Hi, Jonathan Best Regards! Anson Huang > -----Original Message----- > From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx] > Sent: 2018年12月23日 1:15 > To: Anson Huang <anson.huang@xxxxxxx> > Cc: knaack.h@xxxxxx; lars@xxxxxxxxxx; pmeerw@xxxxxxxxxx; > linux-iio@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; festevam@xxxxxxxxx; > preid@xxxxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> > Subject: Re: [PATCH V7] iio: light: isl29018: add vcc regulator operation > support > > On Mon, 17 Dec 2018 03:25:17 +0000 > Anson Huang <anson.huang@xxxxxxx> wrote: > > > The light sensor's power supply could be controllable by regulator on > > some platforms, such as i.MX6Q-SABRESD board, the light sensor > > isl29023's power supply is controlled by a GPIO fixed regulator, need > > to make sure the regulator is enabled before any operation of sensor, > > this patch adds vcc regulator operation support. > > > > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx> > Hi Anson > > See below. > > > --- > > ChangeLog since V6 > > - using devm_regulator_get() instead of devm_regulator_get_optional() > since the regulator is > > there anyway, if dtb does NOT specify one, regulator framework will > assign dummy regulator for it; > > - Setup devm action for cleaning up regulator resource for error > handling. > > --- > > drivers/iio/light/isl29018.c | 58 > > ++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 58 insertions(+) > > > > diff --git a/drivers/iio/light/isl29018.c > > b/drivers/iio/light/isl29018.c index b45400f..63f7b9d 100644 > > --- a/drivers/iio/light/isl29018.c > > +++ b/drivers/iio/light/isl29018.c > > @@ -23,6 +23,7 @@ > > #include <linux/mutex.h> > > #include <linux/delay.h> > > #include <linux/regmap.h> > > +#include <linux/regulator/consumer.h> > > #include <linux/slab.h> > > #include <linux/iio/iio.h> > > #include <linux/iio/sysfs.h> > > @@ -95,6 +96,7 @@ struct isl29018_chip { > > struct isl29018_scale scale; > > int prox_scheme; > > bool suspended; > > + struct regulator *vcc_reg; > > }; > > > > static int isl29018_set_integration_time(struct isl29018_chip *chip, > > @@ -708,6 +710,17 @@ static const char > *isl29018_match_acpi_device(struct device *dev, int *data) > > return dev_name(dev); > > } > > > > +static void isl29018_disable_regulator_action(void *_data) { > > + struct isl29018_chip *chip = _data; > > + int err; > > + > > + err = regulator_disable(chip->vcc_reg); > > + if (err) > > + dev_err(regmap_get_device(chip->regmap), > > + "failed to disable VCC regulator!\n"); } > > + > > static int isl29018_probe(struct i2c_client *client, > > const struct i2c_device_id *id) > > { > > @@ -742,6 +755,37 @@ static int isl29018_probe(struct i2c_client *client, > > chip->scale = isl29018_scales[chip->int_time][0]; > > chip->suspended = false; > > > > + chip->vcc_reg = devm_regulator_get(&client->dev, "vcc"); > > + if (IS_ERR(chip->vcc_reg)) { > > + err = PTR_ERR(chip->vcc_reg); > > + if (err != -EPROBE_DEFER) > > + dev_err(&client->dev, "failed to get VCC regulator!\n"); > > + return err; > > + } > > + > > + err = regulator_enable(chip->vcc_reg); > > + if (err) { > > + dev_err(&client->dev, "failed to enable VCC regulator!\n"); > > + return err; > > + } > > + > > + chip->regmap = devm_regmap_init_i2c(client, > > + isl29018_chip_info_tbl[dev_id].regmap_cfg); > > + if (IS_ERR(chip->regmap)) { > > + err = PTR_ERR(chip->regmap); > > + dev_err(&client->dev, "regmap initialization fails: %d\n", err); > > + regulator_disable(chip->vcc_reg); > > + return err; > > + } > > + > > + err = devm_add_action(&client->dev, isl29018_disable_regulator_action, > > + chip); > > + if (err) { > > I'm a little confused, why not do this before devm_regmap_init_i2c. > That way you won't have to disable the regulator in that one error path. > Also, devm_add_action_or_reset will call isl29018_disable_regulator_action > for you on error. It is because I used dev_err() in isl29018_disable_regulator_action which need regmap to get "dev" by regmap_get_device(chip->regmap), if it is accepted by just using pr_err() instead of dev_err, then I can do the devm_add_action before devm_regmap_init_i2c. I think using pr_err should be OK, I will use it in V8 patch. > > > + isl29018_disable_regulator_action(chip); > > + dev_err(&client->dev, "failed to setup regulator cleanup action!\n"); > > + return err; > > + } > > + > > chip->regmap = devm_regmap_init_i2c(client, > > isl29018_chip_info_tbl[dev_id].regmap_cfg); > > if (IS_ERR(chip->regmap)) { > > @@ -768,6 +812,7 @@ static int isl29018_probe(struct i2c_client > > *client, static int isl29018_suspend(struct device *dev) { > > struct isl29018_chip *chip = iio_priv(dev_get_drvdata(dev)); > > + int ret; > > > > mutex_lock(&chip->lock); > > > > @@ -777,6 +822,12 @@ static int isl29018_suspend(struct device *dev) > > * So we do not have much to do here. > > */ > > chip->suspended = true; > > + ret = regulator_disable(chip->vcc_reg); > > + if (ret) { > > + dev_err(dev, "failed to disable VCC regulator\n"); > > + mutex_unlock(&chip->lock); > > + return ret; > > Given you are about to unlock anyway a common pattern is to not check ret > until after the unlock, thus simplifying the code. I will improve this in V8 patch, thanks. Anson. > > > + } > > > > mutex_unlock(&chip->lock); > > > > @@ -790,6 +841,13 @@ static int isl29018_resume(struct device *dev) > > > > mutex_lock(&chip->lock); > > > > + err = regulator_enable(chip->vcc_reg); > > + if (err) { > > + dev_err(dev, "failed to enable VCC regulator\n"); > > + mutex_unlock(&chip->lock); > > + return err; > > + } > > + > > err = isl29018_chip_init(chip); > > if (!err) > > chip->suspended = false;
