diff mbox series

[v2,06/13] thermal: tegra: Do not register cooling device

Message ID 20231012175836.3408077-7-thierry.reding@gmail.com
State New
Headers show
Series thermal: tegra: Do not register cooling device | expand

Commit Message

Thierry Reding Oct. 12, 2023, 5:58 p.m. UTC 
From: Thierry Reding <treding@nvidia.com>

The SOCTHERM's built-in throttling mechanism doesn't map well to the
concept of a cooling device because it will automatically start to
throttle when the programmed temperature threshold is crossed.

Remove the cooling device implementation and instead unconditionally
program the throttling for the CPU and GPU thermal zones.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
Changes in v2:
- adapt to new DT bindings

 drivers/thermal/tegra/soctherm.c          | 287 +++++++++-------------
 drivers/thermal/tegra/soctherm.h          |   1 +
 drivers/thermal/tegra/tegra124-soctherm.c |   4 +
 drivers/thermal/tegra/tegra132-soctherm.c |   4 +
 drivers/thermal/tegra/tegra210-soctherm.c |   4 +
 5 files changed, 132 insertions(+), 168 deletions(-)

Comments

Daniel Lezcano Oct. 13, 2023, 3:57 p.m. UTC | #1 
On 12/10/2023 19:58, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> The SOCTHERM's built-in throttling mechanism doesn't map well to the
> concept of a cooling device because it will automatically start to
> throttle when the programmed temperature threshold is crossed.
> 
> Remove the cooling device implementation and instead unconditionally
> program the throttling for the CPU and GPU thermal zones.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---

[ ... ]

> +	ret = of_property_read_u32(np, "temperature-millicelsius",
> +				   &stc->temperature);
> +	if (ret < 0)
> +		goto err;
> +
> +	ret = of_property_read_u32(np, "hysteresis-millicelsius",
> +				   &stc->hysteresis);
> +	if (ret < 0)
> +		goto err;
> +
> +	stc->num_zones = of_count_phandle_with_args(np, "nvidia,thermal-zones",
> +						    NULL);
> +	if (stc->num_zones > 0) {
> +		struct device_node *zone;
> +		unsigned int i;
> +
> +		stc->zones = devm_kcalloc(ts->dev, stc->num_zones, sizeof(zone),
> +					  GFP_KERNEL);
> +		if (!stc->zones)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < stc->num_zones; i++) {
> +			zone = of_parse_phandle(np, "nvidia,thermal-zones", i);
> +			stc->zones[i] = zone;
> +		}
> +	}

What is the connection between the temperature sensor and the hardware 
limiter?

I mean, one hand there is the hardware limiter which is not connected to 
the sensor neither a thermal zone and it could be self contained in a 
separate driver. And then there is the temperature sensor.

The thermal zone phandle things connected with the throttling bindings 
sounds like strange to me.

What prevents to split the throttling and the sensor into separate code?
Thierry Reding Nov. 10, 2023, 1:55 p.m. UTC | #2 
On Fri, Oct 13, 2023 at 05:57:13PM +0200, Daniel Lezcano wrote:
> On 12/10/2023 19:58, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > The SOCTHERM's built-in throttling mechanism doesn't map well to the
> > concept of a cooling device because it will automatically start to
> > throttle when the programmed temperature threshold is crossed.
> > 
> > Remove the cooling device implementation and instead unconditionally
> > program the throttling for the CPU and GPU thermal zones.
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> 
> [ ... ]
> 
> > +	ret = of_property_read_u32(np, "temperature-millicelsius",
> > +				   &stc->temperature);
> > +	if (ret < 0)
> > +		goto err;
> > +
> > +	ret = of_property_read_u32(np, "hysteresis-millicelsius",
> > +				   &stc->hysteresis);
> > +	if (ret < 0)
> > +		goto err;
> > +
> > +	stc->num_zones = of_count_phandle_with_args(np, "nvidia,thermal-zones",
> > +						    NULL);
> > +	if (stc->num_zones > 0) {
> > +		struct device_node *zone;
> > +		unsigned int i;
> > +
> > +		stc->zones = devm_kcalloc(ts->dev, stc->num_zones, sizeof(zone),
> > +					  GFP_KERNEL);
> > +		if (!stc->zones)
> > +			return -ENOMEM;
> > +
> > +		for (i = 0; i < stc->num_zones; i++) {
> > +			zone = of_parse_phandle(np, "nvidia,thermal-zones", i);
> > +			stc->zones[i] = zone;
> > +		}
> > +	}
> 
> What is the connection between the temperature sensor and the hardware
> limiter?
> 
> I mean, one hand there is the hardware limiter which is not connected to the
> sensor neither a thermal zone and it could be self contained in a separate
> driver. And then there is the temperature sensor.
> 
> The thermal zone phandle things connected with the throttling bindings
> sounds like strange to me.
> 
> What prevents to split the throttling and the sensor into separate code?

