diff mbox series

[v6,51/52] PM / devfreq: tegra30: Support interconnect and OPPs from device-tree

Message ID 20201025221735.3062-52-digetx@gmail.com
State New
Headers show
Series [v6,01/52] clk: tegra: Export Tegra20 EMC kernel symbols | expand

Commit Message

Dmitry Osipenko Oct. 25, 2020, 10:17 p.m. UTC
This patch moves ACTMON driver away from generating OPP table by itself,
transitioning it to use the table which comes from device-tree. This
change breaks compatibility with older device-trees in order to bring
support for the interconnect framework to the driver. This is a mandatory
change which needs to be done in order to implement interconnect-based
memory DVFS. Users of legacy device-trees will get a message telling that
theirs DT needs to be upgraded. Now ACTMON issues memory bandwidth request
using dev_pm_opp_set_bw(), instead of driving EMC clock rate directly.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 91 ++++++++++++++++---------------
 1 file changed, 48 insertions(+), 43 deletions(-)

Comments

Chanwoo Choi Nov. 1, 2020, 2:39 p.m. UTC | #1
Hi Dmitry,

On Mon, Oct 26, 2020 at 7:22 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>
> This patch moves ACTMON driver away from generating OPP table by itself,
> transitioning it to use the table which comes from device-tree. This
> change breaks compatibility with older device-trees in order to bring
> support for the interconnect framework to the driver. This is a mandatory
> change which needs to be done in order to implement interconnect-based
> memory DVFS. Users of legacy device-trees will get a message telling that
> theirs DT needs to be upgraded. Now ACTMON issues memory bandwidth request
> using dev_pm_opp_set_bw(), instead of driving EMC clock rate directly.
>
> Tested-by: Peter Geis <pgwipeout@gmail.com>
> Tested-by: Nicolas Chauvet <kwizart@gmail.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 91 ++++++++++++++++---------------
>  1 file changed, 48 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 3f732ab53573..1b0b91a71886 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -19,6 +19,8 @@
>  #include <linux/reset.h>
>  #include <linux/workqueue.h>
>
> +#include <soc/tegra/fuse.h>
> +
>  #include "governor.h"
>
>  #define ACTMON_GLB_STATUS                                      0x0
> @@ -155,6 +157,7 @@ struct tegra_devfreq_device {
>
>  struct tegra_devfreq {
>         struct devfreq          *devfreq;
> +       struct opp_table        *opp_table;
>
>         struct reset_control    *reset;
>         struct clk              *clock;
> @@ -612,34 +615,19 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
>                                 u32 flags)
>  {
> -       struct tegra_devfreq *tegra = dev_get_drvdata(dev);
> -       struct devfreq *devfreq = tegra->devfreq;
>         struct dev_pm_opp *opp;
> -       unsigned long rate;
> -       int err;
> +       int ret;
>
>         opp = devfreq_recommended_opp(dev, freq, flags);
>         if (IS_ERR(opp)) {
> -               dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
> +               dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
>                 return PTR_ERR(opp);
>         }
> -       rate = dev_pm_opp_get_freq(opp);
> -       dev_pm_opp_put(opp);
> -
> -       err = clk_set_min_rate(tegra->emc_clock, rate * KHZ);
> -       if (err)
> -               return err;
> -
> -       err = clk_set_rate(tegra->emc_clock, 0);
> -       if (err)
> -               goto restore_min_rate;
>
> -       return 0;
> -
> -restore_min_rate:
> -       clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
> +       ret = dev_pm_opp_set_bw(dev, opp);
> +       dev_pm_opp_put(opp);
>
> -       return err;
> +       return ret;
>  }
>
>  static int tegra_devfreq_get_dev_status(struct device *dev,
> @@ -655,7 +643,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev,
>         stat->private_data = tegra;
>
>         /* The below are to be used by the other governors */
> -       stat->current_frequency = cur_freq;
> +       stat->current_frequency = cur_freq * KHZ;

I can't find any change related to the frequency unit on this patch.
Do you fix the previous bug of the frequency unit?

