[PATCH v6 1/4] PM / devfreq: Register devfreq as a cooling device on demand

[PATCH v6 1/4] PM / devfreq: Register devfreq as a cooling device on demand

[Daniel Lezcano]

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

Instead of adding the code in the drivers for the thermal cooling
device registering, let's provide a flag in the devfreq's profile to
tell the common devfreq code to register the newly created devfreq as
a cooling device.

Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
---
 V6:
   - Did one line string instead of multiline
   - Removed thermal.h header inclusion as it is in devfreq_cooling.h
   - Added forward declaration for thermal_cooling_device pointer in devfreq.h
 V5:
   - Changed subject prefix by:  PM / devfreq
 V4:
   - Replaced thermal_cooling_device_unregister() by
     devfreq_cooling_unregister()
 V3:
   - Rebased on linux-pm branch without units.h
   - Set the cdev to NULL in case of error
   - Added description for the cdev field in the devfreq structure
 V2:
   - Added is_cooling_device boolean in profile structure
   - Register cooling device when the is_cooling_device boolean is set
   - Remove devfreq cooling device registration in the backend drivers
 V1:
   - Register devfreq as a cooling device unconditionnally
---
 drivers/devfreq/devfreq.c | 9 +++++++++
 include/linux/devfreq.h   | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bf3047896e41..b6d3e7db0b09 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>
@@ -935,6 +936,12 @@ struct devfreq *devfreq_add_device(struct device *dev,
 
 	mutex_unlock(&devfreq_list_lock);
 
+	if (devfreq->profile->is_cooling_device) {
+		devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
+		if (IS_ERR(devfreq->cdev))
+			devfreq->cdev = NULL;
+	}
+
 	return devfreq;
 
 err_init:
@@ -960,6 +967,8 @@ int devfreq_remove_device(struct devfreq *devfreq)
 	if (!devfreq)
 		return -EINVAL;
 
+	devfreq_cooling_unregister(devfreq->cdev);
+
 	if (devfreq->governor) {
 		devfreq->governor->event_handler(devfreq,
 						 DEVFREQ_GOV_STOP, NULL);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 26ea0850be9b..142474b4af96 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -38,6 +38,7 @@ enum devfreq_timer {
 
 struct devfreq;
 struct devfreq_governor;
+struct thermal_cooling_device;
 
 /**
  * struct devfreq_dev_status - Data given from devfreq user device to
@@ -98,11 +99,15 @@ struct devfreq_dev_status {
  * @freq_table:		Optional list of frequencies to support statistics
  *			and freq_table must be generated in ascending order.
  * @max_state:		The size of freq_table.
+ *
+ * @is_cooling_device: A self-explanatory boolean giving the device a
+ *                     cooling effect property.
  */
 struct devfreq_dev_profile {
 	unsigned long initial_freq;
 	unsigned int polling_ms;
 	enum devfreq_timer timer;
+	bool is_cooling_device;
 
 	int (*target)(struct device *dev, unsigned long *freq, u32 flags);
 	int (*get_dev_status)(struct device *dev,
@@ -156,6 +161,7 @@ struct devfreq_stats {
  * @suspend_count:	 suspend requests counter for a device.
  * @stats:	Statistics of devfreq device behavior
  * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
+ * @cdev:	Cooling device pointer if the devfreq has cooling property
  * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY
  * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY
  *
@@ -198,6 +204,9 @@ 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

[PATCH v6 2/4] PM / devfreq: msm: Use devfreq cooling device registration

[Daniel Lezcano]

The devfreq core code is able to register the devfreq device as a
cooling device if the 'is_cooling_device' flag is set in the profile.

Use this flag and remove the cooling device registering code.

Tested on dragonboard 845c

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/gpu/drm/msm/msm_gpu.c | 12 +-----------
 drivers/gpu/drm/msm/msm_gpu.h |  2 --
 2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index ab7c167b0623..eade94271a60 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>
 
@@ -82,6 +81,7 @@ static struct devfreq_dev_profile msm_devfreq_profile = {
 	.target = msm_devfreq_target,
 	.get_dev_status = msm_devfreq_get_dev_status,
 	.get_cur_freq = msm_devfreq_get_cur_freq,
+	.is_cooling_device = true,
 };
 
 static void msm_devfreq_init(struct msm_gpu *gpu)
@@ -112,14 +112,6 @@ 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 +1048,4 @@ 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)
-- 
2.17.1

[PATCH v6 3/4] PM / devfreq: panfrost: Use devfreq cooling device registration

[Daniel Lezcano]

The devfreq core code is able to register the devfreq device as a
cooling device if the 'is_cooling_device' flag is set in the profile.

Use this flag and remove the cooling device registering code.

