Re: [PATCH] iio: hid: Add temperature sensor support

* Re: [PATCH] iio: hid: Add temperature sensor support
  2017-02-04 13:47 ` Song Hongyan
@ 2017-02-04 12:02     ` Jonathan Cameron
  -1 siblings, 0 replies; 6+ messages in thread
From: Jonathan Cameron @ 2017-02-04 12:02 UTC (permalink / raw)
  To: Song Hongyan, linux-input-u79uwXL29TY76Z2rM5mHXA,
	linux-iio-u79uwXL29TY76Z2rM5mHXA
  Cc: jikos-DgEjT+Ai2ygdnm+yROfE0A, srinivas.pandruvada-ral2JQCrhuEAvxtiuMwx3w

On 04/02/17 13:47, Song Hongyan wrote:
> Environmental temperature sensor is a hid defined sensor,
> it measures temperature.
> 
> More information can be found in:
> http://www.usb.org/developers/hidpage/HUTRR39b.pdf
> 
> According to IIO ABI definition, IIO_TEMP data output unit is
> milli degrees Celsius. Add the unit convert from degree to milli degree.
> 
> Signed-off-by: Song Hongyan <hongyan.song-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
A few bits and bobs inline.  Clearly I'll want Srinivas to comment on this
one as well!

Jonathan
> ---
>  .../iio/common/hid-sensors/hid-sensor-attributes.c |   3 +
>  drivers/iio/temperature/Kconfig                    |  14 +
>  drivers/iio/temperature/Makefile                   |   1 +
>  drivers/iio/temperature/hid-sensor-temperature.c   | 332 +++++++++++++++++++++
>  include/linux/hid-sensor-ids.h                     |   4 +
>  5 files changed, 354 insertions(+)
>  create mode 100644 drivers/iio/temperature/hid-sensor-temperature.c
> 
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> index 7ef94a9..68c2bb0 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> @@ -58,6 +58,9 @@
>  
>  	{HID_USAGE_SENSOR_PRESSURE, 0, 100, 0},
>  	{HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 0, 1000000},
> +
> +	{HID_USAGE_SENSOR_TEMPERATURE, 0, 1000, 0},
> +	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},
>  };
>  
>  static int pow_10(unsigned power)
> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
> index 5ea77a7..5f7b9f7 100644
> --- a/drivers/iio/temperature/Kconfig
> +++ b/drivers/iio/temperature/Kconfig
> @@ -19,6 +19,20 @@ config MAXIM_THERMOCOUPLE
>  	  This driver can also be built as a module. If so, the module will
>  	  be called maxim_thermocouple.
>  
> +config HID_SENSOR_TEMP
> +	tristate "HID Environmental temperature sensor"
> +	depends on HID_SENSOR_HUB
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	select HID_SENSOR_IIO_COMMON
> +	select HID_SENSOR_IIO_TRIGGER
> +	help
> +	  Say yes here to build support for the HID SENSOR
> +	  temperature driver
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called hid-sensor-temperature.
> +
>  config MLX90614
>  	tristate "MLX90614 contact-less infrared sensor"
>  	depends on I2C
> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
> index 78c3de0..e157eda 100644
> --- a/drivers/iio/temperature/Makefile
> +++ b/drivers/iio/temperature/Makefile
> @@ -7,3 +7,4 @@ obj-$(CONFIG_MLX90614) += mlx90614.o
>  obj-$(CONFIG_TMP006) += tmp006.o
>  obj-$(CONFIG_TSYS01) += tsys01.o
>  obj-$(CONFIG_TSYS02D) += tsys02d.o
> +obj-$(CONFIG_HID_SENSOR_TEMP)   += hid-sensor-temperature.o
> diff --git a/drivers/iio/temperature/hid-sensor-temperature.c b/drivers/iio/temperature/hid-sensor-temperature.c
> new file mode 100644
> index 0000000..3b64c73
> --- /dev/null
> +++ b/drivers/iio/temperature/hid-sensor-temperature.c
> @@ -0,0 +1,332 @@
> +/* 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 "../common/hid-sensors/hid-sensor-trigger.h"
> +
> +#define CHANNEL_SCAN_INDEX_TEMPERATURE 0
This adds nothing useful so just put the variable inline.
> +
> +struct temperature_state {
> +	struct hid_sensor_hub_callbacks callbacks;
Random asside whilst I'm here.  I'd like ideally to see the callbacks
structure split into constant function pointers and data that actually
changes (such as the priv field passed as a parameter to the callbacks).
Would lead to slightly neater and safter code.

