[v3,3/5] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()
diff mbox series

Message ID 20190719150535.15501-4-k.konieczny@partner.samsung.com
State Not Applicable, archived
Headers show
Series
  • add coupled regulators for Exynos5422/5800
Related show

Commit Message

Kamil Konieczny July 19, 2019, 3:05 p.m. UTC
Reuse opp core code for setting bus clock and voltage. As a side
effect this allow useage of coupled regulators feature (required
for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
uses regulator_set_voltage_triplet() for setting regulator voltage
while the old code used regulator_set_voltage_tol() with fixed
tolerance. This patch also removes no longer needed parsing of DT
property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
it).

Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
---
 drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
 1 file changed, 37 insertions(+), 106 deletions(-)

Comments

Chanwoo Choi July 25, 2019, 10:17 a.m. UTC | #1
Hi Kamil,

Looks good to me. But, I have some comment. Please check them.

After this patch, exynos_bus_target is perfectly same with
exynos_bus_passive_target. The exynos_bus_passive_target() could be removed.

On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
> Reuse opp core code for setting bus clock and voltage. As a side
> effect this allow useage of coupled regulators feature (required

s/useage/usage ?

> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
> uses regulator_set_voltage_triplet() for setting regulator voltage
> while the old code used regulator_set_voltage_tol() with fixed
> tolerance. This patch also removes no longer needed parsing of DT
> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
> it).
> 
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
>  drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
>  1 file changed, 37 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index f391044aa39d..c2147b0912a0 100644
> --- a/drivers/devfreq/exynos-bus.c
> +++ b/drivers/devfreq/exynos-bus.c
> @@ -25,7 +25,6 @@
>  #include <linux/slab.h>
>  
>  #define DEFAULT_SATURATION_RATIO	40
> -#define DEFAULT_VOLTAGE_TOLERANCE	2
>  
>  struct exynos_bus {
>  	struct device *dev;
> @@ -37,9 +36,9 @@ struct exynos_bus {
>  
>  	unsigned long curr_freq;
>  
> -	struct regulator *regulator;
> +	struct opp_table *opp_table;
> +
>  	struct clk *clk;
> -	unsigned int voltage_tolerance;
>  	unsigned int ratio;
>  };
>  
> @@ -99,56 +98,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
>  {
>  	struct exynos_bus *bus = dev_get_drvdata(dev);
>  	struct dev_pm_opp *new_opp;
> -	unsigned long old_freq, new_freq, new_volt, tol;
>  	int ret = 0;
>  
> -	/* Get new opp-bus instance according to new bus clock */
> +	/* Get correct frequency for bus. */
>  	new_opp = devfreq_recommended_opp(dev, freq, flags);
>  	if (IS_ERR(new_opp)) {
>  		dev_err(dev, "failed to get recommended opp instance\n");
>  		return PTR_ERR(new_opp);
>  	}
>  
> -	new_freq = dev_pm_opp_get_freq(new_opp);
> -	new_volt = dev_pm_opp_get_voltage(new_opp);
>  	dev_pm_opp_put(new_opp);
>  
> -	old_freq = bus->curr_freq;
> -
> -	if (old_freq == new_freq)
> -		return 0;
> -	tol = new_volt * bus->voltage_tolerance / 100;
> -
>  	/* Change voltage and frequency according to new OPP level */
>  	mutex_lock(&bus->lock);
> +	ret = dev_pm_opp_set_rate(dev, *freq);
> +	if (!ret)
> +		bus->curr_freq = *freq;
>  
> -	if (old_freq < new_freq) {
> -		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> -		if (ret < 0) {
> -			dev_err(bus->dev, "failed to set voltage\n");
> -			goto out;
> -		}
> -	}
> -
> -	ret = clk_set_rate(bus->clk, new_freq);
> -	if (ret < 0) {
> -		dev_err(dev, "failed to change clock of bus\n");
> -		clk_set_rate(bus->clk, old_freq);
> -		goto out;
> -	}
> -
> -	if (old_freq > new_freq) {
> -		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> -		if (ret < 0) {
> -			dev_err(bus->dev, "failed to set voltage\n");
> -			goto out;
> -		}
> -	}
> -	bus->curr_freq = new_freq;
> -
> -	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> -			old_freq, new_freq, clk_get_rate(bus->clk));
> -out:
>  	mutex_unlock(&bus->lock);
>  
>  	return ret;
> @@ -195,8 +161,8 @@ static void exynos_bus_exit(struct device *dev)
>  		dev_warn(dev, "failed to disable the devfreq-event devices\n");
>  
>  	clk_disable_unprepare(bus->clk);
> -	if (bus->regulator)
> -		regulator_disable(bus->regulator);
> +	if (bus->opp_table)
> +		dev_pm_opp_put_regulators(bus->opp_table);
>  
>  	dev_pm_opp_of_remove_table(dev);
>  }
> @@ -209,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
>  {
>  	struct exynos_bus *bus = dev_get_drvdata(dev);
>  	struct dev_pm_opp *new_opp;
> -	unsigned long old_freq, new_freq;
> -	int ret = 0;
> +	int ret;
>  
> -	/* Get new opp-bus instance according to new bus clock */
> +	/* Get correct frequency for bus. */
>  	new_opp = devfreq_recommended_opp(dev, freq, flags);
>  	if (IS_ERR(new_opp)) {
>  		dev_err(dev, "failed to get recommended opp instance\n");
>  		return PTR_ERR(new_opp);
>  	}
>  
> -	new_freq = dev_pm_opp_get_freq(new_opp);
>  	dev_pm_opp_put(new_opp);
>  
> -	old_freq = bus->curr_freq;
> -
> -	if (old_freq == new_freq)
> -		return 0;
> -
>  	/* Change the frequency according to new OPP level */
>  	mutex_lock(&bus->lock);
> +	ret = dev_pm_opp_set_rate(dev, *freq);
> +	if (!ret)
> +		bus->curr_freq = *freq;
>  
> -	ret = clk_set_rate(bus->clk, new_freq);
> -	if (ret < 0) {
> -		dev_err(dev, "failed to set the clock of bus\n");
> -		goto out;
> -	}
> -
> -	*freq = new_freq;
> -	bus->curr_freq = new_freq;
> -
> -	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> -			old_freq, new_freq, clk_get_rate(bus->clk));
> -out:
>  	mutex_unlock(&bus->lock);
>  
>  	return ret;
> @@ -259,20 +209,9 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>  					struct exynos_bus *bus)
>  {
>  	struct device *dev = bus->dev;
> -	int i, ret, count, size;
> -
> -	/* Get the regulator to provide each bus with the power */
> -	bus->regulator = devm_regulator_get(dev, "vdd");
> -	if (IS_ERR(bus->regulator)) {
> -		dev_err(dev, "failed to get VDD regulator\n");
> -		return PTR_ERR(bus->regulator);
> -	}
> -
> -	ret = regulator_enable(bus->regulator);
> -	if (ret < 0) {
> -		dev_err(dev, "failed to enable VDD regulator\n");
> -		return ret;
> -	}
> +	struct opp_table *opp_table;
> +	const char *vdd = "vdd";
> +	int i, count, size;
>  
>  	/*
>  	 * Get the devfreq-event devices to get the current utilization of
> @@ -281,26 +220,29 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>  	count = devfreq_event_get_edev_count(dev);
>  	if (count < 0) {
>  		dev_err(dev, "failed to get the count of devfreq-event dev\n");
> -		ret = count;
> -		goto err_regulator;
> +		return count;
>  	}
> -	bus->edev_count = count;
>  
> +	bus->edev_count = count;
>  	size = sizeof(*bus->edev) * count;
>  	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
> -	if (!bus->edev) {
> -		ret = -ENOMEM;
> -		goto err_regulator;
> -	}
> +	if (!bus->edev)
> +		return -ENOMEM;
>  
>  	for (i = 0; i < count; i++) {
>  		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
> -		if (IS_ERR(bus->edev[i])) {
> -			ret = -EPROBE_DEFER;
> -			goto err_regulator;
> -		}
> +		if (IS_ERR(bus->edev[i]))
> +			return -EPROBE_DEFER;
> +	}
> +
> +	opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
> +	if (IS_ERR(opp_table)) {
> +		i = PTR_ERR(opp_table);
> +		dev_err(dev, "failed to set regulators %d\n", i);
> +		return i;

Maybe, you just used the 'i' defined variable instead of adding
new variable. But, I think that you better to add new variable
like 'err' for the readability. Or, jut use the 'PTR_ERR(opp_table)'
directly without any additional variable.

>  	}
>  
> +	bus->opp_table = opp_table;

Add blank line. 

