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linux/drivers/iio/pressure/st_pressure_core.c

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/*
* STMicroelectronics pressures driver
*
* Copyright 2013 STMicroelectronics Inc.
*
* Denis Ciocca <denis.ciocca@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/buffer.h>
#include <asm/unaligned.h>
#include <linux/iio/common/st_sensors.h>
#include "st_pressure.h"
/*
* About determining pressure scaling factors
* ------------------------------------------
*
* Datasheets specify typical pressure sensitivity so that pressure is computed
* according to the following equation :
* pressure[mBar] = raw / sensitivity
* where :
* raw the 24 bits long raw sampled pressure
* sensitivity a scaling factor specified by the datasheet in LSB/mBar
*
* IIO ABI expects pressure to be expressed as kPascal, hence pressure should be
* computed according to :
* pressure[kPascal] = pressure[mBar] / 10
* = raw / (sensitivity * 10) (1)
*
* Finally, st_press_read_raw() returns pressure scaling factor as an
* IIO_VAL_INT_PLUS_NANO with a zero integral part and "gain" as decimal part.
* Therefore, from (1), "gain" becomes :
* gain = 10^9 / (sensitivity * 10)
* = 10^8 / sensitivity
*
* About determining temperature scaling factors and offsets
* ---------------------------------------------------------
*
* Datasheets specify typical temperature sensitivity and offset so that
* temperature is computed according to the following equation :
* temp[Celsius] = offset[Celsius] + (raw / sensitivity)
* where :
* raw the 16 bits long raw sampled temperature
* offset a constant specified by the datasheet in degree Celsius
* (sometimes zero)
* sensitivity a scaling factor specified by the datasheet in LSB/Celsius
*
* IIO ABI expects temperature to be expressed as milli degree Celsius such as
* user space should compute temperature according to :
* temp[mCelsius] = temp[Celsius] * 10^3
* = (offset[Celsius] + (raw / sensitivity)) * 10^3
* = ((offset[Celsius] * sensitivity) + raw) *
* (10^3 / sensitivity) (2)
*
* IIO ABI expects user space to apply offset and scaling factors to raw samples
* according to :
* temp[mCelsius] = (OFFSET + raw) * SCALE
* where :
* OFFSET an arbitrary constant exposed by device
* SCALE an arbitrary scaling factor exposed by device
*
* Matching OFFSET and SCALE with members of (2) gives :
* OFFSET = offset[Celsius] * sensitivity (3)
* SCALE = 10^3 / sensitivity (4)
*
* st_press_read_raw() returns temperature scaling factor as an
* IIO_VAL_FRACTIONAL with a 10^3 numerator and "gain2" as denominator.
* Therefore, from (3), "gain2" becomes :
* gain2 = sensitivity
*
* When declared within channel, i.e. for a non zero specified offset,
* st_press_read_raw() will return the latter as an IIO_VAL_FRACTIONAL such as :
* numerator = OFFSET * 10^3
* denominator = 10^3
* giving from (4):
* numerator = offset[Celsius] * 10^3 * sensitivity
* = offset[mCelsius] * gain2
*/
#define MCELSIUS_PER_CELSIUS 1000
/* Default pressure sensitivity */
#define ST_PRESS_LSB_PER_MBAR 4096UL
#define ST_PRESS_KPASCAL_NANO_SCALE (100000000UL / \
ST_PRESS_LSB_PER_MBAR)
/* Default temperature sensitivity */
#define ST_PRESS_LSB_PER_CELSIUS 480UL
#define ST_PRESS_MILLI_CELSIUS_OFFSET 42500UL
/* FULLSCALE */
#define ST_PRESS_FS_AVL_1100MB 1100
#define ST_PRESS_FS_AVL_1260MB 1260
#define ST_PRESS_1_OUT_XL_ADDR 0x28
#define ST_TEMP_1_OUT_L_ADDR 0x2b
/* LPS001WP pressure resolution */
#define ST_PRESS_LPS001WP_LSB_PER_MBAR 16UL
/* LPS001WP temperature resolution */
#define ST_PRESS_LPS001WP_LSB_PER_CELSIUS 64UL
/* LPS001WP pressure gain */
