IIO driver, perhaps a reference driver, since this sensor is already supported in hwmon/jc42 driver. Driver supports continuous conversion, resolution changes and suspend/resume power ops. Signed-off-by: Alison Schofield <amsfield22@xxxxxxxxx> Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx> --- drivers/iio/temperature/Kconfig | 10 ++ drivers/iio/temperature/Makefile | 1 + drivers/iio/temperature/mcp9808.c | 269 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 280 insertions(+) create mode 100644 drivers/iio/temperature/mcp9808.c diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig index c4664e5..25915d2 100644 --- a/drivers/iio/temperature/Kconfig +++ b/drivers/iio/temperature/Kconfig @@ -3,6 +3,16 @@ # menu "Temperature sensors" +config MCP9808 + tristate "MCP9808 temperature sensor" + depends on I2C + help + If you say yes here you get support for the Microchip + MCP9808 temperature sensor connected with I2C. + + This driver can also be built as a module. If so, the module will + be called mcp9808. + config MLX90614 tristate "MLX90614 contact-less infrared sensor" depends on I2C diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile index 02bc79d..92cd1e6 100644 --- a/drivers/iio/temperature/Makefile +++ b/drivers/iio/temperature/Makefile @@ -2,6 +2,7 @@ # Makefile for industrial I/O temperature drivers # +obj-$(CONFIG_MCP9808) += mcp9808.o obj-$(CONFIG_MLX90614) += mlx90614.o obj-$(CONFIG_TMP006) += tmp006.o obj-$(CONFIG_TSYS01) += tsys01.o diff --git a/drivers/iio/temperature/mcp9808.c b/drivers/iio/temperature/mcp9808.c new file mode 100644 index 0000000..adab708 --- /dev/null +++ b/drivers/iio/temperature/mcp9808.c @@ -0,0 +1,269 @@ +/* + * mcp9808.c - Support for Microchip MCP9808 Digital Temperature Sensor + * + * Copyright (C) 2016 Alison Schofield <amsfield22@xxxxxxxxx> + * + * 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. + * + * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/25095A.pdf + */ + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define MCP9808_REG_CONFIG 0x01 +#define MCP9808_REG_TAMBIENT 0x05 +#define MCP9808_REG_MANUF_ID 0x06 +#define MCP9808_REG_DEVICE_ID 0x07 +#define MCP9808_REG_RESOLUTION 0x08 + +#define MCP9808_CONFIG_DEFAULT 0x00 +#define MCP9808_CONFIG_SHUTDOWN 0x0100 + +#define MCP9808_RES_DEFAULT 62500 + +#define MCP9808_MANUF_ID 0x54 +#define MCP9808_DEVICE_ID 0x0400 +#define MCP9808_DEVICE_ID_MASK 0xff00 + +struct mcp9808_data { + struct i2c_client *client; + struct mutex lock; /* protect resolution changes */ + int res_index; /* current resolution index */ +}; + +/* Resolution, MCP9808_REG_RESOLUTION bits, Conversion Time ms */ +static const int mcp9808_res[][3] = { + {500000, 0, 30}, + {250000, 1, 65}, + {125000, 2, 130}, + { 62500, 3, 250}, +}; + +static IIO_CONST_ATTR(temp_integration_time_available, + "0.5 0.25 0.125 0.0625"); + +static struct attribute *mcp9808_attributes[] = { + &iio_const_attr_temp_integration_time_available.dev_attr.attr, + NULL +}; + +static struct attribute_group mcp9808_attribute_group = { + .attrs = mcp9808_attributes, +}; + +static int mcp9808_set_resolution(struct mcp9808_data *data, int val2) +{ + int i; + int ret = -EINVAL; + int conv_t = mcp9808_res[data->res_index][2]; + + for (i = 0; i < ARRAY_SIZE(mcp9808_res); i++) { + if (val2 == mcp9808_res[i][0]) { + mutex_lock(&data->lock); + ret = i2c_smbus_write_byte_data(data->client, + MCP9808_REG_RESOLUTION, + mcp9808_res[i][1]); + data->res_index = i; + mutex_unlock(&data->lock); + + /* delay old + new conversion time */ + msleep(conv_t + mcp9808_res[i][2]); + break; + } + } + return ret; +} + +static int mcp9808_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, + int *val, int *val2, long mask) + +{ + struct mcp9808_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = i2c_smbus_read_word_swapped(data->client, + MCP9808_REG_TAMBIENT); + if (ret < 0) + return ret; + *val = sign_extend32(ret, 12); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = 62500; + return IIO_VAL_INT_PLUS_MICRO; + + case IIO_CHAN_INFO_INT_TIME: + *val = 0; + *val2 = mcp9808_res[data->res_index][0]; + return IIO_VAL_INT_PLUS_MICRO; + + default: + break; + } + + return -EINVAL; +} + +static int mcp9808_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, + int val, int val2, long mask) +{ + struct mcp9808_data *data = iio_priv(indio_dev); + int ret = -EINVAL; + + if (mask == IIO_CHAN_INFO_INT_TIME) { + if (!val) + ret = mcp9808_set_resolution(data, val2); + } + return ret; +} + +static const struct iio_chan_spec mcp9808_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_INT_TIME) + } +}; + +static const struct iio_info mcp9808_info = { + .read_raw = mcp9808_read_raw, + .write_raw = mcp9808_write_raw, + .attrs = &mcp9808_attribute_group, + .driver_module = THIS_MODULE, +}; + +static bool mcp9808_check_id(struct i2c_client *client) +{ + int mid, did; + + mid = i2c_smbus_read_word_swapped(client, MCP9808_REG_MANUF_ID); + if (mid < 0) + return false; + + did = i2c_smbus_read_word_swapped(client, MCP9808_REG_DEVICE_ID); + if (did < 0) + return false; + + return ((mid == MCP9808_MANUF_ID) && + ((did & MCP9808_DEVICE_ID_MASK) == MCP9808_DEVICE_ID)); +} + +static int mcp9808_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct mcp9808_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA + | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) + return -EOPNOTSUPP; + + if (!mcp9808_check_id(client)) { + dev_err(&client->dev, "no MCP9808 sensor\n"); + return -ENODEV; + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + mutex_init(&data->lock); + + indio_dev->dev.parent = &client->dev; + indio_dev->name = id->name; + indio_dev->info = &mcp9808_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = mcp9808_channels; + indio_dev->num_channels = ARRAY_SIZE(mcp9808_channels); + + /* set config register to power-on default */ + ret = i2c_smbus_write_word_swapped(data->client, MCP9808_REG_CONFIG, + MCP9808_CONFIG_DEFAULT); + if (ret < 0) + return ret; + + /* set resolution register to power-on default */ + ret = mcp9808_set_resolution(data, MCP9808_RES_DEFAULT); + if (ret < 0) + return ret; + + return iio_device_register(indio_dev); +} + +static int mcp9808_shutdown(struct mcp9808_data *data) +{ + return i2c_smbus_write_word_swapped(data->client, MCP9808_REG_CONFIG, + MCP9808_CONFIG_SHUTDOWN); +} + +static int mcp9808_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + + return mcp9808_shutdown(iio_priv(indio_dev)); +} + +#ifdef CONFIG_PM_SLEEP +static int mcp9808_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + + return mcp9808_shutdown(iio_priv(indio_dev)); +} + +static int mcp9808_resume(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + struct mcp9808_data *data = iio_priv(indio_dev); + int ret; + + ret = mcp9808_set_resolution(data, mcp9808_res[data->res_index][0]); + if (ret < 0) + return ret; + + return i2c_smbus_write_word_swapped(data->client, MCP9808_REG_CONFIG, + MCP9808_CONFIG_DEFAULT); +} +#endif + +static SIMPLE_DEV_PM_OPS(mcp9808_pm_ops, mcp9808_suspend, mcp9808_resume); + +static const struct i2c_device_id mcp9808_id[] = { + { "mcp9808", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, mcp9808_id); + +static struct i2c_driver mcp9808_driver = { + .driver = { + .name = "mcp9808", + .pm = &mcp9808_pm_ops, + }, + .probe = mcp9808_probe, + .remove = mcp9808_remove, + .id_table = mcp9808_id, +}; +module_i2c_driver(mcp9808_driver); + +MODULE_AUTHOR("Alison Schofield <amsfield22@xxxxxxxxx>"); +MODULE_DESCRIPTION("MCP9808 Temperature Sensor Driver"); +MODULE_LICENSE("GPL v2"); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
