[PATCH v2 0/3] Add suspend and resume functions

[PATCH v2 0/3] Add suspend and resume functions

[Nicolin Chen]

This series of patches add system suspend and resume functiosn for
ina3221 hwmon driver. To do so, it also needs two small fixes.

Changelog
v1->v2:
 * Added PATCH-2 to fix macros
 * Added power-down setting during suspend in PATCH-3

Nicolin Chen (3):
  hwmon: ina3221: Add INA3221_CONFIG to volatile_table
  hwmon: ina3221: Fix INA3221_CONFIG_MODE macros
  hwmon: ina3221: Add suspend and resume functions

 drivers/hwmon/ina3221.c | 71 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 67 insertions(+), 4 deletions(-)

-- 
2.17.1

[PATCH v2 1/3] hwmon: ina3221: Add INA3221_CONFIG to volatile_table

[Nicolin Chen]

The MSB (15th bit) of INA3221_CONFIG is a self-clear reset bit.
So this register should be added to the volatile_table of the
regmap_config. Otherwise, we will see this bit is sticky in the
regcache which might accidentally reset the chip when an actual
write happens to the register.

This might not be a severe bug for the current code line since
there's no second place touching the INA3221_CONFIG except the
reset routine in the probe().

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
 drivers/hwmon/ina3221.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index e6b49500c52a..cfe65ff01051 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -353,7 +353,7 @@ static struct attribute *ina3221_attrs[] = {
 ATTRIBUTE_GROUPS(ina3221);
 
 static const struct regmap_range ina3221_yes_ranges[] = {
-	regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
+	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
 };
 
-- 
2.17.1

[PATCH v2 2/3] hwmon: ina3221: Fix INA3221_CONFIG_MODE macros

[Nicolin Chen]

The three INA3221_CONFIG_MODE macros are not correctly defined here.
The MODE3-1 filed is loacted at BIT 2-0 according to the datasheet.

So this patch just fixes them by shifting all of them with a correct
offset. However, this isn't a crital bug fix as the driver does not
use any of them at this point.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
 drivers/hwmon/ina3221.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index cfe65ff01051..e0c4f4d83f4e 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -38,9 +38,9 @@
 #define INA3221_WARN3			0x0c
 #define INA3221_MASK_ENABLE		0x0f
 
-#define INA3221_CONFIG_MODE_SHUNT	BIT(1)
-#define INA3221_CONFIG_MODE_BUS		BIT(2)
-#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(3)
+#define INA3221_CONFIG_MODE_SHUNT	BIT(0)
+#define INA3221_CONFIG_MODE_BUS		BIT(1)
+#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
 
 #define INA3221_RSHUNT_DEFAULT		10000
 
-- 
2.17.1

[PATCH v2 3/3] hwmon: ina3221: Add suspend and resume functions

[Nicolin Chen]

Depending on the hardware design, an INA3221 chip might lose
its power during system suspend/resume. So this patch adds
a set of suspend and resume functions to cache the register
values including config register value and limit settings.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
Changelog
v1->v2:
 * Added power-down setting during suspend for power saving

 drivers/hwmon/ina3221.c | 63 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index e0c4f4d83f4e..877952efaa88 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -38,6 +38,8 @@
 #define INA3221_WARN3			0x0c
 #define INA3221_MASK_ENABLE		0x0f
 
+#define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
+#define INA3221_CONFIG_MODE_POWERDOWN	0
 #define INA3221_CONFIG_MODE_SHUNT	BIT(0)
 #define INA3221_CONFIG_MODE_BUS		BIT(1)
 #define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
@@ -91,11 +93,13 @@ static const unsigned int register_channel[] = {
  * @regmap: Register map of the device
  * @fields: Register fields of the device
  * @shunt_resistors: Array of resistor values per channel
+ * @reg_config: Register value of INA3221_CONFIG
  */
 struct ina3221_data {
 	struct regmap *regmap;
 	struct regmap_field *fields[F_MAX_FIELDS];
 	int shunt_resistors[INA3221_NUM_CHANNELS];
+	u32 reg_config;
 };
 
 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
@@ -415,9 +419,67 @@ static int ina3221_probe(struct i2c_client *client,
 		return PTR_ERR(hwmon_dev);
 	}
 