#define ST_PRESS_LPS001WP_FS_AVL_PRESS_GAIN \
(100000000UL / ST_PRESS_LPS001WP_LSB_PER_MBAR)
/* LPS001WP pressure and temp L addresses */
#define ST_PRESS_LPS001WP_OUT_L_ADDR 0x28
#define ST_TEMP_LPS001WP_OUT_L_ADDR 0x2a
/* LPS25H pressure and temp L addresses */
#define ST_PRESS_LPS25H_OUT_XL_ADDR 0x28
#define ST_TEMP_LPS25H_OUT_L_ADDR 0x2b
/* LPS22HB temperature sensitivity */
#define ST_PRESS_LPS22HB_LSB_PER_CELSIUS 100UL
static const struct iio_chan_spec st_press_1_channels[] = {
{
.type = IIO_PRESSURE,
.address = ST_PRESS_1_OUT_XL_ADDR,
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 24,
.storagebits = 32,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
{
.type = IIO_TEMP,
.address = ST_TEMP_1_OUT_L_ADDR,
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
IIO_CHAN_SOFT_TIMESTAMP(2)
};
static const struct iio_chan_spec st_press_lps001wp_channels[] = {
{
.type = IIO_PRESSURE,
.address = ST_PRESS_LPS001WP_OUT_L_ADDR,
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
},
{
.type = IIO_TEMP,
.address = ST_TEMP_LPS001WP_OUT_L_ADDR,
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
},
IIO_CHAN_SOFT_TIMESTAMP(2)
};
static const struct iio_chan_spec st_press_lps22hb_channels[] = {
{
.type = IIO_PRESSURE,
.address = ST_PRESS_1_OUT_XL_ADDR,
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 24,
.storagebits = 32,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
{
.type = IIO_TEMP,
.address = ST_TEMP_1_OUT_L_ADDR,
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
IIO_CHAN_SOFT_TIMESTAMP(2)
};
static const struct st_sensor_settings st_press_sensors_settings[] = {
{
/*
* CUSTOM VALUES FOR LPS331AP SENSOR
* See LPS331AP datasheet:
* http://www2.st.com/resource/en/datasheet/lps331ap.pdf
*/
.wai = 0xbb,
.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
.sensors_supported = {
[0] = LPS331AP_PRESS_DEV_NAME,
},
.ch = (struct iio_chan_spec *)st_press_1_channels,
.num_ch = ARRAY_SIZE(st_press_1_channels),
.odr = {
.addr = 0x20,
.mask = 0x70,
.odr_avl = {
{ .hz = 1, .value = 0x01 },
{ .hz = 7, .value = 0x05 },
{ .hz = 13, .value = 0x06 },
{ .hz = 25, .value = 0x07 },
},
},
.pw = {
.addr = 0x20,
.mask = 0x80,
.value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE,
.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
},
.fs = {
.addr = 0x23,
.mask = 0x30,
.fs_avl = {
/*
* Pressure and temperature sensitivity values
* as defined in table 3 of LPS331AP datasheet.
*/
[0] = {
.num = ST_PRESS_FS_AVL_1260MB,
.gain = ST_PRESS_KPASCAL_NANO_SCALE,
.gain2 = ST_PRESS_LSB_PER_CELSIUS,
},
},
},
.bdu = {
.addr = 0x20,
.mask = 0x04,
},
.drdy_irq = {
.int1 = {
.addr = 0x22,
.mask = 0x04,
.addr_od = 0x22,
.mask_od = 0x40,
},
.int2 = {
.addr = 0x22,
.mask = 0x20,
.addr_od = 0x22,
.mask_od = 0x40,
},
.addr_ihl = 0x22,
.mask_ihl = 0x80,
.stat_drdy = {
.addr = ST_SENSORS_DEFAULT_STAT_ADDR,
.mask = 0x03,
},
},
.sim = {
.addr = 0x20,
.value = BIT(0),
},
.multi_read_bit = true,
.bootime = 2,
},
{
/*
* CUSTOM VALUES FOR LPS001WP SENSOR
*/
.wai = 0xba,
.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
.sensors_supported = {
[0] = LPS001WP_PRESS_DEV_NAME,
},
.ch = (struct iio_chan_spec *)st_press_lps001wp_channels,
.num_ch = ARRAY_SIZE(st_press_lps001wp_channels),
.odr = {
.addr = 0x20,
.mask = 0x30,
.odr_avl = {
{ .hz = 1, .value = 0x01 },
{ .hz = 7, .value = 0x02 },
{ .hz = 13, .value = 0x03 },
},
},
.pw = {
.addr = 0x20,
.mask = 0x40,
.value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE,
.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
},
.fs = {
.fs_avl = {
/*
* Pressure and temperature resolution values
* as defined in table 3 of LPS001WP datasheet.