>  	/*
>  	 * Optionally, Get the saturation ratio according to Exynos SoC
>  	 * When measuring the utilization of each AXI bus with devfreq-event
> @@ -314,16 +256,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>  	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
>  		bus->ratio = DEFAULT_SATURATION_RATIO;
>  
> -	if (of_property_read_u32(np, "exynos,voltage-tolerance",
> -					&bus->voltage_tolerance))
> -		bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
> -
>  	return 0;
> -
> -err_regulator:
> -	regulator_disable(bus->regulator);
> -
> -	return ret;
>  }
>  
>  static int exynos_bus_parse_of(struct exynos_bus *bus)
> @@ -414,12 +347,8 @@ static int exynos_bus_probe(struct platform_device *pdev)
>  
>  	/* Parse the device-tree to get the resource information */
>  	ret = exynos_bus_parse_of(bus);
> -	if (ret < 0) {
> -		if (!passive)
> -			regulator_disable(bus->regulator);
> -
> -		return ret;
> -	}
> +	if (ret < 0)
> +		goto err_reg;
>  
>  	if (passive)
>  		goto passive;
> @@ -512,10 +441,12 @@ static int exynos_bus_probe(struct platform_device *pdev)
>  
>  err:
>  	clk_disable_unprepare(bus->clk);
> -	if (!passive)
> -		regulator_disable(bus->regulator);
> -
>  	dev_pm_opp_of_remove_table(dev);

This function removes the 'opp_table'. But, the below code
uses the 'opp_table' variable by dev_pm_opp_put_regulators().

To disable the regulator, you have to call dev_pm_opp_of_remove_table(dev)
after dev_pm_opp_put_regulators(bus->opp_table).

> +err_reg:
> +	if (bus->opp_table) {
> +		dev_pm_opp_put_regulators(bus->opp_table);
> +		bus->opp_table = NULL;
> +	}
>  
>  	return ret;
>  }
>
Kamil Konieczny July 25, 2019, 1:35 p.m. UTC | #2
Hi Chanwoo,

On 25.07.2019 12:17, Chanwoo Choi wrote:
> Hi Kamil,
> 
> Looks good to me. But, I have some comment. Please check them.

Thank you for review, please see answers below.

> After this patch, exynos_bus_target is perfectly same with
> exynos_bus_passive_target. The exynos_bus_passive_target() could be removed.

Ok, I will make it in separate patch to simplify review process.

> On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
>> Reuse opp core code for setting bus clock and voltage. As a side
>> effect this allow useage of coupled regulators feature (required
> 
> s/useage/usage ?

Good catch, I will change it.

>> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
>> uses regulator_set_voltage_triplet() for setting regulator voltage
>> while the old code used regulator_set_voltage_tol() with fixed
>> tolerance. This patch also removes no longer needed parsing of DT
>> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
>> it).
>>
>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>> ---
>>  drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
>>  1 file changed, 37 insertions(+), 106 deletions(-)
>>
>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>> index f391044aa39d..c2147b0912a0 100644
>> --- a/drivers/devfreq/exynos-bus.c
>> +++ b/drivers/devfreq/exynos-bus.c
>> @@ -25,7 +25,6 @@
>>  #include <linux/slab.h>
>>  
>>  #define DEFAULT_SATURATION_RATIO	40
>> -#define DEFAULT_VOLTAGE_TOLERANCE	2
>>  
>>  struct exynos_bus {
>>  	struct device *dev;
>> @@ -37,9 +36,9 @@ struct exynos_bus {
>>  
>>  	unsigned long curr_freq;
>>  
>> -	struct regulator *regulator;
>> +	struct opp_table *opp_table;
>> +
>>  	struct clk *clk;
>> -	unsigned int voltage_tolerance;
>>  	unsigned int ratio;
>>  };
>>  
>> @@ -99,56 +98,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
>>  {
>>  	struct exynos_bus *bus = dev_get_drvdata(dev);
>>  	struct dev_pm_opp *new_opp;
>> -	unsigned long old_freq, new_freq, new_volt, tol;
>>  	int ret = 0;
>>  
>> -	/* Get new opp-bus instance according to new bus clock */
>> +	/* Get correct frequency for bus. */
>>  	new_opp = devfreq_recommended_opp(dev, freq, flags);
>>  	if (IS_ERR(new_opp)) {
>>  		dev_err(dev, "failed to get recommended opp instance\n");
>>  		return PTR_ERR(new_opp);
>>  	}
>>  
>> -	new_freq = dev_pm_opp_get_freq(new_opp);
>> -	new_volt = dev_pm_opp_get_voltage(new_opp);
>>  	dev_pm_opp_put(new_opp);
>>  
>> -	old_freq = bus->curr_freq;
>> -
>> -	if (old_freq == new_freq)
>> -		return 0;
>> -	tol = new_volt * bus->voltage_tolerance / 100;
>> -
>>  	/* Change voltage and frequency according to new OPP level */
>>  	mutex_lock(&bus->lock);
>> +	ret = dev_pm_opp_set_rate(dev, *freq);
>> +	if (!ret)
>> +		bus->curr_freq = *freq;
>>  
>> -	if (old_freq < new_freq) {
>> -		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>> -		if (ret < 0) {
>> -			dev_err(bus->dev, "failed to set voltage\n");
>> -			goto out;
>> -		}
>> -	}
>> -
>> -	ret = clk_set_rate(bus->clk, new_freq);
>> -	if (ret < 0) {
>> -		dev_err(dev, "failed to change clock of bus\n");
>> -		clk_set_rate(bus->clk, old_freq);
>> -		goto out;
>> -	}
>> -
>> -	if (old_freq > new_freq) {
>> -		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>> -		if (ret < 0) {
>> -			dev_err(bus->dev, "failed to set voltage\n");
>> -			goto out;
>> -		}
>> -	}
>> -	bus->curr_freq = new_freq;
>> -
>> -	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>> -			old_freq, new_freq, clk_get_rate(bus->clk));
>> -out:
>>  	mutex_unlock(&bus->lock);
>>  
>>  	return ret;
>> @@ -195,8 +161,8 @@ static void exynos_bus_exit(struct device *dev)
>>  		dev_warn(dev, "failed to disable the devfreq-event devices\n");
>>  
>>  	clk_disable_unprepare(bus->clk);
>> -	if (bus->regulator)
>> -		regulator_disable(bus->regulator);
>> +	if (bus->opp_table)
>> +		dev_pm_opp_put_regulators(bus->opp_table);
>>  
>>  	dev_pm_opp_of_remove_table(dev);
>>  }
>> @@ -209,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
>>  {
>>  	struct exynos_bus *bus = dev_get_drvdata(dev);
>>  	struct dev_pm_opp *new_opp;
>> -	unsigned long old_freq, new_freq;
>> -	int ret = 0;
>> +	int ret;
>>  
>> -	/* Get new opp-bus instance according to new bus clock */
>> +	/* Get correct frequency for bus. */
>>  	new_opp = devfreq_recommended_opp(dev, freq, flags);
>>  	if (IS_ERR(new_opp)) {
>>  		dev_err(dev, "failed to get recommended opp instance\n");
>>  		return PTR_ERR(new_opp);
>>  	}
>>  
>> -	new_freq = dev_pm_opp_get_freq(new_opp);
>>  	dev_pm_opp_put(new_opp);
>>  
>> -	old_freq = bus->curr_freq;
>> -
>> -	if (old_freq == new_freq)
>> -		return 0;
>> -
>>  	/* Change the frequency according to new OPP level */
>>  	mutex_lock(&bus->lock);
>> +	ret = dev_pm_opp_set_rate(dev, *freq);
>> +	if (!ret)
>> +		bus->curr_freq = *freq;
>>  
>> -	ret = clk_set_rate(bus->clk, new_freq);
>> -	if (ret < 0) {
>> -		dev_err(dev, "failed to set the clock of bus\n");
>> -		goto out;
>> -	}
>> -
>> -	*freq = new_freq;
>> -	bus->curr_freq = new_freq;
>> -
>> -	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>> -			old_freq, new_freq, clk_get_rate(bus->clk));
>> -out:
>>  	mutex_unlock(&bus->lock);
>>  
>>  	return ret;
>> @@ -259,20 +209,9 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>  					struct exynos_bus *bus)
>>  {
>>  	struct device *dev = bus->dev;
>> -	int i, ret, count, size;
>> -
>> -	/* Get the regulator to provide each bus with the power */
>> -	bus->regulator = devm_regulator_get(dev, "vdd");
>> -	if (IS_ERR(bus->regulator)) {
>> -		dev_err(dev, "failed to get VDD regulator\n");
>> -		return PTR_ERR(bus->regulator);
>> -	}
>> -
>> -	ret = regulator_enable(bus->regulator);
>> -	if (ret < 0) {
>> -		dev_err(dev, "failed to enable VDD regulator\n");
>> -		return ret;
>> -	}
>> +	struct opp_table *opp_table;
>> +	const char *vdd = "vdd";
>> +	int i, count, size;
>>  
>>  	/*
>>  	 * Get the devfreq-event devices to get the current utilization of
>> @@ -281,26 +220,29 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>  	count = devfreq_event_get_edev_count(dev);
>>  	if (count < 0) {
>>  		dev_err(dev, "failed to get the count of devfreq-event dev\n");
>> -		ret = count;
>> -		goto err_regulator;
>> +		return count;
>>  	}
>> -	bus->edev_count = count;
>>  
>> +	bus->edev_count = count;
>>  	size = sizeof(*bus->edev) * count;
>>  	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
>> -	if (!bus->edev) {
>> -		ret = -ENOMEM;
>> -		goto err_regulator;
>> -	}
>> +	if (!bus->edev)
>> +		return -ENOMEM;
>>  
>>  	for (i = 0; i < count; i++) {
>>  		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
>> -		if (IS_ERR(bus->edev[i])) {
>> -			ret = -EPROBE_DEFER;
>> -			goto err_regulator;
>> -		}
>> +		if (IS_ERR(bus->edev[i]))
>> +			return -EPROBE_DEFER;
>> +	}
>> +
>> +	opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
>> +	if (IS_ERR(opp_table)) {
>> +		i = PTR_ERR(opp_table);
>> +		dev_err(dev, "failed to set regulators %d\n", i);
>> +		return i;
> 
> Maybe, you just used the 'i' defined variable instead of adding
> new variable. But, I think that you better to add new variable
> like 'err' for the readability. Or, jut use the 'PTR_ERR(opp_table)'
> directly without any additional variable.

