[PATCH 0/3] add coupled regulators for Exynos5422/5800

[PATCH 0/3] add coupled regulators for Exynos5422/5800

[k.konieczny]

From: Kamil Konieczny <k.konieczny@partner.samsung.com>

Hi,

The main purpose of this patch series is to add coupled regulators for
Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
and vdd_int to be at most 300mV. In exynos-bus instead of using
regulator_set_voltage_tol() with default voltage tolerance it should be
used regulator_set_voltage_triplet() with volatege range, and this is
already present in opp/core.c code, so it can be reused. While at this,
move setting regulators into opp/core.

This patchset was tested on Odroid XU3.

The last patch depends on two previous.

Regards,
Kamil

Kamil Konieczny (2):
  opp: core: add regulators enable and disable
  devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

Marek Szyprowski (1):
  ARM: dts: exynos: add initial data for coupled regulators for
    Exynos5422/5800

 arch/arm/boot/dts/exynos5420.dtsi             |  34 ++--
 arch/arm/boot/dts/exynos5422-odroid-core.dtsi |   4 +
 arch/arm/boot/dts/exynos5800-peach-pi.dts     |   4 +
 arch/arm/boot/dts/exynos5800.dtsi             |  32 ++--
 drivers/devfreq/exynos-bus.c                  | 172 +++++++-----------
 drivers/opp/core.c                            |  13 ++
 6 files changed, 120 insertions(+), 139 deletions(-)

-- 
2.22.0

[PATCH 1/3] opp: core: add regulators enable and disable

[k.konieczny]

From: Kamil Konieczny <k.konieczny@partner.samsung.com>

Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). This prepares for
converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().

Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
---
 drivers/opp/core.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 0e7703fe733f..947cac452854 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
 	if (ret)
 		goto free_regulators;
 
+	for (i = 0; i < opp_table->regulator_count; i++) {
+		ret = regulator_enable(opp_table->regulators[i]);
+		if (ret < 0)
+			goto disable;
+	}
+
 	return opp_table;
 
+disable:
+	while (i != 0)
+		regulator_disable(opp_table->regulators[--i]);
+
+	i = opp_table->regulator_count;
 free_regulators:
 	while (i != 0)
 		regulator_put(opp_table->regulators[--i]);
@@ -1609,6 +1620,8 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
 
 	/* Make sure there are no concurrent readers while updating opp_table */
 	WARN_ON(!list_empty(&opp_table->opp_list));
+	for (i = opp_table->regulator_count - 1; i >= 0; i--)
+		regulator_disable(opp_table->regulators[i]);
 
 	for (i = opp_table->regulator_count - 1; i >= 0; i--)
 		regulator_put(opp_table->regulators[i]);
-- 
2.22.0

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Viresh Kumar]

On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
> 
> Add enable regulators to dev_pm_opp_set_regulators() and disable
> regulators to dev_pm_opp_put_regulators(). This prepares for
> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
> 
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
>  drivers/opp/core.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 0e7703fe733f..947cac452854 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>  	if (ret)
>  		goto free_regulators;
>  
> +	for (i = 0; i < opp_table->regulator_count; i++) {
> +		ret = regulator_enable(opp_table->regulators[i]);
> +		if (ret < 0)
> +			goto disable;
> +	}

I am wondering on why is this really required as this isn't done for
any other platform, probably because the regulators are enabled by
bootloader and are always on.

-- 
viresh

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 09.07.2019 07:40, Viresh Kumar wrote:
> On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>
>> Add enable regulators to dev_pm_opp_set_regulators() and disable
>> regulators to dev_pm_opp_put_regulators(). This prepares for
>> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>>
>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>> ---
>>  drivers/opp/core.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>> index 0e7703fe733f..947cac452854 100644
>> --- a/drivers/opp/core.c
>> +++ b/drivers/opp/core.c
>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>  	if (ret)
>>  		goto free_regulators;
>>  
>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>> +		ret = regulator_enable(opp_table->regulators[i]);
>> +		if (ret < 0)
>> +			goto disable;
>> +	}
> 
> I am wondering on why is this really required as this isn't done for
> any other platform, probably because the regulators are enabled by
> bootloader and are always on.

It was not enabled for historical reasons, from design point regualtors
should be enabled before use.

