[PATCH v2] iio: ak8975: add Vid regulator

[PATCH v2] iio: ak8975: add Vid regulator

[Linus Walleij]

The AK8975 has two power sources: Vdd (analog voltage supply)
and Vid (digital voltage supply). Optionally also obtain the Vid
supply regulator and enable it.

If an error occurs when enabling one of the regulators: bail out.

Cc: Gregor Boirie <gregor.boirie@parrot.com>
Cc: Richard Leitner <dev@g0hl1n.net>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Just obtain the other regulator exactly like the first without
  trying to be fancy.
---
 drivers/iio/magnetometer/ak8975.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 609a2c401b5d..e0e43f497f40 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -379,6 +379,7 @@ struct ak8975_data {
 	u8			cntl_cache;
 	struct iio_mount_matrix orientation;
 	struct regulator	*vdd;
+	struct regulator	*vid;
 };
 
 /* Enable attached power regulator if any. */
@@ -396,10 +397,26 @@ static int ak8975_power_on(struct i2c_client *client)
 	} else {
 		ret = regulator_enable(data->vdd);
 	}
+	if (ret) {
+		dev_warn(&client->dev,
+			 "Failed to enable specified Vdd supply\n");
+		return ret;
+	}
 
-	if (ret)
-		dev_err(&client->dev, "failed to enable Vdd supply: %d\n", ret);
-	return ret;
+	data->vid = devm_regulator_get(&client->dev, "vid");
+	if (IS_ERR_OR_NULL(data->vid)) {
+		ret = PTR_ERR(data->vdd);
+		if (ret == -ENODEV)
+			ret = 0;
+	} else {
+		ret = regulator_enable(data->vdd);
+	}
+	if (ret) {
+		dev_warn(&client->dev,
+			 "Failed to enable specified Vid supply\n");
+		return ret;
+	}
+	return 0;
 }
 
 /* Disable attached power regulator if any. */
-- 
2.4.11

Re: [PATCH v2] iio: ak8975: add Vid regulator

[Linus Walleij]

On Thu, Jun 16, 2016 at 5:58 PM, Linus Walleij <linus.walleij@linaro.org> wrote:

> The AK8975 has two power sources: Vdd (analog voltage supply)
> and Vid (digital voltage supply). Optionally also obtain the Vid
> supply regulator and enable it.
>
> If an error occurs when enabling one of the regulators: bail out.
>
> Cc: Gregor Boirie <gregor.boirie@parrot.com>
> Cc: Richard Leitner <dev@g0hl1n.net>
> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

After discussing with Mark Brown it was discovered that this regulator
code is just wrong, IS_ERR_OR_NULL() shall never be used with
regulators.

I extended the patch series to fix this, then add the Vid regulator,
then factor things around and add runtime PM.

Sending in a moment.

Yours,
Linus Walleij