I will remove not related changes, so here I will reuse 'ret' variable.

>>  	}
>>  
>> +	bus->opp_table = opp_table;
> 
> Add blank line. 

OK

>>  	/*
>>  	 * Optionally, Get the saturation ratio according to Exynos SoC
>>  	 * When measuring the utilization of each AXI bus with devfreq-event
>> @@ -314,16 +256,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>  	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
>>  		bus->ratio = DEFAULT_SATURATION_RATIO;
>>  
>> -	if (of_property_read_u32(np, "exynos,voltage-tolerance",
>> -					&bus->voltage_tolerance))
>> -		bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
>> -
>>  	return 0;
>> -
>> -err_regulator:
>> -	regulator_disable(bus->regulator);
>> -
>> -	return ret;
>>  }
>>  
>>  static int exynos_bus_parse_of(struct exynos_bus *bus)
>> @@ -414,12 +347,8 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>  
>>  	/* Parse the device-tree to get the resource information */
>>  	ret = exynos_bus_parse_of(bus);
>> -	if (ret < 0) {
>> -		if (!passive)
>> -			regulator_disable(bus->regulator);
>> -
>> -		return ret;
>> -	}
>> +	if (ret < 0)
>> +		goto err_reg;
>>  
>>  	if (passive)
>>  		goto passive;
>> @@ -512,10 +441,12 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>  
>>  err:
>>  	clk_disable_unprepare(bus->clk);
>> -	if (!passive)
>> -		regulator_disable(bus->regulator);
>> -
>>  	dev_pm_opp_of_remove_table(dev);
> 
> This function removes the 'opp_table'. But, the below code
> uses the 'opp_table' variable by dev_pm_opp_put_regulators().
> 
> To disable the regulator, you have to call dev_pm_opp_of_remove_table(dev)
> after dev_pm_opp_put_regulators(bus->opp_table).

Regulators should be set before dev_pm_opp_add_table(), so exit sequence
should be in reverse order,

init order:

exynos_bus_parent_parse_of()
	dev_pm_opp_set_regulators()
exynos_bus_parse_of()
	clk_prepare_enable()
	dev_pm_opp_of_add_table()

exit or error order:

dev_pm_opp_of_remove_table()
clk_disable_unprepare()
if (bus->opp_table)
	dev_pm_opp_put_regulators(bus->opp_table);

I will send v4 soon.

>> +err_reg:
>> +	if (bus->opp_table) {
>> +		dev_pm_opp_put_regulators(bus->opp_table);
>> +		bus->opp_table = NULL;
>> +	}
>>  
>>  	return ret;
>>  }
Chanwoo Choi July 25, 2019, 2:53 p.m. UTC | #3
2019년 7월 25일 (목) 오후 11:19, Kamil Konieczny
<k.konieczny@partner.samsung.com>님이 작성:
>
> Hi Chanwoo,
>
> On 25.07.2019 12:17, Chanwoo Choi wrote:
> > Hi Kamil,
> >
> > Looks good to me. But, I have some comment. Please check them.
>
> Thank you for review, please see answers below.
>
> > After this patch, exynos_bus_target is perfectly same with
> > exynos_bus_passive_target. The exynos_bus_passive_target() could be removed.
>
> Ok, I will make it in separate patch to simplify review process.

I think you can just modify this patch without any separate patch.