>
>         actmon_dev = &tegra->devices[MCALL];
>
> @@ -705,7 +693,7 @@ static int tegra_governor_get_target(struct devfreq *devfreq,
>                 target_freq = max(target_freq, dev->target_freq);
>         }
>
> -       *freq = target_freq;
> +       *freq = target_freq * KHZ;

ditto.

>
>         return 0;
>  }
> @@ -773,13 +761,22 @@ static struct devfreq_governor tegra_devfreq_governor = {
>
>  static int tegra_devfreq_probe(struct platform_device *pdev)
>  {
> +       u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
>         struct tegra_devfreq_device *dev;
>         struct tegra_devfreq *tegra;
> +       struct opp_table *opp_table;
>         struct devfreq *devfreq;
>         unsigned int i;
>         long rate;
>         int err;
>
> +       /* legacy device-trees don't have OPP table and must be updated */
> +       if (!device_property_present(&pdev->dev, "operating-points-v2")) {
> +               dev_err(&pdev->dev, "OPP table not found, cannot continue\n");
> +               dev_err(&pdev->dev, "please update your device tree\n");
> +               return -ENODEV;
> +       }

As you mentioned, it breaks the old dtb. I have no objection to improving
the driver. Instead, you need confirmation from the Devicetree maintainer.

And,
I recommend that you use dev_pm_opp_of_get_opp_desc_node(&pdev->dev)
to check whether a device contains opp-table or not.

> +
>         tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>         if (!tegra)
>                 return -ENOMEM;
> @@ -821,11 +818,29 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>                 return err;
>         }
>
> +       tegra->opp_table = dev_pm_opp_get_opp_table(&pdev->dev);
> +       if (IS_ERR(tegra->opp_table))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(tegra->opp_table),
> +                                    "Failed to prepare OPP table\n");

As I knew, each device can contain the opp_table on devicetree.
It means that opp_table has not depended to another device driver.
Did you see this exception case with EPROBE_DEFER error?