Both the temperature sensor and the hardware throttle mechanism are part
of the same IP block, so it would be quite difficult (and unnecessary)
to split them into separate drivers.

The hardware throttler uses the temperature sensor's data to initiate
throttling automatically when certain (programmable) temperature
thresholds are reached.

The reason why we need to reference the thermal zone is because the
registers needed to program the throttler are contained within the
sensor group (which are effectively mapped to thermal zones).

I suppose there are a number of other ways how this could be described.
The thermal zones could be extended with extra information about the
throttling, or we could use just the sensor group ID instead of a full
phandle to reference this.

I was sort of trying to keep things somewhat aligned with the concept of
thermal zones and not rewrite the entire thing, but perhaps I should go
back to the drawing board and think about whether there's an even better
way to describe this in DT.

Thierry
Thierry Reding Nov. 10, 2023, 2:52 p.m. UTC | #3 
On Fri, Nov 10, 2023 at 02:55:15PM +0100, Thierry Reding wrote:
> On Fri, Oct 13, 2023 at 05:57:13PM +0200, Daniel Lezcano wrote:
> > On 12/10/2023 19:58, Thierry Reding wrote:
> > > From: Thierry Reding <treding@nvidia.com>
> > > 
> > > The SOCTHERM's built-in throttling mechanism doesn't map well to the
> > > concept of a cooling device because it will automatically start to
> > > throttle when the programmed temperature threshold is crossed.
> > > 
> > > Remove the cooling device implementation and instead unconditionally
> > > program the throttling for the CPU and GPU thermal zones.
> > > 
> > > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > > ---
> > 
> > [ ... ]
> > 
> > > +	ret = of_property_read_u32(np, "temperature-millicelsius",
> > > +				   &stc->temperature);
> > > +	if (ret < 0)
> > > +		goto err;
> > > +
> > > +	ret = of_property_read_u32(np, "hysteresis-millicelsius",
> > > +				   &stc->hysteresis);
> > > +	if (ret < 0)
> > > +		goto err;
> > > +
> > > +	stc->num_zones = of_count_phandle_with_args(np, "nvidia,thermal-zones",
> > > +						    NULL);
> > > +	if (stc->num_zones > 0) {
> > > +		struct device_node *zone;
> > > +		unsigned int i;
> > > +
> > > +		stc->zones = devm_kcalloc(ts->dev, stc->num_zones, sizeof(zone),
> > > +					  GFP_KERNEL);
> > > +		if (!stc->zones)
> > > +			return -ENOMEM;
> > > +
> > > +		for (i = 0; i < stc->num_zones; i++) {
> > > +			zone = of_parse_phandle(np, "nvidia,thermal-zones", i);
> > > +			stc->zones[i] = zone;
> > > +		}
> > > +	}
> > 
> > What is the connection between the temperature sensor and the hardware
> > limiter?
> > 
> > I mean, one hand there is the hardware limiter which is not connected to the
> > sensor neither a thermal zone and it could be self contained in a separate
> > driver. And then there is the temperature sensor.
> > 
> > The thermal zone phandle things connected with the throttling bindings
> > sounds like strange to me.
> > 
> > What prevents to split the throttling and the sensor into separate code?
> 
> Both the temperature sensor and the hardware throttle mechanism are part
> of the same IP block, so it would be quite difficult (and unnecessary)
> to split them into separate drivers.
> 
> The hardware throttler uses the temperature sensor's data to initiate
> throttling automatically when certain (programmable) temperature
> thresholds are reached.
> 
> The reason why we need to reference the thermal zone is because the
> registers needed to program the throttler are contained within the
> sensor group (which are effectively mapped to thermal zones).
> 
> I suppose there are a number of other ways how this could be described.
> The thermal zones could be extended with extra information about the
> throttling, or we could use just the sensor group ID instead of a full
> phandle to reference this.
> 
> I was sort of trying to keep things somewhat aligned with the concept of
> thermal zones and not rewrite the entire thing, but perhaps I should go
> back to the drawing board and think about whether there's an even better
> way to describe this in DT.