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 10.07.2019 12:16, Kamil Konieczny wrote:
> 
> 
> On 09.07.2019 07:40, Viresh Kumar wrote:
>> On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
>>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>>
>>> Add enable regulators to dev_pm_opp_set_regulators() and disable
>>> regulators to dev_pm_opp_put_regulators(). This prepares for
>>> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>>>
>>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>> ---
>>>  drivers/opp/core.c | 13 +++++++++++++
>>>  1 file changed, 13 insertions(+)
>>>
>>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>>> index 0e7703fe733f..947cac452854 100644
>>> --- a/drivers/opp/core.c
>>> +++ b/drivers/opp/core.c
>>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>>  	if (ret)
>>>  		goto free_regulators;
>>>  
>>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>>> +		ret = regulator_enable(opp_table->regulators[i]);
>>> +		if (ret < 0)
>>> +			goto disable;
>>> +	}
>>
>> I am wondering on why is this really required as this isn't done for
>> any other platform, probably because the regulators are enabled by
>> bootloader and are always on.
> 
> It was not enabled for historical reasons, from design point regualtors
> should be enabled before use.
 
On Exynos platform devfreq driver (exynos-bus) always enabled them,
so I wanted to preserve the current behaviour.

I've also checked the change with cpufreq-dt driver and it doesn't cause
issues.

Do you find this change acceptable?


-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 09.07.2019 07:40, Viresh Kumar wrote:
> On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>
>> Add enable regulators to dev_pm_opp_set_regulators() and disable
>> regulators to dev_pm_opp_put_regulators(). This prepares for
>> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>>
>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>> ---
>>  drivers/opp/core.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>> index 0e7703fe733f..947cac452854 100644
>> --- a/drivers/opp/core.c
>> +++ b/drivers/opp/core.c
>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>  	if (ret)
>>  		goto free_regulators;
>>  
>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>> +		ret = regulator_enable(opp_table->regulators[i]);
>> +		if (ret < 0)
>> +			goto disable;
>> +	}
> 
> I am wondering on why is this really required as this isn't done for
> any other platform, probably because the regulators are enabled by
> bootloader and are always on.

It is not ABI break, it should work with existing DTBs

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 10.07.2019 12:43, Kamil Konieczny wrote:
> On 09.07.2019 07:40, Viresh Kumar wrote:
>> On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
>>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>>
>>> Add enable regulators to dev_pm_opp_set_regulators() and disable
>>> regulators to dev_pm_opp_put_regulators(). This prepares for
>>> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>>>
>>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>> ---
>>>  drivers/opp/core.c | 13 +++++++++++++
>>>  1 file changed, 13 insertions(+)
>>>
>>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>>> index 0e7703fe733f..947cac452854 100644
>>> --- a/drivers/opp/core.c
>>> +++ b/drivers/opp/core.c
>>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>>  	if (ret)
>>>  		goto free_regulators;
>>>  
>>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>>> +		ret = regulator_enable(opp_table->regulators[i]);
>>> +		if (ret < 0)
>>> +			goto disable;
>>> +	}
>>
>> I am wondering on why is this really required as this isn't done for
>> any other platform, probably because the regulators are enabled by
>> bootloader and are always on.
> 
> It is not ABI break, it should work with existing DTBs

Sorry, this answer should go to question by Krzysztof

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Krzysztof Kozlowski]

On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>
> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>
> Add enable regulators to dev_pm_opp_set_regulators() and disable
> regulators to dev_pm_opp_put_regulators(). This prepares for
> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
>  drivers/opp/core.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Viresh Kumar]

On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
> 
> Add enable regulators to dev_pm_opp_set_regulators() and disable
> regulators to dev_pm_opp_put_regulators(). This prepares for
> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
> 
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
>  drivers/opp/core.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 0e7703fe733f..947cac452854 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>  	if (ret)
>  		goto free_regulators;
>  
> +	for (i = 0; i < opp_table->regulator_count; i++) {
> +		ret = regulator_enable(opp_table->regulators[i]);
> +		if (ret < 0)
> +			goto disable;
> +	}

What about doing this in the same loop of regulator_get_optional() ?

> +
>  	return opp_table;
>  
> +disable:
> +	while (i != 0)
> +		regulator_disable(opp_table->regulators[--i]);
> +
> +	i = opp_table->regulator_count;

You also need to call _free_set_opp_data() here.