> +
> +       opp_table = dev_pm_opp_set_supported_hw(&pdev->dev, &hw_version, 1);
> +       err = PTR_ERR_OR_ZERO(opp_table);
> +       if (err) {
> +               dev_err(&pdev->dev, "Failed to set supported HW: %d\n", err);
> +               goto put_table;
> +       }
> +
> +       err = dev_pm_opp_of_add_table(&pdev->dev);
> +       if (err) {
> +               dev_err(&pdev->dev, "Failed to add OPP table: %d\n", err);
> +               goto put_hw;
> +       }
> +
>         err = clk_prepare_enable(tegra->clock);
>         if (err) {
>                 dev_err(&pdev->dev,
>                         "Failed to prepare and enable ACTMON clock\n");
> -               return err;
> +               goto remove_table;
>         }
>
>         err = reset_control_reset(tegra->reset);
> @@ -849,23 +864,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>                 dev->regs = tegra->regs + dev->config->offset;
>         }
>
> -       for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
> -               rate = clk_round_rate(tegra->emc_clock, rate);
> -
> -               if (rate < 0) {
> -                       dev_err(&pdev->dev,
> -                               "Failed to round clock rate: %ld\n", rate);
> -                       err = rate;
> -                       goto remove_opps;
> -               }
> -
> -               err = dev_pm_opp_add(&pdev->dev, rate / KHZ, 0);
> -               if (err) {
> -                       dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
> -                       goto remove_opps;
> -               }
> -       }
> -
>         platform_set_drvdata(pdev, tegra);
>
>         tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb;
> @@ -881,7 +879,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>         }
>
>         tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
> -       tegra_devfreq_profile.initial_freq /= KHZ;
>
>         devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
>                                      "tegra_actmon", NULL);
> @@ -901,6 +898,12 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>         reset_control_reset(tegra->reset);
>  disable_clk:
>         clk_disable_unprepare(tegra->clock);
> +remove_table:
> +       dev_pm_opp_of_remove_table(&pdev->dev);
> +put_hw:
> +       dev_pm_opp_put_supported_hw(tegra->opp_table);
> +put_table:
> +       dev_pm_opp_put_opp_table(tegra->opp_table);
>
>         return err;
>  }
> @@ -912,11 +915,13 @@ static int tegra_devfreq_remove(struct platform_device *pdev)
>         devfreq_remove_device(tegra->devfreq);
>         devfreq_remove_governor(&tegra_devfreq_governor);
>
> -       dev_pm_opp_remove_all_dynamic(&pdev->dev);
> -
>         reset_control_reset(tegra->reset);
>         clk_disable_unprepare(tegra->clock);
>
> +       dev_pm_opp_of_remove_table(&pdev->dev);
> +       dev_pm_opp_put_supported_hw(tegra->opp_table);
> +       dev_pm_opp_put_opp_table(tegra->opp_table);
> +
>         return 0;
>  }
>
> --
> 2.27.0
>
Dmitry Osipenko Nov. 1, 2020, 3:24 p.m. UTC | #2
01.11.2020 17:44, Chanwoo Choi пишет:
> Hi Dmitry,
> 
> On Mon, Oct 26, 2020 at 7:22 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>>
>> This patch moves ACTMON driver away from generating OPP table by itself,
>> transitioning it to use the table which comes from device-tree. This
>> change breaks compatibility with older device-trees in order to bring
>> support for the interconnect framework to the driver. This is a mandatory
>> change which needs to be done in order to implement interconnect-based
>> memory DVFS. Users of legacy device-trees will get a message telling that
>> theirs DT needs to be upgraded. Now ACTMON issues memory bandwidth request
>> using dev_pm_opp_set_bw(), instead of driving EMC clock rate directly.
>>
>> Tested-by: Peter Geis <pgwipeout@gmail.com>
>> Tested-by: Nicolas Chauvet <kwizart@gmail.com>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  drivers/devfreq/tegra30-devfreq.c | 91 ++++++++++++++++---------------
>>  1 file changed, 48 insertions(+), 43 deletions(-)
>>
>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>> index 3f732ab53573..1b0b91a71886 100644
>> --- a/drivers/devfreq/tegra30-devfreq.c
>> +++ b/drivers/devfreq/tegra30-devfreq.c
>> @@ -19,6 +19,8 @@
>>  #include <linux/reset.h>
>>  #include <linux/workqueue.h>
>>
>> +#include <soc/tegra/fuse.h>
>> +
> 
> This patch touches the OPP. Is it related to this change?

Yes, this is needed for the dev_pm_opp_set_supported_hw().

>>  #include "governor.h"
>>
>>  #define ACTMON_GLB_STATUS                                      0x0
>> @@ -155,6 +157,7 @@ struct tegra_devfreq_device {
>>
>>  struct tegra_devfreq {
>>         struct devfreq          *devfreq;
>> +       struct opp_table        *opp_table;
>>
>>         struct reset_control    *reset;
>>         struct clk              *clock;
>> @@ -612,34 +615,19 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
>>                                 u32 flags)
>>  {
>> -       struct tegra_devfreq *tegra = dev_get_drvdata(dev);
>> -       struct devfreq *devfreq = tegra->devfreq;
>>         struct dev_pm_opp *opp;
>> -       unsigned long rate;
>> -       int err;
>> +       int ret;
>>
>>         opp = devfreq_recommended_opp(dev, freq, flags);
>>         if (IS_ERR(opp)) {
>> -               dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
>> +               dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
> 
> You used the 'Failed to' format in almost every error case.
> Don't need to change it.
> (snip)