I've looked at the documentation in a bit more details and here's an
high-level overview of what SOCTHERM is.

We have four groups (CPU, GPU, MEM and PLLX), each of which can be
programmed at four different levels (each level is an identical set of
registers to program temperature thresholds, throttling and enable or
disable). For temperature thresholds an interrupt can be configured.

There's an additional "thermtrip" level, which only has a threshold
that, when reached, will cause an emergency, hardware-induced shutdown
of the system.

Any of the generic levels can be used in whatever way we want. The
convention currently is to program the thermal zone trip points using
level 0. So for each group we create a thermal zone and level 0 for each
of the zones is programmed with the low and high thresholds for a given
trip point.

Currently we also use levels 1 and 2 to program the "light" and "heavy"
throttling "indicators". These will in turn be used to generate outputs
to the actual throttling mechanisms (CPU-light, CPU-heavy, GPU-light and
GPU-heavy).

There are a few other things that can be done, but I don't fully
understand how they would be useful and I don't think they've ever been
used, so I'll skip those for now.

Given the above, the thermal zone trip points are fairly clear. They are
fine as they are implemented. For the throttling mechanism we could do
something that maps more explicitly to the above groups and levels
concepts, but I think that could easily conflict with the trip points
programming, so keeping with the current conventions seems good and
designing the device tree bindings accordingly would help avoid any
conflicts.

So I think keeping the throttle-cfgs node is a good fit. We don't really
need to establish a connection between the thermal zone and the throttle
mechanism, though. We can derive the level from the indicator (light or
heavy) and for the group we only need an ID. The reason why I proposed a
link to the thermal-zone is because that thermal zone contains that ID
already, but we could equally well just add an nvidia,group property or
something along those lines so we know which group to use rather than
try and get it from a thermal zone.

I'll revise the bindings to see if I can come up with something.

Thierry
diff mbox series

Patch

diff --git a/drivers/thermal/tegra/soctherm.c b/drivers/thermal/tegra/soctherm.c
index 11c23ace2c81..105ec20d509d 100644
--- a/drivers/thermal/tegra/soctherm.c
+++ b/drivers/thermal/tegra/soctherm.c
@@ -33,7 +33,6 @@ 
 
 #include <dt-bindings/thermal/tegra124-soctherm.h>
 
-#include "../thermal_core.h"
 #include "soctherm.h"
 
 #define SENSOR_CONFIG0				0
@@ -317,12 +316,16 @@  struct soctherm_throt_cfg {
 	const char *name;
 	unsigned int id;
 	u8 priority;
+	int temperature;
+	int hysteresis;
 	u8 cpu_throt_level;
 	u32 cpu_throt_depth;
 	u32 gpu_throt_level;
 	struct soctherm_oc_cfg oc_cfg;
-	struct thermal_cooling_device *cdev;
 	bool init;
+
+	unsigned int num_zones;
+	struct device_node **zones;
 };
 
