[PATCH 3/4] iio: fxas21002c: add ODR/Scale support

From: Afonso Bordado
Date: Sat Aug 25 2018 - 16:35:10 EST


This patch adds support for reading/writing ODR/Scale

We don't support the scale boost modes.

Signed-off-by: Afonso Bordado <afonsobordado@xxxxxx>
---
drivers/iio/gyro/fxas21002c.c | 162 +++++++++++++++++++++++++++++++---
1 file changed, 149 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/gyro/fxas21002c.c b/drivers/iio/gyro/fxas21002c.c
index 6fef210630e0..dc0cb9848386 100644
--- a/drivers/iio/gyro/fxas21002c.c
+++ b/drivers/iio/gyro/fxas21002c.c
@@ -7,7 +7,7 @@
* IIO driver for FXAS21002C (7-bit I2C slave address 0x20 or 0x21).
* Datasheet: https://www.nxp.com/docs/en/data-sheet/FXAS21002.pdf
* TODO:
- * ODR / Scale Support
+ * Scale boost mode
* Power management
* LowPass/HighPass Filters
* Buffers
@@ -40,7 +40,10 @@
#define FXAS21002C_REG_F_EVENT 0x0A
#define FXAS21002C_REG_INT_SRC_FLAG 0x0B
#define FXAS21002C_REG_WHO_AM_I 0x0C
+
#define FXAS21002C_REG_CTRL_REG0 0x0D
+#define FXAS21002C_SCALE_MASK (BIT(0) | BIT(1))
+
#define FXAS21002C_REG_RT_CFG 0x0E
#define FXAS21002C_REG_RT_SRC 0x0F
#define FXAS21002C_REG_RT_THS 0x10
@@ -52,13 +55,12 @@
#define FXAS21002C_ACTIVE_BIT BIT(1)
#define FXAS21002C_READY_BIT BIT(0)

-#define FXAS21002C_REG_CTRL_REG2 0x14
-#define FXAS21002C_REG_CTRL_REG3 0x15
+#define FXAS21002C_ODR_SHIFT 2
+#define FXAS21002C_ODR_MASK (BIT(2) | BIT(3) | BIT(4))

-#define FXAS21002C_DEFAULT_ODR_HZ 800

-// 0.0625 deg/s
-#define FXAS21002C_DEFAULT_SENSITIVITY IIO_DEGREE_TO_RAD(62500)
+#define FXAS21002C_REG_CTRL_REG2 0x14
+#define FXAS21002C_REG_CTRL_REG3 0x15

enum fxas21002c_id {
ID_FXAS21002C,
@@ -76,6 +78,40 @@ struct fxas21002c_data {
struct regmap *regmap;
};

+enum fxas21002c_scale {
+ FXAS21002C_SCALE_62MDPS,
+ FXAS21002C_SCALE_31MDPS,
+ FXAS21002C_SCALE_15MDPS,
+ FXAS21002C_SCALE_7MDPS,
+};
+
+static const int fxas21002c_anglevel_scale_avail[4][2] = {
+ [FXAS21002C_SCALE_62MDPS] = { 0, IIO_DEGREE_TO_RAD(62500) },
+ [FXAS21002C_SCALE_31MDPS] = { 0, IIO_DEGREE_TO_RAD(31250) },
+ [FXAS21002C_SCALE_15MDPS] = { 0, IIO_DEGREE_TO_RAD(15625) },
+ [FXAS21002C_SCALE_7MDPS] = { 0, IIO_DEGREE_TO_RAD(7812) },
+};
+
+enum fxas21002c_odr {
+ FXAS21002C_ODR_800,
+ FXAS21002C_ODR_400,
+ FXAS21002C_ODR_200,
+ FXAS21002C_ODR_100,
+ FXAS21002C_ODR_50,
+ FXAS21002C_ODR_25,
+ FXAS21002C_ODR_12_5,
+};
+
+static const int fxas21002c_sample_freq_avail[7][2] = {
+ [FXAS21002C_ODR_800] = { 800, 0 },
+ [FXAS21002C_ODR_400] = { 400, 0 },
+ [FXAS21002C_ODR_200] = { 200, 0 },
+ [FXAS21002C_ODR_100] = { 100, 0 },
+ [FXAS21002C_ODR_50] = { 50, 0 },
+ [FXAS21002C_ODR_25] = { 25, 0 },
+ [FXAS21002C_ODR_12_5] = { 12, 500000 },
+};
+
static const struct regmap_range fxas21002c_writable_ranges[] = {
regmap_reg_range(FXAS21002C_REG_F_SETUP, FXAS21002C_REG_F_SETUP),
regmap_reg_range(FXAS21002C_REG_CTRL_REG0, FXAS21002C_REG_RT_CFG),
@@ -242,6 +278,47 @@ static int fxas21002c_read_oneshot(struct fxas21002c_data *data,
return IIO_VAL_INT;
}