>  free_regulators:
>  	while (i != 0)
>  		regulator_put(opp_table->regulators[--i]);
> @@ -1609,6 +1620,8 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
>  
>  	/* Make sure there are no concurrent readers while updating opp_table */
>  	WARN_ON(!list_empty(&opp_table->opp_list));

Preserve the blank line here.

> +	for (i = opp_table->regulator_count - 1; i >= 0; i--)
> +		regulator_disable(opp_table->regulators[i]);
>  
>  	for (i = opp_table->regulator_count - 1; i >= 0; i--)
>  		regulator_put(opp_table->regulators[i]);

Only single loop should be sufficient for this.

> -- 
> 2.22.0

-- 
viresh

Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 11.07.2019 08:22, Viresh Kumar wrote:
> On 08-07-19, 16:11, k.konieczny@partner.samsung.com wrote:
>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>
>> Add enable regulators to dev_pm_opp_set_regulators() and disable
>> regulators to dev_pm_opp_put_regulators(). This prepares for
>> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>>
>> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
>> ---
>>  drivers/opp/core.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>> index 0e7703fe733f..947cac452854 100644
>> --- a/drivers/opp/core.c
>> +++ b/drivers/opp/core.c
>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>  	if (ret)
>>  		goto free_regulators;
>>  
>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>> +		ret = regulator_enable(opp_table->regulators[i]);
>> +		if (ret < 0)
>> +			goto disable;
>> +	}
> 
> What about doing this in the same loop of regulator_get_optional() ?

yes, this is good, it will simplify code

>> +
>>  	return opp_table;
>>  
>> +disable:
>> +	while (i != 0)
>> +		regulator_disable(opp_table->regulators[--i]);
>> +
>> +	i = opp_table->regulator_count;
> 
> You also need to call _free_set_opp_data() here.

good catch
if I move enable in loop above, then this will not be needed

>>  free_regulators:
>>  	while (i != 0)
>>  		regulator_put(opp_table->regulators[--i]);
>> @@ -1609,6 +1620,8 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
>>  
>>  	/* Make sure there are no concurrent readers while updating opp_table */
>>  	WARN_ON(!list_empty(&opp_table->opp_list));
> 
> Preserve the blank line here.
> 
>> +	for (i = opp_table->regulator_count - 1; i >= 0; i--)
>> +		regulator_disable(opp_table->regulators[i]);
>>  
>>  	for (i = opp_table->regulator_count - 1; i >= 0; i--)
>>  		regulator_put(opp_table->regulators[i]);
> 
> Only single loop should be sufficient for this.

you are right, I will do this in single loop

I will send v2

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

[PATCH 2/3] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

[k.konieczny]

From: Kamil Konieczny <k.konieczny@partner.samsung.com>

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 | 172 ++++++++++++++---------------------
 1 file changed, 66 insertions(+), 106 deletions(-)

diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index 486cc5b422f1..7fc4f76bd848 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 +98,25 @@ 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 */
+	/*
+	 * New frequency for bus may not be exactly matched to opp, adjust
+	 * *freq to correct value.
+	 */
 	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;
@@ -194,10 +162,11 @@ static void exynos_bus_exit(struct device *dev)
 	if (ret < 0)
 		dev_warn(dev, "failed to disable the devfreq-event devices\n");
 
-	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);
+
 	clk_disable_unprepare(bus->clk);
 }
 
@@ -209,39 +178,26 @@ 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 */
+	/*
+	 * New frequency for bus may not be exactly matched to opp, adjust
+	 * *freq to correct value.
+	 */
 	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 +215,7 @@ 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;
-	}
+	int i, count, size;
 
 	/*
 	 * Get the devfreq-event devices to get the current utilization of
@@ -281,24 +224,20 @@ 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;
 
 	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;
 	}
 
 	/*
@@ -314,22 +253,15 @@ 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 device_node *np,
-			      struct exynos_bus *bus)
+			      struct exynos_bus *bus, bool passive)
 {
 	struct device *dev = bus->dev;
+	struct opp_table *opp_table;
+	const char *vdd = "vdd";
 	struct dev_pm_opp *opp;
 	unsigned long rate;
 	int ret;
@@ -347,11 +279,22 @@ static int exynos_bus_parse_of(struct device_node *np,
 		return ret;
 	}
 
