_table *regulators_opp_table;
-	struct thermal_cooling_device *cooling;
 
 	ktime_t busy_time;
 	ktime_t idle_time;
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index ab7c167b0623..d7f80ebfe9df 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -14,7 +14,6 @@
 #include <generated/utsrelease.h>
 #include <linux/string_helpers.h>
 #include <linux/devfreq.h>
-#include <linux/devfreq_cooling.h>
 #include <linux/devcoredump.h>
 #include <linux/sched/task.h>
 
@@ -112,14 +111,6 @@ static void msm_devfreq_init(struct msm_gpu *gpu)
 	}
 
 	devfreq_suspend_device(gpu->devfreq.devfreq);
-
-	gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node,
-			gpu->devfreq.devfreq);
-	if (IS_ERR(gpu->cooling)) {
-		DRM_DEV_ERROR(&gpu->pdev->dev,
-				"Couldn't register GPU cooling device\n");
-		gpu->cooling = NULL;
-	}
 }
 
 static int enable_pwrrail(struct msm_gpu *gpu)
@@ -1056,6 +1047,4 @@ void msm_gpu_cleanup(struct msm_gpu *gpu)
 	if (gpu->worker) {
 		kthread_destroy_worker(gpu->worker);
 	}
-
-	devfreq_cooling_unregister(gpu->cooling);
 }
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index d7cd02cd2109..93419368bac8 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -155,8 +155,6 @@ struct msm_gpu {
 	struct msm_gpu_state *crashstate;
 	/* True if the hardware supports expanded apriv (a650 and newer) */
 	bool hw_apriv;
-
-	struct thermal_cooling_device *cooling;
 };
 
 static inline struct msm_gpu *dev_to_gpu(struct device *dev)
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 56b3f5935703..2cb6300de1f1 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -3,7 +3,6 @@
 
 #include <linux/clk.h>
 #include <linux/devfreq.h>
-#include <linux/devfreq_cooling.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
 
@@ -90,7 +89,6 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
 	struct device *dev = &pfdev->pdev->dev;
 	struct devfreq *devfreq;
 	struct opp_table *opp_table;
-	struct thermal_cooling_device *cooling;
 	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
 
 	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
@@ -139,12 +137,6 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
 	}
 	pfdevfreq->devfreq = devfreq;
 
-	cooling = devfreq_cooling_em_register(devfreq, NULL);
-	if (IS_ERR(cooling))
-		DRM_DEV_INFO(dev, "Failed to register cooling device\n");
-	else
-		pfdevfreq->cooling = cooling;
-
 	return 0;
 
 err_fini:
@@ -156,11 +148,6 @@ void panfrost_devfreq_fini(struct panfrost_device *pfdev)
 {
 	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
 
-	if (pfdevfreq->cooling) {
-		devfreq_cooling_unregister(pfdevfreq->cooling);
-		pfdevfreq->cooling = NULL;
-	}
-
 	if (pfdevfreq->opp_of_table_added) {
 		dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
 		pfdevfreq->opp_of_table_added = false;
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 26ea0850be9b..690bd4affe18 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -198,6 +198,9 @@ struct devfreq {
 
 	struct srcu_notifier_head transition_notifier_list;
 
+	/* Pointer to the cooling device if used for thermal mitigation */
+	struct thermal_cooling_device *cdev;
+
 	struct notifier_block nb_min;
 	struct notifier_block nb_max;
 };
-- 
2.17.1