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Date: Tue, 11 Dec 2018 04:29:29 +0000
From: Anson Huang <anson.huang@....com>
To: Phil Reid <preid@...ctromag.com.au>,
"jic23@...nel.org" <jic23@...nel.org>,
"knaack.h@....de" <knaack.h@....de>,
"lars@...afoo.de" <lars@...afoo.de>,
"pmeerw@...erw.net" <pmeerw@...erw.net>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"mark.rutland@....com" <mark.rutland@....com>,
"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"festevam@...il.com" <festevam@...il.com>
CC: dl-linux-imx <linux-imx@....com>
Subject: RE: [PATCH V4 2/2] iio: light: isl29018: add optional vdd/vdda
regulator operation support
Hi, Phil
Best Regards!
Anson Huang
> -----Original Message-----
> From: Phil Reid [mailto:preid@...ctromag.com.au]
> Sent: 2018年12月11日 11:56
> To: Anson Huang <anson.huang@....com>; jic23@...nel.org;
> knaack.h@....de; lars@...afoo.de; pmeerw@...erw.net;
> robh+dt@...nel.org; mark.rutland@....com; linux-iio@...r.kernel.org;
> devicetree@...r.kernel.org; linux-kernel@...r.kernel.org;
> festevam@...il.com
> Cc: dl-linux-imx <linux-imx@....com>
> Subject: Re: [PATCH V4 2/2] iio: light: isl29018: add optional vdd/vdda
> regulator operation support
>
> G'day Anson,
>
> Just pulled up the datasheet for this chip.
>
> The absolute max for Vdda is speced as Vddd +/-0.5 With a note that Vdda
> should be externally shorted to Vddd.
The data sheet says vdda should be connected to vdd externally, then I think we should just
use one regulator vdd, then it will be much easier for the driver, what do you think?
Anson.
>
>
> On 11/12/2018 11:43 am, Anson Huang wrote:
> > Hi, Phil
> >
> > Best Regards!
> > Anson Huang
> >
> >> -----Original Message-----
> >> From: Phil Reid [mailto:preid@...ctromag.com.au]
> >> Sent: 2018年12月11日 11:36
> >> To: Anson Huang <anson.huang@....com>; jic23@...nel.org;
> >> knaack.h@....de; lars@...afoo.de; pmeerw@...erw.net;
> >> robh+dt@...nel.org; mark.rutland@....com; linux-iio@...r.kernel.org;
> >> devicetree@...r.kernel.org; linux-kernel@...r.kernel.org;
> >> festevam@...il.com
> >> Cc: dl-linux-imx <linux-imx@....com>
> >> Subject: Re: [PATCH V4 2/2] iio: light: isl29018: add optional
> >> vdd/vdda regulator operation support
> >>
> >> On 11/12/2018 11:24 am, Anson Huang wrote:
> >>> The light sensor's power supply could be controlled 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 optional vdd/vdda regulator operation support.
> >>>
> >>> Signed-off-by: Anson Huang <Anson.Huang@....com>
> >>> ---
> >>> ChangeLog since V3:
> >>> - improve the error handling of devm_regulator_get_optional;
> >>> - make sure regulators are disabled in error path.