+	if (!passive) {
+		opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
+		if (IS_ERR(opp_table)) {
+			ret = PTR_ERR(opp_table);
+			dev_err(dev, "failed to set regulators %d\n", ret);
+			goto err_clk;
+		}
+
+		bus->opp_table = opp_table;
+	}
+
 	/* Get the freq and voltage from OPP table to scale the bus freq */
 	ret = dev_pm_opp_of_add_table(dev);
 	if (ret < 0) {
 		dev_err(dev, "failed to get OPP table\n");
-		goto err_clk;
+		goto err_regulator;
 	}
 
 	rate = clk_get_rate(bus->clk);
@@ -362,6 +305,7 @@ static int exynos_bus_parse_of(struct device_node *np,
 		ret = PTR_ERR(opp);
 		goto err_opp;
 	}
+
 	bus->curr_freq = dev_pm_opp_get_freq(opp);
 	dev_pm_opp_put(opp);
 
@@ -369,6 +313,13 @@ static int exynos_bus_parse_of(struct device_node *np,
 
 err_opp:
 	dev_pm_opp_of_remove_table(dev);
+
+err_regulator:
+	if (bus->opp_table) {
+		dev_pm_opp_put_regulators(bus->opp_table);
+		bus->opp_table = NULL;
+	}
+
 err_clk:
 	clk_disable_unprepare(bus->clk);
 
@@ -386,6 +337,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
 	struct exynos_bus *bus;
 	int ret, max_state;
 	unsigned long min_freq, max_freq;
+	bool passive = false;
 
 	if (!np) {
 		dev_err(dev, "failed to find devicetree node\n");
@@ -395,12 +347,18 @@ static int exynos_bus_probe(struct platform_device *pdev)
 	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
 	if (!bus)
 		return -ENOMEM;
+
 	mutex_init(&bus->lock);
 	bus->dev = &pdev->dev;
 	platform_set_drvdata(pdev, bus);
+	node = of_parse_phandle(dev->of_node, "devfreq", 0);
+	if (node) {
+		of_node_put(node);
+		passive = true;
+	}
 
 	/* Parse the device-tree to get the resource information */
-	ret = exynos_bus_parse_of(np, bus);
+	ret = exynos_bus_parse_of(np, bus, passive);
 	if (ret < 0)
 		return ret;
 
@@ -410,13 +368,10 @@ static int exynos_bus_probe(struct platform_device *pdev)
 		goto err;
 	}
 
-	node = of_parse_phandle(dev->of_node, "devfreq", 0);
-	if (node) {
-		of_node_put(node);
+	if (passive)
 		goto passive;
-	} else {
-		ret = exynos_bus_parent_parse_of(np, bus);
-	}
+
+	ret = exynos_bus_parent_parse_of(np, bus);
 
 	if (ret < 0)
 		goto err;
@@ -509,6 +464,11 @@ static int exynos_bus_probe(struct platform_device *pdev)
 
 err:
 	dev_pm_opp_of_remove_table(dev);
+	if (bus->opp_table) {
+		dev_pm_opp_put_regulators(bus->opp_table);
+		bus->opp_table = NULL;
+	}
+
 	clk_disable_unprepare(bus->clk);
 
 	return ret;
-- 
2.22.0

Re: [PATCH 2/3] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

[Krzysztof Kozlowski]

On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>
> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>
> 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

Please also update the bindings in such case. Both with removal of
unused property and with example/recommended regulator couplings.

Best regards,
Krzysztof

Re: [PATCH 2/3] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

[Kamil Konieczny]

On 10.07.2019 19:04, Krzysztof Kozlowski wrote:
> On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>>
>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>
>> 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
> 
> Please also update the bindings in such case. Both with removal of
> unused property and with example/recommended regulator couplings.

Right, I will remove it.

