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iio: magnetometer: ak8974: debug AMI306 calibration data

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Use AMI306 calibration data for randomness and debugging.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Michał Mirosław 2017-08-17 15:56:12 +02:00 committed by Jonathan Cameron
parent 9991f99eed
commit 0a60340f19
1 changed files with 41 additions and 0 deletions
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41
drivers/iio/magnetometer/ak8974.c
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@ -445,6 +445,20 @@ static int ak8974_selftest(struct ak8974 *ak8974)
return 0;
}
static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
__le16 *tab, size_t tab_size)
{
int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
if (ret) {
memset(tab, 0xFF, tab_size);
dev_warn(&ak8974->i2c->dev,
"can't read calibration data (regs %u..%zu): %d\n",
reg, reg + tab_size - 1, ret);
} else {
add_device_randomness(tab, tab_size);
}
}
static int ak8974_detect(struct ak8974 *ak8974)
{
unsigned int whoami;
@ -489,6 +503,33 @@ static int ak8974_detect(struct ak8974 *ak8974)
ak8974->name = name;
ak8974->variant = whoami;
if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
__le16 fab_data1[9], fab_data2[3];
int i;
ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
fab_data1, sizeof(fab_data1));
ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
fab_data2, sizeof(fab_data2));
for (i = 0; i < 3; ++i) {
static const char axis[3] = "XYZ";
static const char pgaxis[6] = "ZYZXYX";
unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
unsigned fine = le16_to_cpu(fab_data1[i]);
unsigned sens = le16_to_cpu(fab_data1[i + 3]);
unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
unsigned pgain2 = pgain1 >> 8;
pgain1 &= 0xFF;
dev_info(&ak8974->i2c->dev,
"factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
axis[i], offz, sens, fine, pgaxis[i * 2],
pgain1, pgaxis[i * 2 + 1], pgain2);
}
}
return 0;
}