[PATCH 1/3] mfd: sec-core: Dump PMIC revision to find out the HW

[PATCH 1/3] mfd: sec-core: Dump PMIC revision to find out the HW

[Krzysztof Kozlowski]

There are different revisions of the same chipset. For example S2MPS13 has
more than 2 revisions. They differ slightly in regulator constraints.
Print the revision number to easily find which PMIC is used on the board.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
 drivers/mfd/sec-core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
index 2d1137a7a0ee..589e5efc2d7f 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -253,6 +253,15 @@ static const struct regmap_config s5m8767_regmap_config = {
 	.cache_type = REGCACHE_FLAT,
 };
 
+static void sec_pmic_dump_rev(struct sec_pmic_dev *sec_pmic)
+{
+	unsigned int val;
+
+	/* For each device type, the REG_ID is always the first register */
+	if (!regmap_read(sec_pmic->regmap_pmic, S2MPS11_REG_ID, &val))
+		dev_dbg(sec_pmic->dev, "Revision: 0x%x\n", val);
+}
+
 #ifdef CONFIG_OF
 /*
  * Only the common platform data elements for s5m8767 are parsed here from the
@@ -425,6 +434,7 @@ static int sec_pmic_probe(struct i2c_client *i2c,
 		goto err_mfd;
 
 	device_init_wakeup(sec_pmic->dev, sec_pmic->wakeup);
+	sec_pmic_dump_rev(sec_pmic);
 
 	return ret;
 
-- 
1.9.1

[PATCH 2/3] mfd: dt-bindings: Document pulled down WRSTBI pin on S2MPS1X

[Krzysztof Kozlowski]

Document a new Device Tree property 'samsung,s2mps11-wrstbi-ground'
indicating that WRSTBI pin of S2MPS13 PMIC is pulled down so
corresponding buck warm reset function should be disabled.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
 Documentation/devicetree/bindings/mfd/s2mps11.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/s2mps11.txt b/Documentation/devicetree/bindings/mfd/s2mps11.txt
index 90eaef393325..890f0b0e1643 100644
--- a/Documentation/devicetree/bindings/mfd/s2mps11.txt
+++ b/Documentation/devicetree/bindings/mfd/s2mps11.txt
@@ -19,6 +19,9 @@ Optional properties:
   connected to the ground so the PMIC must manually set PWRHOLD bit in CTRL1
   register to turn off the power. Usually the ACOKB is pulled up to VBATT so
   when PWRHOLD pin goes low, the rising ACOKB will trigger power off.
+- samsung,s2mps11-wrstbi-ground: Indicates that WRSTBI pin of PMIC is pulled
+  down. When the system is suspended it will always go down thus triggerring
+  unwanted buck warm reset (setting buck voltages to default values).
 
 Optional nodes:
 - clocks: s2mps11, s2mps13 and s5m8767 provide three(AP/CP/BT) buffered 32.768
-- 
1.9.1

[PATCH 3/3] mfd: sec-core: Disable buck voltage reset on watchdog falling edge

[Krzysztof Kozlowski]

The WRSTBI bit (disabled by default but enabled by bootloader), when
set, is responsible for resetting voltages to default values of
certain bucks on falling edge of Warm Reset Input pin from AP.

However on some boards (with S2MPS13) the pin is pulled down so any
suspend will effectively trigger the reset of bucks supplying the power
to the little and big cores. In the same time when resuming, these bucks
must provide voltage greater or equal to voltage before suspend to match
the frequency chosen by cpufreq. If voltage (default value of voltage
after reset) is lower than one set by cpufreq before suspend, then
system will hang during resuming.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
 drivers/mfd/sec-core.c              | 26 ++++++++++++++++++++++++++
 include/linux/mfd/samsung/core.h    |  2 ++
 include/linux/mfd/samsung/s2mps13.h |  1 +
 3 files changed, 29 insertions(+)

diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
index 589e5efc2d7f..2626fc0b5b8c 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -262,6 +262,29 @@ static void sec_pmic_dump_rev(struct sec_pmic_dev *sec_pmic)
 		dev_dbg(sec_pmic->dev, "Revision: 0x%x\n", val);
 }
 