> > On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
> >> Reuse opp core code for setting bus clock and voltage. As a side
> >> effect this allow useage of coupled regulators feature (required
> >
> > s/useage/usage ?
>
> Good catch, I will change it.
>
> >> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
> >> uses regulator_set_voltage_triplet() for setting regulator voltage
> >> while the old code used regulator_set_voltage_tol() with fixed
> >> tolerance. This patch also removes no longer needed parsing of DT
> >> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
> >> it).
> >>
> >> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> >> ---
> >>  drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
> >>  1 file changed, 37 insertions(+), 106 deletions(-)
> >>
> >> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> >> index f391044aa39d..c2147b0912a0 100644
> >> --- a/drivers/devfreq/exynos-bus.c
> >> +++ b/drivers/devfreq/exynos-bus.c
> >> @@ -25,7 +25,6 @@
> >>  #include <linux/slab.h>
> >>
> >>  #define DEFAULT_SATURATION_RATIO    40
> >> -#define DEFAULT_VOLTAGE_TOLERANCE   2
> >>
> >>  struct exynos_bus {
> >>      struct device *dev;
> >> @@ -37,9 +36,9 @@ struct exynos_bus {
> >>
> >>      unsigned long curr_freq;
> >>
> >> -    struct regulator *regulator;
> >> +    struct opp_table *opp_table;
> >> +
> >>      struct clk *clk;
> >> -    unsigned int voltage_tolerance;
> >>      unsigned int ratio;
> >>  };
> >>
> >> @@ -99,56 +98,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
> >>  {
> >>      struct exynos_bus *bus = dev_get_drvdata(dev);
> >>      struct dev_pm_opp *new_opp;
> >> -    unsigned long old_freq, new_freq, new_volt, tol;
> >>      int ret = 0;
> >>
> >> -    /* Get new opp-bus instance according to new bus clock */
> >> +    /* Get correct frequency for bus. */
> >>      new_opp = devfreq_recommended_opp(dev, freq, flags);
> >>      if (IS_ERR(new_opp)) {
> >>              dev_err(dev, "failed to get recommended opp instance\n");
> >>              return PTR_ERR(new_opp);
> >>      }
> >>
> >> -    new_freq = dev_pm_opp_get_freq(new_opp);
> >> -    new_volt = dev_pm_opp_get_voltage(new_opp);
> >>      dev_pm_opp_put(new_opp);
> >>
> >> -    old_freq = bus->curr_freq;
> >> -
> >> -    if (old_freq == new_freq)
> >> -            return 0;
> >> -    tol = new_volt * bus->voltage_tolerance / 100;
> >> -
> >>      /* Change voltage and frequency according to new OPP level */
> >>      mutex_lock(&bus->lock);
> >> +    ret = dev_pm_opp_set_rate(dev, *freq);
> >> +    if (!ret)
> >> +            bus->curr_freq = *freq;
> >>
> >> -    if (old_freq < new_freq) {
> >> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> >> -            if (ret < 0) {
> >> -                    dev_err(bus->dev, "failed to set voltage\n");
> >> -                    goto out;
> >> -            }
> >> -    }
> >> -
> >> -    ret = clk_set_rate(bus->clk, new_freq);
> >> -    if (ret < 0) {
> >> -            dev_err(dev, "failed to change clock of bus\n");
> >> -            clk_set_rate(bus->clk, old_freq);
> >> -            goto out;
> >> -    }
> >> -
> >> -    if (old_freq > new_freq) {
> >> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> >> -            if (ret < 0) {
> >> -                    dev_err(bus->dev, "failed to set voltage\n");
> >> -                    goto out;
> >> -            }
> >> -    }
> >> -    bus->curr_freq = new_freq;
> >> -
> >> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> >> -                    old_freq, new_freq, clk_get_rate(bus->clk));
> >> -out:
> >>      mutex_unlock(&bus->lock);
> >>
> >>      return ret;
> >> @@ -195,8 +161,8 @@ static void exynos_bus_exit(struct device *dev)
> >>              dev_warn(dev, "failed to disable the devfreq-event devices\n");
> >>
> >>      clk_disable_unprepare(bus->clk);
> >> -    if (bus->regulator)
> >> -            regulator_disable(bus->regulator);
> >> +    if (bus->opp_table)
> >> +            dev_pm_opp_put_regulators(bus->opp_table);
> >>
> >>      dev_pm_opp_of_remove_table(dev);
> >>  }
> >> @@ -209,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
> >>  {
> >>      struct exynos_bus *bus = dev_get_drvdata(dev);
> >>      struct dev_pm_opp *new_opp;
> >> -    unsigned long old_freq, new_freq;
> >> -    int ret = 0;
> >> +    int ret;
> >>
> >> -    /* Get new opp-bus instance according to new bus clock */
> >> +    /* Get correct frequency for bus. */
> >>      new_opp = devfreq_recommended_opp(dev, freq, flags);
> >>      if (IS_ERR(new_opp)) {
> >>              dev_err(dev, "failed to get recommended opp instance\n");
> >>              return PTR_ERR(new_opp);
> >>      }
> >>
> >> -    new_freq = dev_pm_opp_get_freq(new_opp);
> >>      dev_pm_opp_put(new_opp);
> >>
> >> -    old_freq = bus->curr_freq;
> >> -
> >> -    if (old_freq == new_freq)
> >> -            return 0;
> >> -
> >>      /* Change the frequency according to new OPP level */
> >>      mutex_lock(&bus->lock);
> >> +    ret = dev_pm_opp_set_rate(dev, *freq);
> >> +    if (!ret)
> >> +            bus->curr_freq = *freq;
> >>
> >> -    ret = clk_set_rate(bus->clk, new_freq);
> >> -    if (ret < 0) {
> >> -            dev_err(dev, "failed to set the clock of bus\n");
> >> -            goto out;
> >> -    }
> >> -
> >> -    *freq = new_freq;
> >> -    bus->curr_freq = new_freq;
> >> -
> >> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> >> -                    old_freq, new_freq, clk_get_rate(bus->clk));
> >> -out:
> >>      mutex_unlock(&bus->lock);
> >>
> >>      return ret;
> >> @@ -259,20 +209,9 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
> >>                                      struct exynos_bus *bus)
> >>  {
> >>      struct device *dev = bus->dev;
> >> -    int i, ret, count, size;
> >> -
> >> -    /* Get the regulator to provide each bus with the power */
> >> -    bus->regulator = devm_regulator_get(dev, "vdd");
> >> -    if (IS_ERR(bus->regulator)) {
> >> -            dev_err(dev, "failed to get VDD regulator\n");
> >> -            return PTR_ERR(bus->regulator);
> >> -    }
> >> -
> >> -    ret = regulator_enable(bus->regulator);
> >> -    if (ret < 0) {
> >> -            dev_err(dev, "failed to enable VDD regulator\n");
> >> -            return ret;
> >> -    }
> >> +    struct opp_table *opp_table;
> >> +    const char *vdd = "vdd";
> >> +    int i, count, size;
> >>
> >>      /*
> >>       * Get the devfreq-event devices to get the current utilization of
> >> @@ -281,26 +220,29 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
> >>      count = devfreq_event_get_edev_count(dev);
> >>      if (count < 0) {
> >>              dev_err(dev, "failed to get the count of devfreq-event dev\n");
> >> -            ret = count;
> >> -            goto err_regulator;
> >> +            return count;
> >>      }
> >> -    bus->edev_count = count;
> >>
> >> +    bus->edev_count = count;
> >>      size = sizeof(*bus->edev) * count;
> >>      bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
> >> -    if (!bus->edev) {
> >> -            ret = -ENOMEM;
> >> -            goto err_regulator;
> >> -    }
> >> +    if (!bus->edev)
> >> +            return -ENOMEM;
> >>
> >>      for (i = 0; i < count; i++) {
> >>              bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
> >> -            if (IS_ERR(bus->edev[i])) {
> >> -                    ret = -EPROBE_DEFER;
> >> -                    goto err_regulator;
> >> -            }
> >> +            if (IS_ERR(bus->edev[i]))
> >> +                    return -EPROBE_DEFER;
> >> +    }
> >> +
> >> +    opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
> >> +    if (IS_ERR(opp_table)) {
> >> +            i = PTR_ERR(opp_table);
> >> +            dev_err(dev, "failed to set regulators %d\n", i);
> >> +            return i;
> >
> > Maybe, you just used the 'i' defined variable instead of adding
> > new variable. But, I think that you better to add new variable
> > like 'err' for the readability. Or, jut use the 'PTR_ERR(opp_table)'
> > directly without any additional variable.
>
> I will remove not related changes, so here I will reuse 'ret' variable.
>
> >>      }
> >>
> >> +    bus->opp_table = opp_table;
> >
> > Add blank line.
>
> OK
>
> >>      /*
> >>       * Optionally, Get the saturation ratio according to Exynos SoC
> >>       * When measuring the utilization of each AXI bus with devfreq-event
> >> @@ -314,16 +256,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
> >>      if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
> >>              bus->ratio = DEFAULT_SATURATION_RATIO;
> >>
> >> -    if (of_property_read_u32(np, "exynos,voltage-tolerance",
> >> -                                    &bus->voltage_tolerance))
> >> -            bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
> >> -
> >>      return 0;
> >> -
> >> -err_regulator:
> >> -    regulator_disable(bus->regulator);
> >> -
> >> -    return ret;
> >>  }
> >>
> >>  static int exynos_bus_parse_of(struct exynos_bus *bus)
> >> @@ -414,12 +347,8 @@ static int exynos_bus_probe(struct platform_device *pdev)
> >>
> >>      /* Parse the device-tree to get the resource information */
> >>      ret = exynos_bus_parse_of(bus);
> >> -    if (ret < 0) {
> >> -            if (!passive)
> >> -                    regulator_disable(bus->regulator);
> >> -
> >> -            return ret;
> >> -    }
> >> +    if (ret < 0)
> >> +            goto err_reg;
> >>
> >>      if (passive)
> >>              goto passive;
> >> @@ -512,10 +441,12 @@ static int exynos_bus_probe(struct platform_device *pdev)
> >>
> >>  err:
> >>      clk_disable_unprepare(bus->clk);
> >> -    if (!passive)
> >> -            regulator_disable(bus->regulator);
> >> -
> >>      dev_pm_opp_of_remove_table(dev);
> >
> > This function removes the 'opp_table'. But, the below code
> > uses the 'opp_table' variable by dev_pm_opp_put_regulators().
> >
> > To disable the regulator, you have to call dev_pm_opp_of_remove_table(dev)
> > after dev_pm_opp_put_regulators(bus->opp_table).
>
> Regulators should be set before dev_pm_opp_add_table(), so exit sequence
> should be in reverse order,
>
> init order:
>
> exynos_bus_parent_parse_of()
>         dev_pm_opp_set_regulators()
> exynos_bus_parse_of()
>         clk_prepare_enable()
>         dev_pm_opp_of_add_table()
>
> exit or error order:
>
> dev_pm_opp_of_remove_table()
> clk_disable_unprepare()
> if (bus->opp_table)
>         dev_pm_opp_put_regulators(bus->opp_table);

dev_pm_opp_of_remove_table() have to be called at the end of exit sequence
after disabling clock and put regulators. Because dev_pm_opp_of_remove_table()
frees the 'opp_table' pointer of device.

clk_disable_unprepare()
if (bus->opp_table)
          dev_pm_opp_put_regulators(bus->opp_table);
dev_pm_opp_of_remove_table()

>
> I will send v4 soon.
>
> >> +err_reg:
> >> +    if (bus->opp_table) {
> >> +            dev_pm_opp_put_regulators(bus->opp_table);
> >> +            bus->opp_table = NULL;
> >> +    }
> >>
> >>      return ret;
> >>  }
>
> --
> Best regards,
> Kamil Konieczny
> Samsung R&D Institute Poland
>
Kamil Konieczny July 25, 2019, 3:15 p.m. UTC | #4
Hi,

On 25.07.2019 16:53, Chanwoo Choi wrote:
> 2019년 7월 25일 (목) 오후 11:19, Kamil Konieczny
> <k.konieczny@partner.samsung.com>님이 작성:
>>
>> Hi Chanwoo,
>>
>> On 25.07.2019 12:17, Chanwoo Choi wrote:
>>> Hi Kamil,
>>>
>>> Looks good to me. But, I have some comment. Please check them.
>>
>> Thank you for review, please see answers below.
>>
>>> After this patch, exynos_bus_target is perfectly same with
>>> exynos_bus_passive_target. The exynos_bus_passive_target() could be removed.
>>
>> Ok, I will make it in separate patch to simplify review process.
> 
> I think you can just modify this patch without any separate patch.

Do you want me to send v5 with patch 5 squashed in patch 3 ?
 