Good catch, thanks.
Chanwoo Choi Nov. 1, 2020, 3:45 p.m. UTC | #3
Hi Dmitry,

On Mon, Nov 2, 2020 at 12:24 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>
> 01.11.2020 17:44, Chanwoo Choi пишет:
> > Hi Dmitry,
> >
> > On Mon, Oct 26, 2020 at 7:22 AM Dmitry Osipenko <digetx@gmail.com> wrote:
> >>
> >> This patch moves ACTMON driver away from generating OPP table by itself,
> >> transitioning it to use the table which comes from device-tree. This
> >> change breaks compatibility with older device-trees in order to bring
> >> support for the interconnect framework to the driver. This is a mandatory
> >> change which needs to be done in order to implement interconnect-based
> >> memory DVFS. Users of legacy device-trees will get a message telling that
> >> theirs DT needs to be upgraded. Now ACTMON issues memory bandwidth request
> >> using dev_pm_opp_set_bw(), instead of driving EMC clock rate directly.
> >>
> >> Tested-by: Peter Geis <pgwipeout@gmail.com>
> >> Tested-by: Nicolas Chauvet <kwizart@gmail.com>
> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> >> ---
> >>  drivers/devfreq/tegra30-devfreq.c | 91 ++++++++++++++++---------------
> >>  1 file changed, 48 insertions(+), 43 deletions(-)
> >>
> >> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> >> index 3f732ab53573..1b0b91a71886 100644
> >> --- a/drivers/devfreq/tegra30-devfreq.c
> >> +++ b/drivers/devfreq/tegra30-devfreq.c
> >> @@ -19,6 +19,8 @@
> >>  #include <linux/reset.h>
> >>  #include <linux/workqueue.h>
> >>
> >> +#include <soc/tegra/fuse.h>
> >> +
> >
> > This patch touches the OPP. Is it related to this change?
>
> Yes, this is needed for the dev_pm_opp_set_supported_hw().

OK.

>
> >>  #include "governor.h"
> >>
> >>  #define ACTMON_GLB_STATUS                                      0x0
> >> @@ -155,6 +157,7 @@ struct tegra_devfreq_device {
> >>
> >>  struct tegra_devfreq {
> >>         struct devfreq          *devfreq;
> >> +       struct opp_table        *opp_table;
> >>
> >>         struct reset_control    *reset;
> >>         struct clk              *clock;
> >> @@ -612,34 +615,19 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
> >>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
> >>                                 u32 flags)
> >>  {
> >> -       struct tegra_devfreq *tegra = dev_get_drvdata(dev);
> >> -       struct devfreq *devfreq = tegra->devfreq;
> >>         struct dev_pm_opp *opp;
> >> -       unsigned long rate;
> >> -       int err;
> >> +       int ret;
> >>
> >>         opp = devfreq_recommended_opp(dev, freq, flags);
> >>         if (IS_ERR(opp)) {
> >> -               dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
> >> +               dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
> >
> > You used the 'Failed to' format in almost every error case.
> > Don't need to change it.
> > (snip)
>
> Good catch, thanks.
Chanwoo Choi Nov. 1, 2020, 3:57 p.m. UTC | #4
On Mon, Nov 2, 2020 at 12:49 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>
> 01.11.2020 18:44, Chanwoo Choi пишет:
> >> OPP core will try to grab the clock reference for the table and it may
> >> cause EPROBE_DEFER. Although, it shouldn't happen here because we have
> >> devm_clk_get() before the get_opp_table(), hence seems the deferred
> >> probe indeed shouldn't happen in this case.
> > It is my missing point. If there, you're right.
> > Could you provide the code point to check the clock reference on the OPP core?
>
> Please see it here:
>
> https://elixir.bootlin.com/linux/v5.10-rc1/source/drivers/opp/core.c#L1101

Thanks. It seems that if device tree node contains the any node,
it is not EPROBE_DEFER because of just using "clk_get(dev, NULL)".

The patch[1] used the 'dev_err_probe' for getting the "emc" clock.
Do you need to check it more?

