Commit 62979904 authored by Akinobu Mita's avatar Akinobu Mita Committed by Jonathan Cameron

iio: pressure: bmp280: add ability to control oversampling rate

This adds ability to control the oversampling ratio of the temperature
and pressure measurement for both bmp180 and bmp280.
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: default avatarVlad Dogaru <vlad.dogaru@intel.com>
Cc: Christoph Mair <christoph.mair@gmail.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 6dba72ec
......@@ -48,19 +48,21 @@
#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5))
#define BMP280_OSRS_TEMP_SKIP 0
#define BMP280_OSRS_TEMP_1X BIT(5)
#define BMP280_OSRS_TEMP_2X BIT(6)
#define BMP280_OSRS_TEMP_4X (BIT(6) | BIT(5))
#define BMP280_OSRS_TEMP_8X BIT(7)
#define BMP280_OSRS_TEMP_16X (BIT(7) | BIT(5))
#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5)
#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1)
#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2)
#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3)
#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4)
#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5)
#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2))
#define BMP280_OSRS_PRESS_SKIP 0
#define BMP280_OSRS_PRESS_1X BIT(2)
#define BMP280_OSRS_PRESS_2X BIT(3)
#define BMP280_OSRS_PRESS_4X (BIT(3) | BIT(2))
#define BMP280_OSRS_PRESS_8X BIT(4)
#define BMP280_OSRS_PRESS_16X (BIT(4) | BIT(2))
#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2)
#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1)
#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2)
#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3)
#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4)
#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5)
#define BMP280_MODE_MASK (BIT(1) | BIT(0))
#define BMP280_MODE_SLEEP 0
......@@ -98,6 +100,10 @@ struct bmp280_data {
struct regmap *regmap;
const struct bmp280_chip_info *chip_info;
/* log of base 2 of oversampling rate */
u8 oversampling_press;
u8 oversampling_temp;
/*
* Carryover value from temperature conversion, used in pressure
* calculation.
......@@ -108,6 +114,12 @@ struct bmp280_data {
struct bmp280_chip_info {
const struct regmap_config *regmap_config;
const int *oversampling_temp_avail;
int num_oversampling_temp_avail;
const int *oversampling_press_avail;
int num_oversampling_press_avail;
int (*chip_config)(struct bmp280_data *);
int (*read_temp)(struct bmp280_data *, int *);
int (*read_press)(struct bmp280_data *, int *, int *);
......@@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
static const struct iio_chan_spec bmp280_channels[] = {
{
.type = IIO_PRESSURE,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
},
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
},
};
......@@ -333,32 +347,160 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
break;
}
break;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->type) {
case IIO_PRESSURE:
*val = 1 << data->oversampling_press;
ret = IIO_VAL_INT;
break;
case IIO_TEMP:
*val = 1 << data->oversampling_temp;
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
break;
}
break;
default:
ret = -EINVAL;
break;
}
mutex_unlock(&data->lock);
return ret;
}
static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
int val)
{
int i;
const int *avail = data->chip_info->oversampling_temp_avail;
const int n = data->chip_info->num_oversampling_temp_avail;
for (i = 0; i < n; i++) {
if (avail[i] == val) {
data->oversampling_temp = ilog2(val);
return data->chip_info->chip_config(data);
}
}
return -EINVAL;
}
static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
int val)
{
int i;
const int *avail = data->chip_info->oversampling_press_avail;
const int n = data->chip_info->num_oversampling_press_avail;
for (i = 0; i < n; i++) {
if (avail[i] == val) {
data->oversampling_press = ilog2(val);
return data->chip_info->chip_config(data);
}
}
return -EINVAL;
}
static int bmp280_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret = 0;
struct bmp280_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
mutex_lock(&data->lock);
switch (chan->type) {
case IIO_PRESSURE:
ret = bmp280_write_oversampling_ratio_press(data, val);
break;
case IIO_TEMP:
ret = bmp280_write_oversampling_ratio_temp(data, val);
break;
default:
ret = -EINVAL;
break;
}
mutex_unlock(&data->lock);
break;
default:
return -EINVAL;
}
return ret;
}
static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
{
size_t len = 0;
int i;
for (i = 0; i < n; i++)
len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
buf[len - 1] = '\n';
return len;
}
static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
data->chip_info->num_oversampling_temp_avail);
}
static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
data->chip_info->num_oversampling_press_avail);
}
static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
static struct attribute *bmp280_attributes[] = {
&iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
&iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
NULL,
};
static const struct attribute_group bmp280_attrs_group = {
.attrs = bmp280_attributes,
};
static const struct iio_info bmp280_info = {
.driver_module = THIS_MODULE,
.read_raw = &bmp280_read_raw,
.write_raw = &bmp280_write_raw,
.attrs = &bmp280_attrs_group,
};
static int bmp280_chip_config(struct bmp280_data *data)
{
int ret;
u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
BMP280_OSRS_TEMP_MASK |
BMP280_OSRS_PRESS_MASK |
BMP280_MODE_MASK,
BMP280_OSRS_TEMP_2X |
BMP280_OSRS_PRESS_16X |
BMP280_MODE_NORMAL);
osrs | BMP280_MODE_NORMAL);
if (ret < 0) {
dev_err(&data->client->dev,
"failed to write ctrl_meas register\n");
......@@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
return ret;
}
static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
static const struct bmp280_chip_info bmp280_chip_info = {
.regmap_config = &bmp280_regmap_config,
.oversampling_temp_avail = bmp280_oversampling_avail,
.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
.oversampling_press_avail = bmp280_oversampling_avail,
.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
.chip_config = bmp280_chip_config,
.read_temp = bmp280_read_temp,
.read_press = bmp280_read_press,
......@@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
if (ctrl_meas == BMP180_MEAS_TEMP)
delay_us = 4500;
else
delay_us = conversion_time_max[ilog2(8)];
delay_us = conversion_time_max[data->oversampling_press];
usleep_range(delay_us, delay_us + 1000);
......@@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
{
int ret;
__be32 tmp = 0;
u8 oss = ilog2(8);
u8 oss = data->oversampling_press;
ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
if (ret)
......@@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
s32 x1, x2, x3, p;
s32 b3, b6;
u32 b4, b7;
s32 oss = ilog2(8);
s32 oss = data->oversampling_press;
struct bmp180_calib calib;
ret = bmp180_read_calib(data, &calib);
......@@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
return 0;
}
static const int bmp180_oversampling_temp_avail[] = { 1 };
static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
static const struct bmp280_chip_info bmp180_chip_info = {
.regmap_config = &bmp180_regmap_config,
.oversampling_temp_avail = bmp180_oversampling_temp_avail,
.num_oversampling_temp_avail =
ARRAY_SIZE(bmp180_oversampling_temp_avail),
.oversampling_press_avail = bmp180_oversampling_press_avail,
.num_oversampling_press_avail =
ARRAY_SIZE(bmp180_oversampling_press_avail),
.chip_config = bmp180_chip_config,
.read_temp = bmp180_read_temp,
.read_press = bmp180_read_press,
......@@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
switch (id->driver_data) {
case BMP180_CHIP_ID:
data->chip_info = &bmp180_chip_info;
data->oversampling_press = ilog2(8);
data->oversampling_temp = ilog2(1);
break;
case BMP280_CHIP_ID:
data->chip_info = &bmp280_chip_info;
data->oversampling_press = ilog2(16);
data->oversampling_temp = ilog2(2);
break;
default:
return -EINVAL;
......
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