>>> On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
>>>> Reuse opp core code for setting bus clock and voltage. As a side
>>>> effect this allow useage of coupled regulators feature (required
>>>
>>> s/useage/usage ?
>>
>> Good catch, I will change it.
>>
>>>> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
>>>> uses regulator_set_voltage_triplet() for setting regulator voltage
>>>> while the old code used regulator_set_voltage_tol() with fixed
>>>> tolerance. This patch also removes no longer needed parsing of DT
>>>> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
>>>> it).
>>>>
>>>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>>> ---
>>>>  drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
>>>>  1 file changed, 37 insertions(+), 106 deletions(-)
>>>>
>>>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>>>> index f391044aa39d..c2147b0912a0 100644
>>>> --- a/drivers/devfreq/exynos-bus.c
>>>> +++ b/drivers/devfreq/exynos-bus.c
>>>> @@ -25,7 +25,6 @@
>>>>  #include <linux/slab.h>
>>>>
>>>>  #define DEFAULT_SATURATION_RATIO    40
>>>> -#define DEFAULT_VOLTAGE_TOLERANCE   2
>>>>
>>>>  struct exynos_bus {
>>>>      struct device *dev;
>>>> @@ -37,9 +36,9 @@ struct exynos_bus {
>>>>
>>>>      unsigned long curr_freq;
>>>>
>>>> -    struct regulator *regulator;
>>>> +    struct opp_table *opp_table;
>>>> +
>>>>      struct clk *clk;
>>>> -    unsigned int voltage_tolerance;
>>>>      unsigned int ratio;
>>>>  };
>>>>
>>>> @@ -99,56 +98,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
>>>>  {
>>>>      struct exynos_bus *bus = dev_get_drvdata(dev);
>>>>      struct dev_pm_opp *new_opp;
>>>> -    unsigned long old_freq, new_freq, new_volt, tol;
>>>>      int ret = 0;
>>>>
>>>> -    /* Get new opp-bus instance according to new bus clock */
>>>> +    /* Get correct frequency for bus. */
>>>>      new_opp = devfreq_recommended_opp(dev, freq, flags);
>>>>      if (IS_ERR(new_opp)) {
>>>>              dev_err(dev, "failed to get recommended opp instance\n");
>>>>              return PTR_ERR(new_opp);
>>>>      }
>>>>
>>>> -    new_freq = dev_pm_opp_get_freq(new_opp);
>>>> -    new_volt = dev_pm_opp_get_voltage(new_opp);
>>>>      dev_pm_opp_put(new_opp);
>>>>
>>>> -    old_freq = bus->curr_freq;
>>>> -
>>>> -    if (old_freq == new_freq)
>>>> -            return 0;
>>>> -    tol = new_volt * bus->voltage_tolerance / 100;
>>>> -
>>>>      /* Change voltage and frequency according to new OPP level */
>>>>      mutex_lock(&bus->lock);
>>>> +    ret = dev_pm_opp_set_rate(dev, *freq);
>>>> +    if (!ret)
>>>> +            bus->curr_freq = *freq;
>>>>
>>>> -    if (old_freq < new_freq) {
>>>> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>>>> -            if (ret < 0) {
>>>> -                    dev_err(bus->dev, "failed to set voltage\n");
>>>> -                    goto out;
>>>> -            }
>>>> -    }
>>>> -
>>>> -    ret = clk_set_rate(bus->clk, new_freq);
>>>> -    if (ret < 0) {
>>>> -            dev_err(dev, "failed to change clock of bus\n");
>>>> -            clk_set_rate(bus->clk, old_freq);
>>>> -            goto out;
>>>> -    }
>>>> -
>>>> -    if (old_freq > new_freq) {
>>>> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>>>> -            if (ret < 0) {
>>>> -                    dev_err(bus->dev, "failed to set voltage\n");
>>>> -                    goto out;
>>>> -            }
>>>> -    }
>>>> -    bus->curr_freq = new_freq;
>>>> -
>>>> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>>>> -                    old_freq, new_freq, clk_get_rate(bus->clk));
>>>> -out:
>>>>      mutex_unlock(&bus->lock);
>>>>
>>>>      return ret;
>>>> @@ -195,8 +161,8 @@ static void exynos_bus_exit(struct device *dev)
>>>>              dev_warn(dev, "failed to disable the devfreq-event devices\n");
>>>>
>>>>      clk_disable_unprepare(bus->clk);
>>>> -    if (bus->regulator)
>>>> -            regulator_disable(bus->regulator);
>>>> +    if (bus->opp_table)
>>>> +            dev_pm_opp_put_regulators(bus->opp_table);
>>>>
>>>>      dev_pm_opp_of_remove_table(dev);
>>>>  }
>>>> @@ -209,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
>>>>  {
>>>>      struct exynos_bus *bus = dev_get_drvdata(dev);
>>>>      struct dev_pm_opp *new_opp;
>>>> -    unsigned long old_freq, new_freq;
>>>> -    int ret = 0;
>>>> +    int ret;
>>>>
>>>> -    /* Get new opp-bus instance according to new bus clock */
>>>> +    /* Get correct frequency for bus. */
>>>>      new_opp = devfreq_recommended_opp(dev, freq, flags);
>>>>      if (IS_ERR(new_opp)) {
>>>>              dev_err(dev, "failed to get recommended opp instance\n");
>>>>              return PTR_ERR(new_opp);
>>>>      }
>>>>
>>>> -    new_freq = dev_pm_opp_get_freq(new_opp);
>>>>      dev_pm_opp_put(new_opp);
>>>>
>>>> -    old_freq = bus->curr_freq;
>>>> -
>>>> -    if (old_freq == new_freq)
>>>> -            return 0;
>>>> -
>>>>      /* Change the frequency according to new OPP level */
>>>>      mutex_lock(&bus->lock);
>>>> +    ret = dev_pm_opp_set_rate(dev, *freq);
>>>> +    if (!ret)
>>>> +            bus->curr_freq = *freq;
>>>>
>>>> -    ret = clk_set_rate(bus->clk, new_freq);
>>>> -    if (ret < 0) {
>>>> -            dev_err(dev, "failed to set the clock of bus\n");
>>>> -            goto out;
>>>> -    }
>>>> -
>>>> -    *freq = new_freq;
>>>> -    bus->curr_freq = new_freq;
>>>> -
>>>> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>>>> -                    old_freq, new_freq, clk_get_rate(bus->clk));
>>>> -out:
>>>>      mutex_unlock(&bus->lock);
>>>>
>>>>      return ret;
>>>> @@ -259,20 +209,9 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>                                      struct exynos_bus *bus)
>>>>  {
>>>>      struct device *dev = bus->dev;
>>>> -    int i, ret, count, size;
>>>> -
>>>> -    /* Get the regulator to provide each bus with the power */
>>>> -    bus->regulator = devm_regulator_get(dev, "vdd");
>>>> -    if (IS_ERR(bus->regulator)) {
>>>> -            dev_err(dev, "failed to get VDD regulator\n");
>>>> -            return PTR_ERR(bus->regulator);
>>>> -    }
>>>> -
>>>> -    ret = regulator_enable(bus->regulator);
>>>> -    if (ret < 0) {
>>>> -            dev_err(dev, "failed to enable VDD regulator\n");
>>>> -            return ret;
>>>> -    }
>>>> +    struct opp_table *opp_table;
>>>> +    const char *vdd = "vdd";
>>>> +    int i, count, size;
>>>>
>>>>      /*
>>>>       * Get the devfreq-event devices to get the current utilization of
>>>> @@ -281,26 +220,29 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>      count = devfreq_event_get_edev_count(dev);
>>>>      if (count < 0) {
>>>>              dev_err(dev, "failed to get the count of devfreq-event dev\n");
>>>> -            ret = count;
>>>> -            goto err_regulator;
>>>> +            return count;
>>>>      }
>>>> -    bus->edev_count = count;
>>>>
>>>> +    bus->edev_count = count;
>>>>      size = sizeof(*bus->edev) * count;
>>>>      bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
>>>> -    if (!bus->edev) {
>>>> -            ret = -ENOMEM;
>>>> -            goto err_regulator;
>>>> -    }
>>>> +    if (!bus->edev)
>>>> +            return -ENOMEM;
>>>>
>>>>      for (i = 0; i < count; i++) {
>>>>              bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
>>>> -            if (IS_ERR(bus->edev[i])) {
>>>> -                    ret = -EPROBE_DEFER;
>>>> -                    goto err_regulator;
>>>> -            }
>>>> +            if (IS_ERR(bus->edev[i]))
>>>> +                    return -EPROBE_DEFER;
>>>> +    }
>>>> +
>>>> +    opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
>>>> +    if (IS_ERR(opp_table)) {
>>>> +            i = PTR_ERR(opp_table);
>>>> +            dev_err(dev, "failed to set regulators %d\n", i);
>>>> +            return i;
>>>
>>> Maybe, you just used the 'i' defined variable instead of adding
>>> new variable. But, I think that you better to add new variable
>>> like 'err' for the readability. Or, jut use the 'PTR_ERR(opp_table)'
>>> directly without any additional variable.
>>
>> I will remove not related changes, so here I will reuse 'ret' variable.
>>
>>>>      }
>>>>
>>>> +    bus->opp_table = opp_table;
>>>
>>> Add blank line.
>>
>> OK
>>
>>>>      /*
>>>>       * Optionally, Get the saturation ratio according to Exynos SoC
>>>>       * When measuring the utilization of each AXI bus with devfreq-event
>>>> @@ -314,16 +256,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>      if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
>>>>              bus->ratio = DEFAULT_SATURATION_RATIO;
>>>>
>>>> -    if (of_property_read_u32(np, "exynos,voltage-tolerance",
>>>> -                                    &bus->voltage_tolerance))
>>>> -            bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
>>>> -
>>>>      return 0;
>>>> -
>>>> -err_regulator:
>>>> -    regulator_disable(bus->regulator);
>>>> -
>>>> -    return ret;
>>>>  }
>>>>
>>>>  static int exynos_bus_parse_of(struct exynos_bus *bus)
>>>> @@ -414,12 +347,8 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>>>
>>>>      /* Parse the device-tree to get the resource information */
>>>>      ret = exynos_bus_parse_of(bus);
>>>> -    if (ret < 0) {
>>>> -            if (!passive)
>>>> -                    regulator_disable(bus->regulator);
>>>> -
>>>> -            return ret;
>>>> -    }
>>>> +    if (ret < 0)
>>>> +            goto err_reg;
>>>>
>>>>      if (passive)
>>>>              goto passive;
>>>> @@ -512,10 +441,12 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>>>
>>>>  err:
>>>>      clk_disable_unprepare(bus->clk);
>>>> -    if (!passive)
>>>> -            regulator_disable(bus->regulator);
>>>> -
>>>>      dev_pm_opp_of_remove_table(dev);
>>>
>>> This function removes the 'opp_table'. But, the below code
>>> uses the 'opp_table' variable by dev_pm_opp_put_regulators().
>>>
>>> To disable the regulator, you have to call dev_pm_opp_of_remove_table(dev)
>>> after dev_pm_opp_put_regulators(bus->opp_table).
>>
>> Regulators should be set before dev_pm_opp_add_table(), so exit sequence
>> should be in reverse order,
>>
>> init order:
>>
>> exynos_bus_parent_parse_of()
>>         dev_pm_opp_set_regulators()
>> exynos_bus_parse_of()
>>         clk_prepare_enable()
>>         dev_pm_opp_of_add_table()
>>
>> exit or error order:
>>
>> dev_pm_opp_of_remove_table()
>> clk_disable_unprepare()
>> if (bus->opp_table)
>>         dev_pm_opp_put_regulators(bus->opp_table);
> 
> dev_pm_opp_of_remove_table() have to be called at the end of exit sequence
> after disabling clock and put regulators. Because dev_pm_opp_of_remove_table()
> frees the 'opp_table' pointer of device.
> 
> clk_disable_unprepare()
> if (bus->opp_table)
>           dev_pm_opp_put_regulators(bus->opp_table);
> dev_pm_opp_of_remove_table()