 struct tegra_soctherm {
@@ -497,9 +500,7 @@  static int thermtrip_program(struct tegra_soctherm *ts,
  * throttrip_program() - Configures the hardware to throttle the
  * pulse if a given sensor group reaches a given temperature
  * @ts: pointer to a struct tegra_soctherm
- * @sg: pointer to the sensor group to set the thermtrip temperature for
  * @stc: pointer to the throttle need to be triggered
- * @trip_temp: the temperature in millicelsius to trigger the thermal trip at
  *
  * Sets the thermal trip threshold and throttle event of the given sensor
  * group. If this threshold is crossed, the hardware will trigger the
@@ -510,43 +511,68 @@  static int thermtrip_program(struct tegra_soctherm *ts,
  *
  * Return: 0 upon success, or %-EINVAL upon failure.
  */
-static int throttrip_program(struct tegra_soctherm *ts,
-			     const struct tegra_tsensor_group *sg,
-			     struct soctherm_throt_cfg *stc,
-			     int trip_temp)
+static int throttrip_program(struct tegra_soctherm *tegra,
+			     struct soctherm_throt_cfg *stc)
 {
-	int temp, cpu_throt, gpu_throt;
-	unsigned int throt;
-	u32 r, reg_off;
+	int high, low, cpu_throt, gpu_throt;
+	unsigned int throt, i, j;
 
-	if (!sg || !stc || !stc->init)
-		return -EINVAL;
+	high = enforce_temp_range(tegra, stc->temperature);
+	high /= tegra->soc->thresh_grain;
+	low = enforce_temp_range(tegra, stc->temperature - stc->hysteresis);
+	low /= tegra->soc->thresh_grain;
 
-	temp = enforce_temp_range(ts, trip_temp) / ts->soc->thresh_grain;
+	for (i = 0; i < stc->num_zones; i++) {
+		struct tegra_thermctl_zone *zone = NULL;
+		unsigned int offset;
+		u32 r;
 
-	/* Hardcode LIGHT on LEVEL1 and HEAVY on LEVEL2 */
-	throt = stc->id;
-	reg_off = THERMCTL_LVL_REG(sg->thermctl_lvl0_offset, throt + 1);
+		for (j = 0; j < tegra->soc->num_ttgs; j++) {
+			struct thermal_zone_device *tz = tegra->thermctl_tzs[j];
 
-	if (throt == THROTTLE_LIGHT) {
-		cpu_throt = THERMCTL_LVL0_CPU0_CPU_THROT_LIGHT;
-		gpu_throt = THERMCTL_LVL0_CPU0_GPU_THROT_LIGHT;
-	} else {
-		cpu_throt = THERMCTL_LVL0_CPU0_CPU_THROT_HEAVY;
-		gpu_throt = THERMCTL_LVL0_CPU0_GPU_THROT_HEAVY;
-		if (throt != THROTTLE_HEAVY)
-			dev_warn(ts->dev,
-				 "invalid throt id %d - assuming HEAVY",
-				 throt);
-	}
+			if (tz->device.of_node == stc->zones[i]) {
+				zone = thermal_zone_device_priv(tz);
+				break;
+			}
+		}
 
-	r = readl(ts->regs + reg_off);
-	r = REG_SET_MASK(r, sg->thermctl_lvl0_up_thresh_mask, temp);
-	r = REG_SET_MASK(r, sg->thermctl_lvl0_dn_thresh_mask, temp);
-	r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_CPU_THROT_MASK, cpu_throt);
-	r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_GPU_THROT_MASK, gpu_throt);
-	r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_EN_MASK, 1);
-	writel(r, ts->regs + reg_off);
+		if (!zone)
+			continue;
+
+		if (!zone->sg->can_throttle) {
+			dev_warn(tegra->dev, "zone %s cannot be throttled\n",
+				 zone->sg->name);
+			continue;
+		}
+
+		/* Hardcode LIGHT on LEVEL1 and HEAVY on LEVEL2 */
+		throt = stc->id;
+		offset = THERMCTL_LVL_REG(zone->sg->thermctl_lvl0_offset, throt + 1);
+
+		if (throt == THROTTLE_LIGHT) {
+			cpu_throt = THERMCTL_LVL0_CPU0_CPU_THROT_LIGHT;
+			gpu_throt = THERMCTL_LVL0_CPU0_GPU_THROT_LIGHT;
+		} else {
+			cpu_throt = THERMCTL_LVL0_CPU0_CPU_THROT_HEAVY;
+			gpu_throt = THERMCTL_LVL0_CPU0_GPU_THROT_HEAVY;
+			if (throt != THROTTLE_HEAVY)
+				dev_warn(tegra->dev,
+					 "invalid throt id %d - assuming HEAVY",
+					 throt);
+		}
+
+		r = readl(tegra->regs + offset);
+		r = REG_SET_MASK(r, zone->sg->thermctl_lvl0_up_thresh_mask, high);
+		r = REG_SET_MASK(r, zone->sg->thermctl_lvl0_dn_thresh_mask, low);
+		r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_CPU_THROT_MASK, cpu_throt);
+		r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_GPU_THROT_MASK, gpu_throt);
+		r = REG_SET_MASK(r, THERMCTL_LVL0_CPU0_EN_MASK, 1);
+		writel(r, tegra->regs + offset);
+
+		dev_info(tegra->dev,
+			 "throttrip: will throttle when %s reaches %d mC\n",
+			 zone->sg->name, stc->temperature);
+	}
 
