diff options
Diffstat (limited to 'drivers/iio/pressure/hp206c.c')
| -rw-r--r-- | drivers/iio/pressure/hp206c.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/drivers/iio/pressure/hp206c.c b/drivers/iio/pressure/hp206c.c new file mode 100644 index 000000000..c38c19678 --- /dev/null +++ b/drivers/iio/pressure/hp206c.c @@ -0,0 +1,426 @@ +/* + * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor + * + * Copyright (c) 2016, Intel Corporation. + * + * This file is subject to the terms and conditions of version 2 of + * the GNU General Public License. See the file COPYING in the main + * directory of this archive for more details. + * + * (7-bit I2C slave address 0x76) + * + * Datasheet: + * http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/delay.h> +#include <linux/util_macros.h> +#include <linux/acpi.h> + +/* I2C commands: */ +#define HP206C_CMD_SOFT_RST 0x06 + +#define HP206C_CMD_ADC_CVT 0x40 + +#define HP206C_CMD_ADC_CVT_OSR_4096 0x00 +#define HP206C_CMD_ADC_CVT_OSR_2048 0x04 +#define HP206C_CMD_ADC_CVT_OSR_1024 0x08 +#define HP206C_CMD_ADC_CVT_OSR_512 0x0c +#define HP206C_CMD_ADC_CVT_OSR_256 0x10 +#define HP206C_CMD_ADC_CVT_OSR_128 0x14 + +#define HP206C_CMD_ADC_CVT_CHNL_PT 0x00 +#define HP206C_CMD_ADC_CVT_CHNL_T 0x02 + +#define HP206C_CMD_READ_P 0x30 +#define HP206C_CMD_READ_T 0x32 + +#define HP206C_CMD_READ_REG 0x80 +#define HP206C_CMD_WRITE_REG 0xc0 + +#define HP206C_REG_INT_EN 0x0b +#define HP206C_REG_INT_CFG 0x0c + +#define HP206C_REG_INT_SRC 0x0d +#define HP206C_FLAG_DEV_RDY 0x40 + +#define HP206C_REG_PARA 0x0f +#define HP206C_FLAG_CMPS_EN 0x80 + +/* Maximum spin for DEV_RDY */ +#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20 +#define HP206C_DEV_RDY_WAIT_US 20000 + +struct hp206c_data { + struct mutex mutex; + struct i2c_client *client; + int temp_osr_index; + int pres_osr_index; +}; + +struct hp206c_osr_setting { + u8 osr_mask; + unsigned int temp_conv_time_us; + unsigned int pres_conv_time_us; +}; + +/* Data from Table 5 in datasheet. */ +static const struct hp206c_osr_setting hp206c_osr_settings[] = { + { HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 }, + { HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 }, + { HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 }, + { HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 }, + { HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 }, + { HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 }, +}; +static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 }; +static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128"; + +static inline int hp206c_read_reg(struct i2c_client *client, u8 reg) +{ + return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg); +} + +static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val) +{ + return i2c_smbus_write_byte_data(client, + HP206C_CMD_WRITE_REG | reg, val); +} + +static int hp206c_read_20bit(struct i2c_client *client, u8 cmd) +{ + int ret; + u8 values[3]; + + ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values); + if (ret < 0) + return ret; + if (ret != 3) + return -EIO; + return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]); +} + +/* Spin for max 160ms until DEV_RDY is 1, or return error. */ +static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev) +{ + int ret; + int count = 0; + struct hp206c_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + + while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) { + ret = hp206c_read_reg(client, HP206C_REG_INT_SRC); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret); + return ret; + } + if (ret & HP206C_FLAG_DEV_RDY) + return 0; + usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2); + } + return -ETIMEDOUT; +} + +static int hp206c_set_compensation(struct i2c_client *client, bool enabled) +{ + int val; + + val = hp206c_read_reg(client, HP206C_REG_PARA); + if (val < 0) + return val; + if (enabled) + val |= HP206C_FLAG_CMPS_EN; + else + val &= ~HP206C_FLAG_CMPS_EN; + + return hp206c_write_reg(client, HP206C_REG_PARA, val); +} + +/* Do a soft reset */ +static int hp206c_soft_reset(struct iio_dev *indio_dev) +{ + int ret; + struct hp206c_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + + ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST); + if (ret) { + dev_err(&client->dev, "Failed to reset device: %d\n", ret); + return ret; + } + + usleep_range(400, 600); + + ret = hp206c_wait_dev_rdy(indio_dev); + if (ret) { + dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret); + return ret; + } + + ret = hp206c_set_compensation(client, true); + if (ret) + dev_err(&client->dev, "Failed to enable compensation: %d\n", ret); + return ret; +} + +static int hp206c_conv_and_read(struct iio_dev *indio_dev, + u8 conv_cmd, u8 read_cmd, + unsigned int sleep_us) +{ + int ret; + struct hp206c_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + + ret = hp206c_wait_dev_rdy(indio_dev); + if (ret < 0) { + dev_err(&indio_dev->dev, "Device not ready: %d\n", ret); + return