diff options
Diffstat (limited to 'drivers/iio/humidity/hts221_core.c')
| -rw-r--r-- | drivers/iio/humidity/hts221_core.c | 687 |
1 files changed, 687 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hts221_core.c b/drivers/iio/humidity/hts221_core.c new file mode 100644 index 000000000000..3f3ef4a1a474 --- /dev/null +++ b/drivers/iio/humidity/hts221_core.c @@ -0,0 +1,687 @@ +/* + * STMicroelectronics hts221 sensor driver + * + * Copyright 2016 STMicroelectronics Inc. + * + * Lorenzo Bianconi <lorenzo.bianconi@st.com> + * + * Licensed under the GPL-2. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/iio/sysfs.h> +#include <linux/delay.h> +#include <asm/unaligned.h> + +#include "hts221.h" + +#define HTS221_REG_WHOAMI_ADDR 0x0f +#define HTS221_REG_WHOAMI_VAL 0xbc + +#define HTS221_REG_CNTRL1_ADDR 0x20 +#define HTS221_REG_CNTRL2_ADDR 0x21 +#define HTS221_REG_CNTRL3_ADDR 0x22 + +#define HTS221_REG_AVG_ADDR 0x10 +#define HTS221_REG_H_OUT_L 0x28 +#define HTS221_REG_T_OUT_L 0x2a + +#define HTS221_HUMIDITY_AVG_MASK 0x07 +#define HTS221_TEMP_AVG_MASK 0x38 + +#define HTS221_ODR_MASK 0x87 +#define HTS221_BDU_MASK BIT(2) + +#define HTS221_DRDY_MASK BIT(2) + +#define HTS221_ENABLE_SENSOR BIT(7) + +#define HTS221_HUMIDITY_AVG_4 0x00 /* 0.4 %RH */ +#define HTS221_HUMIDITY_AVG_8 0x01 /* 0.3 %RH */ +#define HTS221_HUMIDITY_AVG_16 0x02 /* 0.2 %RH */ +#define HTS221_HUMIDITY_AVG_32 0x03 /* 0.15 %RH */ +#define HTS221_HUMIDITY_AVG_64 0x04 /* 0.1 %RH */ +#define HTS221_HUMIDITY_AVG_128 0x05 /* 0.07 %RH */ +#define HTS221_HUMIDITY_AVG_256 0x06 /* 0.05 %RH */ +#define HTS221_HUMIDITY_AVG_512 0x07 /* 0.03 %RH */ + +#define HTS221_TEMP_AVG_2 0x00 /* 0.08 degC */ +#define HTS221_TEMP_AVG_4 0x08 /* 0.05 degC */ +#define HTS221_TEMP_AVG_8 0x10 /* 0.04 degC */ +#define HTS221_TEMP_AVG_16 0x18 /* 0.03 degC */ +#define HTS221_TEMP_AVG_32 0x20 /* 0.02 degC */ +#define HTS221_TEMP_AVG_64 0x28 /* 0.015 degC */ +#define HTS221_TEMP_AVG_128 0x30 /* 0.01 degC */ +#define HTS221_TEMP_AVG_256 0x38 /* 0.007 degC */ + +/* calibration registers */ +#define HTS221_REG_0RH_CAL_X_H 0x36 +#define HTS221_REG_1RH_CAL_X_H 0x3a +#define HTS221_REG_0RH_CAL_Y_H 0x30 +#define HTS221_REG_1RH_CAL_Y_H 0x31 +#define HTS221_REG_0T_CAL_X_L 0x3c +#define HTS221_REG_1T_CAL_X_L 0x3e +#define HTS221_REG_0T_CAL_Y_H 0x32 +#define HTS221_REG_1T_CAL_Y_H 0x33 +#define HTS221_REG_T1_T0_CAL_Y_H 0x35 + +struct hts221_odr { + u8 hz; + u8 val; +}; + +struct hts221_avg { + u8 addr; + u8 mask; + struct hts221_avg_avl avg_avl[HTS221_AVG_DEPTH]; +}; + +static const struct hts221_odr hts221_odr_table[] = { + { 1, 0x01 }, /* 1Hz */ + { 7, 0x02 }, /* 7Hz */ + { 13, 0x03 }, /* 12.5Hz */ +}; + +static const struct hts221_avg hts221_avg_list[] = { + { + .addr = HTS221_REG_AVG_ADDR, + .mask = HTS221_HUMIDITY_AVG_MASK, + .avg_avl = { + { 4, HTS221_HUMIDITY_AVG_4 }, + { 8, HTS221_HUMIDITY_AVG_8 }, + { 16, HTS221_HUMIDITY_AVG_16 }, + { 32, HTS221_HUMIDITY_AVG_32 }, + { 64, HTS221_HUMIDITY_AVG_64 }, + { 128, HTS221_HUMIDITY_AVG_128 }, + { 256, HTS221_HUMIDITY_AVG_256 }, + { 512, HTS221_HUMIDITY_AVG_512 }, + }, + }, + { + .addr = HTS221_REG_AVG_ADDR, + .mask = HTS221_TEMP_AVG_MASK, + .avg_avl = { + { 