diff options
Diffstat (limited to 'drivers/iio/pressure/ms5611_core.c')
-rw-r--r-- | drivers/iio/pressure/ms5611_core.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c new file mode 100644 index 0000000000..2fc706f9d8 --- /dev/null +++ b/drivers/iio/pressure/ms5611_core.c @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MS5611 pressure and temperature sensor driver + * + * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> + * + * 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 == 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(st, i, &st->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->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(st, temp, pressure); + if (ret < 0) { + dev_err(&indio_dev->dev, + "failed to read temperature and pressure\n"); + return ret; + } + + return st->compensate_temp_and_pressure(st, temp, pressure); +} + +static int ms5611_temp_and_pressure_compensate(struct ms5611_state *st, + s32 *temp, s32 *pressure) +{ + s32 t = *temp, p = *pressure; + s64 off, sens, dt; + + dt = t - (st->prom[5] << 8); + off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7); + sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8); + + t = 2000 + ((st->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_state *st, + s32 *temp, s32 *pressure) +{ + s32 t = *temp, p = *pressure; + s64 off, sens, dt; + + dt = t - (st->prom[5] << 8); + off = ((s64)st->prom[2] << 17) + ((st->prom[4] * dt) >> 6); + sens = ((s64)st->prom[1] << 16) + ((st->prom[3] * dt) >> 7); + + t = 2000 + ((st->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(st); + 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); + /* Ensure buffer elements are naturally aligned */ + struct { + s32 channels[2]; + s64 ts __aligned(8); + } scan; + int ret; + + mutex_lock(&st->lock); + ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], + &scan.channels[0]); + mutex_unlock(&st->lock); + if (ret < 0) + goto err; + + iio_push_to_buffers_with_timestamp(indio_dev, &scan, + 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 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, +}; + +static int ms5611_init(struct iio_dev *indio_dev) +{ + int ret; + + /* Enable attached regulator if any. */ + ret = devm_regulator_get_enable(indio_dev->dev.parent, "vdd"); + if (ret) + return ret; + + ret = ms5611_reset(indio_dev); + if (ret < 0) + return ret; + + ret = ms5611_read_prom(indio_dev); + if (ret < 0) + return ret; + + return 0; +} + +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); + + switch (type) { + case MS5611: + st->compensate_temp_and_pressure = + ms5611_temp_and_pressure_compensate; + break; + case MS5607: + st->compensate_temp_and_pressure = + ms5607_temp_and_pressure_compensate; + break; + default: + return -EINVAL; + } + + 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->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 = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, + ms5611_trigger_handler, NULL); + if (ret < 0) { + dev_err(dev, "iio triggered buffer setup failed\n"); + return ret; + } + + ret = devm_iio_device_register(dev, indio_dev); + if (ret < 0) { + dev_err(dev, "unable to register iio device\n"); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_NS(ms5611_probe, IIO_MS5611); + +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); +MODULE_DESCRIPTION("MS5611 core driver"); +MODULE_LICENSE("GPL v2"); |