ret; + } + + ret = i2c_smbus_write_byte(client, conv_cmd); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed convert: %d\n", ret); + return ret; + } + + usleep_range(sleep_us, sleep_us * 3 / 2); + + ret = hp206c_wait_dev_rdy(indio_dev); + if (ret < 0) { + dev_err(&indio_dev->dev, "Device not ready: %d\n", ret); + return ret; + } + + ret = hp206c_read_20bit(client, read_cmd); + if (ret < 0) + dev_err(&indio_dev->dev, "Failed read: %d\n", ret); + + return ret; +} + +static int hp206c_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + int ret; + struct hp206c_data *data = iio_priv(indio_dev); + const struct hp206c_osr_setting *osr_setting; + u8 conv_cmd; + + mutex_lock(&data->mutex); + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + switch (chan->type) { + case IIO_TEMP: + *val = hp206c_osr_rates[data->temp_osr_index]; + ret = IIO_VAL_INT; + break; + + case IIO_PRESSURE: + *val = hp206c_osr_rates[data->pres_osr_index]; + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + } + break; + + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_TEMP: + osr_setting = &hp206c_osr_settings[data->temp_osr_index]; + conv_cmd = HP206C_CMD_ADC_CVT | + osr_setting->osr_mask | + HP206C_CMD_ADC_CVT_CHNL_T; + ret = hp206c_conv_and_read(indio_dev, + conv_cmd, + HP206C_CMD_READ_T, + osr_setting->temp_conv_time_us); + if (ret >= 0) { + /* 20 significant bits are provided. + * Extend sign over the rest. + */ + *val = sign_extend32(ret, 19); + ret = IIO_VAL_INT; + } + break; + + case IIO_PRESSURE: + osr_setting = &hp206c_osr_settings[data->pres_osr_index]; + conv_cmd = HP206C_CMD_ADC_CVT | + osr_setting->osr_mask | + HP206C_CMD_ADC_CVT_CHNL_PT; + ret = hp206c_conv_and_read(indio_dev, + conv_cmd, + HP206C_CMD_READ_P, + osr_setting->pres_conv_time_us); + if (ret >= 0) { + *val = ret; + ret = IIO_VAL_INT; + } + break; + default: + ret = -EINVAL; + } + break; + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_TEMP: + *val = 0; + *val2 = 10000; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + + case IIO_PRESSURE: + *val = 0; + *val2 = 1000; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + default: + ret = -EINVAL; + } + break; + + default: + ret = -EINVAL; + } + + mutex_unlock(&data->mutex); + return ret; +} + +static int hp206c_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + int ret = 0; + struct hp206c_data *data = iio_priv(indio_dev); + + if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) + return -EINVAL; + mutex_lock(&data->mutex); + switch (chan->type) { + case IIO_TEMP: + data->temp_osr_index = find_closest_descending(val, + hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates)); + break; + case IIO_PRESSURE: + data->pres_osr_index = find_closest_descending(val, + hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates)); + break; + default: + ret = -EINVAL; + } + mutex_unlock(&data->mutex); + return ret; +} + +static const struct iio_chan_spec hp206c_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + }, + { + .type = IIO_PRESSURE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + } +}; + +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str); + +static struct attribute *hp206c_attributes[] = { + &iio_const_attr_sampling_frequency_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group hp206c_attribute_group = { + .attrs = hp206c_attributes, +}; + +static const struct iio_info hp206c_info = { + .attrs = &hp206c_attribute_group, + .read_raw = hp206c_read_raw, + .write_raw = hp206c_write_raw, +}; + +static int hp206c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct hp206c_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + dev_err(&client->dev, "Adapter does not support " + "all required i2c functionality\n"); + return -ENODEV; + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + data->client = client; + mutex_init(&data->mutex); + + indio_dev->info = &hp206c_info; + indio_dev->name = id->name; + indio_dev->dev.parent = &client->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = hp206c_channels; + indio_dev->num_channels = ARRAY_SIZE(hp206c_channels); + + i2c_set_clientdata(client, indio_dev); + + /* Do a soft reset on probe */ + ret = hp206c_soft_reset(indio_dev); + if (ret) { + dev_err(&client->dev, "Failed to reset on startup: %d\n", ret); + return -ENODEV; + } + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id hp206c_id[] = { + {"hp206c"}, + {} +}; +MODULE_DEVICE_TABLE(i2c, hp206c_id); + +#ifdef CONFIG_ACPI +static const struct acpi_device_id hp206c_acpi_match[] = { + {"HOP206C", 0}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match); +#endif + +static struct i2c_driver hp206c_driver = { + .probe = hp206c_probe, + .id_table = hp206c_id, + .driver = { + .name = "hp206c", + .acpi_match_table = ACPI_PTR(hp206c_acpi_match), + }, +}; + +module_i2c_driver(hp206c_driver); + +MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor"); +MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>"); +MODULE_LICENSE("GPL v2"); |