The table is reference counted so it will be freed after count go to zero.

>> I will send v4 soon.
>>
>>>> +err_reg:
>>>> +    if (bus->opp_table) {
>>>> +            dev_pm_opp_put_regulators(bus->opp_table);
>>>> +            bus->opp_table = NULL;
>>>> +    }
>>>>
>>>>      return ret;
>>>>  }
Chanwoo Choi July 26, 2019, 1:02 a.m. UTC | #5
Hi,

On 19. 7. 26. 오전 12:15, Kamil Konieczny wrote:
> Hi,
> 
> On 25.07.2019 16:53, Chanwoo Choi wrote:
>> 2019년 7월 25일 (목) 오후 11:19, Kamil Konieczny
>> <k.konieczny@partner.samsung.com>님이 작성:
>>>
>>> Hi Chanwoo,
>>>
>>> On 25.07.2019 12:17, Chanwoo Choi wrote:
>>>> Hi Kamil,
>>>>
>>>> Looks good to me. But, I have some comment. Please check them.
>>>
>>> Thank you for review, please see answers below.
>>>
>>>> After this patch, exynos_bus_target is perfectly same with
>>>> exynos_bus_passive_target. The exynos_bus_passive_target() could be removed.
>>>
>>> Ok, I will make it in separate patch to simplify review process.
>>
>> I think you can just modify this patch without any separate patch.
> 
> Do you want me to send v5 with patch 5 squashed in patch 3 ?

Yes. In result, it made two functions same by this patch
So, I think that can combine them without separate patch.