*/
[0] = {
.num = ST_PRESS_FS_AVL_1100MB,
.gain = ST_PRESS_LPS001WP_FS_AVL_PRESS_GAIN,
.gain2 = ST_PRESS_LPS001WP_LSB_PER_CELSIUS,
},
},
},
.bdu = {
.addr = 0x20,
.mask = 0x04,
},
.sim = {
.addr = 0x20,
.value = BIT(0),
},
.multi_read_bit = true,
.bootime = 2,
},
{
/*
* CUSTOM VALUES FOR LPS25H SENSOR
* See LPS25H datasheet:
* http://www2.st.com/resource/en/datasheet/lps25h.pdf
*/
.wai = 0xbd,
.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
.sensors_supported = {
[0] = LPS25H_PRESS_DEV_NAME,
},
.ch = (struct iio_chan_spec *)st_press_1_channels,
.num_ch = ARRAY_SIZE(st_press_1_channels),
.odr = {
.addr = 0x20,
.mask = 0x70,
.odr_avl = {
{ .hz = 1, .value = 0x01 },
{ .hz = 7, .value = 0x02 },
{ .hz = 13, .value = 0x03 },
{ .hz = 25, .value = 0x04 },
},
},
.pw = {
.addr = 0x20,
.mask = 0x80,
.value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE,
.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
},
.fs = {
.fs_avl = {
/*
* Pressure and temperature sensitivity values
* as defined in table 3 of LPS25H datasheet.
*/
[0] = {
.num = ST_PRESS_FS_AVL_1260MB,
.gain = ST_PRESS_KPASCAL_NANO_SCALE,
.gain2 = ST_PRESS_LSB_PER_CELSIUS,
},
},
},
.bdu = {
.addr = 0x20,
.mask = 0x04,
},
.drdy_irq = {
.int1 = {
.addr = 0x23,
.mask = 0x01,
.addr_od = 0x22,
.mask_od = 0x40,
},
.addr_ihl = 0x22,
.mask_ihl = 0x80,
.stat_drdy = {
.addr = ST_SENSORS_DEFAULT_STAT_ADDR,
.mask = 0x03,
},
},
.sim = {
.addr = 0x20,
.value = BIT(0),
},
.multi_read_bit = true,
.bootime = 2,
},
{
/*
* CUSTOM VALUES FOR LPS22HB SENSOR
* See LPS22HB datasheet:
* http://www2.st.com/resource/en/datasheet/lps22hb.pdf
*/
.wai = 0xb1,
.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
.sensors_supported = {
[0] = LPS22HB_PRESS_DEV_NAME,
[1] = LPS33HW_PRESS_DEV_NAME,
[2] = LPS35HW_PRESS_DEV_NAME,
},
.ch = (struct iio_chan_spec *)st_press_lps22hb_channels,
.num_ch = ARRAY_SIZE(st_press_lps22hb_channels),
.odr = {
.addr = 0x10,
.mask = 0x70,
.odr_avl = {
{ .hz = 1, .value = 0x01 },
{ .hz = 10, .value = 0x02 },
{ .hz = 25, .value = 0x03 },
{ .hz = 50, .value = 0x04 },
{ .hz = 75, .value = 0x05 },
},
},
.pw = {
.addr = 0x10,
.mask = 0x70,
.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
},
.fs = {
.fs_avl = {
/*
* Pressure and temperature sensitivity values
* as defined in table 3 of LPS22HB datasheet.
*/
[0] = {
.num = ST_PRESS_FS_AVL_1260MB,
.gain = ST_PRESS_KPASCAL_NANO_SCALE,
.gain2 = ST_PRESS_LPS22HB_LSB_PER_CELSIUS,
},
},
},
.bdu = {
.addr = 0x10,
.mask = 0x02,
},
.drdy_irq = {
.int1 = {
.addr = 0x12,
.mask = 0x04,
.addr_od = 0x12,
.mask_od = 0x40,
},
.addr_ihl = 0x12,
.mask_ihl = 0x80,
.stat_drdy = {
.addr = ST_SENSORS_DEFAULT_STAT_ADDR,
.mask = 0x03,
},
},
.sim = {
.addr = 0x10,
.value = BIT(0),
},
.multi_read_bit = false,
.bootime = 2,
},
};
static int st_press_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *ch,
int val,
int val2,
long mask)
{
int err;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
if (val2)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
err = st_sensors_set_odr(indio_dev, val);
mutex_unlock(&indio_dev->mlock);
return err;
default:
return -EINVAL;
}
}
static int st_press_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *ch, int *val,
int *val2, long mask)
{
int err;
struct st_sensor_data *press_data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
err = st_sensors_read_info_raw(indio_dev, ch, val);
if (err < 0)
goto read_error;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (ch->type) {
case IIO_PRESSURE:
*val = 0;
*val2 = press_data->current_fullscale->gain;
return IIO_VAL_INT_PLUS_NANO;
case IIO_TEMP:
*val = MCELSIUS_PER_CELSIUS;
*val2 = press_data->current_fullscale->gain2;
return IIO_VAL_FRACTIONAL;
default:
err = -EINVAL;
goto read_error;
}
case IIO_CHAN_INFO_OFFSET:
switch (ch->type) {
case IIO_TEMP:
