diff options
Diffstat (limited to 'drivers/iio/pressure')
| -rw-r--r-- | drivers/iio/pressure/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/iio/pressure/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iio/pressure/hp03.c | 312 |
3 files changed, 324 insertions, 0 deletions
diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig index 8de0192..54c6165 100644 --- a/drivers/iio/pressure/Kconfig +++ b/drivers/iio/pressure/Kconfig @@ -30,6 +30,17 @@ config HID_SENSOR_PRESS To compile this driver as a module, choose M here: the module will be called hid-sensor-press. +config HP03 + tristate "Hope RF HP03 temperature and pressure sensor driver" + depends on I2C + select REGMAP_I2C + help + Say yes here to build support for Hope RF HP03 pressure and + temperature sensor. + + To compile this driver as a module, choose M here: the module + will be called hp03. + config MPL115 tristate diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile index 6e60863..17d6e7a 100644 --- a/drivers/iio/pressure/Makefile +++ b/drivers/iio/pressure/Makefile @@ -5,6 +5,7 @@ # When adding new entries keep the list in alphabetical order obj-$(CONFIG_BMP280) += bmp280.o obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o +obj-$(CONFIG_HP03) += hp03.o obj-$(CONFIG_MPL115) += mpl115.o obj-$(CONFIG_MPL115_I2C) += mpl115_i2c.o obj-$(CONFIG_MPL115_SPI) += mpl115_spi.o diff --git a/drivers/iio/pressure/hp03.c b/drivers/iio/pressure/hp03.c new file mode 100644 index 0000000..ac76515 --- /dev/null +++ b/drivers/iio/pressure/hp03.c @@ -0,0 +1,312 @@ +/* + * 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 = { + .driver_module = THIS_MODULE, + .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 struct i2c_driver hp03_driver = { + .driver = { + .name = "hp03", + }, + .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"); |