 	return 0;
 }
@@ -606,25 +632,6 @@  static int tegra_thermctl_set_trip_temp(struct thermal_zone_device *tz, int trip
 			return thermtrip_program(ts, sg, temp);
 		else
 			return 0;
-
-	} else if (trip.type == THERMAL_TRIP_HOT) {
-		int i;
-
-		for (i = 0; i < THROTTLE_SIZE; i++) {
-			struct thermal_cooling_device *cdev;
-			struct soctherm_throt_cfg *stc;
-
-			if (!ts->throt_cfgs[i].init)
-				continue;
-
-			cdev = ts->throt_cfgs[i].cdev;
-			if (get_thermal_instance(tz, cdev, trip_id))
-				stc = find_throttle_cfg_by_name(ts, cdev->type);
-			else
-				continue;
-
-			return throttrip_program(ts, sg, stc, temp);
-		}
 	}
 
 	return 0;
@@ -685,29 +692,9 @@  static const struct thermal_zone_device_ops tegra_of_thermal_ops = {
 	.set_trips = tegra_thermctl_set_trips,
 };
 
-static int get_hot_temp(struct thermal_zone_device *tz, int *trip_id, int *temp)
-{
-	int i, ret;
-	struct thermal_trip trip;
-
-	for (i = 0; i < thermal_zone_get_num_trips(tz); i++) {
-
-		ret = thermal_zone_get_trip(tz, i, &trip);
-		if (ret)
-			return -EINVAL;
-
-		if (trip.type == THERMAL_TRIP_HOT) {
-			*trip_id = i;
-			return 0;
-		}
-	}
-
-	return -EINVAL;
-}
-
 /**
  * tegra_soctherm_set_hwtrips() - set HW trip point from DT data
- * @dev: struct device * of the SOC_THERM instance
+ * @ts: pointer to a struct tegra_soctherm
  * @sg: pointer to the sensor group to set the thermtrip temperature for
  * @tz: struct thermal_zone_device *
  *
@@ -725,16 +712,12 @@  static int get_hot_temp(struct thermal_zone_device *tz, int *trip_id, int *temp)
  * THERMTRIP has been enabled successfully when a message similar to
  * this one appears on the serial console:
  * "thermtrip: will shut down when sensor group XXX reaches YYYYYY mC"
- * THROTTLE has been enabled successfully when a message similar to
- * this one appears on the serial console:
- * ""throttrip: will throttle when sensor group XXX reaches YYYYYY mC"
  */
 static int tegra_soctherm_set_hwtrips(struct tegra_soctherm *ts,
 				      const struct tegra_tsensor_group *sg,
 				      struct thermal_zone_device *tz)
 {
-	struct soctherm_throt_cfg *stc;
-	int i, trip, temperature, ret;
+	int temperature, ret;
 
 	/* Get thermtrips. If missing, try to get critical trips. */
 	temperature = tsensor_group_thermtrip_get(ts, sg->id);
@@ -752,43 +735,31 @@  static int tegra_soctherm_set_hwtrips(struct tegra_soctherm *ts,
 	dev_info(ts->dev, "thermtrip: will shut down when %s reaches %d mC\n",
 		 sg->name, temperature);
 
