linux/drivers/iio/pressure/ms5611_core.c
Alison Schofield 3bc1abcddb iio: pressure: ms5611: claim direct mode during oversampling changes
Driver was checking for direct mode before changing oversampling
ratios, but was not locking it.  Use the claim/release helper
functions to guarantee the device stays in direct mode while the
oversampling ratios are being updated.  Continue to use the drivers
private state lock to protect against conflicting direct mode access
of the state data.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-01-21 12:31:05 +00:00

490 lines
11 KiB
C

/*
* MS5611 pressure and temperature sensor driver
*
* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Data sheet:
* http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
* http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
*
*/
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include "ms5611.h"
#define MS5611_INIT_OSR(_cmd, _conv_usec, _rate) \
{ .cmd = _cmd, .conv_usec = _conv_usec, .rate = _rate }
static const struct ms5611_osr ms5611_avail_pressure_osr[] = {
MS5611_INIT_OSR(0x40, 600, 256),
MS5611_INIT_OSR(0x42, 1170, 512),
MS5611_INIT_OSR(0x44, 2280, 1024),
MS5611_INIT_OSR(0x46, 4540, 2048),
MS5611_INIT_OSR(0x48, 9040, 4096)
};
static const struct ms5611_osr ms5611_avail_temp_osr[] = {
MS5611_INIT_OSR(0x50, 600, 256),
MS5611_INIT_OSR(0x52, 1170, 512),
MS5611_INIT_OSR(0x54, 2280, 1024),
MS5611_INIT_OSR(0x56, 4540, 2048),
MS5611_INIT_OSR(0x58, 9040, 4096)
};
static const char ms5611_show_osr[] = "256 512 1024 2048 4096";
static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr);
static struct attribute *ms5611_attributes[] = {
&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ms5611_attribute_group = {
.attrs = ms5611_attributes,
};
static bool ms5611_prom_is_valid(u16 *prom, size_t len)
{
int i, j;
uint16_t crc = 0, crc_orig = prom[7] & 0x000F;
prom[7] &= 0xFF00;
for (i = 0; i < len * 2; i++) {
if (i % 2 == 1)
crc ^= prom[i >> 1] & 0x00FF;
else
crc ^= prom[i >> 1] >> 8;
for (j = 0; j < 8; j++) {
if (crc & 0x8000)
crc = (crc << 1) ^ 0x3000;
else
crc <<= 1;
}
}
crc = (crc >> 12) & 0x000F;
return crc_orig != 0x0000 && crc == crc_orig;
}
static int ms5611_read_prom(struct iio_dev *indio_dev)
{
int ret, i;
struct ms5611_state *st = iio_priv(indio_dev);
for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
ret = st->read_prom_word(&indio_dev->dev,
i, &st->chip_info->prom[i]);
if (ret < 0) {
dev_err(&indio_dev->dev,
"failed to read prom at %d\n", i);
return ret;
}
}
if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
dev_err(&indio_dev->dev, "PROM integrity check failed\n");
return -ENODEV;
}
return 0;
}
static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
s32 *temp, s32 *pressure)
{
int ret;
struct ms5611_state *st = iio_priv(indio_dev);
ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
if (ret < 0) {
dev_err(&indio_dev->dev,
"failed to read temperature and pressure\n");
return ret;
}
return st->chip_info->temp_and_pressure_compensate(st->chip_info,
temp, pressure);
}
static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
s32 *temp, s32 *pressure)
{
s32 t = *temp, p = *pressure;
s64 off, sens, dt;
dt = t - (chip_info->prom[5] << 8);
off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);
t = 2000 + ((chip_info->prom[6] * dt) >> 23);
if (t < 2000) {
s64 off2, sens2, t2;
t2 = (dt * dt) >> 31;
off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
sens2 = off2 >> 1;
if (t < -1500) {
s64 tmp = (t + 1500) * (t + 1500);
off2 += 7 * tmp;
sens2 += (11 * tmp) >> 1;
}
t -= t2;
off -= off2;
sens -= sens2;
}
*temp = t;
*pressure = (((p * sens) >> 21) - off) >> 15;
return 0;
}
static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
s32 *temp, s32 *pressure)
{
s32 t = *temp, p = *pressure;
s64 off, sens, dt;
dt = t - (chip_info->prom[5] << 8);
off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);
t = 2000 + ((chip_info->prom[6] * dt) >> 23);
if (t < 2000) {
s64 off2, sens2, t2, tmp;
t2 = (dt * dt) >> 31;
tmp = (t - 2000) * (t - 2000);
off2 = (61 * tmp) >> 4;
sens2 = tmp << 1;
if (t < -1500) {
tmp = (t + 1500) * (t + 1500);
off2 += 15 * tmp;
sens2 += 8 * tmp;
}
t -= t2;
off -= off2;
sens -= sens2;
}
*temp = t;
*pressure = (((p * sens) >> 21) - off) >> 15;
return 0;
}
static int ms5611_reset(struct iio_dev *indio_dev)
{
int ret;
struct ms5611_state *st = iio_priv(indio_dev);
ret = st->reset(&indio_dev->dev);
if (ret < 0) {
dev_err(&indio_dev->dev, "failed to reset device\n");
return ret;
}
usleep_range(3000, 4000);
return 0;
}
static irqreturn_t ms5611_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ms5611_state *st = iio_priv(indio_dev);
s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
int ret;
mutex_lock(&st->lock);
ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