+static int fxas21002c_scale_read(struct fxas21002c_data *data, int *val,
+ int *val2)
+{
+ int ret;
+ unsigned int raw;
+
+ ret = regmap_read(data->regmap, FXAS21002C_REG_CTRL_REG0, &raw);
+ if (ret)
+ return ret;
+
+ raw &= FXAS21002C_SCALE_MASK;
+
+ *val = fxas21002c_anglevel_scale_avail[raw][0];
+ *val2 = fxas21002c_anglevel_scale_avail[raw][1];
+
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int fxas21002c_odr_read(struct fxas21002c_data *data, int *val,
+ int *val2)
+{
+ int ret;
+ unsigned int raw;
+
+ ret = regmap_read(data->regmap, FXAS21002C_REG_CTRL_REG1, &raw);
+ if (ret)
+ return ret;
+
+ raw = (raw & FXAS21002C_ODR_MASK) >> FXAS21002C_ODR_SHIFT;
+
+ // We don't use this mode but according to the datasheet its
+ // also a 12.5Hz
+ if (raw == 7)
+ raw = FXAS21002C_ODR_12_5;
+
+ *val = fxas21002c_sample_freq_avail[raw][0];
+ *val2 = fxas21002c_sample_freq_avail[raw][1];
+
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
static int fxas21002c_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
@@ -255,24 +332,83 @@ static int fxas21002c_read_raw(struct iio_dev *indio_dev,
if (chan->type != IIO_ANGL_VEL)
return -EINVAL;

- *val = 0;
- *val2 = FXAS21002C_DEFAULT_SENSITIVITY;
-
- return IIO_VAL_INT_PLUS_MICRO;
+ return fxas21002c_scale_read(data, val, val2);
case IIO_CHAN_INFO_SAMP_FREQ:
if (chan->type != IIO_ANGL_VEL)
return -EINVAL;

- *val = FXAS21002C_DEFAULT_ODR_HZ;
-
- return IIO_VAL_INT;
+ return fxas21002c_odr_read(data, val, val2);
}

return -EINVAL;
}

+static int fxas21002c_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct fxas21002c_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+ int i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ for (i = 0; i < ARRAY_SIZE(fxas21002c_sample_freq_avail); i++) {
+ if (fxas21002c_sample_freq_avail[i][0] == val &&
+ fxas21002c_sample_freq_avail[i][1] == val2)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(fxas21002c_sample_freq_avail))
+ break;
+
+ ret = regmap_update_bits(data->regmap, FXAS21002C_REG_CTRL_REG1,
+ FXAS21002C_ODR_MASK,
+ i << FXAS21002C_ODR_SHIFT);
+
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ for (i = 0; i < ARRAY_SIZE(fxas21002c_anglevel_scale_avail);
+ i++) {
+ if (fxas21002c_anglevel_scale_avail[i][0] == val &&
+ fxas21002c_anglevel_scale_avail[i][1] == val2)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(fxas21002c_anglevel_scale_avail))
+ break;
+
+ ret = regmap_update_bits(data->regmap, FXAS21002C_REG_CTRL_REG0,
+ FXAS21002C_SCALE_MASK, i);
+
+ break;
+ }
+
+ return ret;
+}
+
+static IIO_CONST_ATTR(anglevel_scale_available,
+ "0.001090831 " // 62.5 mdps
+ "0.000545415 " // 31.25 mdps
+ "0.000272708 " // 15.625 mdps
+ "0.000136354"); // 7.8125 mdps
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("800 400 200 100 50 25 12.5");
+
+static struct attribute *fxas21002c_attributes[] = {
+ &iio_const_attr_anglevel_scale_available.dev_attr.attr,
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group fxas21002c_attribute_group = {
+ .attrs = fxas21002c_attributes,
+};
+
static const struct iio_info fxas21002c_info = {
.read_raw = fxas21002c_read_raw,
+ .write_raw = fxas21002c_write_raw,
+ .attrs = &fxas21002c_attribute_group,
};

static int fxas21002c_probe(struct i2c_client *client,
--
2.18.0