*val = ST_PRESS_MILLI_CELSIUS_OFFSET *
press_data->current_fullscale->gain2;
*val2 = MCELSIUS_PER_CELSIUS;
break;
default:
err = -EINVAL;
goto read_error;
}
return IIO_VAL_FRACTIONAL;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = press_data->odr;
return IIO_VAL_INT;
default:
return -EINVAL;
}
read_error:
return err;
}
static ST_SENSORS_DEV_ATTR_SAMP_FREQ_AVAIL();
static struct attribute *st_press_attributes[] = {
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
static const struct attribute_group st_press_attribute_group = {
.attrs = st_press_attributes,
};
static const struct iio_info press_info = {
.attrs = &st_press_attribute_group,
.read_raw = &st_press_read_raw,
.write_raw = &st_press_write_raw,
.debugfs_reg_access = &st_sensors_debugfs_reg_access,
};
#ifdef CONFIG_IIO_TRIGGER
static const struct iio_trigger_ops st_press_trigger_ops = {
.set_trigger_state = ST_PRESS_TRIGGER_SET_STATE,
.validate_device = st_sensors_validate_device,
};
#define ST_PRESS_TRIGGER_OPS (&st_press_trigger_ops)
#else
#define ST_PRESS_TRIGGER_OPS NULL
#endif
int st_press_common_probe(struct iio_dev *indio_dev)
{
struct st_sensor_data *press_data = iio_priv(indio_dev);
struct st_sensors_platform_data *pdata =
(struct st_sensors_platform_data *)press_data->dev->platform_data;
int irq = press_data->get_irq_data_ready(indio_dev);
int err;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &press_info;
mutex_init(&press_data->tb.buf_lock);
err = st_sensors_power_enable(indio_dev);
if (err)
return err;
err = st_sensors_check_device_support(indio_dev,
ARRAY_SIZE(st_press_sensors_settings),
st_press_sensors_settings);
if (err < 0)
goto st_press_power_off;
/*
* Skip timestamping channel while declaring available channels to
* common st_sensor layer. Look at st_sensors_get_buffer_element() to
* see how timestamps are explicitly pushed as last samples block
* element.
*/
press_data->num_data_channels = press_data->sensor_settings->num_ch - 1;
press_data->multiread_bit = press_data->sensor_settings->multi_read_bit;
indio_dev->channels = press_data->sensor_settings->ch;
indio_dev->num_channels = press_data->sensor_settings->num_ch;
press_data->current_fullscale =
(struct st_sensor_fullscale_avl *)
&press_data->sensor_settings->fs.fs_avl[0];
press_data->odr = press_data->sensor_settings->odr.odr_avl[0].hz;
/* Some devices don't support a data ready pin. */
if (!pdata && (press_data->sensor_settings->drdy_irq.int1.addr ||
press_data->sensor_settings->drdy_irq.int2.addr))
pdata = (struct st_sensors_platform_data *)&default_press_pdata;
err = st_sensors_init_sensor(indio_dev, press_data->dev->platform_data);
if (err < 0)
goto st_press_power_off;
err = st_press_allocate_ring(indio_dev);
if (err < 0)
goto st_press_power_off;
if (irq > 0) {
err = st_sensors_allocate_trigger(indio_dev,
ST_PRESS_TRIGGER_OPS);
if (err < 0)
goto st_press_probe_trigger_error;
}
err = iio_device_register(indio_dev);
if (err)
goto st_press_device_register_error;
dev_info(&indio_dev->dev, "registered pressure sensor %s\n",
indio_dev->name);
return err;
st_press_device_register_error:
if (irq > 0)
st_sensors_deallocate_trigger(indio_dev);
st_press_probe_trigger_error:
st_press_deallocate_ring(indio_dev);
st_press_power_off:
st_sensors_power_disable(indio_dev);
return err;
}
EXPORT_SYMBOL(st_press_common_probe);
void st_press_common_remove(struct iio_dev *indio_dev)
{
struct st_sensor_data *press_data = iio_priv(indio_dev);
st_sensors_power_disable(indio_dev);
iio_device_unregister(indio_dev);
if (press_data->get_irq_data_ready(indio_dev) > 0)
st_sensors_deallocate_trigger(indio_dev);
st_press_deallocate_ring(indio_dev);
}
EXPORT_SYMBOL(st_press_common_remove);
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics pressures driver");
MODULE_LICENSE("GPL v2");
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