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iio: ak8975 : Add AK8963 compatibility mode support

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AK8963 and AK8975 use same register definitions, except the range
of X,Y,Z values. Added support of 8963 based on i2c_device_id.
Unfortunately there is no way to detect the type via registers,
both device registers return 0x48 as id of chipset.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Srinivas Pandruvada 2014-03-19 16:56:00 +00:00 committed by Jonathan Cameron
parent 239670ef48
commit 6027c077f6
2 changed files with 31 additions and 6 deletions
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3
drivers/iio/magnetometer/Kconfig
View File

@ -11,7 +11,8 @@ config AK8975
depends on GPIOLIB
help
Say yes here to build support for Asahi Kasei AK8975 3-Axis
Magnetometer.
Magnetometer. This driver can also support AK8963, if i2c
device name is identified as ak8963.
To compile this driver as a module, choose M here: the module
will be called ak8975.

34
drivers/iio/magnetometer/ak8975.c
View File

@ -85,7 +85,14 @@
#define AK8975_MAX_CONVERSION_TIMEOUT 500
#define AK8975_CONVERSION_DONE_POLL_TIME 10
#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
#define RAW_TO_GAUSS(asa) ((((asa) + 128) * 3000) / 256)
#define RAW_TO_GAUSS_8975(asa) ((((asa) + 128) * 3000) / 256)
#define RAW_TO_GAUSS_8963(asa) ((((asa) + 128) * 6000) / 256)
/* Compatible Asahi Kasei Compass parts */
enum asahi_compass_chipset {
AK8975,
AK8963,
};
/*
* Per-instance context data for the device.
@ -101,6 +108,7 @@ struct ak8975_data {
int eoc_irq;
wait_queue_head_t data_ready_queue;
unsigned long flags;
enum asahi_compass_chipset chipset;
};
static const int ak8975_index_to_reg[] = {
@ -272,9 +280,21 @@ static int ak8975_setup(struct i2c_client *client)
* Since ASA doesn't change, we cache the resultant scale factor into the
* device context in ak8975_setup().
*/
data->raw_to_gauss[0] = RAW_TO_GAUSS(data->asa[0]);
data->raw_to_gauss[1] = RAW_TO_GAUSS(data->asa[1]);
data->raw_to_gauss[2] = RAW_TO_GAUSS(data->asa[2]);
if (data->chipset == AK8963) {
/*
* H range is +-8190 and magnetometer range is +-4912.
* So HuT using the above explanation for 8975,
* 4912/8190 = ~ 6/10.
* So the Hadj should use 6/10 instead of 3/10.
*/
data->raw_to_gauss[0] = RAW_TO_GAUSS_8963(data->asa[0]);
data->raw_to_gauss[1] = RAW_TO_GAUSS_8963(data->asa[1]);
data->raw_to_gauss[2] = RAW_TO_GAUSS_8963(data->asa[2]);
} else {
data->raw_to_gauss[0] = RAW_TO_GAUSS_8975(data->asa[0]);
data->raw_to_gauss[1] = RAW_TO_GAUSS_8975(data->asa[1]);
data->raw_to_gauss[2] = RAW_TO_GAUSS_8975(data->asa[2]);
}
return 0;
}
@ -499,6 +519,9 @@ static int ak8975_probe(struct i2c_client *client,
data->eoc_gpio = eoc_gpio;
data->eoc_irq = 0;
data->chipset = (enum asahi_compass_chipset)(id->driver_data);
dev_dbg(&client->dev, "Asahi compass chip %s\n", id->name);
/* Perform some basic start-of-day setup of the device. */
err = ak8975_setup(client);
if (err < 0) {
@ -552,7 +575,8 @@ static int ak8975_remove(struct i2c_client *client)
}
static const struct i2c_device_id ak8975_id[] = {
{"ak8975", 0},
{"ak8975", AK8975},
{"ak8963", AK8963},
{}
};