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Message-ID: <0b08c0d1-afe2-5ade-9333-2eb7d57d4db6@electromag.com.au>
Date: Tue, 11 Dec 2018 11:56:09 +0800
From: Phil Reid <preid@...ctromag.com.au>
To: Anson Huang <anson.huang@....com>,
"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
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.
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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