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

[PATCH 3/3] ARM: dts: exynos: add initial data for coupled regulators for Exynos5422/5800

[k.konieczny]

From: Marek Szyprowski <m.szyprowski@samsung.com>

Declare Exynos5422/5800 voltage ranges for opp points for big cpu core and
bus wcore and couple their voltage supllies as vdd_arm and vdd_int should
be in 300mV range.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
---
 arch/arm/boot/dts/exynos5420.dtsi             | 34 +++++++++----------
 arch/arm/boot/dts/exynos5422-odroid-core.dtsi |  4 +++
 arch/arm/boot/dts/exynos5800-peach-pi.dts     |  4 +++
 arch/arm/boot/dts/exynos5800.dtsi             | 32 ++++++++---------
 4 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 5fb2326875dc..0cbf74750553 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -48,62 +48,62 @@
 			opp-shared;
 			opp-1800000000 {
 				opp-hz = /bits/ 64 <1800000000>;
-				opp-microvolt = <1250000>;
+				opp-microvolt = <1250000 1250000 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1700000000 {
 				opp-hz = /bits/ 64 <1700000000>;
-				opp-microvolt = <1212500>;
+				opp-microvolt = <1212500 1212500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1600000000 {
 				opp-hz = /bits/ 64 <1600000000>;
-				opp-microvolt = <1175000>;
+				opp-microvolt = <1175000 1175000 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1500000000 {
 				opp-hz = /bits/ 64 <1500000000>;
-				opp-microvolt = <1137500>;
+				opp-microvolt = <1137500 1137500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1400000000 {
 				opp-hz = /bits/ 64 <1400000000>;
-				opp-microvolt = <1112500>;
+				opp-microvolt = <1112500 1112500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1300000000 {
 				opp-hz = /bits/ 64 <1300000000>;
-				opp-microvolt = <1062500>;
+				opp-microvolt = <1062500 1062500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1200000000 {
 				opp-hz = /bits/ 64 <1200000000>;
-				opp-microvolt = <1037500>;
+				opp-microvolt = <1037500 1037500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1100000000 {
 				opp-hz = /bits/ 64 <1100000000>;
-				opp-microvolt = <1012500>;
+				opp-microvolt = <1012500 1012500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-1000000000 {
 				opp-hz = /bits/ 64 <1000000000>;
-				opp-microvolt = < 987500>;
+				opp-microvolt = < 987500 987500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-900000000 {
 				opp-hz = /bits/ 64 <900000000>;
-				opp-microvolt = < 962500>;
+				opp-microvolt = < 962500 962500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-800000000 {
 				opp-hz = /bits/ 64 <800000000>;
-				opp-microvolt = < 937500>;
+				opp-microvolt = < 937500 937500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 			opp-700000000 {
 				opp-hz = /bits/ 64 <700000000>;
-				opp-microvolt = < 912500>;
+				opp-microvolt = < 912500 912500 1500000>;
 				clock-latency-ns = <140000>;
 			};
 		};
@@ -1100,23 +1100,23 @@
 
 			opp00 {
 				opp-hz = /bits/ 64 <84000000>;
-				opp-microvolt = <925000>;
+				opp-microvolt = <925000 925000 1400000>;
 			};
 			opp01 {
 				opp-hz = /bits/ 64 <111000000>;
-				opp-microvolt = <950000>;
+				opp-microvolt = <950000 950000 1400000>;
 			};
 			opp02 {
 				opp-hz = /bits/ 64 <222000000>;
-				opp-microvolt = <950000>;
+				opp-microvolt = <950000 950000 1400000>;
 			};
 			opp03 {
 				opp-hz = /bits/ 64 <333000000>;
-				opp-microvolt = <950000>;
+				opp-microvolt = <950000 950000 1400000>;
 			};
 			opp04 {
 				opp-hz = /bits/ 64 <400000000>;
-				opp-microvolt = <987500>;
+				opp-microvolt = <987500 987500 1400000>;
 			};
 		};
 
diff --git a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
index 25d95de15c9b..65d094256b54 100644
--- a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
+++ b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
@@ -428,6 +428,8 @@
 				regulator-max-microvolt = <1500000>;
 				regulator-always-on;
 				regulator-boot-on;
+				regulator-coupled-with = <&buck3_reg>;
+				regulator-coupled-max-spread = <300000>;
 			};
 
 			buck3_reg: BUCK3 {
@@ -436,6 +438,8 @@
 				regulator-max-microvolt = <1400000>;
 				regulator-always-on;
 				regulator-boot-on;
+				regulator-coupled-with = <&buck2_reg>;
+				regulator-coupled-max-spread = <300000>;
 			};
 