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-next&id=09d56d92ad25b58113f4ec677e9b1ac1e2c3072b
Dmitry Osipenko Nov. 2, 2020, 7:58 p.m. UTC | #5
01.11.2020 18:57, Chanwoo Choi пишет:
> On Mon, Nov 2, 2020 at 12:49 AM Dmitry Osipenko <digetx@gmail.com> wrote:
>>
>> 01.11.2020 18:44, Chanwoo Choi пишет:
>>>> OPP core will try to grab the clock reference for the table and it may
>>>> cause EPROBE_DEFER. Although, it shouldn't happen here because we have
>>>> devm_clk_get() before the get_opp_table(), hence seems the deferred
>>>> probe indeed shouldn't happen in this case.
>>> It is my missing point. If there, you're right.
>>> Could you provide the code point to check the clock reference on the OPP core?
>>
>> Please see it here:
>>
>> https://elixir.bootlin.com/linux/v5.10-rc1/source/drivers/opp/core.c#L1101
> 
> Thanks. It seems that if device tree node contains the any node,
> it is not EPROBE_DEFER because of just using "clk_get(dev, NULL)".
> 
> The patch[1] used the 'dev_err_probe' for getting the "emc" clock.
> Do you need to check it more?
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-next&id=09d56d92ad25b58113f4ec677e9b1ac1e2c3072b

It should be safe to assume that the EPROBE_DEFER won't happen for
dev_pm_opp_get_opp_table(). I'll improve it in v7, thanks.
Dmitry Osipenko Nov. 2, 2020, 8 p.m. UTC | #6
01.11.2020 18:44, Chanwoo Choi пишет:
>>> I recommend that you use dev_pm_opp_of_get_opp_desc_node(&pdev->dev)

>>> to check whether a device contains opp-table or not.

>> I'm not sure what are the benefits, this will make code less

>> expressive/readable and we will need to add extra of_node_put(), which

>> device_property_present() handles for us.

>>

>> Could you please give the rationale?

> IMO, 'operating-points-v2' word was defined on OPP core. I think that

> the external user

> of OPP better to use the public helper function instead of using the

> interval definition

> or value of OPP core directly. Basically, I prefer the provided helper

> function if there.

> But, it is not critical and doesn't affect the operation. If you want

> to keep, it is ok.

> 


I'll prefer to keep it since it's better for the readability of the
code, thanks.
diff mbox series

Patch

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index 3f732ab53573..1b0b91a71886 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -19,6 +19,8 @@ 
 #include <linux/reset.h>
 #include <linux/workqueue.h>
 
+#include <soc/tegra/fuse.h>
+
 #include "governor.h"
 
 #define ACTMON_GLB_STATUS					0x0
@@ -155,6 +157,7 @@  struct tegra_devfreq_device {
 
 struct tegra_devfreq {
 	struct devfreq		*devfreq;
+	struct opp_table	*opp_table;
 
 	struct reset_control	*reset;
 	struct clk		*clock;
@@ -612,34 +615,19 @@  static void tegra_actmon_stop(struct tegra_devfreq *tegra)
 static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 				u32 flags)
 {
-	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
-	struct devfreq *devfreq = tegra->devfreq;
 	struct dev_pm_opp *opp;
-	unsigned long rate;
-	int err;
+	int ret;
 
 	opp = devfreq_recommended_opp(dev, freq, flags);
 	if (IS_ERR(opp)) {
-		dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
+		dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
 		return PTR_ERR(opp);
 	}
-	rate = dev_pm_opp_get_freq(opp);
-	dev_pm_opp_put(opp);
-
-	err = clk_set_min_rate(tegra->emc_clock, rate * KHZ);
-	if (err)
-		return err;
-
-	err = clk_set_rate(tegra->emc_clock, 0);
-	if (err)
-		goto restore_min_rate;
 
-	return 0;
-
-restore_min_rate:
-	clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
+	ret = dev_pm_opp_set_bw(dev, opp);
+	dev_pm_opp_put(opp);
 
-	return err;
+	return ret;
 }
 
 static int tegra_devfreq_get_dev_status(struct device *dev,
@@ -655,7 +643,7 @@  static int tegra_devfreq_get_dev_status(struct device *dev,
 	stat->private_data = tegra;
 
 	/* The below are to be used by the other governors */
-	stat->current_frequency = cur_freq;
+	stat->current_frequency = cur_freq * KHZ;
 
 	actmon_dev = &tegra->devices[MCALL];
 
