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path: root/drivers/iio/magnetometer/mmc35240.c
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Diffstat (limited to 'drivers/iio/magnetometer/mmc35240.c')
-rw-r--r--drivers/iio/magnetometer/mmc35240.c115
1 files changed, 91 insertions, 24 deletions
diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c
index aa6e25d3bfc3..7a2ea71c659a 100644
--- a/drivers/iio/magnetometer/mmc35240.c
+++ b/drivers/iio/magnetometer/mmc35240.c
@@ -58,6 +58,31 @@
#define MMC35240_WAIT_CHARGE_PUMP 50000 /* us */
#define MMC53240_WAIT_SET_RESET 1000 /* us */
+/*
+ * Memsic OTP process code piece is put here for reference:
+ *
+ * #define OTP_CONVERT(REG) ((float)((REG) >=32 ? (32 - (REG)) : (REG)) * 0.006
+ * 1) For X axis, the COEFFICIENT is always 1.
+ * 2) For Y axis, the COEFFICIENT is as below:
+ * f_OTP_matrix[4] = OTP_CONVERT(((reg_data[1] & 0x03) << 4) |
+ * (reg_data[2] >> 4)) + 1.0;
+ * 3) For Z axis, the COEFFICIENT is as below:
+ * f_OTP_matrix[8] = (OTP_CONVERT(reg_data[3] & 0x3f) + 1) * 1.35;
+ * We implemented the OTP logic into driver.
+ */
+
+/* scale = 1000 here for Y otp */
+#define MMC35240_OTP_CONVERT_Y(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 6)
+
+/* 0.6 * 1.35 = 0.81, scale 10000 for Z otp */
+#define MMC35240_OTP_CONVERT_Z(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 81)
+
+#define MMC35240_X_COEFF(x) (x)
+#define MMC35240_Y_COEFF(y) (y + 1000)
+#define MMC35240_Z_COEFF(z) (z + 13500)
+
+#define MMC35240_OTP_START_ADDR 0x1B
+
enum mmc35240_resolution {
MMC35240_16_BITS_SLOW = 0, /* 100 Hz */
MMC35240_16_BITS_FAST, /* 200 Hz */
@@ -77,7 +102,7 @@ static const struct {
} mmc35240_props_table[] = {
/* 16 bits, 100Hz ODR */
{
- {1024, 1024, 770},
+ {1024, 1024, 1024},
32768,
},
/* 16 bits, 200Hz ODR */
@@ -102,6 +127,10 @@ struct mmc35240_data {
struct mutex mutex;
struct regmap *regmap;
enum mmc35240_resolution res;
+
+ /* OTP compensation */
+ int axis_coef[3];
+ int axis_scale[3];
};
static const int mmc35240_samp_freq[] = {100, 200, 333, 666};
@@ -113,8 +142,9 @@ static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666");
.modified = 1, \
.channel2 = IIO_MOD_ ## _axis, \
.address = AXIS_ ## _axis, \
- .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
- .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec mmc35240_channels[] = {
@@ -125,6 +155,7 @@ static const struct iio_chan_spec mmc35240_channels[] = {
static struct attribute *mmc35240_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
};
static const struct attribute_group mmc35240_attribute_group = {
@@ -170,8 +201,9 @@ static int mmc35240_hw_set(struct mmc35240_data *data, bool set)
static int mmc35240_init(struct mmc35240_data *data)
{
- int ret;
+ int ret, y_convert, z_convert;
unsigned int reg_id;
+ u8 otp_data[6];
ret = regmap_read(data->regmap, MMC35240_REG_ID, &reg_id);
if (ret < 0) {
@@ -195,9 +227,30 @@ static int mmc35240_init(struct mmc35240_data *data)
return ret;
/* set default sampling frequency */
- return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
- MMC35240_CTRL1_BW_MASK,
- data->res << MMC35240_CTRL1_BW_SHIFT);
+ ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
+ MMC35240_CTRL1_BW_MASK,
+ data->res << MMC35240_CTRL1_BW_SHIFT);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR,
+ (u8 *)otp_data, sizeof(otp_data));
+ if (ret < 0)
+ return ret;
+
+ y_convert = MMC35240_OTP_CONVERT_Y(((otp_data[1] & 0x03) << 4) |
+ (otp_data[2] >> 4));
