Re: [PATCH 2/3] media: i2c: max9286: Add support for port regulators

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Thomas,

On Mon, Dec 20, 2021 at 04:06:26PM +0100, Thomas Nizan wrote:
> On 2021-12-16 11:09 p.m., Laurent Pinchart wrote:
> > From: Thomas Nizan <tnizan@witekio.com>
> > 
> > Allow users to use one PoC regulator per port, instead of a global
> > regulator.
> > 
> > The properties '^port[0-3]-poc-supply$' in the DT node are used to
> > indicate the regulators for individual ports.
>
> Signed-off-by: Thomas Nizan <tnizan@witekio.com>

Thank you.

> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  drivers/media/i2c/max9286.c | 112 +++++++++++++++++++++++++++++++-----
> >  1 file changed, 98 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index 7c663fd587bb..fa2f6a823fe6 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -136,8 +136,10 @@
> >  #define MAX9286_SRC_PAD			4
> >  
> >  struct max9286_source {
> > +	unsigned int index;
> >  	struct v4l2_subdev *sd;
> >  	struct fwnode_handle *fwnode;
> > +	struct regulator *regulator;
> >  };
> >  
> >  struct max9286_asd {
> > @@ -1072,6 +1074,49 @@ static int max9286_register_gpio(struct max9286_priv *priv)
> >  	return ret;
> >  }
> >  
> > +static int max9286_poc_power_on(struct max9286_priv *priv)
> > +{
> > +	struct max9286_source *source;
> > +	unsigned int enabled = 0;
> > +	int ret;
> > +
> > +	/* Enable the global regulator if available. */
> > +	if (priv->regulator)
> > +		return regulator_enable(priv->regulator);
> > +
> > +	/* Otherwise use the per-port regulators. */
> > +	for_each_source(priv, source) {
> > +		ret = regulator_enable(source->regulator);
> > +		if (ret < 0)
> > +			goto error;
> > +
> > +		enabled |= BIT(source->index);
> > +	}
> > +
> > +	return 0;
> > +
> > +error:
> > +	for_each_source(priv, source) {
> > +		if (enabled & BIT(source->index))
> > +			regulator_disable(source->regulator);
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void max9286_poc_power_off(struct max9286_priv *priv)
> > +{
> > +	struct max9286_source *source;
> > +
> > +	if (priv->regulator) {
> > +		regulator_disable(priv->regulator);
> > +		return;
> > +	}
> > +
> > +	for_each_source(priv, source)
> > +		regulator_disable(source->regulator);
> > +}
> > +
> >  static int max9286_init(struct device *dev)
> >  {
> >  	struct max9286_priv *priv;
> > @@ -1082,9 +1127,9 @@ static int max9286_init(struct device *dev)
> >  	priv = i2c_get_clientdata(client);
> >  
> >  	/* Enable the bus power. */
> > -	ret = regulator_enable(priv->regulator);
> > +	ret = max9286_poc_power_on(priv);
> >  	if (ret < 0) {
> > -		dev_err(&client->dev, "Unable to turn PoC on\n");
> > +		dev_err(dev, "Unable to turn PoC on\n");
> >  		return ret;
> >  	}
> >  
> > @@ -1118,7 +1163,7 @@ static int max9286_init(struct device *dev)
> >  err_v4l2_register:
> >  	max9286_v4l2_unregister(priv);
> >  err_regulator:
> > -	regulator_disable(priv->regulator);
> > +	max9286_poc_power_off(priv);
> >  
> >  	return ret;
> >  }
> > @@ -1215,6 +1260,7 @@ static int max9286_parse_dt(struct max9286_priv *priv)
> >  		}
> >  
> >  		source = &priv->sources[ep.port];
> > +		source->index = ep.port;
> >  		source->fwnode = fwnode_graph_get_remote_endpoint(
> >  						of_fwnode_handle(node));
> >  		if (!source->fwnode) {
> > @@ -1249,6 +1295,50 @@ static int max9286_parse_dt(struct max9286_priv *priv)
> >  	return 0;
> >  }
> >  
> > +static int max9286_get_poc_supplies(struct max9286_priv *priv)
> > +{
> > +	struct device *dev = &priv->client->dev;
> > +	struct max9286_source *source;
> > +
> > +	/*
> > +	 * Start by getting the global regulator. Usage of the exclusive API is
> > +	 * required to receive an error in case the supply isn't specified in
> > +	 * the device tree.
> > +	 */
> > +	priv->regulator = devm_regulator_get_exclusive(dev, "poc");
> > +	if (!IS_ERR(priv->regulator))
> > +		return 0;
> > +
> > +	if (PTR_ERR(priv->regulator) != -ENODEV) {
> > +		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> > +			dev_err(dev, "Unable to get PoC regulator: %ld\n",
> > +				PTR_ERR(priv->regulator));
> > +		return PTR_ERR(priv->regulator);
> > +	}
> > +
> > +	/* If there's no global regulator, get per-port regulators. */
> > +	dev_dbg(dev,
> > +		"No global PoC regulator, looking for per-port regulators\n");
> > +	priv->regulator = NULL;
> > +
> > +	for_each_source(priv, source) {
> > +		char name[10];
> > +
> > +		snprintf(name, sizeof(name), "port%u-poc", source->index);
> > +		source->regulator = devm_regulator_get_exclusive(dev, name);
> > +		if (IS_ERR(source->regulator)) {
> > +			if (PTR_ERR(source->regulator) != -EPROBE_DEFER)
> > +				dev_err(dev,
> > +					"Unable to get port %u PoC regulator: %ld\n",
> > +					source->index,
> > +					PTR_ERR(source->regulator));
> > +			return PTR_ERR(source->regulator);
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  static int max9286_probe(struct i2c_client *client)
> >  {
> >  	struct max9286_priv *priv;
> > @@ -1293,17 +1383,11 @@ static int max9286_probe(struct i2c_client *client)
> >  	if (ret)
> >  		goto err_powerdown;
> >  
> > -	priv->regulator = devm_regulator_get(&client->dev, "poc");
> > -	if (IS_ERR(priv->regulator)) {
> > -		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> > -			dev_err(&client->dev,
> > -				"Unable to get PoC regulator (%ld)\n",
> > -				PTR_ERR(priv->regulator));
> > -		ret = PTR_ERR(priv->regulator);
> > -		goto err_powerdown;
> > -	}
> > -
> >  	ret = max9286_parse_dt(priv);
> > +	if (ret)
> > +		goto err_cleanup_dt;
> > +
> > +	ret = max9286_get_poc_supplies(priv);
> >  	if (ret)
> >  		goto err_powerdown;
> >  
> > @@ -1329,7 +1413,7 @@ static int max9286_remove(struct i2c_client *client)
> >  
> >  	max9286_v4l2_unregister(priv);
> >  
> > -	regulator_disable(priv->regulator);
> > +	max9286_poc_power_off(priv);
> >  
> >  	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> >  

-- 
Regards,

Laurent Pinchart