>  
>>>> On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
>>>>> Reuse opp core code for setting bus clock and voltage. As a side
>>>>> effect this allow useage of coupled regulators feature (required
>>>>
>>>> s/useage/usage ?
>>>
>>> Good catch, I will change it.
>>>
>>>>> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
>>>>> uses regulator_set_voltage_triplet() for setting regulator voltage
>>>>> while the old code used regulator_set_voltage_tol() with fixed
>>>>> tolerance. This patch also removes no longer needed parsing of DT
>>>>> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
>>>>> it).
>>>>>
>>>>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>>>> ---
>>>>>  drivers/devfreq/exynos-bus.c | 143 +++++++++--------------------------
>>>>>  1 file changed, 37 insertions(+), 106 deletions(-)
>>>>>
>>>>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>>>>> index f391044aa39d..c2147b0912a0 100644
>>>>> --- a/drivers/devfreq/exynos-bus.c
>>>>> +++ b/drivers/devfreq/exynos-bus.c
>>>>> @@ -25,7 +25,6 @@
>>>>>  #include <linux/slab.h>
>>>>>
>>>>>  #define DEFAULT_SATURATION_RATIO    40
>>>>> -#define DEFAULT_VOLTAGE_TOLERANCE   2
>>>>>
>>>>>  struct exynos_bus {
>>>>>      struct device *dev;
>>>>> @@ -37,9 +36,9 @@ struct exynos_bus {
>>>>>
>>>>>      unsigned long curr_freq;
>>>>>
>>>>> -    struct regulator *regulator;
>>>>> +    struct opp_table *opp_table;
>>>>> +
>>>>>      struct clk *clk;
>>>>> -    unsigned int voltage_tolerance;
>>>>>      unsigned int ratio;
>>>>>  };
>>>>>
>>>>> @@ -99,56 +98,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
>>>>>  {
>>>>>      struct exynos_bus *bus = dev_get_drvdata(dev);
>>>>>      struct dev_pm_opp *new_opp;
>>>>> -    unsigned long old_freq, new_freq, new_volt, tol;
>>>>>      int ret = 0;
>>>>>
>>>>> -    /* Get new opp-bus instance according to new bus clock */
>>>>> +    /* Get correct frequency for bus. */
>>>>>      new_opp = devfreq_recommended_opp(dev, freq, flags);
>>>>>      if (IS_ERR(new_opp)) {
>>>>>              dev_err(dev, "failed to get recommended opp instance\n");
>>>>>              return PTR_ERR(new_opp);
>>>>>      }
>>>>>
>>>>> -    new_freq = dev_pm_opp_get_freq(new_opp);
>>>>> -    new_volt = dev_pm_opp_get_voltage(new_opp);
>>>>>      dev_pm_opp_put(new_opp);
>>>>>
>>>>> -    old_freq = bus->curr_freq;
>>>>> -
>>>>> -    if (old_freq == new_freq)
>>>>> -            return 0;
>>>>> -    tol = new_volt * bus->voltage_tolerance / 100;
>>>>> -
>>>>>      /* Change voltage and frequency according to new OPP level */
>>>>>      mutex_lock(&bus->lock);
>>>>> +    ret = dev_pm_opp_set_rate(dev, *freq);
>>>>> +    if (!ret)
>>>>> +            bus->curr_freq = *freq;
>>>>>
>>>>> -    if (old_freq < new_freq) {
>>>>> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>>>>> -            if (ret < 0) {
>>>>> -                    dev_err(bus->dev, "failed to set voltage\n");
>>>>> -                    goto out;
>>>>> -            }
>>>>> -    }
>>>>> -
>>>>> -    ret = clk_set_rate(bus->clk, new_freq);
>>>>> -    if (ret < 0) {
>>>>> -            dev_err(dev, "failed to change clock of bus\n");
>>>>> -            clk_set_rate(bus->clk, old_freq);
>>>>> -            goto out;
>>>>> -    }
>>>>> -
>>>>> -    if (old_freq > new_freq) {
>>>>> -            ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
>>>>> -            if (ret < 0) {
>>>>> -                    dev_err(bus->dev, "failed to set voltage\n");
>>>>> -                    goto out;
>>>>> -            }
>>>>> -    }
>>>>> -    bus->curr_freq = new_freq;
>>>>> -
>>>>> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>>>>> -                    old_freq, new_freq, clk_get_rate(bus->clk));
>>>>> -out:
>>>>>      mutex_unlock(&bus->lock);
>>>>>
>>>>>      return ret;
>>>>> @@ -195,8 +161,8 @@ static void exynos_bus_exit(struct device *dev)
>>>>>              dev_warn(dev, "failed to disable the devfreq-event devices\n");
>>>>>
>>>>>      clk_disable_unprepare(bus->clk);
>>>>> -    if (bus->regulator)
>>>>> -            regulator_disable(bus->regulator);
>>>>> +    if (bus->opp_table)
>>>>> +            dev_pm_opp_put_regulators(bus->opp_table);
>>>>>
>>>>>      dev_pm_opp_of_remove_table(dev);
>>>>>  }
>>>>> @@ -209,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
>>>>>  {
>>>>>      struct exynos_bus *bus = dev_get_drvdata(dev);
>>>>>      struct dev_pm_opp *new_opp;
>>>>> -    unsigned long old_freq, new_freq;
>>>>> -    int ret = 0;
>>>>> +    int ret;
>>>>>
>>>>> -    /* Get new opp-bus instance according to new bus clock */
>>>>> +    /* Get correct frequency for bus. */
>>>>>      new_opp = devfreq_recommended_opp(dev, freq, flags);
>>>>>      if (IS_ERR(new_opp)) {
>>>>>              dev_err(dev, "failed to get recommended opp instance\n");
>>>>>              return PTR_ERR(new_opp);
>>>>>      }
>>>>>
>>>>> -    new_freq = dev_pm_opp_get_freq(new_opp);
>>>>>      dev_pm_opp_put(new_opp);
>>>>>
>>>>> -    old_freq = bus->curr_freq;
>>>>> -
>>>>> -    if (old_freq == new_freq)
>>>>> -            return 0;
>>>>> -
>>>>>      /* Change the frequency according to new OPP level */
>>>>>      mutex_lock(&bus->lock);
>>>>> +    ret = dev_pm_opp_set_rate(dev, *freq);
>>>>> +    if (!ret)
>>>>> +            bus->curr_freq = *freq;
>>>>>
>>>>> -    ret = clk_set_rate(bus->clk, new_freq);
>>>>> -    if (ret < 0) {
>>>>> -            dev_err(dev, "failed to set the clock of bus\n");
>>>>> -            goto out;
>>>>> -    }
>>>>> -
>>>>> -    *freq = new_freq;
>>>>> -    bus->curr_freq = new_freq;
>>>>> -
>>>>> -    dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
>>>>> -                    old_freq, new_freq, clk_get_rate(bus->clk));
>>>>> -out:
>>>>>      mutex_unlock(&bus->lock);
>>>>>
>>>>>      return ret;
>>>>> @@ -259,20 +209,9 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>>                                      struct exynos_bus *bus)
>>>>>  {
>>>>>      struct device *dev = bus->dev;
>>>>> -    int i, ret, count, size;
>>>>> -
>>>>> -    /* Get the regulator to provide each bus with the power */
>>>>> -    bus->regulator = devm_regulator_get(dev, "vdd");
>>>>> -    if (IS_ERR(bus->regulator)) {
>>>>> -            dev_err(dev, "failed to get VDD regulator\n");
>>>>> -            return PTR_ERR(bus->regulator);
>>>>> -    }
>>>>> -
>>>>> -    ret = regulator_enable(bus->regulator);
>>>>> -    if (ret < 0) {
>>>>> -            dev_err(dev, "failed to enable VDD regulator\n");
>>>>> -            return ret;
>>>>> -    }
>>>>> +    struct opp_table *opp_table;
>>>>> +    const char *vdd = "vdd";
>>>>> +    int i, count, size;
>>>>>
>>>>>      /*
>>>>>       * Get the devfreq-event devices to get the current utilization of
>>>>> @@ -281,26 +220,29 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>>      count = devfreq_event_get_edev_count(dev);
>>>>>      if (count < 0) {
>>>>>              dev_err(dev, "failed to get the count of devfreq-event dev\n");
>>>>> -            ret = count;
>>>>> -            goto err_regulator;
>>>>> +            return count;
>>>>>      }
>>>>> -    bus->edev_count = count;
>>>>>
>>>>> +    bus->edev_count = count;
>>>>>      size = sizeof(*bus->edev) * count;
>>>>>      bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
>>>>> -    if (!bus->edev) {
>>>>> -            ret = -ENOMEM;
>>>>> -            goto err_regulator;
>>>>> -    }
>>>>> +    if (!bus->edev)
>>>>> +            return -ENOMEM;
>>>>>
>>>>>      for (i = 0; i < count; i++) {
>>>>>              bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
>>>>> -            if (IS_ERR(bus->edev[i])) {
>>>>> -                    ret = -EPROBE_DEFER;
>>>>> -                    goto err_regulator;
>>>>> -            }
>>>>> +            if (IS_ERR(bus->edev[i]))
>>>>> +                    return -EPROBE_DEFER;
>>>>> +    }
>>>>> +
>>>>> +    opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
>>>>> +    if (IS_ERR(opp_table)) {
>>>>> +            i = PTR_ERR(opp_table);
>>>>> +            dev_err(dev, "failed to set regulators %d\n", i);
>>>>> +            return i;
>>>>
>>>> Maybe, you just used the 'i' defined variable instead of adding
>>>> new variable. But, I think that you better to add new variable
>>>> like 'err' for the readability. Or, jut use the 'PTR_ERR(opp_table)'
>>>> directly without any additional variable.
>>>
>>> I will remove not related changes, so here I will reuse 'ret' variable.
>>>
>>>>>      }
>>>>>
>>>>> +    bus->opp_table = opp_table;
>>>>
>>>> Add blank line.
>>>
>>> OK
>>>
>>>>>      /*
>>>>>       * Optionally, Get the saturation ratio according to Exynos SoC
>>>>>       * When measuring the utilization of each AXI bus with devfreq-event
>>>>> @@ -314,16 +256,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>>>>>      if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
>>>>>              bus->ratio = DEFAULT_SATURATION_RATIO;
>>>>>
>>>>> -    if (of_property_read_u32(np, "exynos,voltage-tolerance",
>>>>> -                                    &bus->voltage_tolerance))
>>>>> -            bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
>>>>> -
>>>>>      return 0;
>>>>> -
>>>>> -err_regulator:
>>>>> -    regulator_disable(bus->regulator);
>>>>> -
>>>>> -    return ret;
>>>>>  }
>>>>>
>>>>>  static int exynos_bus_parse_of(struct exynos_bus *bus)
>>>>> @@ -414,12 +347,8 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>>>>
>>>>>      /* Parse the device-tree to get the resource information */
>>>>>      ret = exynos_bus_parse_of(bus);
>>>>> -    if (ret < 0) {
>>>>> -            if (!passive)
>>>>> -                    regulator_disable(bus->regulator);
>>>>> -
>>>>> -            return ret;
>>>>> -    }
>>>>> +    if (ret < 0)
>>>>> +            goto err_reg;
>>>>>
>>>>>      if (passive)
>>>>>              goto passive;
>>>>> @@ -512,10 +441,12 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>>>>
>>>>>  err:
>>>>>      clk_disable_unprepare(bus->clk);
>>>>> -    if (!passive)
>>>>> -            regulator_disable(bus->regulator);
>>>>> -
>>>>>      dev_pm_opp_of_remove_table(dev);
>>>>
>>>> This function removes the 'opp_table'. But, the below code
>>>> uses the 'opp_table' variable by dev_pm_opp_put_regulators().
>>>>
>>>> To disable the regulator, you have to call dev_pm_opp_of_remove_table(dev)
>>>> after dev_pm_opp_put_regulators(bus->opp_table).
>>>
>>> Regulators should be set before dev_pm_opp_add_table(), so exit sequence
>>> should be in reverse order,
>>>
>>> init order:
>>>
>>> exynos_bus_parent_parse_of()
>>>         dev_pm_opp_set_regulators()
>>> exynos_bus_parse_of()
>>>         clk_prepare_enable()
>>>         dev_pm_opp_of_add_table()
>>>
>>> exit or error order:
>>>
>>> dev_pm_opp_of_remove_table()
>>> clk_disable_unprepare()
>>> if (bus->opp_table)
>>>         dev_pm_opp_put_regulators(bus->opp_table);
>>
>> dev_pm_opp_of_remove_table() have to be called at the end of exit sequence
>> after disabling clock and put regulators. Because dev_pm_opp_of_remove_table()
>> frees the 'opp_table' pointer of device.
>>
>> clk_disable_unprepare()
>> if (bus->opp_table)
>>           dev_pm_opp_put_regulators(bus->opp_table);
>> dev_pm_opp_of_remove_table()
> 
> The table is reference counted so it will be freed after count go to zero.