+ z_convert = MMC35240_OTP_CONVERT_Z(otp_data[3] & 0x3f);
+
+ data->axis_coef[0] = MMC35240_X_COEFF(1);
+ data->axis_coef[1] = MMC35240_Y_COEFF(y_convert);
+ data->axis_coef[2] = MMC35240_Z_COEFF(z_convert);
+
+ data->axis_scale[0] = 1;
+ data->axis_scale[1] = 1000;
+ data->axis_scale[2] = 10000;
+
+ return 0;
}
static int mmc35240_take_measurement(struct mmc35240_data *data)
@@ -217,7 +270,8 @@ static int mmc35240_take_measurement(struct mmc35240_data *data)
return ret;
if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT)
break;
- msleep(20);
+ /* minimum wait time to complete measurement is 10 ms */
+ usleep_range(10000, 11000);
}
if (tries < 0) {
@@ -240,9 +294,19 @@ static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3])
3 * sizeof(__le16));
}
-static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index,
- __le16 buf[],
- int *val, int *val2)
+/**
+ * mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply
+ compensation for output value.
+ *
+ * @data: device private data
+ * @index: axis index for which we want the conversion
+ * @buf: raw data to be converted, 2 bytes in little endian format
+ * @val: compensated output reading (unit is milli gauss)
+ *
+ * Returns: 0 in case of success, -EINVAL when @index is not valid
+ */
+static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index,
+ __le16 buf[], int *val)
{
int raw_x, raw_y, raw_z;
int sens_x, sens_y, sens_z;
@@ -260,22 +324,22 @@ static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index,
switch (index) {
case AXIS_X:
- *val = (raw_x - nfo) / sens_x;
- *val2 = ((raw_x - nfo) % sens_x) * 1000000;
+ *val = (raw_x - nfo) * 1000 / sens_x;
break;
case AXIS_Y:
- *val = (raw_y - nfo) / sens_y - (raw_z - nfo) / sens_z;
- *val2 = (((raw_y - nfo) % sens_y - (raw_z - nfo) % sens_z))
- * 1000000;
+ *val = (raw_y - nfo) * 1000 / sens_y -
+ (raw_z - nfo) * 1000 / sens_z;
break;
case AXIS_Z:
- *val = (raw_y - nfo) / sens_y + (raw_z - nfo) / sens_z;
- *val2 = (((raw_y - nfo) % sens_y + (raw_z - nfo) % sens_z))
- * 1000000;
+ *val = (raw_y - nfo) * 1000 / sens_y +
+ (raw_z - nfo) * 1000 / sens_z;
break;
default:
return -EINVAL;
}
+ /* apply OTP compensation */
+ *val = (*val) * data->axis_coef[index] / data->axis_scale[index];
+
return 0;
}
@@ -289,16 +353,19 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev,
__le16 buf[3];
switch (mask) {
- case IIO_CHAN_INFO_PROCESSED:
+ case IIO_CHAN_INFO_RAW:
mutex_lock(&data->mutex);
ret = mmc35240_read_measurement(data, buf);
mutex_unlock(&data->mutex);
if (ret < 0)
return ret;
- ret = mmc35240_raw_to_gauss(data, chan->address,
- buf, val, val2);
+ ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val);
if (ret < 0)
return ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 0;
+ *val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
mutex_lock(&data->mutex);
@@ -308,7 +375,7 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev,
return ret;
i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT;
- if (i < 0 || i > ARRAY_SIZE(mmc35240_samp_freq))
+ if (i < 0 || i >= ARRAY_SIZE(mmc35240_samp_freq))
return -EINVAL;
*val = mmc35240_samp_freq[i];
@@ -490,7 +557,7 @@ static const struct acpi_device_id mmc35240_acpi_match[] = {
MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match);
static const struct i2c_device_id mmc35240_id[] = {
- {"MMC35240", 0},
+ {"mmc35240", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, mmc35240_id);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 23:49:07 +0000