+	dev_set_drvdata(dev, ina);
+
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int ina3221_suspend(struct device *dev)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	/* Save config register value and enable cache-only */
+	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
+	if (ret)
+		return ret;
+
+	/* Set to power-down mode for power saving */
+	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
+				 INA3221_CONFIG_MODE_MASK,
+				 INA3221_CONFIG_MODE_POWERDOWN);
+	if (ret)
+		return ret;
+
+	regcache_cache_only(ina->regmap, true);
+	regcache_mark_dirty(ina->regmap);
+
+	return 0;
+}
+
+static int ina3221_resume(struct device *dev)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	regcache_cache_only(ina->regmap, false);
+
+	/* Software reset the chip */
+	ret = regmap_field_write(ina->fields[F_RST], true);
+	if (ret) {
+		dev_err(dev, "Unable to reset device\n");
+		return ret;
+	}
+
+	/* Restore cached register values to hardware */
+	ret = regcache_sync(ina->regmap);
+	if (ret)
+		return ret;
+
+	/* Restore config register value to hardware */
+	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops ina3221_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(ina3221_suspend, ina3221_resume)
+};
+
 static const struct of_device_id ina3221_of_match_table[] = {
 	{ .compatible = "ti,ina3221", },
 	{ /* sentinel */ }
@@ -435,6 +497,7 @@ static struct i2c_driver ina3221_i2c_driver = {
 	.driver = {
 		.name = INA3221_DRIVER_NAME,
 		.of_match_table = ina3221_of_match_table,
+		.pm = &ina3221_pm,
 	},
 	.id_table = ina3221_ids,
 };
-- 
2.17.1

Re: [PATCH v2 1/3] hwmon: ina3221: Add INA3221_CONFIG to volatile_table

[Guenter Roeck]

On Sat, Sep 29, 2018 at 02:44:05PM -0700, Nicolin Chen wrote:
> The MSB (15th bit) of INA3221_CONFIG is a self-clear reset bit.
> So this register should be added to the volatile_table of the
> regmap_config. Otherwise, we will see this bit is sticky in the
> regcache which might accidentally reset the chip when an actual
> write happens to the register.
> 
> This might not be a severe bug for the current code line since
> there's no second place touching the INA3221_CONFIG except the
> reset routine in the probe().
> 
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>

Applied to hwmon-next.

Thanks,
Guenter

> ---
>  drivers/hwmon/ina3221.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> index e6b49500c52a..cfe65ff01051 100644
> --- a/drivers/hwmon/ina3221.c
> +++ b/drivers/hwmon/ina3221.c
> @@ -353,7 +353,7 @@ static struct attribute *ina3221_attrs[] = {
>  ATTRIBUTE_GROUPS(ina3221);
>  
>  static const struct regmap_range ina3221_yes_ranges[] = {
> -	regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
> +	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
>  	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
>  };
>  

Re: [PATCH v2 2/3] hwmon: ina3221: Fix INA3221_CONFIG_MODE macros

[Guenter Roeck]

On Sat, Sep 29, 2018 at 02:44:06PM -0700, Nicolin Chen wrote:
> The three INA3221_CONFIG_MODE macros are not correctly defined here.
> The MODE3-1 filed is loacted at BIT 2-0 according to the datasheet.
> 
located

> So this patch just fixes them by shifting all of them with a correct
> offset. However, this isn't a crital bug fix as the driver does not
> use any of them at this point.
> 
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>

No need to resend; I fixed it up. Applied to hwmon-next.

Thanks,
Guenter

> ---
>  drivers/hwmon/ina3221.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> index cfe65ff01051..e0c4f4d83f4e 100644
> --- a/drivers/hwmon/ina3221.c
> +++ b/drivers/hwmon/ina3221.c
> @@ -38,9 +38,9 @@
>  #define INA3221_WARN3			0x0c
>  #define INA3221_MASK_ENABLE		0x0f
>  
> -#define INA3221_CONFIG_MODE_SHUNT	BIT(1)
> -#define INA3221_CONFIG_MODE_BUS		BIT(2)
> -#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(3)
> +#define INA3221_CONFIG_MODE_SHUNT	BIT(0)
> +#define INA3221_CONFIG_MODE_BUS		BIT(1)
> +#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
>  
>  #define INA3221_RSHUNT_DEFAULT		10000
>  

Re: [PATCH v2 3/3] hwmon: ina3221: Add suspend and resume functions

[Guenter Roeck]

On Sat, Sep 29, 2018 at 02:44:07PM -0700, Nicolin Chen wrote:
> Depending on the hardware design, an INA3221 chip might lose
> its power during system suspend/resume. So this patch adds
> a set of suspend and resume functions to cache the register
> values including config register value and limit settings.
> 
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>

Applied to hwmon-next, with a minor change; see below.