You're right. I checked it with OPP code.

> 
>>> I will send v4 soon.
>>>
>>>>> +err_reg:
>>>>> +    if (bus->opp_table) {
>>>>> +            dev_pm_opp_put_regulators(bus->opp_table);
>>>>> +            bus->opp_table = NULL;
>>>>> +    }
>>>>>
>>>>>      return ret;
>>>>>  }
>

Patch
diff mbox series

diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index f391044aa39d..c2147b0912a0 100644
--- a/drivers/devfreq/exynos-bus.c
+++ b/drivers/devfreq/exynos-bus.c
@@ -25,7 +25,6 @@ 
 #include <linux/slab.h>
 
 #define DEFAULT_SATURATION_RATIO	40
-#define DEFAULT_VOLTAGE_TOLERANCE	2
 
 struct exynos_bus {
 	struct device *dev;
@@ -37,9 +36,9 @@  struct exynos_bus {
 
 	unsigned long curr_freq;
 
-	struct regulator *regulator;
+	struct opp_table *opp_table;
+
 	struct clk *clk;
-	unsigned int voltage_tolerance;
 	unsigned int ratio;
 };
 
@@ -99,56 +98,23 @@  static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
 {
 	struct exynos_bus *bus = dev_get_drvdata(dev);
 	struct dev_pm_opp *new_opp;
-	unsigned long old_freq, new_freq, new_volt, tol;
 	int ret = 0;
 
-	/* Get new opp-bus instance according to new bus clock */
+	/* Get correct frequency for bus. */
 	new_opp = devfreq_recommended_opp(dev, freq, flags);
 	if (IS_ERR(new_opp)) {
 		dev_err(dev, "failed to get recommended opp instance\n");
 		return PTR_ERR(new_opp);
 	}
 
-	new_freq = dev_pm_opp_get_freq(new_opp);
-	new_volt = dev_pm_opp_get_voltage(new_opp);
 	dev_pm_opp_put(new_opp);
 
-	old_freq = bus->curr_freq;
-
-	if (old_freq == new_freq)
-		return 0;
-	tol = new_volt * bus->voltage_tolerance / 100;
-
 	/* Change voltage and frequency according to new OPP level */
 	mutex_lock(&bus->lock);
+	ret = dev_pm_opp_set_rate(dev, *freq);
+	if (!ret)
+		bus->curr_freq = *freq;
 
-	if (old_freq < new_freq) {
-		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
-		if (ret < 0) {
-			dev_err(bus->dev, "failed to set voltage\n");
-			goto out;
-		}
-	}
-
-	ret = clk_set_rate(bus->clk, new_freq);
-	if (ret < 0) {
-		dev_err(dev, "failed to change clock of bus\n");
-		clk_set_rate(bus->clk, old_freq);
-		goto out;
-	}
-
-	if (old_freq > new_freq) {
-		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
-		if (ret < 0) {
-			dev_err(bus->dev, "failed to set voltage\n");
-			goto out;
-		}
-	}
-	bus->curr_freq = new_freq;
-
-	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
-			old_freq, new_freq, clk_get_rate(bus->clk));
-out:
 	mutex_unlock(&bus->lock);
 
 	return ret;
@@ -195,8 +161,8 @@  static void exynos_bus_exit(struct device *dev)
 		dev_warn(dev, "failed to disable the devfreq-event devices\n");
 
 	clk_disable_unprepare(bus->clk);
-	if (bus->regulator)
-		regulator_disable(bus->regulator);
+	if (bus->opp_table)
+		dev_pm_opp_put_regulators(bus->opp_table);
 
 	dev_pm_opp_of_remove_table(dev);
 }
@@ -209,39 +175,23 @@  static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
 {
 	struct exynos_bus *bus = dev_get_drvdata(dev);
 	struct dev_pm_opp *new_opp;
-	unsigned long old_freq, new_freq;
-	int ret = 0;
+	int ret;
 
-	/* Get new opp-bus instance according to new bus clock */
+	/* Get correct frequency for bus. */
 	new_opp = devfreq_recommended_opp(dev, freq, flags);
 	if (IS_ERR(new_opp)) {
 		dev_err(dev, "failed to get recommended opp instance\n");
 		return PTR_ERR(new_opp);
 	}
 
-	new_freq = dev_pm_opp_get_freq(new_opp);
 	dev_pm_opp_put(new_opp);
 
-	old_freq = bus->curr_freq;
-
-	if (old_freq == new_freq)
-		return 0;
-
 	/* Change the frequency according to new OPP level */
 	mutex_lock(&bus->lock);
+	ret = dev_pm_opp_set_rate(dev, *freq);
+	if (!ret)
+		bus->curr_freq = *freq;
 
-	ret = clk_set_rate(bus->clk, new_freq);
-	if (ret < 0) {
-		dev_err(dev, "failed to set the clock of bus\n");
-		goto out;
-	}
-
-	*freq = new_freq;
-	bus->curr_freq = new_freq;
-
-	dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
-			old_freq, new_freq, clk_get_rate(bus->clk));
-out:
 	mutex_unlock(&bus->lock);
 
 	return ret;
@@ -259,20 +209,9 @@  static int exynos_bus_parent_parse_of(struct device_node *np,
 					struct exynos_bus *bus)
 {
 	struct device *dev = bus->dev;
-	int i, ret, count, size;
-
-	/* Get the regulator to provide each bus with the power */
-	bus->regulator = devm_regulator_get(dev, "vdd");
-	if (IS_ERR(bus->regulator)) {
-		dev_err(dev, "failed to get VDD regulator\n");
-		return PTR_ERR(bus->regulator);
-	}
-
-	ret = regulator_enable(bus->regulator);
-	if (ret < 0) {
-		dev_err(dev, "failed to enable VDD regulator\n");
-		return ret;
-	}
+	struct opp_table *opp_table;
+	const char *vdd = "vdd";
+	int i, count, size;
 
 	/*
 	 * Get the devfreq-event devices to get the current utilization of
@@ -281,26 +220,29 @@  static int exynos_bus_parent_parse_of(struct device_node *np,
 	count = devfreq_event_get_edev_count(dev);
 	if (count < 0) {
 		dev_err(dev, "failed to get the count of devfreq-event dev\n");
-		ret = count;
-		goto err_regulator;
+		return count;
 	}
-	bus->edev_count = count;
 
+	bus->edev_count = count;
 	size = sizeof(*bus->edev) * count;
 	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
-	if (!bus->edev) {
-		ret = -ENOMEM;
-		goto err_regulator;
-	}
+	if (!bus->edev)
+		return -ENOMEM;
 
 	for (i = 0; i < count; i++) {
 		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
-		if (IS_ERR(bus->edev[i])) {
-			ret = -EPROBE_DEFER;
-			goto err_regulator;
-		}
+		if (IS_ERR(bus->edev[i]))
+			return -EPROBE_DEFER;
+	}
+
+	opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
+	if (IS_ERR(opp_table)) {
+		i = PTR_ERR(opp_table);
+		dev_err(dev, "failed to set regulators %d\n", i);
+		return i;
 	}
 
+	bus->opp_table = opp_table;
 	/*
 	 * Optionally, Get the saturation ratio according to Exynos SoC
 	 * When measuring the utilization of each AXI bus with devfreq-event
@@ -314,16 +256,7 @@  static int exynos_bus_parent_parse_of(struct device_node *np,
 	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
 		bus->ratio = DEFAULT_SATURATION_RATIO;
 
-	if (of_property_read_u32(np, "exynos,voltage-tolerance",
-					&bus->voltage_tolerance))
-		bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
-
 	return 0;
-
-err_regulator:
-	regulator_disable(bus->regulator);
-
-	return ret;
 }
 
 static int exynos_bus_parse_of(struct exynos_bus *bus)
@@ -414,12 +347,8 @@  static int exynos_bus_probe(struct platform_device *pdev)
 
 	/* Parse the device-tree to get the resource information */
 	ret = exynos_bus_parse_of(bus);
-	if (ret < 0) {
-		if (!passive)
-			regulator_disable(bus->regulator);
-
-		return ret;
-	}
+	if (ret < 0)
+		goto err_reg;
 
 	if (passive)
 		goto passive;
@@ -512,10 +441,12 @@  static int exynos_bus_probe(struct platform_device *pdev)
 
 err:
 	clk_disable_unprepare(bus->clk);
-	if (!passive)
-		regulator_disable(bus->regulator);
-
 	dev_pm_opp_of_remove_table(dev);
+err_reg:
+	if (bus->opp_table) {
+		dev_pm_opp_put_regulators(bus->opp_table);
+		bus->opp_table = NULL;
+	}
 
 	return ret;
 }