2, HTS221_TEMP_AVG_2 }, + { 4, HTS221_TEMP_AVG_4 }, + { 8, HTS221_TEMP_AVG_8 }, + { 16, HTS221_TEMP_AVG_16 }, + { 32, HTS221_TEMP_AVG_32 }, + { 64, HTS221_TEMP_AVG_64 }, + { 128, HTS221_TEMP_AVG_128 }, + { 256, HTS221_TEMP_AVG_256 }, + }, + }, +}; + +static const struct iio_chan_spec hts221_channels[] = { + { + .type = IIO_HUMIDITYRELATIVE, + .address = HTS221_REG_H_OUT_L, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_LE, + }, + }, + { + .type = IIO_TEMP, + .address = HTS221_REG_T_OUT_L, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), + .scan_index = 1, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_LE, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(2), +}; + +static int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask, + u8 val) +{ + u8 data; + int err; + + mutex_lock(&hw->lock); + + err = hw->tf->read(hw->dev, addr, sizeof(data), &data); + if (err < 0) { + dev_err(hw->dev, "failed to read %02x register\n", addr); + goto unlock; + } + + data = (data & ~mask) | (val & mask); + + err = hw->tf->write(hw->dev, addr, sizeof(data), &data); + if (err < 0) + dev_err(hw->dev, "failed to write %02x register\n", addr); + +unlock: + mutex_unlock(&hw->lock); + + return err; +} + +static int hts221_check_whoami(struct hts221_hw *hw) +{ + u8 data; + int err; + + err = hw->tf->read(hw->dev, HTS221_REG_WHOAMI_ADDR, sizeof(data), + &data); + if (err < 0) { + dev_err(hw->dev, "failed to read whoami register\n"); + return err; + } + + if (data != HTS221_REG_WHOAMI_VAL) { + dev_err(hw->dev, "wrong whoami {%02x vs %02x}\n", + data, HTS221_REG_WHOAMI_VAL); + return -ENODEV; + } + + return 0; +} + +int hts221_config_drdy(struct hts221_hw *hw, bool enable) +{ + u8 val = enable ? BIT(2) : 0; + int err; + + err = hts221_write_with_mask(hw, HTS221_REG_CNTRL3_ADDR, + HTS221_DRDY_MASK, val); + + return err < 0 ? err : 0; +} + +static int hts221_update_odr(struct hts221_hw *hw, u8 odr) +{ + int i, err; + u8 val; + + for (i = 0; i < ARRAY_SIZE(hts221_odr_table); i++) + if (hts221_odr_table[i].hz == odr) + break; + + if (i == ARRAY_SIZE(hts221_odr_table)) + return -EINVAL; + + val = HTS221_ENABLE_SENSOR | HTS221_BDU_MASK | hts221_odr_table[i].val; + err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR, + HTS221_ODR_MASK, val); + if (err < 0) + return err; + + hw->odr = odr; + + return 0; +} + +static int hts221_update_avg(struct hts221_hw *hw, + enum hts221_sensor_type type, + u16 val) +{ + int i, err; + const struct hts221_avg *avg = &hts221_avg_list[type]; + + for (i = 0; i < HTS221_AVG_DEPTH; i++) + if (avg->avg_avl[i].avg == val) + break; + + if (i == HTS221_AVG_DEPTH) + return -EINVAL; + + err = hts221_write_with_mask(hw, avg->addr, avg->mask, + avg->avg_avl[i].val); + if (err < 0) + return err; + + hw->sensors[type].cur_avg_idx = i; + + return 0; +} + +static ssize_t hts221_sysfs_sampling_freq(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int i; + ssize_t len = 0; + + for (i = 0; i < ARRAY_SIZE(hts221_odr_table); i++) + len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", + hts221_odr_table[i].hz); + buf[len - 1] = '\n'; + + return len; +} + +static ssize_t +hts221_sysfs_rh_oversampling_avail(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + const struct hts221_avg *avg = &hts221_avg_list[HTS221_SENSOR_H]; + ssize_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(avg->avg_avl); i++) + len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", + avg->avg_avl[i].avg); + buf[len - 1] = '\n'; + + return len; +} + +static ssize_t +hts221_sysfs_temp_oversampling_avail(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + const struct hts221_avg *avg = &hts221_avg_list[HTS221_SENSOR_T]; + ssize_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(avg->avg_avl); i++) + len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", + avg->avg_avl[i].avg); + buf[len - 1] = '\n'; + + return len; +} + +int hts221_power_on(struct hts221_hw *hw) +{ + return hts221_update_odr(hw, hw->odr); +} + +int hts221_power_off(struct hts221_hw *hw) +{ + u8 data[] = {0x00, 0x00}; + + return hw->tf->write(hw->dev, HTS221_REG_CNTRL1_ADDR, sizeof(data), + data); +} + +static int hts221_parse_temp_caldata(struct hts221_hw *hw) +{ + int err, *slope, *b_gen; + s16 cal_x0, cal_x1, cal_y0, cal_y1; + u8 cal0, cal1; + + err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_Y_H, + sizeof(cal0), &cal0); + if (err < 0) + return err; + + err = hw->tf->read(hw->dev, HTS221_REG_T1_T0_CAL_Y_H, + sizeof(cal1), &cal1); + if (err < 0) + return err; + cal_y0 = (le16_to_cpu(cal1 & 0x3) << 8) | cal0; + + err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_Y_H, + sizeof(cal0), &cal0); + if (err < 0) + return err; + cal_y1 = (((cal1 & 0xc) >> 2) << 8) | cal0; + + err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_X_L, sizeof(cal_x0), + (u8 *)&cal_x0); + if (err < 0) + return err; + cal_x0 = le16_to_cpu(cal_x0); + + err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_X_L, sizeof(cal_x1), + (u8 *)&cal_x1); + if (err < 0) + return err; + cal_x1 = le16_to_cpu(cal_x1); + + slope = &hw->sensors[HTS221_SENSOR_T].slope; + b_gen = &hw->sensors[HTS221_SENSOR_T].b_gen; + + *slope = ((cal_y1 - cal_y0) * 8000) / (cal_x1 - cal_x0); + *b_gen = (((s32)cal_x1 * cal_y0 - (s32)cal_x0 * cal_y1) * 1000) / + (cal_x1 - cal_x0); + *b_gen *= 8; + + return 0; +} + +static int hts221_parse_rh_caldata(struct hts221_hw *hw) +{ + int err, *slope, *b_gen; + s16 cal_x0, cal_x1, cal_y0, cal_y1; + u8 data; + + err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_Y_H, sizeof(data), + &data); + if (err < 0) + return err; + cal_y0 = data; + + err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_Y_H, sizeof(data), + &data); + if (err < 0) + return err; + cal_y1 = data; + + err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_X_H, sizeof(cal_x0), + (u8 *)&cal_x0); + if (err < 0) + return err; + cal_x0 = le16_to_cpu(cal_x0); + + err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_X_H, sizeof(cal_x1), + (u8 *)&cal_x1); + if (err < 0) + return err; + cal_x1 = le16_to_cpu(cal_x1); + + slope = &hw->sensors[HTS221_SENSOR_H].slope; + b_gen = &hw->sensors[HTS221_SENSOR_H].b_gen; + + *slope = ((cal_y1 - cal_y0) * 8000) / (cal_x1 - cal_x0); + *b_gen = (((s32)cal_x1 * cal_y0 - (s32)cal_x0 * cal_y1) * 1000) / + (cal_x1 - cal_x0); + *b_gen *= 8; + + return 0; +} + +static