[PATCH] staging:iio:magnetometer:ak8975: set power-down mode after reading fuse ROM data

[PATCH] staging:iio:magnetometer:ak8975: set power-down mode after reading fuse ROM data

[Leed Aguilar]

Fuse ROM data access mode is the only mode which does not
transition to power-down mode automatically.

As per the AK8975 data sheet, it is recomended to set the
power-down mode first before attempting to change into
another mode.

Change-Id: I4013c7963b19b3fe4b67553521b1083f018507bb
Signed-off-by: Leed Aguilar <leed.aguilar@ti.com>
Cc: Jonathan Cameron <jic23@kernel.org>
---
 drivers/staging/iio/magnetometer/ak8975.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c
index 52833cd..b06bd2d 100644
--- a/drivers/staging/iio/magnetometer/ak8975.c
+++ b/drivers/staging/iio/magnetometer/ak8975.c
@@ -194,6 +194,17 @@ static int ak8975_setup(struct i2c_client *client)
 		return ret;
 	}
 
+	/* After reading fuse ROM data set power-down mode */
+	ret = ak8975_write_data(client,
+				AK8975_REG_CNTL,
+				AK8975_REG_CNTL_MODE_POWER_DOWN,
+				AK8975_REG_CNTL_MODE_MASK,
+				AK8975_REG_CNTL_MODE_SHIFT);
+	if (ret < 0) {
+		dev_err(&client->dev, "Error in setting power-down mode\n");
+		return ret;
+	}
+
 /*
  * Precalculate scale factor (in Gauss units) for each axis and
  * store in the device data.
-- 
1.7.1

Re: [PATCH] staging:iio:magnetometer:ak8975: set power-down mode after reading fuse ROM data

[Jonathan Cameron]

Sounds sensible, but I don't have one of these so cc'ing Laxman
> Fuse ROM data access mode is the only mode which does not
> transition to power-down mode automatically.
>
> As per the AK8975 data sheet, it is recomended to set the
> power-down mode first before attempting to change into
> another mode.
>
> Change-Id: I4013c7963b19b3fe4b67553521b1083f018507bb
> Signed-off-by: Leed Aguilar<leed.aguilar@ti.com>
> Cc: Jonathan Cameron<jic23@kernel.org>
> ---
>   drivers/staging/iio/magnetometer/ak8975.c |   11 +++++++++++
>   1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c
> index 52833cd..b06bd2d 100644
> --- a/drivers/staging/iio/magnetometer/ak8975.c
> +++ b/drivers/staging/iio/magnetometer/ak8975.c
> @@ -194,6 +194,17 @@ static int ak8975_setup(struct i2c_client *client)
>   		return ret;
>   	}
>
> +	/* After reading fuse ROM data set power-down mode */
> +	ret = ak8975_write_data(client,
> +				AK8975_REG_CNTL,
> +				AK8975_REG_CNTL_MODE_POWER_DOWN,
> +				AK8975_REG_CNTL_MODE_MASK,
> +				AK8975_REG_CNTL_MODE_SHIFT);
> +	if (ret<  0) {
> +		dev_err(&client->dev, "Error in setting power-down mode\n");
> +		return ret;
> +	}
> +
>   /*
>    * Precalculate scale factor (in Gauss units) for each axis and
>    * store in the device data.

Re: [PATCH] staging:iio:magnetometer:ak8975: set power-down mode after reading fuse ROM data

[Laxman Dewangan]

On Thursday 31 May 2012 12:51 PM, Jonathan Cameron wrote:
> Sounds sensible, but I don't have one of these so cc'ing Laxman
>> Fuse ROM data access mode is the only mode which does not
>> transition to power-down mode automatically.
>>
>> As per the AK8975 data sheet, it is recomended to set the
>> power-down mode first before attempting to change into
>> another mode.

Acked-by: Laxman Dewangan <ldewangan@nvidia.com>

I verified from datasheet that this is correct change.

Thanks,
Laxman


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