-	ret = get_hot_temp(tz, &trip, &temperature);
-	if (ret) {
-		dev_info(ts->dev, "throttrip: %s: missing hot temperature\n",
-			 sg->name);
-		return 0;
-	}
-
-	for (i = 0; i < THROTTLE_OC1; i++) {
-		struct thermal_cooling_device *cdev;
-
-		if (!ts->throt_cfgs[i].init)
-			continue;
-
-		cdev = ts->throt_cfgs[i].cdev;
-		if (get_thermal_instance(tz, cdev, trip))
-			stc = find_throttle_cfg_by_name(ts, cdev->type);
-		else
-			continue;
-
-		ret = throttrip_program(ts, sg, stc, temperature);
-		if (ret) {
-			dev_err(ts->dev, "throttrip: %s: error during enable\n",
-				sg->name);
-			return ret;
-		}
+	return 0;
+}
 
-		dev_info(ts->dev,
-			 "throttrip: will throttle when %s reaches %d mC\n",
-			 sg->name, temperature);
-		break;
-	}
+/*
+ * soctherm_enable_hw_throttling() - enable hardware throttling trip points
+ * @tegra: pointer to a struct tegra_soctherm
+ *
+ * THROTTLE has been enabled successfully when a message similar to
+ * this one appears on the serial console:
+ * ""throttrip: will throttle when sensor group XXX reaches YYYYYY mC"
+ */
+static void soctherm_enable_hw_throttling(struct tegra_soctherm *tegra)
+{
+	struct soctherm_throt_cfg *stc;
+	int err;
 
-	if (i == THROTTLE_SIZE)
-		dev_info(ts->dev, "throttrip: %s: missing throttle cdev\n",
-			 sg->name);
+	/* if configured, program the pulse skipper for CPU and GPU zones */
+	stc = find_throttle_cfg_by_name(tegra, "heavy");
+	if (!stc)
+		return;
 
-	return 0;
+	err = throttrip_program(tegra, stc);
+	if (err)
+		dev_err(tegra->dev, "throttrip: %s: failed to enable: %d\n",
+			stc->name, err);
 }
 
 static irqreturn_t soctherm_thermal_isr(int irq, void *dev_id)
@@ -1494,40 +1465,6 @@  static int soctherm_clk_enable(struct tegra_soctherm *tegra, bool enable)
 	return 0;
 }
 
-static int throt_get_cdev_max_state(struct thermal_cooling_device *cdev,
-				    unsigned long *max_state)
-{
-	*max_state = 1;
-	return 0;
-}
-
-static int throt_get_cdev_cur_state(struct thermal_cooling_device *cdev,
-				    unsigned long *cur_state)
-{
-	struct tegra_soctherm *ts = cdev->devdata;
-	u32 r;
-
-	r = readl(ts->regs + THROT_STATUS);
-	if (REG_GET_MASK(r, THROT_STATUS_STATE_MASK))
-		*cur_state = 1;
-	else
-		*cur_state = 0;
-
-	return 0;
-}
-
-static int throt_set_cdev_state(struct thermal_cooling_device *cdev,
-				unsigned long cur_state)
-{
-	return 0;
-}
-
-static const struct thermal_cooling_device_ops throt_cooling_ops = {
-	.get_max_state = throt_get_cdev_max_state,
-	.get_cur_state = throt_get_cdev_cur_state,
-	.set_cur_state = throt_set_cdev_state,
-};
-
 static int soctherm_thermtrips_parse(struct tegra_soctherm *ts)
 {
 	struct tsensor_group_thermtrips *tt = ts->soc->thermtrips;
@@ -1633,6 +1570,33 @@  static int soctherm_throt_cfg_parse(struct tegra_soctherm *ts,
 	else
 		goto err;
 