Tested on rock960.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Steven Price <steven.price@arm.com>
---
 drivers/gpu/drm/panfrost/panfrost_devfreq.c | 14 +-------------
 drivers/gpu/drm/panfrost/panfrost_devfreq.h |  3 ---
 2 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 56b3f5935703..4d96edf1bc54 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>
 
@@ -80,6 +79,7 @@ static struct devfreq_dev_profile panfrost_devfreq_profile = {
 	.polling_ms = 50, /* ~3 frames */
 	.target = panfrost_devfreq_target,
 	.get_dev_status = panfrost_devfreq_get_dev_status,
+	.is_cooling_device = true,
 };
 
 int panfrost_devfreq_init(struct panfrost_device *pfdev)
@@ -90,7 +90,6 @@ 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 +138,6 @@ 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 +149,6 @@ 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/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
index db6ea48e21f9..470f5c974703 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
@@ -9,14 +9,11 @@
 
 struct devfreq;
 struct opp_table;
-struct thermal_cooling_device;
-
 struct panfrost_device;
 
 struct panfrost_devfreq {
 	struct devfreq *devfreq;
 	struct opp_table *regulators_opp_table;
-	struct thermal_cooling_device *cooling;
 	bool opp_of_table_added;
 
 	ktime_t busy_time;
-- 
2.17.1

[PATCH v6 4/4] PM / devfreq: lima: Use devfreq cooling device registration

[Daniel Lezcano]

The devfreq core code is able to register the devfreq device as a
cooling device if the 'is_cooling_device' flag is set in the profile.

Use this flag and remove the cooling device registering code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/gpu/drm/lima/lima_devfreq.c | 14 +-------------
 drivers/gpu/drm/lima/lima_devfreq.h |  2 --
 2 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/lima/lima_devfreq.c b/drivers/gpu/drm/lima/lima_devfreq.c
index 5686ad4aaf7c..86aea1bdc4f4 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>
@@ -84,17 +83,13 @@ static struct devfreq_dev_profile lima_devfreq_profile = {
 	.polling_ms = 50, /* ~3 frames */
 	.target = lima_devfreq_target,
 	.get_dev_status = lima_devfreq_get_dev_status,
+	.is_cooling_device = true,
 };
 
 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 +105,6 @@ 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 +167,6 @@ 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;
-- 
2.17.1

Re: [PATCH v6 1/4] PM / devfreq: Register devfreq as a cooling device on demand

[Chanwoo Choi]

Hi,

On 3/8/21 10:30 PM, Daniel Lezcano wrote:
> Currently the default behavior is to manually having the devfreq
> backend to register themselves as a devfreq cooling device.
> 
> Instead of adding the code in the drivers for the thermal cooling
> device registering, let's provide a flag in the devfreq's profile to
> tell the common devfreq code to register the newly created devfreq as
> a cooling device.
> 
> Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> Reviewed-by: Steven Price <steven.price@arm.com>
> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
> ---
>  V6:
>    - Did one line string instead of multiline
>    - Removed thermal.h header inclusion as it is in devfreq_cooling.h
>    - Added forward declaration for thermal_cooling_device pointer in devfreq.h
>  V5:
>    - Changed subject prefix by:  PM / devfreq
>  V4:
>    - Replaced thermal_cooling_device_unregister() by
>      devfreq_cooling_unregister()
>  V3:
>    - Rebased on linux-pm branch without units.h
>    - Set the cdev to NULL in case of error
>    - Added description for the cdev field in the devfreq structure
>  V2:
>    - Added is_cooling_device boolean in profile structure
>    - Register cooling device when the is_cooling_device boolean is set
>    - Remove devfreq cooling device registration in the backend drivers
>  V1:
>    - Register devfreq as a cooling device unconditionnally
> ---
>  drivers/devfreq/devfreq.c | 9 +++++++++
>  include/linux/devfreq.h   | 9 +++++++++
>  2 files changed, 18 insertions(+)

(snip)

Applied it. Thanks.

I made the pull request with immutable branch
for preventing the conflict on other git repo as following:

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics


The following changes since commit fe07bfda2fb9cdef8a4d4008a409bb02f35f1bd8:

  Linux 5.12-rc1 (2021-02-28 16:05:19 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git immutable-devfreq-v5.13-rc1

for you to fetch changes up to 1224451bb6f938023dd7fa4e7ba43bfb185bc9e3:

  PM / devfreq: Register devfreq as a cooling device on demand (2021-03-09 15:40:16 +0900)

----------------------------------------------------------------
Daniel Lezcano (1):
      PM / devfreq: Register devfreq as a cooling device on demand

 drivers/devfreq/devfreq.c | 9 +++++++++
 include/linux/devfreq.h   | 9 +++++++++
 2 files changed, 18 insertions(+)