Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 1 | /* |
| 2 | * MS5611 pressure and temperature sensor driver |
| 3 | * |
| 4 | * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * Data sheet: |
| 11 | * http://www.meas-spec.com/downloads/MS5611-01BA03.pdf |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 12 | * http://www.meas-spec.com/downloads/MS5607-02BA03.pdf |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/iio/iio.h> |
| 18 | #include <linux/delay.h> |
| 19 | |
| 20 | #include "ms5611.h" |
| 21 | |
| 22 | static bool ms5611_prom_is_valid(u16 *prom, size_t len) |
| 23 | { |
| 24 | int i, j; |
| 25 | uint16_t crc = 0, crc_orig = prom[7] & 0x000F; |
| 26 | |
| 27 | prom[7] &= 0xFF00; |
| 28 | |
| 29 | for (i = 0; i < len * 2; i++) { |
| 30 | if (i % 2 == 1) |
| 31 | crc ^= prom[i >> 1] & 0x00FF; |
| 32 | else |
| 33 | crc ^= prom[i >> 1] >> 8; |
| 34 | |
| 35 | for (j = 0; j < 8; j++) { |
| 36 | if (crc & 0x8000) |
| 37 | crc = (crc << 1) ^ 0x3000; |
| 38 | else |
| 39 | crc <<= 1; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | crc = (crc >> 12) & 0x000F; |
| 44 | |
| 45 | return crc_orig != 0x0000 && crc == crc_orig; |
| 46 | } |
| 47 | |
| 48 | static int ms5611_read_prom(struct iio_dev *indio_dev) |
| 49 | { |
| 50 | int ret, i; |
| 51 | struct ms5611_state *st = iio_priv(indio_dev); |
| 52 | |
| 53 | for (i = 0; i < MS5611_PROM_WORDS_NB; i++) { |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 54 | ret = st->read_prom_word(&indio_dev->dev, |
| 55 | i, &st->chip_info->prom[i]); |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 56 | if (ret < 0) { |
| 57 | dev_err(&indio_dev->dev, |
| 58 | "failed to read prom at %d\n", i); |
| 59 | return ret; |
| 60 | } |
| 61 | } |
| 62 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 63 | if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) { |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 64 | dev_err(&indio_dev->dev, "PROM integrity check failed\n"); |
| 65 | return -ENODEV; |
| 66 | } |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev, |
| 72 | s32 *temp, s32 *pressure) |
| 73 | { |
| 74 | int ret; |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 75 | struct ms5611_state *st = iio_priv(indio_dev); |
| 76 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 77 | ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure); |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 78 | if (ret < 0) { |
| 79 | dev_err(&indio_dev->dev, |
| 80 | "failed to read temperature and pressure\n"); |
| 81 | return ret; |
| 82 | } |
| 83 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 84 | return st->chip_info->temp_and_pressure_compensate(st->chip_info, |
| 85 | temp, pressure); |
| 86 | } |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 87 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 88 | static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info, |
| 89 | s32 *temp, s32 *pressure) |
| 90 | { |
| 91 | s32 t = *temp, p = *pressure; |
| 92 | s64 off, sens, dt; |
| 93 | |
| 94 | dt = t - (chip_info->prom[5] << 8); |
| 95 | off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7); |
| 96 | sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8); |
| 97 | |
| 98 | t = 2000 + ((chip_info->prom[6] * dt) >> 23); |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 99 | if (t < 2000) { |
| 100 | s64 off2, sens2, t2; |
| 101 | |
| 102 | t2 = (dt * dt) >> 31; |
| 103 | off2 = (5 * (t - 2000) * (t - 2000)) >> 1; |
| 104 | sens2 = off2 >> 1; |
| 105 | |
| 106 | if (t < -1500) { |
| 107 | s64 tmp = (t + 1500) * (t + 1500); |
| 108 | |
| 109 | off2 += 7 * tmp; |
| 110 | sens2 += (11 * tmp) >> 1; |
| 111 | } |
| 112 | |
| 113 | t -= t2; |
| 114 | off -= off2; |
| 115 | sens -= sens2; |
| 116 | } |
| 117 | |
| 118 | *temp = t; |
| 119 | *pressure = (((p * sens) >> 21) - off) >> 15; |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 124 | static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info, |
| 125 | s32 *temp, s32 *pressure) |
| 126 | { |
| 127 | s32 t = *temp, p = *pressure; |
| 128 | s64 off, sens, dt; |
| 129 | |
| 130 | dt = t - (chip_info->prom[5] << 8); |
| 131 | off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6); |
| 132 | sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7); |
| 133 | |
| 134 | t = 2000 + ((chip_info->prom[6] * dt) >> 23); |
| 135 | if (t < 2000) { |
