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@xxxxxxxxxxxxxxxxx]
Sent: 2018年12月11日 11:36
To: Anson Huang <anson.huang@xxxxxxx>; jic23@xxxxxxxxxx;
knaack.h@xxxxxx; lars@xxxxxxxxxx; pmeerw@xxxxxxxxxx;
robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; linux-iio@xxxxxxxxxxxxxxx;
devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
festevam@xxxxxxxxx
Cc: dl-linux-imx <linux-imx@xxxxxxx>
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@xxxxxxx>
---
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
