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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 | /* * Copyright (c) 2016 Marek Vasut <marex@denx.de> * * Driver for Hope RF HP03 digital temperature and pressure sensor. * * 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. */ #define pr_fmt(fmt) "hp03: " fmt #include <linux/module.h> #include <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/regmap.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> /* * The HP03 sensor occupies two fixed I2C addresses: * 0x50 ... read-only EEPROM with calibration data * 0x77 ... read-write ADC for pressure and temperature */ #define HP03_EEPROM_ADDR 0x50 #define HP03_ADC_ADDR 0x77 #define HP03_EEPROM_CX_OFFSET 0x10 #define HP03_EEPROM_AB_OFFSET 0x1e #define HP03_EEPROM_CD_OFFSET 0x20 #define HP03_ADC_WRITE_REG 0xff #define HP03_ADC_READ_REG 0xfd #define HP03_ADC_READ_PRESSURE 0xf0 /* D1 in datasheet */ #define HP03_ADC_READ_TEMP 0xe8 /* D2 in datasheet */ struct hp03_priv { struct i2c_client *client; struct mutex lock; struct gpio_desc *xclr_gpio; struct i2c_client *eeprom_client; struct regmap *eeprom_regmap; s32 pressure; /* kPa */ s32 temp; /* Deg. C */ }; static const struct iio_chan_spec hp03_channels[] = { { .type = IIO_PRESSURE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), }, { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), }, }; static bool hp03_is_writeable_reg(struct device *dev, unsigned int reg) { return false; } static bool hp03_is_volatile_reg(struct device *dev, unsigned int reg) { return false; } static const struct regmap_config hp03_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = HP03_EEPROM_CD_OFFSET + 1, .cache_type = REGCACHE_RBTREE, .writeable_reg = hp03_is_writeable_reg, .volatile_reg = hp03_is_volatile_reg, }; static int hp03_get_temp_pressure(struct hp03_priv *priv, const u8 reg) { int ret; ret = i2c_smbus_write_byte_data(priv->client, HP03_ADC_WRITE_REG, reg); if (ret < 0) return ret; msleep(50); /* Wait for conversion to finish */ return i2c_smbus_read_word_data(priv->client, HP03_ADC_READ_REG); } static int hp03_update_temp_pressure(struct hp03_priv *priv) { struct device *dev = &priv->client->dev; u8 coefs[18]; u16 cx_val[7]; int ab_val, d1_val, d2_val, diff_val, dut, off, sens, x; int i, ret; /* Sample coefficients from EEPROM */ ret = regmap_bulk_read(priv->eeprom_regmap, HP03_EEPROM_CX_OFFSET, coefs, sizeof(coefs)); if (ret < 0) { dev_err(dev, "Failed to read EEPROM (reg=%02x)\n", HP03_EEPROM_CX_OFFSET); return ret; } /* Sample Temperature and Pressure */ gpiod_set_value_cansleep(priv->xclr_gpio, 1); ret = hp03_get_temp_pressure(priv, HP03_ADC_READ_PRESSURE); if (ret < 0) { dev_err(dev, "Failed to read pressure\n"); goto err_adc; } d1_val = ret; ret = hp03_get_temp_pressure(priv, HP03_ADC_READ_TEMP); if (ret < 0) { dev_err(dev, "Failed to read temperature\n"); goto err_adc; } d2_val = ret; gpiod_set_value_cansleep(priv->xclr_gpio, 0); /* The Cx coefficients and Temp/Pressure values are MSB first. */ for (i = 0; i < 7; i++) cx_val[i] = (coefs[2 * i] << 8) | (coefs[(2 * i) + 1] << 0); d1_val = ((d1_val >> 8) & 0xff) | ((d1_val & 0xff) << 8); d2_val = ((d2_val >> 8) & 0xff) | ((d2_val & 0xff) << 8); /* Coefficient voodoo from the HP03 datasheet. */ if (d2_val >= cx_val[4]) ab_val = coefs[14]; /* A-value */ else ab_val = coefs[15]; /* B-value */ diff_val = d2_val - cx_val[4]; dut = (ab_val * (diff_val >> 7) * (diff_val >> 7)) >> coefs[16]; dut = diff_val - dut; off = (cx_val[1] + (((cx_val[3] - 1024) * dut) >> 