diff options
Diffstat (limited to 'drivers/iio/pressure/t5403.c')
| -rw-r--r-- | drivers/iio/pressure/t5403.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/iio/pressure/t5403.c b/drivers/iio/pressure/t5403.c new file mode 100644 index 000000000..92c00f603 --- /dev/null +++ b/drivers/iio/pressure/t5403.c @@ -0,0 +1,274 @@ +/* + * t5403.c - Support for EPCOS T5403 pressure/temperature sensor + * + * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net> + * + * 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 0x77) + * + * TODO: end-of-conversion irq + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/delay.h> + +#define T5403_DATA 0xf5 /* data, LSB first, 16 bit */ +#define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */ +#define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */ +#define T5403_COMMAND 0xf1 + +/* command bits */ +#define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */ +#define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */ +#define T5403_SCO BIT(0) /* start conversion */ + +#define T5403_MODE_LOW 0 +#define T5403_MODE_STANDARD 1 +#define T5403_MODE_HIGH 2 +#define T5403_MODE_ULTRA_HIGH 3 + +#define T5403_I2C_MASK (~BIT(7)) +#define T5403_I2C_ADDR 0x77 + +static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66}; + +struct t5403_data { + struct i2c_client *client; + struct mutex lock; + int mode; + __le16 c[10]; +}; + +#define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1]) +#define T5403_C(i) sign_extend32(T5403_C_U16(i), 15) + +static int t5403_read(struct t5403_data *data, bool pressure) +{ + int wait_time = 3; /* wakeup time in ms */ + + int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND, + (pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) | + T5403_SCO); + if (ret < 0) + return ret; + + wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2; + + msleep(wait_time); + + return i2c_smbus_read_word_data(data->client, T5403_DATA); +} + +static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2) +{ + int ret; + s16 t_r; + u16 p_r; + s32 S, O, X; + + mutex_lock(&data->lock); + + ret = t5403_read(data, false); + if (ret < 0) + goto done; + t_r = ret; + + ret = t5403_read(data, true); + if (ret < 0) + goto done; + p_r = ret; + + /* see EPCOS application note */ + S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 + + T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 + + T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000; + + O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 + + T5403_C(8) * t_r / 0x8000 * t_r / 16 + + T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r; + + X = (S * p_r + O) / 0x4000; + + X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) * + T5403_C(10) / 0x10000; + + *val = X / 1000; + *val2 = (X % 1000) * 1000; + +done: + mutex_unlock(&data->lock); + return ret; +} + +static int t5403_comp_temp(struct t5403_data *data, int *val) +{ + int ret; + s16 t_r; + + mutex_lock(&data->lock); + ret = t5403_read(data, false); + if (ret < 0) + goto done; + t_r = ret; + + /* see EPCOS application note */ + *val = ((s32) T5403_C_U16(1) * t_r / 0x100 + + (s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000; + +done: + mutex_unlock(&data->lock); + return ret; +} + +static int t5403_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct t5403_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_PROCESSED: + switch (chan->type) { + case IIO_PRESSURE: + ret = t5403_comp_pressure(data, val, val2); + if (ret < 0) + return ret; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_TEMP: + ret = t5403_comp_temp(data, val); + if (ret < 0) + return ret; + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_INT_TIME: + *val = 0; + *val2 = t5403_pressure_conv_ms[data->mode] * 1000; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static int t5403_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct t5403_data *data = iio_priv(indio_dev); + int i; + + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + if (val != 0) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++) + if (val2 == t5403_pressure_conv_ms[i] * 1000) { + mutex_lock(&data->lock); + data->mode = i; + mutex_unlock(&data->lock); + return 0; + } + return -EINVAL; + default: + return -EINVAL; + } +} + +static const struct iio_chan_spec t5403_channels[] = { + { + .type = IIO_PRESSURE, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_INT_TIME), + }, + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + }, +}; + +static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066"); + +static struct attribute *t5403_attributes[] = { + &iio_const_attr_integration_time_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group t5403_attribute_group = { + .attrs = t5403_attributes, +}; + +static const struct iio_info t5403_info = { + .read_raw = &t5403_read_raw, + .write_raw = &t5403_write_raw, + .attrs = &t5403_attribute_group, +}; + +static int t5403_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct t5403_data *data; + struct iio_dev *indio_dev; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_I2C_BLOCK)) + return -EOPNOTSUPP; + + ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR); + if (ret < 0) + return ret; + if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR) + 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->lock); + + i2c_set_clientdata(client, indio_dev); + indio_dev->info = &t5403_info; + indio_dev->name = id->name; + indio_dev->dev.parent = &client->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = t5403_channels; + indio_dev->num_channels = ARRAY_SIZE(t5403_channels); + + data->mode = T5403_MODE_STANDARD; + + ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA, + sizeof(data->c), (u8 *) data->c); + if (ret < 0) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id t5403_id[] = { + { "t5403", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, t5403_id); + +static struct i2c_driver t5403_driver = { + .driver = { + .name = "t5403", + }, + .probe = t5403_probe, + .id_table = t5403_id, +}; +module_i2c_driver(t5403_driver); + +MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); +MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver"); +MODULE_LICENSE("GPL"); |