Hi Jacopo,
On Fri, Dec 17, 2021 at 12:08:08PM +0100, Jacopo Mondi wrote:
> On Fri, Dec 17, 2021 at 12:09:45AM +0200, Laurent Pinchart wrote:
> > From: Thomas Nizan <tnizan@xxxxxxxxxxx>
> >
> > 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: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> These patches will badly conflic with the gpio-poc series :(
I don't mind rebasing.
> > ---
> > 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;
>
> Can't you use the to_index() macro ?
I think I can, indeed.
> > 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);
>
> I would if a regulator can be unconditionally disabled...
They're reference-counted, so they should only be disabled here if they
have been enabled above.
> > + }
> > +
> > + 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");
>
> doesn't get_optional() return -ENODEV if there's no such regulator too
> without locking the usage of the regulator ? Oh wait, maybe we want
> exclusive locking ? :)
No, you're right, I'll use an optional get.
> > + 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);
>
> I guess the fact we don't have a fixed number of sources makes it even
> harder to use the _bulk version of the regulators API...
Yes, and that fact that we may at some point want to power cameras
up/down individually.
> > + 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;
>
> I think the error path is wrong, you should cleanup_dt here.
Oops.
> > @@ -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