mutex_unlock(&st->lock);
if (ret < 0)
goto err;
iio_push_to_buffers_with_timestamp(indio_dev, buf,
iio_get_time_ns(indio_dev));
err:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ms5611_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret;
s32 temp, pressure;
struct ms5611_state *st = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
mutex_lock(&st->lock);
ret = ms5611_read_temp_and_pressure(indio_dev,
&temp, &pressure);
mutex_unlock(&st->lock);
if (ret < 0)
return ret;
switch (chan->type) {
case IIO_TEMP:
*val = temp * 10;
return IIO_VAL_INT;
case IIO_PRESSURE:
*val = pressure / 1000;
*val2 = (pressure % 1000) * 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_TEMP:
*val = 10;
return IIO_VAL_INT;
case IIO_PRESSURE:
*val = 0;
*val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
break;
mutex_lock(&st->lock);
if (chan->type == IIO_TEMP)
*val = (int)st->temp_osr->rate;
else
*val = (int)st->pressure_osr->rate;
mutex_unlock(&st->lock);
return IIO_VAL_INT;
}
return -EINVAL;
}
static const struct ms5611_osr *ms5611_find_osr(int rate,
const struct ms5611_osr *osr,
size_t count)
{
unsigned int r;
for (r = 0; r < count; r++)
if ((unsigned short)rate == osr[r].rate)
break;
if (r >= count)
return NULL;
return &osr[r];
}
static int ms5611_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct ms5611_state *st = iio_priv(indio_dev);
const struct ms5611_osr *osr = NULL;
int ret;
if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
return -EINVAL;
if (chan->type == IIO_TEMP)
osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
ARRAY_SIZE(ms5611_avail_temp_osr));
else if (chan->type == IIO_PRESSURE)
osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
ARRAY_SIZE(ms5611_avail_pressure_osr));
if (!osr)
return -EINVAL;
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
mutex_lock(&st->lock);
if (chan->type == IIO_TEMP)
st->temp_osr = osr;
else
st->pressure_osr = osr;
mutex_unlock(&st->lock);
iio_device_release_direct_mode(indio_dev);
return 0;
}
static const unsigned long ms5611_scan_masks[] = {0x3, 0};
static struct ms5611_chip_info chip_info_tbl[] = {
[MS5611] = {
.temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
},
[MS5607] = {
.temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
}
};
static const struct iio_chan_spec ms5611_channels[] = {
{
.type = IIO_PRESSURE,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 32,
.storagebits = 32,
.endianness = IIO_CPU,
},
},
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 32,
.storagebits = 32,
.endianness = IIO_CPU,
},
},
IIO_CHAN_SOFT_TIMESTAMP(2),
};
static const struct iio_info ms5611_info = {
.read_raw = &ms5611_read_raw,
.write_raw = &ms5611_write_raw,
.attrs = &ms5611_attribute_group,
.driver_module = THIS_MODULE,
};
static int ms5611_init(struct iio_dev *indio_dev)
{
int ret;
struct ms5611_state *st = iio_priv(indio_dev);
/* Enable attached regulator if any. */
st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
if (IS_ERR(st->vdd))
return PTR_ERR(st->vdd);
ret = regulator_enable(st->vdd);
if (ret) {
dev_err(indio_dev->dev.parent,
"failed to enable Vdd supply: %d\n", ret);
return ret;
}
ret = ms5611_reset(indio_dev);
if (ret < 0)
goto err_regulator_disable;
ret = ms5611_read_prom(indio_dev);
if (ret < 0)
goto err_regulator_disable;
return 0;
err_regulator_disable:
regulator_disable(st->vdd);
return ret;
}
static void ms5611_fini(const struct iio_dev *indio_dev)
{
const struct ms5611_state *st = iio_priv(indio_dev);
regulator_disable(st->vdd);
}
int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
const char *name, int type)
{
int ret;
struct ms5611_state *st = iio_priv(indio_dev);
mutex_init(&st->lock);
st->chip_info = &chip_info_tbl[type];
st->temp_osr =
&ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
st->pressure_osr =
&ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
- 1];
indio_dev->dev.parent = dev;
indio_dev->name = name;
indio_dev->info = &ms5611_info;
indio_dev->channels = ms5611_channels;
indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->available_scan_masks = ms5611_scan_masks;
ret = ms5611_init(indio_dev);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
ms5611_trigger_handler, NULL);
if (ret < 0) {
dev_err(dev, "iio triggered buffer setup failed\n");
goto err_fini;
}
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(dev, "unable to register iio device\n");
goto err_buffer_cleanup;
}
return 0;
err_buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
err_fini:
ms5611_fini(indio_dev);
return ret;
}
EXPORT_SYMBOL(ms5611_probe);
int ms5611_remove(struct iio_dev *indio_dev)
{
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
ms5611_fini(indio_dev);
return 0;
}
EXPORT_SYMBOL(ms5611_remove);
MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 core driver");
MODULE_LICENSE("GPL v2");