| 136 | s64 off2, sens2, t2; |
| 137 | |
| 138 | t2 = (dt * dt) >> 31; |
| 139 | off2 = (61 * (t - 2000) * (t - 2000)) >> 4; |
| 140 | sens2 = off2 << 1; |
| 141 | |
| 142 | if (t < -1500) { |
| 143 | s64 tmp = (t + 1500) * (t + 1500); |
| 144 | |
| 145 | off2 += 15 * tmp; |
| 146 | sens2 += (8 * tmp); |
| 147 | } |
| 148 | |
| 149 | t -= t2; |
| 150 | off -= off2; |
| 151 | sens -= sens2; |
| 152 | } |
| 153 | |
| 154 | *temp = t; |
| 155 | *pressure = (((p * sens) >> 21) - off) >> 15; |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 160 | static int ms5611_reset(struct iio_dev *indio_dev) |
| 161 | { |
| 162 | int ret; |
| 163 | struct ms5611_state *st = iio_priv(indio_dev); |
| 164 | |
| 165 | ret = st->reset(&indio_dev->dev); |
| 166 | if (ret < 0) { |
| 167 | dev_err(&indio_dev->dev, "failed to reset device\n"); |
| 168 | return ret; |
| 169 | } |
| 170 | |
| 171 | usleep_range(3000, 4000); |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | static int ms5611_read_raw(struct iio_dev *indio_dev, |
| 177 | struct iio_chan_spec const *chan, |
| 178 | int *val, int *val2, long mask) |
| 179 | { |
| 180 | int ret; |
| 181 | s32 temp, pressure; |
| 182 | struct ms5611_state *st = iio_priv(indio_dev); |
| 183 | |
| 184 | switch (mask) { |
| 185 | case IIO_CHAN_INFO_PROCESSED: |
| 186 | mutex_lock(&st->lock); |
| 187 | ret = ms5611_read_temp_and_pressure(indio_dev, |
| 188 | &temp, &pressure); |
| 189 | mutex_unlock(&st->lock); |
| 190 | if (ret < 0) |
| 191 | return ret; |
| 192 | |
| 193 | switch (chan->type) { |
| 194 | case IIO_TEMP: |
| 195 | *val = temp * 10; |
| 196 | return IIO_VAL_INT; |
| 197 | case IIO_PRESSURE: |
| 198 | *val = pressure / 1000; |
| 199 | *val2 = (pressure % 1000) * 1000; |
| 200 | return IIO_VAL_INT_PLUS_MICRO; |
| 201 | default: |
| 202 | return -EINVAL; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | return -EINVAL; |
| 207 | } |
| 208 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 209 | static struct ms5611_chip_info chip_info_tbl[] = { |
| 210 | [MS5611] = { |
| 211 | .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate, |
| 212 | }, |
| 213 | [MS5607] = { |
| 214 | .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate, |
| 215 | } |
| 216 | }; |
| 217 | |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 218 | static const struct iio_chan_spec ms5611_channels[] = { |
| 219 | { |
| 220 | .type = IIO_PRESSURE, |
Tomasz Duszynski | 7cb46c2 | 2015-06-23 20:45:47 +0200 | [diff] [blame] | 221 | .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 222 | }, |
| 223 | { |
| 224 | .type = IIO_TEMP, |
Tomasz Duszynski | 7cb46c2 | 2015-06-23 20:45:47 +0200 | [diff] [blame] | 225 | .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 226 | } |
| 227 | }; |
| 228 | |
| 229 | static const struct iio_info ms5611_info = { |
| 230 | .read_raw = &ms5611_read_raw, |
| 231 | .driver_module = THIS_MODULE, |
| 232 | }; |
| 233 | |
| 234 | static int ms5611_init(struct iio_dev *indio_dev) |
| 235 | { |
| 236 | int ret; |
| 237 | |
| 238 | ret = ms5611_reset(indio_dev); |
| 239 | if (ret < 0) |
| 240 | return ret; |
| 241 | |
| 242 | return ms5611_read_prom(indio_dev); |
| 243 | } |
| 244 | |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 245 | int ms5611_probe(struct iio_dev *indio_dev, struct device *dev, int type) |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 246 | { |
| 247 | int ret; |
| 248 | struct ms5611_state *st = iio_priv(indio_dev); |
| 249 | |
| 250 | mutex_init(&st->lock); |
Tomasz Duszynski | 9690d81a | 2015-06-23 20:45:48 +0200 | [diff] [blame] | 251 | st->chip_info = &chip_info_tbl[type]; |
Tomasz Duszynski | c064416 | 2015-03-14 21:29:31 +0100 | [diff] [blame] | 252 | indio_dev->dev.parent = dev; |
| 253 | indio_dev->name = dev->driver->name; |
| 254 | indio_dev->info = &ms5611_info; |
| 255 | indio_dev->channels = ms5611_channels; |
| 256 | indio_dev->num_channels = ARRAY_SIZE(ms5611_channels); |
| 257 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 258 | |
| 259 | ret = ms5611_init(indio_dev); |
| 260 | if (ret < 0) |
| 261 | return ret; |
| 262 | |
| 263 | return devm_iio_device_register(dev, indio_dev); |
| 264 | } |
| 265 | EXPORT_SYMBOL(ms5611_probe); |
| 266 | |
| 267 | MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); |
| 268 | MODULE_DESCRIPTION("MS5611 core driver"); |
| 269 | MODULE_LICENSE("GPL v2"); |