diff options
Diffstat (limited to 'drivers/iio/humidity/hid-sensor-humidity.c')
| -rw-r--r-- | drivers/iio/humidity/hid-sensor-humidity.c | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hid-sensor-humidity.c b/drivers/iio/humidity/hid-sensor-humidity.c new file mode 100644 index 000000000000..6e09c1acfe51 --- /dev/null +++ b/drivers/iio/humidity/hid-sensor-humidity.c @@ -0,0 +1,315 @@ +/* + * HID Sensors Driver + * Copyright (c) 2017, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. + */ +#include <linux/device.h> +#include <linux/hid-sensor-hub.h> +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include "hid-sensor-trigger.h" + +struct hid_humidity_state { + struct hid_sensor_common common_attributes; + struct hid_sensor_hub_attribute_info humidity_attr; + s32 humidity_data; + int scale_pre_decml; + int scale_post_decml; + int scale_precision; + int value_offset; +}; + +/* Channel definitions */ +static const struct iio_chan_spec humidity_channels[] = { + { + .type = IIO_HUMIDITYRELATIVE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_HYSTERESIS), + }, + IIO_CHAN_SOFT_TIMESTAMP(1) +}; + +/* Adjust channel real bits based on report descriptor */ +static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels, + int channel, int size) +{ + channels[channel].scan_type.sign = 's'; + /* Real storage bits will change based on the report desc. */ + channels[channel].scan_type.realbits = size * 8; + /* Maximum size of a sample to capture is s32 */ + channels[channel].scan_type.storagebits = sizeof(s32) * 8; +} + +static int humidity_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct hid_humidity_state *humid_st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type != IIO_HUMIDITYRELATIVE) + return -EINVAL; + hid_sensor_power_state(&humid_st->common_attributes, true); + *val = sensor_hub_input_attr_get_raw_value( + humid_st->common_attributes.hsdev, + HID_USAGE_SENSOR_HUMIDITY, + HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY, + humid_st->humidity_attr.report_id, + SENSOR_HUB_SYNC); + hid_sensor_power_state(&humid_st->common_attributes, false); + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = humid_st->scale_pre_decml; + *val2 = humid_st->scale_post_decml; + + return humid_st->scale_precision; + + case IIO_CHAN_INFO_OFFSET: + *val = humid_st->value_offset; + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SAMP_FREQ: + return hid_sensor_read_samp_freq_value( + &humid_st->common_attributes, val, val2); + + case IIO_CHAN_INFO_HYSTERESIS: + return hid_sensor_read_raw_hyst_value( + &humid_st->common_attributes, val, val2); + + default: + return -EINVAL; + } +} + +static int humidity_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct hid_humidity_state *humid_st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + return hid_sensor_write_samp_freq_value( + &humid_st->common_attributes, val, val2); + + case IIO_CHAN_INFO_HYSTERESIS: + return hid_sensor_write_raw_hyst_value( + &humid_st->common_attributes, val, val2); + + default: + return -EINVAL; + } +} + +static const struct iio_info humidity_info = { + .driver_module = THIS_MODULE, + .read_raw = &humidity_read_raw, + .write_raw = &humidity_write_raw, +}; + +/* Callback handler to send event after all samples are received and captured */ +static int humidity_proc_event(struct hid_sensor_hub_device *hsdev, + unsigned int usage_id, void *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct hid_humidity_state *humid_st = iio_priv(indio_dev); + + if (atomic_read(&humid_st->common_attributes.data_ready)) + iio_push_to_buffers_with_timestamp(indio_dev, + &humid_st->humidity_data, + iio_get_time_ns(indio_dev)); + + return 0; +} + +/* Capture samples in local storage */ +static int humidity_capture_sample(struct hid_sensor_hub_device *hsdev, + unsigned int usage_id, size_t raw_len, + char *raw_data, void *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct hid_humidity_state *humid_st = iio_priv(indio_dev); + + switch (usage_id) { + case HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY: + humid_st->humidity_data = *(s32 *)raw_data; + + return 0; + default: + return -EINVAL; + } +} + +/* Parse report which is specific