+	ret = of_property_read_u32(np, "temperature-millicelsius",
+				   &stc->temperature);
+	if (ret < 0)
+		goto err;
+
+	ret = of_property_read_u32(np, "hysteresis-millicelsius",
+				   &stc->hysteresis);
+	if (ret < 0)
+		goto err;
+
+	stc->num_zones = of_count_phandle_with_args(np, "nvidia,thermal-zones",
+						    NULL);
+	if (stc->num_zones > 0) {
+		struct device_node *zone;
+		unsigned int i;
+
+		stc->zones = devm_kcalloc(ts->dev, stc->num_zones, sizeof(zone),
+					  GFP_KERNEL);
+		if (!stc->zones)
+			return -ENOMEM;
+
+		for (i = 0; i < stc->num_zones; i++) {
+			zone = of_parse_phandle(np, "nvidia,thermal-zones", i);
+			stc->zones[i] = zone;
+		}
+	}
+
 	return 0;
 
 err:
@@ -1642,14 +1606,12 @@  static int soctherm_throt_cfg_parse(struct tegra_soctherm *ts,
 }
 
 /**
- * soctherm_init_hw_throt_cdev() - Parse the HW throttle configurations
- * and register them as cooling devices.
+ * soctherm_init_hw_throttling() - parse the HW throttle configurations
  * @tegra: pointer to Tegra soctherm structure
  */
-static void soctherm_init_hw_throt_cdev(struct tegra_soctherm *tegra)
+static void soctherm_init_hw_throttling(struct tegra_soctherm *tegra)
 {
 	struct device_node *np_stc, *np_stcc;
-	const char *name;
 	int i;
 
 	for (i = 0; i < THROTTLE_SIZE; i++) {
@@ -1666,11 +1628,10 @@  static void soctherm_init_hw_throt_cdev(struct tegra_soctherm *tegra)
 	}
 
 	for_each_child_of_node(np_stc, np_stcc) {
+		const char *name = np_stcc->name;
 		struct soctherm_throt_cfg *stc;
-		struct thermal_cooling_device *tcd;
 		int err;
 
-		name = np_stcc->name;
 		stc = find_throttle_cfg_by_name(tegra, name);
 		if (!stc) {
 			dev_err(tegra->dev, "throttle-cfg: could not find %s\n",
@@ -1692,19 +1653,6 @@  static void soctherm_init_hw_throt_cdev(struct tegra_soctherm *tegra)
 		if (stc->id >= THROTTLE_OC1) {
 			soctherm_oc_cfg_parse(tegra, np_stcc, stc);
 			stc->init = true;
-		} else {
-
-			tcd = thermal_of_cooling_device_register(np_stcc,
-							 (char *)name, tegra,
-							 &throt_cooling_ops);
-			if (IS_ERR_OR_NULL(tcd)) {
-				dev_err(tegra->dev,
-					"throttle-cfg: %s: failed to register cooling device\n",
-					name);
-				continue;
-			}
-			stc->cdev = tcd;
-			stc->init = true;
 		}
 	}
 
@@ -2148,7 +2096,7 @@  static int tegra_soctherm_probe(struct platform_device *pdev)
 
 	soctherm_thermtrips_parse(tegra);
 
-	soctherm_init_hw_throt_cdev(tegra);
+	soctherm_init_hw_throttling(tegra);
 
 	soctherm_init(tegra);
 
@@ -2183,6 +2131,7 @@  static int tegra_soctherm_probe(struct platform_device *pdev)
 			goto disable_clocks;
 	}
 
+	soctherm_enable_hw_throttling(tegra);
 	err = soctherm_interrupts_init(tegra);
 
 	soctherm_debug_init(tegra);
@@ -2238,6 +2187,8 @@  static int __maybe_unused soctherm_resume(struct device *dev)
 		}
 	}
 
+	soctherm_enable_hw_throttling(tegra);
+
 	return 0;
 }
 
diff --git a/drivers/thermal/tegra/soctherm.h b/drivers/thermal/tegra/soctherm.h
index 70501e73d586..894bee5d96c5 100644
--- a/drivers/thermal/tegra/soctherm.h
+++ b/drivers/thermal/tegra/soctherm.h
@@ -83,6 +83,7 @@  struct tegra_tsensor_group {
 	u16 thermctl_lvl0_offset;
 	u32 thermctl_lvl0_up_thresh_mask;
 	u32 thermctl_lvl0_dn_thresh_mask;
+	bool can_throttle;
 };
 