 			buck4_reg: BUCK4 {
diff --git a/arch/arm/boot/dts/exynos5800-peach-pi.dts b/arch/arm/boot/dts/exynos5800-peach-pi.dts
index e0f470fe54c8..5c1e965ed7e9 100644
--- a/arch/arm/boot/dts/exynos5800-peach-pi.dts
+++ b/arch/arm/boot/dts/exynos5800-peach-pi.dts
@@ -257,6 +257,8 @@
 				regulator-always-on;
 				regulator-boot-on;
 				regulator-ramp-delay = <12500>;
+				regulator-coupled-with = <&buck3_reg>;
+				regulator-coupled-max-spread = <300000>;
 				regulator-state-mem {
 					regulator-off-in-suspend;
 				};
@@ -269,6 +271,8 @@
 				regulator-always-on;
 				regulator-boot-on;
 				regulator-ramp-delay = <12500>;
+				regulator-coupled-with = <&buck2_reg>;
+				regulator-coupled-max-spread = <300000>;
 				regulator-state-mem {
 					regulator-off-in-suspend;
 				};
diff --git a/arch/arm/boot/dts/exynos5800.dtsi b/arch/arm/boot/dts/exynos5800.dtsi
index 57d3b319fd65..2a74735d161c 100644
--- a/arch/arm/boot/dts/exynos5800.dtsi
+++ b/arch/arm/boot/dts/exynos5800.dtsi
@@ -22,61 +22,61 @@
 
 &cluster_a15_opp_table {
 	opp-1700000000 {
-		opp-microvolt = <1250000>;
+		opp-microvolt = <1250000 1250000 1500000>;
 	};
 	opp-1600000000 {
-		opp-microvolt = <1250000>;
+		opp-microvolt = <1250000 1250000 1500000>;
 	};
 	opp-1500000000 {
-		opp-microvolt = <1100000>;
+		opp-microvolt = <1100000 1100000 1500000>;
 	};
 	opp-1400000000 {
-		opp-microvolt = <1100000>;
+		opp-microvolt = <1100000 1100000 1500000>;
 	};
 	opp-1300000000 {
-		opp-microvolt = <1100000>;
+		opp-microvolt = <1100000 1100000 1500000>;
 	};
 	opp-1200000000 {
-		opp-microvolt = <1000000>;
+		opp-microvolt = <1000000 1000000 1500000>;
 	};
 	opp-1100000000 {
-		opp-microvolt = <1000000>;
+		opp-microvolt = <1000000 1000000 1500000>;
 	};
 	opp-1000000000 {
-		opp-microvolt = <1000000>;
+		opp-microvolt = <1000000 1000000 1500000>;
 	};
 	opp-900000000 {
-		opp-microvolt = <1000000>;
+		opp-microvolt = <1000000 1000000 1500000>;
 	};
 	opp-800000000 {
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 	};
 	opp-700000000 {
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 	};
 	opp-600000000 {
 		opp-hz = /bits/ 64 <600000000>;
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 		clock-latency-ns = <140000>;
 	};
 	opp-500000000 {
 		opp-hz = /bits/ 64 <500000000>;
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 		clock-latency-ns = <140000>;
 	};
 	opp-400000000 {
 		opp-hz = /bits/ 64 <400000000>;
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 		clock-latency-ns = <140000>;
 	};
 	opp-300000000 {
 		opp-hz = /bits/ 64 <300000000>;
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 		clock-latency-ns = <140000>;
 	};
 	opp-200000000 {
 		opp-hz = /bits/ 64 <200000000>;
-		opp-microvolt = <900000>;
+		opp-microvolt = <900000 900000 1500000>;
 		clock-latency-ns = <140000>;
 	};
 };
-- 
2.22.0

Re: [PATCH 3/3] ARM: dts: exynos: add initial data for coupled regulators for Exynos5422/5800

[Krzysztof Kozlowski]

On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>
> From: Marek Szyprowski <m.szyprowski@samsung.com>
>
> Declare Exynos5422/5800 voltage ranges for opp points for big cpu core and
> bus wcore and couple their voltage supllies as vdd_arm and vdd_int should
> be in 300mV range.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
>  arch/arm/boot/dts/exynos5420.dtsi             | 34 +++++++++----------
>  arch/arm/boot/dts/exynos5422-odroid-core.dtsi |  4 +++
>  arch/arm/boot/dts/exynos5800-peach-pi.dts     |  4 +++
>  arch/arm/boot/dts/exynos5800.dtsi             | 32 ++++++++---------
>  4 files changed, 41 insertions(+), 33 deletions(-)

Looks good, I assume bisectability is not affected, because of
dependency on the driver changes I will take it for next next release
(v5.5). Assuming that driver change goes into v5.4.