> >>> ---
> >>> drivers/iio/light/isl29018.c | 83
> >> ++++++++++++++++++++++++++++++++++++++++++--
> >>> 1 file changed, 80 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/drivers/iio/light/isl29018.c
> >>> b/drivers/iio/light/isl29018.c index b45400f..a21652b 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 +96,8 @@ struct isl29018_chip {
> >>> struct isl29018_scale scale;
> >>> int prox_scheme;
> >>> bool suspended;
> >>> + struct regulator *vdd_reg;
> >>> + struct regulator *vdda_reg;
> >>> };
> >>>
> >>> static int isl29018_set_integration_time(struct isl29018_chip
> >>> *chip, @@ -735,6 +738,34 @@ static int isl29018_probe(struct
> >>> i2c_client *client,
> >>>
> >>> mutex_init(&chip->lock);
> >>>
> >>> + chip->vdd_reg = devm_regulator_get_optional(&client->dev, "vdd");
> >>> + if (!IS_ERR(chip->vdd_reg)) {
> >>> + err = regulator_enable(chip->vdd_reg);
> >>> + if (err) {
> >>> + dev_err(&client->dev, "failed to enable VDD regulator\n");
> >>> + return err;
> >>> + }
> >>> + } else {
> >>> + err = PTR_ERR(chip->vdd_reg);
> >>> + if (err != -ENODEV)
> >>> + return err;
> >>> + }
> >>> +
> >>> + chip->vdda_reg = devm_regulator_get_optional(&client->dev,
> "vdda");
> >>> + if (!IS_ERR(chip->vdda_reg)) {
> >>> + err = regulator_enable(chip->vdda_reg);
> >>> + if (err) {
> >>> + dev_err(&client->dev, "failed to enable VDDA
> regulator\n");
> >>> + if (!IS_ERR(chip->vdd_reg))
> >>> + regulator_disable(chip->vdd_reg);
> >>> + return err;
> Not sure about this case at the call to enable failed so I think you only want
> the first one to be disabled.
> You could add another goto statement thou, see below.
>
>
> >>> + }
> >>> + } else {
> >>> + err = PTR_ERR(chip->vdda_reg);
> >>> + if (err != -ENODEV)
> >>> + return err;
> >> maybe goto disable_regulators; to disable vdd.
> >
> > Agree, I will use " goto disable_regulators;" in both here and upper regulator
> enable fail case.
> > Please help review V5, thanks.
>
> Here its safe to call both as vdda_reg will be an error ptr.
>
> >
> > Anson
> >
> >>
> >>> + }
> >>> +
> >>> chip->type = dev_id;
> >>> chip->calibscale = 1;
> >>> chip->ucalibscale = 0;
> >>> @@ -747,12 +778,12 @@ static int isl29018_probe(struct i2c_client
> *client,
> >>> if (IS_ERR(chip->regmap)) {
> >>> err = PTR_ERR(chip->regmap);
> >>> dev_err(&client->dev, "regmap initialization fails: %d\n", err);
> >>> - return err;
> >>> + goto disable_regulators;
> >>> }
> >>>
> >>> err = isl29018_chip_init(chip);
> >>> if (err)
> >>> - return err;
> >>> + goto disable_regulators;
> >>>
> >>> indio_dev->info = isl29018_chip_info_tbl[dev_id].indio_info;
> >>> indio_dev->channels = isl29018_chip_info_tbl[dev_id].channels;
> >>> @@ -761,13 +792,24 @@ static int isl29018_probe(struct i2c_client
> *client,
> >>> indio_dev->dev.parent = &client->dev;
> >>> indio_dev->modes = INDIO_DIRECT_MODE;
> >>>
> >>> - return devm_iio_device_register(&client->dev, indio_dev);
> >>> + err = devm_iio_device_register(&client->dev, indio_dev);
> >>> + if (!err)
> >>> + return 0;
> >>> +
> >>> +disable_regulators:
> >>> + if (!IS_ERR(chip->vdd_reg))
> >>> + regulator_disable(chip->vdd_reg);
> >>> + if (!IS_ERR(chip->vdda_reg))
> >>> + regulator_disable(chip->vdda_reg);
> >>> +
> eg: extra label here.
> Order is changed thou, which may be a problem.
> It's in the reverse order to the enable, which is usually what you want but the
> datasheet concerns above may be an issue.
>
>
> disable_regulators:
> if (!IS_ERR(chip->vdda_reg))
> regulator_disable(chip->vdda_reg);
> disable_regulator_vdd:
> if (!IS_ERR(chip->vdd_reg))
> regulator_disable(chip->vdd_reg);
>
> >>> + return err;
> >>> }
> >>>
> >> [snip]
> >>
>
>
>
> --
> Regards
> Phil
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