int hts221_get_sensor_scale(struct hts221_hw *hw, + enum iio_chan_type ch_type, + int *val, int *val2) +{ + s64 tmp; + s32 rem, div, data; + + switch (ch_type) { + case IIO_HUMIDITYRELATIVE: + data = hw->sensors[HTS221_SENSOR_H].slope; + div = (1 << 4) * 1000; + break; + case IIO_TEMP: + data = hw->sensors[HTS221_SENSOR_T].slope; + div = (1 << 6) * 1000; + break; + default: + return -EINVAL; + } + + tmp = div_s64(data * 1000000000LL, div); + tmp = div_s64_rem(tmp, 1000000000LL, &rem); + + *val = tmp; + *val2 = rem; + + return IIO_VAL_INT_PLUS_NANO; +} + +static int hts221_get_sensor_offset(struct hts221_hw *hw, + enum iio_chan_type ch_type, + int *val, int *val2) +{ + s64 tmp; + s32 rem, div, data; + + switch (ch_type) { + case IIO_HUMIDITYRELATIVE: + data = hw->sensors[HTS221_SENSOR_H].b_gen; + div = hw->sensors[HTS221_SENSOR_H].slope; + break; + case IIO_TEMP: + data = hw->sensors[HTS221_SENSOR_T].b_gen; + div = hw->sensors[HTS221_SENSOR_T].slope; + break; + default: + return -EINVAL; + } + + tmp = div_s64(data * 1000000000LL, div); + tmp = div_s64_rem(tmp, 1000000000LL, &rem); + + *val = tmp; + *val2 = rem; + + return IIO_VAL_INT_PLUS_NANO; +} + +static int hts221_read_oneshot(struct hts221_hw *hw, u8 addr, int *val) +{ + u8 data[HTS221_DATA_SIZE]; + int err; + + err = hts221_power_on(hw); + if (err < 0) + return err; + + msleep(50); + + err = hw->tf->read(hw->dev, addr, sizeof(data), data); + if (err < 0) + return err; + + hts221_power_off(hw); + + *val = (s16)get_unaligned_le16(data); + + return IIO_VAL_INT; +} + +static int hts221_read_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *ch, + int *val, int *val2, long mask) +{ + struct hts221_hw *hw = iio_priv(iio_dev); + int ret; + + ret = iio_device_claim_direct_mode(iio_dev); + if (ret) + return ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = hts221_read_oneshot(hw, ch->address, val); + break; + case IIO_CHAN_INFO_SCALE: + ret = hts221_get_sensor_scale(hw, ch->type, val, val2); + break; + case IIO_CHAN_INFO_OFFSET: + ret = hts221_get_sensor_offset(hw, ch->type, val, val2); + break; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = hw->odr; + ret = IIO_VAL_INT; + break; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: { + u8 idx; + const struct hts221_avg *avg; + + switch (ch->type) { + case IIO_HUMIDITYRELATIVE: + avg = &hts221_avg_list[HTS221_SENSOR_H]; + idx = hw->sensors[HTS221_SENSOR_H].cur_avg_idx; + *val = avg->avg_avl[idx].avg; + ret = IIO_VAL_INT; + break; + case IIO_TEMP: + avg = &hts221_avg_list[HTS221_SENSOR_T]; + idx = hw->sensors[HTS221_SENSOR_T].cur_avg_idx; + *val = avg->avg_avl[idx].avg; + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + break; + } + break; + } + default: + ret = -EINVAL; + break; + } + + iio_device_release_direct_mode(iio_dev); + + return ret; +} + +static int hts221_write_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct hts221_hw *hw = iio_priv(iio_dev); + int ret; + + ret = iio_device_claim_direct_mode(iio_dev); + if (ret) + return ret; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + ret = hts221_update_odr(hw, val); + break; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + switch (chan->type) { + case IIO_HUMIDITYRELATIVE: + ret = hts221_update_avg(hw, HTS221_SENSOR_H, val); + break; + case IIO_TEMP: + ret = hts221_update_avg(hw, HTS221_SENSOR_T, val); + break; + default: + ret = -EINVAL; + break; + } + break; + default: + ret = -EINVAL; + break; + } + + iio_device_release_direct_mode(iio_dev); + + return ret; +} + +static int hts221_validate_trigger(struct iio_dev *iio_dev, + struct iio_trigger *trig) +{ + struct hts221_hw *hw = iio_priv(iio_dev); + + return hw->trig == trig ? 0 : -EINVAL; +} + +static IIO_DEVICE_ATTR(in_humidity_oversampling_ratio_available, S_IRUGO, + hts221_sysfs_rh_oversampling_avail, NULL, 0); +static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available, S_IRUGO, + hts221_sysfs_temp_oversampling_avail, NULL, 0); +static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hts221_sysfs_sampling_freq); + +static struct attribute *hts221_attributes[] = { + &iio_dev_attr_sampling_frequency_available.dev_attr.attr, + &iio_dev_attr_in_humidity_oversampling_ratio_available.dev_attr.attr, + &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group hts221_attribute_group = { + .attrs = hts221_attributes, +}; + +static const struct iio_info hts221_info = { + .driver_module = THIS_MODULE, + .attrs = &hts221_attribute_group, + .read_raw = hts221_read_raw, + .write_raw = hts221_write_raw, + .validate_trigger = hts221_validate_trigger, +}; + +static const unsigned long hts221_scan_masks[] = {0x3, 0x0}; + +int hts221_probe(struct iio_dev *iio_dev) +{ + struct hts221_hw *hw = iio_priv(iio_dev); + int err; + u8 data; + + mutex_init(&hw->lock); + + err = hts221_check_whoami(hw); + if (err < 0) + return err; + + hw->odr = hts221_odr_table[0].hz; + + iio_dev->modes = INDIO_DIRECT_MODE; + iio_dev->dev.parent = hw->dev; + iio_dev->available_scan_masks = hts221_scan_masks; + iio_dev->channels = hts221_channels; + iio_dev->num_channels = ARRAY_SIZE(hts221_channels); + iio_dev->name = HTS221_DEV_NAME; + iio_dev->info = &hts221_info; + + /* configure humidity sensor */ + err = hts221_parse_rh_caldata(hw); + if (err < 0) { + dev_err(hw->dev, "failed to get rh calibration data\n"); + return err; + } + + data = hts221_avg_list[HTS221_SENSOR_H].avg_avl[3].avg; + err = hts221_update_avg(hw, HTS221_SENSOR_H, data); + if (err < 0) { + dev_err(hw->dev, "failed to set rh oversampling ratio\n"); + return err; + } + + /* configure temperature sensor */ + err = hts221_parse_temp_caldata(hw); + if (err < 0) { + dev_err(hw->dev, + "failed to get temperature calibration data\n"); + return err; + } + + data = hts221_avg_list[HTS221_SENSOR_T].avg_avl[3].avg; + err = hts221_update_avg(hw, HTS221_SENSOR_T, data); + if (err < 0) { + dev_err(hw->dev, + "failed to set temperature oversampling ratio\n"); + return err; + } + + if (hw->irq > 0) { + err = hts221_allocate_buffers(hw); + if (err < 0) + return err; + + err = hts221_allocate_trigger(hw); + if (err) + return err; + } + + return devm_iio_device_register(hw->dev, iio_dev); +} +EXPORT_SYMBOL(hts221_probe); + +MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>"); +MODULE_DESCRIPTION("STMicroelectronics hts221 sensor driver"); +MODULE_LICENSE("GPL v2"); |