![Javier Martinez Canillas](/assets/img/avatar_default.png)
The I2C drivers have an i2c_device_id array but that information isn't exported to the modules using the MODULE_DEVICE_TABLE() macro. So the modules autoloading won't work if the I2C device is registered using OF or legacy board files due missing alias information in the modules. The issue was found using Kieran Bingham's coccinelle semantic patch: https://lkml.org/lkml/2016/5/10/520 Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
255 lines
6.3 KiB
C
255 lines
6.3 KiB
C
/*
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* htu21.c - Support for Measurement-Specialties
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* htu21 temperature & humidity sensor
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* and humidity part of MS8607 sensor
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*
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* Copyright (c) 2014 Measurement-Specialties
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*
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* Licensed under the GPL-2.
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*
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* (7-bit I2C slave address 0x40)
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*
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* Datasheet:
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* http://www.meas-spec.com/downloads/HTU21D.pdf
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* Datasheet:
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* http://www.meas-spec.com/downloads/MS8607-02BA01.pdf
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*/
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/stat.h>
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#include <linux/module.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include "../common/ms_sensors/ms_sensors_i2c.h"
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#define HTU21_RESET 0xFE
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enum {
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HTU21,
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MS8607
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};
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static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };
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/* String copy of the above const for readability purpose */
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static const char htu21_show_samp_freq[] = "20 40 70 120";
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static int htu21_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *channel, int *val,
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int *val2, long mask)
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{
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int ret, temperature;
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unsigned int humidity;
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED:
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switch (channel->type) {
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case IIO_TEMP: /* in milli °C */
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ret = ms_sensors_ht_read_temperature(dev_data,
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&temperature);
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if (ret)
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return ret;
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*val = temperature;
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return IIO_VAL_INT;
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case IIO_HUMIDITYRELATIVE: /* in milli %RH */
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ret = ms_sensors_ht_read_humidity(dev_data,
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&humidity);
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if (ret)
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return ret;
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*val = humidity;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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case IIO_CHAN_INFO_SAMP_FREQ:
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*val = htu21_samp_freq[dev_data->res_index];
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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}
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static int htu21_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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int i, ret;
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switch (mask) {
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case IIO_CHAN_INFO_SAMP_FREQ:
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i = ARRAY_SIZE(htu21_samp_freq);
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while (i-- > 0)
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if (val == htu21_samp_freq[i])
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break;
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if (i < 0)
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return -EINVAL;
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mutex_lock(&dev_data->lock);
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dev_data->res_index = i;
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ret = ms_sensors_write_resolution(dev_data, i);
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mutex_unlock(&dev_data->lock);
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return ret;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_chan_spec htu21_channels[] = {
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{
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.type = IIO_TEMP,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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},
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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}
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};
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/*
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* Meas Spec recommendation is to not read temperature
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* on this driver part for MS8607
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*/
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static const struct iio_chan_spec ms8607_channels[] = {
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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}
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};
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static ssize_t htu21_show_battery_low(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_show_battery_low(dev_data, buf);
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}
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static ssize_t htu21_show_heater(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_show_heater(dev_data, buf);
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}
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static ssize_t htu21_write_heater(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t len)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_write_heater(dev_data, buf, len);
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}
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static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);
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static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
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htu21_show_battery_low, NULL, 0);
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static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
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htu21_show_heater, htu21_write_heater, 0);
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static struct attribute *htu21_attributes[] = {
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&iio_const_attr_sampling_frequency_available.dev_attr.attr,
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&iio_dev_attr_battery_low.dev_attr.attr,
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&iio_dev_attr_heater_enable.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group htu21_attribute_group = {
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.attrs = htu21_attributes,
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};
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static const struct iio_info htu21_info = {
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.read_raw = htu21_read_raw,
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.write_raw = htu21_write_raw,
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.attrs = &htu21_attribute_group,
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.driver_module = THIS_MODULE,
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};
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static int htu21_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ms_ht_dev *dev_data;
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struct iio_dev *indio_dev;
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int ret;
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u64 serial_number;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
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I2C_FUNC_SMBUS_WRITE_BYTE |
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I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
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dev_err(&client->dev,
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"Adapter does not support some i2c transaction\n");
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return -EOPNOTSUPP;
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}
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
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if (!indio_dev)
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return -ENOMEM;
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dev_data = iio_priv(indio_dev);
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dev_data->client = client;
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dev_data->res_index = 0;
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mutex_init(&dev_data->lock);
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indio_dev->info = &htu21_info;
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indio_dev->name = id->name;
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indio_dev->dev.parent = &client->dev;
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indio_dev->modes = INDIO_DIRECT_MODE;
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if (id->driver_data == MS8607) {
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indio_dev->channels = ms8607_channels;
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indio_dev->num_channels = ARRAY_SIZE(ms8607_channels);
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} else {
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indio_dev->channels = htu21_channels;
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indio_dev->num_channels = ARRAY_SIZE(htu21_channels);
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}
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i2c_set_clientdata(client, indio_dev);
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ret = ms_sensors_reset(client, HTU21_RESET, 15000);
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if (ret)
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return ret;
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ret = ms_sensors_read_serial(client, &serial_number);
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if (ret)
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return ret;
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dev_info(&client->dev, "Serial number : %llx", serial_number);
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return devm_iio_device_register(&client->dev, indio_dev);
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}
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static const struct i2c_device_id htu21_id[] = {
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{"htu21", HTU21},
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{"ms8607-humidity", MS8607},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, htu21_id);
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static struct i2c_driver htu21_driver = {
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.probe = htu21_probe,
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.id_table = htu21_id,
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.driver = {
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.name = "htu21",
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},
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};
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module_i2c_driver(htu21_driver);
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MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");
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MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
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MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
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MODULE_LICENSE("GPL v2");
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