Best regards,
Krzysztof

Re: [PATCH 0/3] add coupled regulators for Exynos5422/5800

[Krzysztof Kozlowski]

On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>
> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>
> Hi,
>
> The main purpose of this patch series is to add coupled regulators for
> Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
> and vdd_int to be at most 300mV. In exynos-bus instead of using
> regulator_set_voltage_tol() with default voltage tolerance it should be
> used regulator_set_voltage_triplet() with volatege range, and this is
> already present in opp/core.c code, so it can be reused. While at this,
> move setting regulators into opp/core.
>
> This patchset was tested on Odroid XU3.
>
> The last patch depends on two previous.

So you break the ABI... I assume that patchset maintains
bisectability. However there is no explanation why ABI break is needed
so this does not look good...

Best regards,
Krzysztof

>
> Regards,
> Kamil
>
> Kamil Konieczny (2):
>   opp: core: add regulators enable and disable
>   devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()
>
> Marek Szyprowski (1):
>   ARM: dts: exynos: add initial data for coupled regulators for
>     Exynos5422/5800
>
>  arch/arm/boot/dts/exynos5420.dtsi             |  34 ++--
>  arch/arm/boot/dts/exynos5422-odroid-core.dtsi |   4 +
>  arch/arm/boot/dts/exynos5800-peach-pi.dts     |   4 +
>  arch/arm/boot/dts/exynos5800.dtsi             |  32 ++--
>  drivers/devfreq/exynos-bus.c                  | 172 +++++++-----------
>  drivers/opp/core.c                            |  13 ++
>  6 files changed, 120 insertions(+), 139 deletions(-)
>
> --
> 2.22.0
>

Re: [PATCH 0/3] add coupled regulators for Exynos5422/5800

[Kamil Konieczny]

On 10.07.2019 11:00, Krzysztof Kozlowski wrote:
> On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>>
>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>
>> Hi,
>>
>> The main purpose of this patch series is to add coupled regulators for
>> Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
>> and vdd_int to be at most 300mV. In exynos-bus instead of using
>> regulator_set_voltage_tol() with default voltage tolerance it should be
>> used regulator_set_voltage_triplet() with volatege range, and this is
>> already present in opp/core.c code, so it can be reused. While at this,
>> move setting regulators into opp/core.
>>
>> This patchset was tested on Odroid XU3.
>>
>> The last patch depends on two previous.
> 
> So you break the ABI... I assume that patchset maintains
> bisectability. However there is no explanation why ABI break is needed
> so this does not look good...

Patchset is bisectable, first one is simple and do not depends on others,
second depends on first, last depends on first and second.

What do you mean by breaking ABI ?

> Best regards,
> Krzysztof
> 
>>
>> Regards,
>> Kamil
>>
>> Kamil Konieczny (2):
>>   opp: core: add regulators enable and disable
>>   devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()
>>
>> Marek Szyprowski (1):
>>   ARM: dts: exynos: add initial data for coupled regulators for
>>     Exynos5422/5800
>>
>>  arch/arm/boot/dts/exynos5420.dtsi             |  34 ++--
>>  arch/arm/boot/dts/exynos5422-odroid-core.dtsi |   4 +
>>  arch/arm/boot/dts/exynos5800-peach-pi.dts     |   4 +
>>  arch/arm/boot/dts/exynos5800.dtsi             |  32 ++--
>>  drivers/devfreq/exynos-bus.c                  | 172 +++++++-----------
>>  drivers/opp/core.c                            |  13 ++
>>  6 files changed, 120 insertions(+), 139 deletions(-)
>>
>> --
>> 2.22.0

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 0/3] add coupled regulators for Exynos5422/5800

[Krzysztof Kozlowski]

On Wed, 10 Jul 2019 at 12:03, Kamil Konieczny
<k.konieczny@partner.samsung.com> wrote:
>
> On 10.07.2019 11:00, Krzysztof Kozlowski wrote:
> > On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
> >>
> >> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
> >>
> >> Hi,
> >>
> >> The main purpose of this patch series is to add coupled regulators for
> >> Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
> >> and vdd_int to be at most 300mV. In exynos-bus instead of using
> >> regulator_set_voltage_tol() with default voltage tolerance it should be
> >> used regulator_set_voltage_triplet() with volatege range, and this is
> >> already present in opp/core.c code, so it can be reused. While at this,
> >> move setting regulators into opp/core.
> >>
> >> This patchset was tested on Odroid XU3.
> >>
> >> The last patch depends on two previous.
> >
> > So you break the ABI... I assume that patchset maintains
> > bisectability. However there is no explanation why ABI break is needed
> > so this does not look good...
>
> Patchset is bisectable, first one is simple and do not depends on others,
> second depends on first, last depends on first and second.
>
> What do you mean by breaking ABI ?