 struct tegra_tsensor_configuration {
diff --git a/drivers/thermal/tegra/tegra124-soctherm.c b/drivers/thermal/tegra/tegra124-soctherm.c
index 20ad27f4d1a1..7b11fa8fb533 100644
--- a/drivers/thermal/tegra/tegra124-soctherm.c
+++ b/drivers/thermal/tegra/tegra124-soctherm.c
@@ -60,6 +60,7 @@  static const struct tegra_tsensor_group tegra124_tsensor_group_cpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_CPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA124_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA124_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra124_tsensor_group_gpu = {
@@ -79,6 +80,7 @@  static const struct tegra_tsensor_group tegra124_tsensor_group_gpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_GPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA124_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA124_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra124_tsensor_group_pll = {
@@ -96,6 +98,7 @@  static const struct tegra_tsensor_group tegra124_tsensor_group_pll = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_TSENSE,
 	.thermctl_lvl0_up_thresh_mask = TEGRA124_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA124_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group tegra124_tsensor_group_mem = {
@@ -115,6 +118,7 @@  static const struct tegra_tsensor_group tegra124_tsensor_group_mem = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_MEM,
 	.thermctl_lvl0_up_thresh_mask = TEGRA124_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA124_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group *tegra124_tsensor_groups[] = {
diff --git a/drivers/thermal/tegra/tegra132-soctherm.c b/drivers/thermal/tegra/tegra132-soctherm.c
index b76308fdad9e..304561fe9110 100644
--- a/drivers/thermal/tegra/tegra132-soctherm.c
+++ b/drivers/thermal/tegra/tegra132-soctherm.c
@@ -60,6 +60,7 @@  static const struct tegra_tsensor_group tegra132_tsensor_group_cpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_CPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA132_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA132_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra132_tsensor_group_gpu = {
@@ -79,6 +80,7 @@  static const struct tegra_tsensor_group tegra132_tsensor_group_gpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_GPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA132_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA132_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra132_tsensor_group_pll = {
@@ -96,6 +98,7 @@  static const struct tegra_tsensor_group tegra132_tsensor_group_pll = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_TSENSE,
 	.thermctl_lvl0_up_thresh_mask = TEGRA132_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA132_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group tegra132_tsensor_group_mem = {
@@ -115,6 +118,7 @@  static const struct tegra_tsensor_group tegra132_tsensor_group_mem = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_MEM,
 	.thermctl_lvl0_up_thresh_mask = TEGRA132_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA132_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group *tegra132_tsensor_groups[] = {
diff --git a/drivers/thermal/tegra/tegra210-soctherm.c b/drivers/thermal/tegra/tegra210-soctherm.c
index d0ff793f18c5..6277a8e12b8a 100644
--- a/drivers/thermal/tegra/tegra210-soctherm.c
+++ b/drivers/thermal/tegra/tegra210-soctherm.c
@@ -61,6 +61,7 @@  static const struct tegra_tsensor_group tegra210_tsensor_group_cpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_CPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA210_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA210_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra210_tsensor_group_gpu = {
@@ -80,6 +81,7 @@  static const struct tegra_tsensor_group tegra210_tsensor_group_gpu = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_GPU,
 	.thermctl_lvl0_up_thresh_mask = TEGRA210_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA210_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = true,
 };
 
 static const struct tegra_tsensor_group tegra210_tsensor_group_pll = {
@@ -97,6 +99,7 @@  static const struct tegra_tsensor_group tegra210_tsensor_group_pll = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_TSENSE,
 	.thermctl_lvl0_up_thresh_mask = TEGRA210_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA210_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group tegra210_tsensor_group_mem = {
@@ -116,6 +119,7 @@  static const struct tegra_tsensor_group tegra210_tsensor_group_mem = {
 	.thermctl_lvl0_offset = THERMCTL_LEVEL0_GROUP_MEM,
 	.thermctl_lvl0_up_thresh_mask = TEGRA210_THERMCTL_LVL0_UP_THRESH_MASK,
 	.thermctl_lvl0_dn_thresh_mask = TEGRA210_THERMCTL_LVL0_DN_THRESH_MASK,
+	.can_throttle = false,
 };
 
 static const struct tegra_tsensor_group *tegra210_tsensor_groups[] = {