[v2,0/2] hwmon (ina3221) Add single-shot mode support

By default, ina3221, as a hardware monitor, continuously measures
the inputs and generates corresponding data. However, for battery
powered devices, this mode might be power consuming.

This series of patches add a feature of changing default operating
mode to its single-shot mode via DT.

Changelog
v1->v2:
 * Cleaned-up PATCH-2

Nicolin Chen (2):
  dt-bindings: hwmon: ina3221: Add ti,single-shot property
  hwmon: (ina3221) Implement ti,single-shot DT property

 .../devicetree/bindings/hwmon/ina3221.txt     | 10 ++++++++++
 drivers/hwmon/ina3221.c                       | 20 +++++++++++++++++++
 2 files changed, 30 insertions(+)

On Fri, Jan 04, 2019 at 07:06:36PM -0800, Nicolin Chen wrote:
> By default, ina3221, as a hardware monitor, continuously measures
> the inputs and generates corresponding data. However, for battery
> powered devices, this mode might be power consuming.
> 
> The DT binding doc is updated with a new boolean type property to
> allow changing the default operating mode from consuming mode to
> single-shot mode, which will measure input on demand and then shut
> down to save power.
> 
> So this patch implements the DT property accordingly.
> 
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> ---
> Changelog
> v1->v2:
>  * Replaced the useless mode defines with a boolean variable.
> 
>  drivers/hwmon/ina3221.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> index e90ccac8bebb..4258a6ebe195 100644
> --- a/drivers/hwmon/ina3221.c
> +++ b/drivers/hwmon/ina3221.c
> @@ -111,6 +111,7 @@ struct ina3221_input {
>   * @inputs: Array of channel input source specific structures
>   * @lock: mutex lock to serialize sysfs attribute accesses
>   * @reg_config: Register value of INA3221_CONFIG
> + * @single_shot: running in single-shot operating mode
>   */
>  struct ina3221_data {
>  	struct device *pm_dev;
> @@ -119,6 +120,8 @@ struct ina3221_data {
>  	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
>  	struct mutex lock;
>  	u32 reg_config;
> +
> +	bool single_shot;
>  };
>  
>  static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
> @@ -188,6 +191,11 @@ static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
>  		if (!ina3221_is_enabled(ina, channel))
>  			return -ENODATA;
>  
> +		/* Write CONFIG register to trigger a single-shot measurement */
> +		if (ina->single_shot)
> +			regmap_write(ina->regmap, INA3221_CONFIG,
> +				     ina->reg_config);
> +
>  		ret = ina3221_wait_for_data(ina);
>  		if (ret)
>  			return ret;
> @@ -232,6 +240,11 @@ static int ina3221_read_curr(struct device *dev, u32 attr,
>  		if (!ina3221_is_enabled(ina, channel))
>  			return -ENODATA;
>  
> +		/* Write CONFIG register to trigger a single-shot measurement */
> +		if (ina->single_shot)
> +			regmap_write(ina->regmap, INA3221_CONFIG,
> +				     ina->reg_config);
> +
>  		ret = ina3221_wait_for_data(ina);
>  		if (ret)
>  			return ret;
> @@ -617,6 +630,9 @@ static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
>  	if (!np)
>  		return 0;
>  
> +	if (of_property_read_bool(np, "ti,single-shot"))
> +		ina->single_shot = true;
> +
	ina->single_shot = of_property_read_bool(np, "ti,single-shot");

No need to resend right now; let's wait for feedback from Rob.

Guenter

>  	for_each_child_of_node(np, child) {
>  		ret = ina3221_probe_child_from_dt(dev, child, ina);
>  		if (ret)
> @@ -666,6 +682,10 @@ static int ina3221_probe(struct i2c_client *client,
>  	/* The driver will be reset, so use reset value */
>  	ina->reg_config = INA3221_CONFIG_DEFAULT;
>  
> +	/* Clear continuous bit to use single-shot mode */
> +	if (ina->single_shot)
> +		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
> +
>  	/* Disable channels if their inputs are disconnected */
>  	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
>  		if (ina->inputs[i].disconnected)

On Mon, Jan 07, 2019 at 11:35:55AM -0800, Guenter Roeck wrote:

> > +	if (of_property_read_bool(np, "ti,single-shot"))
> > +		ina->single_shot = true;
> > +
> 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
> 
> No need to resend right now; let's wait for feedback from Rob.

Looks like Rob has acked. Is this resend version fine for review?

Thank you
Nicolin

On Thu, Jan 17, 2019 at 02:30:13PM -0800, Nicolin Chen wrote:
> On Mon, Jan 07, 2019 at 11:35:55AM -0800, Guenter Roeck wrote:
> 
> > > +	if (of_property_read_bool(np, "ti,single-shot"))
> > > +		ina->single_shot = true;
> > > +
> > 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
> > 
> > No need to resend right now; let's wait for feedback from Rob.
> 
> Looks like Rob has acked. Is this resend version fine for review?
> 
"Right now" was supposed to mean that you should wait for Rob's
feedback before sending v3 with the feedback above applied.
Did you send that version ? I don't see it in patchwork, nor
in my inbox.

Thanks,
Guenter

On Thu, Jan 17, 2019 at 02:58:42PM -0800, Guenter Roeck wrote:

> "Right now" was supposed to mean that you should wait for Rob's
> feedback before sending v3 with the feedback above applied.
> Did you send that version ? I don't see it in patchwork, nor
> in my inbox.

Oh, sorry. Will resend it.

Thanks for the reply.