iio: accel: Add sampling rate support for STK8BA50
Added support for setting the STK8BA50 accelerometer's
sampling rate.
Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c
index 3302a3d..92229bd 100644
--- a/drivers/iio/accel/stk8ba50.c
+++ b/drivers/iio/accel/stk8ba50.c
@@ -21,6 +21,7 @@
#define STK8BA50_REG_YOUT 0x04
#define STK8BA50_REG_ZOUT 0x06
#define STK8BA50_REG_RANGE 0x0F
+#define STK8BA50_REG_BWSEL 0x10
#define STK8BA50_REG_POWMODE 0x11
#define STK8BA50_REG_SWRST 0x14
@@ -29,6 +30,7 @@
#define STK8BA50_MODE_POWERBIT BIT(7)
#define STK8BA50_DATA_SHIFT 6
#define STK8BA50_RESET_CMD 0xB6
+#define STK8BA50_SR_1792HZ_IDX 7
#define STK8BA50_DRIVER_NAME "stk8ba50"
@@ -57,19 +59,30 @@
{3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
};
+/* Sample rates are stored as { <register value>, <Hz value> } */
+static const struct {
+ u8 reg_val;
+ u16 samp_freq;
+} stk8ba50_samp_freq_table[] = {
+ {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112},
+ {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
+};
+
struct stk8ba50_data {
struct i2c_client *client;
struct mutex lock;
int range;
+ u8 sample_rate_idx;
};
-#define STK8BA50_ACCEL_CHANNEL(reg, axis) { \
- .type = IIO_ACCEL, \
- .address = reg, \
- .modified = 1, \
- .channel2 = IIO_MOD_##axis, \
- .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
- .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+#define STK8BA50_ACCEL_CHANNEL(reg, axis) { \
+ .type = IIO_ACCEL, \
+ .address = reg, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
}
static const struct iio_chan_spec stk8ba50_channels[] = {
@@ -80,8 +93,11 @@
static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
+
static struct attribute *stk8ba50_attributes[] = {
&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
@@ -119,6 +135,11 @@
*val = 0;
*val2 = stk8ba50_scale_table[data->range].scale_val;
return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = stk8ba50_samp_freq_table
+ [data->sample_rate_idx].samp_freq;
+ *val2 = 0;
+ return IIO_VAL_INT;
}
return -EINVAL;
@@ -156,6 +177,25 @@
data->range = index;
return ret;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
+ if (val == stk8ba50_samp_freq_table[i].samp_freq) {
+ index = i;
+ break;
+ }
+ if (index < 0)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ STK8BA50_REG_BWSEL,
+ stk8ba50_samp_freq_table[index].reg_val);
+ if (ret < 0)
+ dev_err(&data->client->dev,
+ "failed to set sampling rate\n");
+ else
+ data->sample_rate_idx = index;
+
+ return ret;
}
return -EINVAL;
@@ -231,6 +271,9 @@
/* The default range is +/-2g */
data->range = 0;
+ /* The default sampling rate is 1792 Hz (maximum) */
+ data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
+
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");