+static void sec_pmic_configure(struct sec_pmic_dev *sec_pmic)
+{
+	int err;
+
+	if (sec_pmic->device_type != S2MPS13X)
+		return;
+
+	if (sec_pmic->pdata->disable_wrstbi) {
+		/*
+		 * If WRSTBI pin is pulled down this feature must be disabled
+		 * because each Suspend to RAM will trigger buck voltage reset
+		 * to default values.
+		 */
+		err = regmap_update_bits(sec_pmic->regmap_pmic,
+					 S2MPS13_REG_WRSTBI,
+					 S2MPS13_REG_WRSTBI_MASK, 0x0);
+		if (err)
+			dev_warn(sec_pmic->dev,
+				 "Cannot initialize WRSTBI config: %d\n",
+				 err);
+	}
+}
+
 #ifdef CONFIG_OF
 /*
  * Only the common platform data elements for s5m8767 are parsed here from the
@@ -289,6 +312,8 @@ static struct sec_platform_data *sec_pmic_i2c_parse_dt_pdata(
 
 	pd->manual_poweroff = of_property_read_bool(dev->of_node,
 						"samsung,s2mps11-acokb-ground");
+	pd->disable_wrstbi = of_property_read_bool(dev->of_node,
+						"samsung,s2mps11-wrstbi-ground");
 	return pd;
 }
 #else
@@ -434,6 +459,7 @@ static int sec_pmic_probe(struct i2c_client *i2c,
 		goto err_mfd;
 
 	device_init_wakeup(sec_pmic->dev, sec_pmic->wakeup);
+	sec_pmic_configure(sec_pmic);
 	sec_pmic_dump_rev(sec_pmic);
 
 	return ret;
diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h
index aa78957e092f..a06098639399 100644
--- a/include/linux/mfd/samsung/core.h
+++ b/include/linux/mfd/samsung/core.h
@@ -134,6 +134,8 @@ struct sec_platform_data {
 	int				buck4_init;
 	/* Whether or not manually set PWRHOLD to low during shutdown. */
 	bool				manual_poweroff;
+	/* Disable the WRSTBI (buck voltage warm reset) when probing? */
+	bool				disable_wrstbi;
 };
 
 /**
diff --git a/include/linux/mfd/samsung/s2mps13.h b/include/linux/mfd/samsung/s2mps13.h
index b1fd675fa36f..239e977ba45d 100644
--- a/include/linux/mfd/samsung/s2mps13.h
+++ b/include/linux/mfd/samsung/s2mps13.h
@@ -184,5 +184,6 @@ enum s2mps13_regulators {
  * Let's assume that default value will be set.
  */
 #define S2MPS13_BUCK_RAMP_DELAY		12500
+#define S2MPS13_REG_WRSTBI_MASK		BIT(5)
 
 #endif /*  __LINUX_MFD_S2MPS13_H */
-- 
1.9.1

Re: [PATCH 3/3] mfd: sec-core: Disable buck voltage reset on watchdog falling edge

[Bartlomiej Zolnierkiewicz]

Hi,

On Friday, October 02, 2015 05:25:51 PM Krzysztof Kozlowski wrote:
> The WRSTBI bit (disabled by default but enabled by bootloader), when
> set, is responsible for resetting voltages to default values of
> certain bucks on falling edge of Warm Reset Input pin from AP.
> 
> However on some boards (with S2MPS13) the pin is pulled down so any
> suspend will effectively trigger the reset of bucks supplying the power
> to the little and big cores. In the same time when resuming, these bucks
> must provide voltage greater or equal to voltage before suspend to match
> the frequency chosen by cpufreq. If voltage (default value of voltage
> after reset) is lower than one set by cpufreq before suspend, then
> system will hang during resuming.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

I tested this (with some additional Exynos5433 patches) and it works
like expected (suspend/resume issue is fixed).

Tested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

You could also add:

Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

(since the issue got narrowed down and reported to you by me :).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> ---
>  drivers/mfd/sec-core.c              | 26 ++++++++++++++++++++++++++
>  include/linux/mfd/samsung/core.h    |  2 ++
>  include/linux/mfd/samsung/s2mps13.h |  1 +
>  3 files changed, 29 insertions(+)
> 
> diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
> index 589e5efc2d7f..2626fc0b5b8c 100644
> --- a/drivers/mfd/sec-core.c
> +++ b/drivers/mfd/sec-core.c
> @@ -262,6 +262,29 @@ static void sec_pmic_dump_rev(struct sec_pmic_dev *sec_pmic)
>  		dev_dbg(sec_pmic->dev, "Revision: 0x%x\n", val);
>  }
>  
> +static void sec_pmic_configure(struct sec_pmic_dev *sec_pmic)
> +{
> +	int err;
> +
> +	if (sec_pmic->device_type != S2MPS13X)
> +		return;
> +
> +	if (sec_pmic->pdata->disable_wrstbi) {
> +		/*
> +		 * If WRSTBI pin is pulled down this feature must be disabled
> +		 * because each Suspend to RAM will trigger buck voltage reset
> +		 * to default values.
> +		 */
> +		err = regmap_update_bits(sec_pmic->regmap_pmic,
> +					 S2MPS13_REG_WRSTBI,
> +					 S2MPS13_REG_WRSTBI_MASK, 0x0);
> +		if (err)
> +			dev_warn(sec_pmic->dev,
> +				 "Cannot initialize WRSTBI config: %d\n",
> +				 err);
> +	}
> +}
> +
>  #ifdef CONFIG_OF
>  /*
>   * Only the common platform data elements for s5m8767 are parsed here from the
> @@ -289,6 +312,8 @@ static struct sec_platform_data *sec_pmic_i2c_parse_dt_pdata(
>  
>  	pd->manual_poweroff = of_property_read_bool(dev->of_node,
>  						"samsung,s2mps11-acokb-ground");
> +	pd->disable_wrstbi = of_property_read_bool(dev->of_node,
> +						"samsung,s2mps11-wrstbi-ground");
>  	return pd;
>  }
>  #else
> @@ -434,6 +459,7 @@ static int sec_pmic_probe(struct i2c_client *i2c,
>  		goto err_mfd;
>  
>  	device_init_wakeup(sec_pmic->dev, sec_pmic->wakeup);
> +	sec_pmic_configure(sec_pmic);
>  	sec_pmic_dump_rev(sec_pmic);
>  
>  	return ret;
> diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h
> index aa78957e092f..a06098639399 100644
> --- a/include/linux/mfd/samsung/core.h
> +++ b/include/linux/mfd/samsung/core.h
> @@ -134,6 +134,8 @@ struct sec_platform_data {
>  	int				buck4_init;
>  	/* Whether or not manually set PWRHOLD to low during shutdown. */
>  	bool				manual_poweroff;
> +	/* Disable the WRSTBI (buck voltage warm reset) when probing? */
> +	bool				disable_wrstbi;
>  };
>  
>  /**
> diff --git a/include/linux/mfd/samsung/s2mps13.h b/include/linux/mfd/samsung/s2mps13.h
> index b1fd675fa36f..239e977ba45d 100644
> --- a/include/linux/mfd/samsung/s2mps13.h
> +++ b/include/linux/mfd/samsung/s2mps13.h
> @@ -184,5 +184,6 @@ enum s2mps13_regulators {
>   * Let's assume that default value will be set.
>   */
>  #define S2MPS13_BUCK_RAMP_DELAY		12500
> +#define S2MPS13_REG_WRSTBI_MASK		BIT(5)
>  
>  #endif /*  __LINUX_MFD_S2MPS13_H */

Re: [PATCH 3/3] mfd: sec-core: Disable buck voltage reset on watchdog falling edge

[Bartlomiej Zolnierkiewicz]

Hi,

On Friday, October 02, 2015 05:25:51 PM Krzysztof Kozlowski wrote:
> The WRSTBI bit (disabled by default but enabled by bootloader), when
> set, is responsible for resetting voltages to default values of
> certain bucks on falling edge of Warm Reset Input pin from AP.
> 
> However on some boards (with S2MPS13) the pin is pulled down so any
> suspend will effectively trigger the reset of bucks supplying the power
> to the little and big cores. In the same time when resuming, these bucks
> must provide voltage greater or equal to voltage before suspend to match
> the frequency chosen by cpufreq. If voltage (default value of voltage
> after reset) is lower than one set by cpufreq before suspend, then
> system will hang during resuming.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

I tested this (with some additional Exynos5433 patches) and it works
like expected (suspend/resume issue is fixed).

Tested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

You could also add:

Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

(since the issue got narrowed down and reported to you by me :).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> ---
>  drivers/mfd/sec-core.c              | 26 ++++++++++++++++++++++++++
>  include/linux/mfd/samsung/core.h    |  2 ++
>  include/linux/mfd/samsung/s2mps13.h |  1 +
>  3 files changed, 29 insertions(+)
> 
> diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
> index 589e5efc2d7f..2626fc0b5b8c 100644
> --- a/drivers/mfd/sec-core.c
> +++ b/drivers/mfd/sec-core.c
> @@ -262,6 +262,29 @@ static void sec_pmic_dump_rev(struct sec_pmic_dev *sec_pmic)
>  		dev_dbg(sec_pmic->dev, "Revision: 0x%x\n", val);
>  }
>  
> +static void sec_pmic_configure(struct sec_pmic_dev *sec_pmic)
> +{
> +	int err;
> +
> +	if (sec_pmic->device_type != S2MPS13X)
> +		return;
> +
> +	if (sec_pmic->pdata->disable_wrstbi) {
> +		/*
> +		 * If WRSTBI pin is pulled down this feature must be disabled
> +		 * because each Suspend to RAM will trigger buck voltage reset
> +		 * to default values.
> +		 */
> +		err = regmap_update_bits(sec_pmic->regmap_pmic,
> +					 S2MPS13_REG_WRSTBI,
> +					 S2MPS13_REG_WRSTBI_MASK, 0x0);
> +		if (err)
> +			dev_warn(sec_pmic->dev,
> +				 "Cannot initialize WRSTBI config: %d\n",
> +				 err);
> +	}
> +}
> +
>  #ifdef CONFIG_OF
>  /*
>   * Only the common platform data elements for s5m8767 are parsed here from the
> @@ -289,6 +312,8 @@ static struct sec_platform_data *sec_pmic_i2c_parse_dt_pdata(
>  
>  	pd->manual_poweroff = of_property_read_bool(dev->of_node,
>  						"samsung,s2mps11-acokb-ground");
> +	pd->disable_wrstbi = of_property_read_bool(dev->of_node,
> +						"samsung,s2mps11-wrstbi-ground");
>  	return pd;
>  }
>  #else
> @@ -434,6 +459,7 @@ static int sec_pmic_probe(struct i2c_client *i2c,
>  		goto err_mfd;
>  
>  	device_init_wakeup(sec_pmic->dev, sec_pmic->wakeup);
> +	sec_pmic_configure(sec_pmic);
>  	sec_pmic_dump_rev(sec_pmic);
>  
>  	return ret;
> diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h
> index aa78957e092f..a06098639399 100644
> --- a/include/linux/mfd/samsung/core.h
> +++ b/include/linux/mfd/samsung/core.h
> @@ -134,6 +134,8 @@ struct sec_platform_data {
>  	int				buck4_init;
>  	/* Whether or not manually set PWRHOLD to low during shutdown. */
>  	bool				manual_poweroff;
> +	/* Disable the WRSTBI (buck voltage warm reset) when probing? */
> +	bool				disable_wrstbi;
>  };
>  
>  /**
> diff --git a/include/linux/mfd/samsung/s2mps13.h b/include/linux/mfd/samsung/s2mps13.h
> index b1fd675fa36f..239e977ba45d 100644
> --- a/include/linux/mfd/samsung/s2mps13.h
> +++ b/include/linux/mfd/samsung/s2mps13.h
> @@ -184,5 +184,6 @@ enum s2mps13_regulators {
>   * Let's assume that default value will be set.
>   */
>  #define S2MPS13_BUCK_RAMP_DELAY		12500
> +#define S2MPS13_REG_WRSTBI_MASK		BIT(5)
>  
>  #endif /*  __LINUX_MFD_S2MPS13_H */

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Re: [PATCH 3/3] mfd: sec-core: Disable buck voltage reset on watchdog falling edge

[Krzysztof Kozlowski]

On 05.10.2015 22:35, Bartlomiej Zolnierkiewicz wrote:
> 
> Hi,
> 
> On Friday, October 02, 2015 05:25:51 PM Krzysztof Kozlowski wrote:
>> The WRSTBI bit (disabled by default but enabled by bootloader), when
>> set, is responsible for resetting voltages to default values of
>> certain bucks on falling edge of Warm Reset Input pin from AP.
>>
>> However on some boards (with S2MPS13) the pin is pulled down so any
>> suspend will effectively trigger the reset of bucks supplying the power
>> to the little and big cores. In the same time when resuming, these bucks
>> must provide voltage greater or equal to voltage before suspend to match
>> the frequency chosen by cpufreq. If voltage (default value of voltage
>> after reset) is lower than one set by cpufreq before suspend, then
>> system will hang during resuming.
>>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> 
> I tested this (with some additional Exynos5433 patches) and it works
> like expected (suspend/resume issue is fixed).
> 
> Tested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> 

Thanks!

> You could also add:
> 
> Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> 
> (since the issue got narrowed down and reported to you by me :).

I didn't put it because I wasn't sure who was the author of our report.
I'll wait a one more day for any comments and add it in v2/resend.

BTW, any comments on the binding itself?
Actually I had hard time choosing the name for binding because unlike
the ACOKB the WRSTBI pin is not grounded but pulled down. However it is
quite similar so I stick to the same convention:
 - samsung,s2mps11-acokb-ground
 - samsung,s2mps11-wrstbi-ground


Best regards,
Krzysztof