14)) * 4; sens = cx_val[0] + ((cx_val[2] * dut) >> 10); x = ((sens * (d1_val - 7168)) >> 14) - off; priv->pressure = ((x * 100) >> 5) + (cx_val[6] * 10); priv->temp = 250 + ((dut * cx_val[5]) >> 16) - (dut >> coefs[17]); return 0; err_adc: gpiod_set_value_cansleep(priv->xclr_gpio, 0); return ret; } static int hp03_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct hp03_priv *priv = iio_priv(indio_dev); int ret; mutex_lock(&priv->lock); ret = hp03_update_temp_pressure(priv); mutex_unlock(&priv->lock); if (ret) return ret; switch (mask) { case IIO_CHAN_INFO_RAW: switch (chan->type) { case IIO_PRESSURE: *val = priv->pressure; return IIO_VAL_INT; case IIO_TEMP: *val = priv->temp; return IIO_VAL_INT; default: return -EINVAL; } break; case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_PRESSURE: *val = 0; *val2 = 1000; return IIO_VAL_INT_PLUS_MICRO; case IIO_TEMP: *val = 10; return IIO_VAL_INT; default: return -EINVAL; } break; default: return -EINVAL; } return -EINVAL; } static const struct iio_info hp03_info = { .read_raw = &hp03_read_raw, }; static int hp03_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct iio_dev *indio_dev; struct hp03_priv *priv; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); if (!indio_dev) return -ENOMEM; priv = iio_priv(indio_dev); priv->client = client; mutex_init(&priv->lock); indio_dev->dev.parent = dev; indio_dev->name = id->name; indio_dev->channels = hp03_channels; indio_dev->num_channels = ARRAY_SIZE(hp03_channels); indio_dev->info = &hp03_info; indio_dev->modes = INDIO_DIRECT_MODE; priv->xclr_gpio = devm_gpiod_get_index(dev, "xclr", 0, GPIOD_OUT_HIGH); if (IS_ERR(priv->xclr_gpio)) { dev_err(dev, "Failed to claim XCLR GPIO\n"); ret = PTR_ERR(priv->xclr_gpio); return ret; } /* * Allocate another device for the on-sensor EEPROM, * which has it's dedicated I2C address and contains * the calibration constants for the sensor. */ priv->eeprom_client = i2c_new_dummy(client->adapter, HP03_EEPROM_ADDR); if (!priv->eeprom_client) { dev_err(dev, "New EEPROM I2C device failed\n"); return -ENODEV; } priv->eeprom_regmap = regmap_init_i2c(priv->eeprom_client, &hp03_regmap_config); if (IS_ERR(priv->eeprom_regmap)) { dev_err(dev, "Failed to allocate EEPROM regmap\n"); ret = PTR_ERR(priv->eeprom_regmap); goto err_cleanup_eeprom_client; } ret = iio_device_register(indio_dev); if (ret) { dev_err(dev, "Failed to register IIO device\n"); goto err_cleanup_eeprom_regmap; } i2c_set_clientdata(client, indio_dev); return 0; err_cleanup_eeprom_regmap: regmap_exit(priv->eeprom_regmap); err_cleanup_eeprom_client: i2c_unregister_device(priv->eeprom_client); return ret; } static int hp03_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct hp03_priv *priv = iio_priv(indio_dev); iio_device_unregister(indio_dev); regmap_exit(priv->eeprom_regmap); i2c_unregister_device(priv->eeprom_client); return 0; } static const struct i2c_device_id hp03_id[] = { { "hp03", 0 }, { }, }; MODULE_DEVICE_TABLE(i2c, hp03_id); static const struct of_device_id hp03_of_match[] = { { .compatible = "hoperf,hp03" }, { }, }; MODULE_DEVICE_TABLE(of, hp03_of_match); static struct i2c_driver hp03_driver = { .driver = { .name = "hp03", .of_match_table = hp03_of_match, }, .probe = hp03_probe, .remove = hp03_remove, .id_table = hp03_id, }; module_i2c_driver(hp03_driver); MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); MODULE_DESCRIPTION("Driver for Hope RF HP03 pressure and temperature sensor"); MODULE_LICENSE("GPL v2"); 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