I mean, that Linux kernel stops working with existing DTBs... or am I
mistaken and there is no problem? Maybe I confused the order...

Best regards,
Krzysztof

Re: [PATCH 0/3] add coupled regulators for Exynos5422/5800

[Kamil Konieczny]

On 10.07.2019 12:14, Krzysztof Kozlowski wrote:
> On Wed, 10 Jul 2019 at 12:03, Kamil Konieczny
> <k.konieczny@partner.samsung.com> wrote:
>>
>> On 10.07.2019 11:00, Krzysztof Kozlowski wrote:
>>> On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
>>>>
>>>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
>>>>
>>>> Hi,
>>>>
>>>> The main purpose of this patch series is to add coupled regulators for
>>>> Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
>>>> and vdd_int to be at most 300mV. In exynos-bus instead of using
>>>> regulator_set_voltage_tol() with default voltage tolerance it should be
>>>> used regulator_set_voltage_triplet() with volatege range, and this is
>>>> already present in opp/core.c code, so it can be reused. While at this,
>>>> move setting regulators into opp/core.
>>>>
>>>> This patchset was tested on Odroid XU3.
>>>>
>>>> The last patch depends on two previous.
>>>
>>> So you break the ABI... I assume that patchset maintains
>>> bisectability. However there is no explanation why ABI break is needed
>>> so this does not look good...
>>
>> Patchset is bisectable, first one is simple and do not depends on others,
>> second depends on first, last depends on first and second.
>>
>> What do you mean by breaking ABI ?
> 
> I mean, that Linux kernel stops working with existing DTBs... or am I
> mistaken and there is no problem? Maybe I confused the order...

It is not ABI break, it should work with existing DTBs

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland

Re: [PATCH 0/3] add coupled regulators for Exynos5422/5800

[Krzysztof Kozlowski]

On Wed, 10 Jul 2019 at 15:51, Kamil Konieczny
<k.konieczny@partner.samsung.com> wrote:
>
> On 10.07.2019 12:14, Krzysztof Kozlowski wrote:
> > On Wed, 10 Jul 2019 at 12:03, Kamil Konieczny
> > <k.konieczny@partner.samsung.com> wrote:
> >>
> >> On 10.07.2019 11:00, Krzysztof Kozlowski wrote:
> >>> On Mon, 8 Jul 2019 at 16:12, <k.konieczny@partner.samsung.com> wrote:
> >>>>
> >>>> From: Kamil Konieczny <k.konieczny@partner.samsung.com>
> >>>>
> >>>> Hi,
> >>>>
> >>>> The main purpose of this patch series is to add coupled regulators for
> >>>> Exynos5422/5800 to keep constrain on voltage difference between vdd_arm
> >>>> and vdd_int to be at most 300mV. In exynos-bus instead of using
> >>>> regulator_set_voltage_tol() with default voltage tolerance it should be
> >>>> used regulator_set_voltage_triplet() with volatege range, and this is
> >>>> already present in opp/core.c code, so it can be reused. While at this,
> >>>> move setting regulators into opp/core.
> >>>>
> >>>> This patchset was tested on Odroid XU3.
> >>>>
> >>>> The last patch depends on two previous.
> >>>
> >>> So you break the ABI... I assume that patchset maintains
> >>> bisectability. However there is no explanation why ABI break is needed
> >>> so this does not look good...
> >>
> >> Patchset is bisectable, first one is simple and do not depends on others,
> >> second depends on first, last depends on first and second.
> >>
> >> What do you mean by breaking ABI ?
> >
> > I mean, that Linux kernel stops working with existing DTBs... or am I
> > mistaken and there is no problem? Maybe I confused the order...
>
> It is not ABI break, it should work with existing DTBs

Ah, thanks. My misunderstanding then. Looks good.

Best regards,
Krzysztof