Use AMI306 calibration data for randomness and debugging.
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
---
drivers/iio/magnetometer/ak8974.c | 41 +++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
index d8c45206ba00..b3221b34606b 100644
--- a/drivers/iio/magnetometer/ak8974.c
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -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..%u): %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;
@@ -490,6 +504,33 @@ 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;
}
--
2.11.0
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