to an usage id */ +static int humidity_parse_report(struct platform_device *pdev, + struct hid_sensor_hub_device *hsdev, + struct iio_chan_spec *channels, + unsigned int usage_id, + struct hid_humidity_state *st) +{ + int ret; + + ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT, + usage_id, + HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY, + &st->humidity_attr); + if (ret < 0) + return ret; + + humidity_adjust_channel_bit_mask(channels, 0, st->humidity_attr.size); + + st->scale_precision = hid_sensor_format_scale( + HID_USAGE_SENSOR_HUMIDITY, + &st->humidity_attr, + &st->scale_pre_decml, + &st->scale_post_decml); + + /* Set Sensitivity field ids, when there is no individual modifier */ + if (st->common_attributes.sensitivity.index < 0) + sensor_hub_input_get_attribute_info(hsdev, + HID_FEATURE_REPORT, usage_id, + HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS | + HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY, + &st->common_attributes.sensitivity); + + return ret; +} + +static struct hid_sensor_hub_callbacks humidity_callbacks = { + .send_event = &humidity_proc_event, + .capture_sample = &humidity_capture_sample, +}; + +/* Function to initialize the processing for usage id */ +static int hid_humidity_probe(struct platform_device *pdev) +{ + static const char *name = "humidity"; + struct iio_dev *indio_dev; + struct hid_humidity_state *humid_st; + struct iio_chan_spec *humid_chans; + struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev); + int ret; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*humid_st)); + if (!indio_dev) + return -ENOMEM; + + humid_st = iio_priv(indio_dev); + humid_st->common_attributes.hsdev = hsdev; + humid_st->common_attributes.pdev = pdev; + + ret = hid_sensor_parse_common_attributes(hsdev, + HID_USAGE_SENSOR_HUMIDITY, + &humid_st->common_attributes); + if (ret) + return ret; + + humid_chans = devm_kmemdup(&indio_dev->dev, humidity_channels, + sizeof(humidity_channels), GFP_KERNEL); + if (!humid_chans) + return -ENOMEM; + + ret = humidity_parse_report(pdev, hsdev, humid_chans, + HID_USAGE_SENSOR_HUMIDITY, humid_st); + if (ret) + return ret; + + indio_dev->channels = humid_chans; + indio_dev->num_channels = ARRAY_SIZE(humidity_channels); + indio_dev->dev.parent = &pdev->dev; + indio_dev->info = &humidity_info; + indio_dev->name = name; + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, + &iio_pollfunc_store_time, NULL, NULL); + if (ret) + return ret; + + atomic_set(&humid_st->common_attributes.data_ready, 0); + ret = hid_sensor_setup_trigger(indio_dev, name, + &humid_st->common_attributes); + if (ret) + return ret; + + platform_set_drvdata(pdev, indio_dev); + + humidity_callbacks.pdev = pdev; + ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY, + &humidity_callbacks); + if (ret) + goto error_remove_trigger; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_remove_callback; + + return ret; + +error_remove_callback: + sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY); +error_remove_trigger: + hid_sensor_remove_trigger(&humid_st->common_attributes); + return ret; +} + +/* Function to deinitialize the processing for usage id */ +static int hid_humidity_remove(struct platform_device *pdev) +{ + struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev); + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct hid_humidity_state *humid_st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_HUMIDITY); + hid_sensor_remove_trigger(&humid_st->common_attributes); + + return 0; +} + +static const struct platform_device_id hid_humidity_ids[] = { + { + /* Format: HID-SENSOR-usage_id_in_hex_lowercase */ + .name = "HID-SENSOR-200032", + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, hid_humidity_ids); + +static struct platform_driver hid_humidity_platform_driver = { + .id_table = hid_humidity_ids, + .driver = { + .name = KBUILD_MODNAME, + .pm = &hid_sensor_pm_ops, + }, + .probe = hid_humidity_probe, + .remove = hid_humidity_remove, +}; +module_platform_driver(hid_humidity_platform_driver); + +MODULE_DESCRIPTION("HID Environmental humidity sensor"); +MODULE_AUTHOR("Song Hongyan <hongyan.song@intel.com>"); +MODULE_LICENSE("GPL v2"); |