Thanks,
Guenter

> ---
> Changelog
> v1->v2:
>  * Added power-down setting during suspend for power saving
> 
>  drivers/hwmon/ina3221.c | 63 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
> 
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> index e0c4f4d83f4e..877952efaa88 100644
> --- a/drivers/hwmon/ina3221.c
> +++ b/drivers/hwmon/ina3221.c
> @@ -38,6 +38,8 @@
>  #define INA3221_WARN3			0x0c
>  #define INA3221_MASK_ENABLE		0x0f
>  
> +#define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
> +#define INA3221_CONFIG_MODE_POWERDOWN	0
>  #define INA3221_CONFIG_MODE_SHUNT	BIT(0)
>  #define INA3221_CONFIG_MODE_BUS		BIT(1)
>  #define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
> @@ -91,11 +93,13 @@ static const unsigned int register_channel[] = {
>   * @regmap: Register map of the device
>   * @fields: Register fields of the device
>   * @shunt_resistors: Array of resistor values per channel
> + * @reg_config: Register value of INA3221_CONFIG
>   */
>  struct ina3221_data {
>  	struct regmap *regmap;
>  	struct regmap_field *fields[F_MAX_FIELDS];
>  	int shunt_resistors[INA3221_NUM_CHANNELS];
> +	u32 reg_config;
>  };
>  
>  static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
> @@ -415,9 +419,67 @@ static int ina3221_probe(struct i2c_client *client,
>  		return PTR_ERR(hwmon_dev);
>  	}
>  
> +	dev_set_drvdata(dev, ina);
> +

It is better to call that function before registering the hwmon device,
to avoid the theroretical possibility that suspend is called before drvdata
is set. I moved the call accordingly.

>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM
> +static int ina3221_suspend(struct device *dev)
> +{
> +	struct ina3221_data *ina = dev_get_drvdata(dev);
> +	int ret;
> +
> +	/* Save config register value and enable cache-only */
> +	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
> +	if (ret)
> +		return ret;
> +
> +	/* Set to power-down mode for power saving */
> +	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
> +				 INA3221_CONFIG_MODE_MASK,
> +				 INA3221_CONFIG_MODE_POWERDOWN);
> +	if (ret)
> +		return ret;
> +
> +	regcache_cache_only(ina->regmap, true);
> +	regcache_mark_dirty(ina->regmap);
> +
> +	return 0;
> +}
> +
> +static int ina3221_resume(struct device *dev)
> +{
> +	struct ina3221_data *ina = dev_get_drvdata(dev);
> +	int ret;
> +
> +	regcache_cache_only(ina->regmap, false);
> +
> +	/* Software reset the chip */
> +	ret = regmap_field_write(ina->fields[F_RST], true);
> +	if (ret) {
> +		dev_err(dev, "Unable to reset device\n");
> +		return ret;
> +	}
> +
> +	/* Restore cached register values to hardware */
> +	ret = regcache_sync(ina->regmap);
> +	if (ret)
> +		return ret;
> +
> +	/* Restore config register value to hardware */
> +	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops ina3221_pm = {
> +	SET_SYSTEM_SLEEP_PM_OPS(ina3221_suspend, ina3221_resume)
> +};
> +
>  static const struct of_device_id ina3221_of_match_table[] = {
>  	{ .compatible = "ti,ina3221", },
>  	{ /* sentinel */ }
> @@ -435,6 +497,7 @@ static struct i2c_driver ina3221_i2c_driver = {
>  	.driver = {
>  		.name = INA3221_DRIVER_NAME,
>  		.of_match_table = ina3221_of_match_table,
> +		.pm = &ina3221_pm,
>  	},
>  	.id_table = ina3221_ids,
>  };

Re: [PATCH v2 3/3] hwmon: ina3221: Add suspend and resume functions

[Nicolin Chen]

On Sun, Sep 30, 2018 at 08:27:49AM -0700, Guenter Roeck wrote:

> >  static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
> > @@ -415,9 +419,67 @@ static int ina3221_probe(struct i2c_client *client,
> >  		return PTR_ERR(hwmon_dev);
> >  	}
> >  
> > +	dev_set_drvdata(dev, ina);
> > +
> 
> It is better to call that function before registering the hwmon device,
> to avoid the theroretical possibility that suspend is called before drvdata
> is set. I moved the call accordingly.

Oh..I see. Another lesson learned. Thank you for the fix!