@@ -705,7 +693,7 @@  static int tegra_governor_get_target(struct devfreq *devfreq,
 		target_freq = max(target_freq, dev->target_freq);
 	}
 
-	*freq = target_freq;
+	*freq = target_freq * KHZ;
 
 	return 0;
 }
@@ -773,13 +761,22 @@  static struct devfreq_governor tegra_devfreq_governor = {
 
 static int tegra_devfreq_probe(struct platform_device *pdev)
 {
+	u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
 	struct tegra_devfreq_device *dev;
 	struct tegra_devfreq *tegra;
+	struct opp_table *opp_table;
 	struct devfreq *devfreq;
 	unsigned int i;
 	long rate;
 	int err;
 
+	/* legacy device-trees don't have OPP table and must be updated */
+	if (!device_property_present(&pdev->dev, "operating-points-v2")) {
+		dev_err(&pdev->dev, "OPP table not found, cannot continue\n");
+		dev_err(&pdev->dev, "please update your device tree\n");
+		return -ENODEV;
+	}
+
 	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
 	if (!tegra)
 		return -ENOMEM;
@@ -821,11 +818,29 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	tegra->opp_table = dev_pm_opp_get_opp_table(&pdev->dev);
+	if (IS_ERR(tegra->opp_table))
+		return dev_err_probe(&pdev->dev, PTR_ERR(tegra->opp_table),
+				     "Failed to prepare OPP table\n");
+
+	opp_table = dev_pm_opp_set_supported_hw(&pdev->dev, &hw_version, 1);
+	err = PTR_ERR_OR_ZERO(opp_table);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to set supported HW: %d\n", err);
+		goto put_table;
+	}
+
+	err = dev_pm_opp_of_add_table(&pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add OPP table: %d\n", err);
+		goto put_hw;
+	}
+
 	err = clk_prepare_enable(tegra->clock);
 	if (err) {
 		dev_err(&pdev->dev,
 			"Failed to prepare and enable ACTMON clock\n");
-		return err;
+		goto remove_table;
 	}
 
 	err = reset_control_reset(tegra->reset);
@@ -849,23 +864,6 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 		dev->regs = tegra->regs + dev->config->offset;
 	}
 
-	for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
-		rate = clk_round_rate(tegra->emc_clock, rate);
-
-		if (rate < 0) {
-			dev_err(&pdev->dev,
-				"Failed to round clock rate: %ld\n", rate);
-			err = rate;
-			goto remove_opps;
-		}
-
-		err = dev_pm_opp_add(&pdev->dev, rate / KHZ, 0);
-		if (err) {
-			dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
-			goto remove_opps;
-		}
-	}
-
 	platform_set_drvdata(pdev, tegra);
 
 	tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb;
@@ -881,7 +879,6 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 	}
 
 	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
-	tegra_devfreq_profile.initial_freq /= KHZ;
 
 	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
 				     "tegra_actmon", NULL);
@@ -901,6 +898,12 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 	reset_control_reset(tegra->reset);
 disable_clk:
 	clk_disable_unprepare(tegra->clock);
+remove_table:
+	dev_pm_opp_of_remove_table(&pdev->dev);
+put_hw:
+	dev_pm_opp_put_supported_hw(tegra->opp_table);
+put_table:
+	dev_pm_opp_put_opp_table(tegra->opp_table);
 
 	return err;
 }
@@ -912,11 +915,13 @@  static int tegra_devfreq_remove(struct platform_device *pdev)
 	devfreq_remove_device(tegra->devfreq);
 	devfreq_remove_governor(&tegra_devfreq_governor);
 
-	dev_pm_opp_remove_all_dynamic(&pdev->dev);
-
 	reset_control_reset(tegra->reset);
 	clk_disable_unprepare(tegra->clock);
 
+	dev_pm_opp_of_remove_table(&pdev->dev);
+	dev_pm_opp_put_supported_hw(tegra->opp_table);
+	dev_pm_opp_put_opp_table(tegra->opp_table);
+
 	return 0;
 }