> +	struct hid_sensor_common common_attributes;
> +	struct hid_sensor_hub_attribute_info temperature_attr;
> +	s32 temperature_data;
> +	int scale_pre_decml;
> +	int scale_post_decml;
> +	int scale_precision;
> +	int value_offset;
> +};
> +
> +/* Channel definitions */
> +static const struct iio_chan_spec temperature_channels[] = {
> +	{
> +		.type = IIO_TEMP,
> +		.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),
> +		.scan_index = CHANNEL_SCAN_INDEX_TEMPERATURE,
> +	}
> +};
> +
> +/* Adjust channel real bits based on report descriptor */
> +static void temperature_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;
> +}
> +
> +/* Channel read_raw handler */
> +static int temperature_read_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int *val, int *val2,
> +			      long mask)
> +{
> +	struct temperature_state *temperature_state = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (chan->type == IIO_TEMP) {
> +			hid_sensor_power_state(
> +				&temperature_state->common_attributes, true);
> +			*val = sensor_hub_input_attr_get_raw_value(
> +				temperature_state->common_attributes.hsdev,
> +				HID_USAGE_SENSOR_TEMPERATURE,
> +				HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
> +				temperature_state->temperature_attr.report_id,
> +				SENSOR_HUB_SYNC);
> +			hid_sensor_power_state(
> +					&temperature_state->common_attributes,
> +					false);
> +		}
> +		ret = IIO_VAL_INT;
> +		break;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = temperature_state->scale_pre_decml;
> +		*val2 = temperature_state->scale_post_decml;
> +		ret = temperature_state->scale_precision;
> +		break;
> +	case IIO_CHAN_INFO_OFFSET:
> +		*val = temperature_state->value_offset;
> +		ret = IIO_VAL_INT;
> +		break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = hid_sensor_read_samp_freq_value(
> +				&temperature_state->common_attributes,
> +				val, val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret = hid_sensor_read_raw_hyst_value(
> +				&temperature_state->common_attributes,
> +				val, val2);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +/* Channel write_raw handler */
> +static int temperature_write_raw(struct iio_dev *indio_dev,
> +			       struct iio_chan_spec const *chan,
> +			       int val,
> +			       int val2,
> +			       long mask)
> +{
> +	struct temperature_state *temperature_state = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = hid_sensor_write_samp_freq_value(
> +				&temperature_state->common_attributes, val,
> +				val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret = hid_sensor_write_raw_hyst_value(
> +				&temperature_state->common_attributes, val,
> +				val2);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_info temperature_info = {
> +	.driver_module = THIS_MODULE,
> +	.read_raw = &temperature_read_raw,
> +	.write_raw = &temperature_write_raw,
> +};
> +
> +/* Function to push data to buffer */
> +static void hid_sensor_push_data(struct iio_dev *indio_dev, const void *data,
> +					int len)
> +{
> +	iio_push_to_buffers(indio_dev, data);
This wrapper does seem somewhat pointless...
> +}
> +
> +/* Callback handler to send event after all samples are received and captured */
> +static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
> +				unsigned int usage_id,
> +				void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
> +	struct temperature_state *temperature_state = iio_priv(indio_dev);
> +
> +	if (atomic_read(&temperature_state->common_attributes.data_ready))
> +		hid_sensor_push_data(indio_dev,
> +				&temperature_state->temperature_data,
> +				sizeof(temperature_state->temperature_data));
> +
> +	return 0;
> +}
> +
> +/* Capture samples in local storage */
> +static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
> +				unsigned int usage_id,
> +				size_t raw_len, char *raw_data,
> +				void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
Why not make priv the indio_dev directly? I would imagine it's the pdev
passed in when registering the callbacks below.

> +	struct temperature_state *temperature_state = iio_priv(indio_dev);
> +
> +	switch (usage_id) {
> +	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
> +		temperature_state->temperature_data = *(s32 *)raw_data;
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +/* Parse report which is specific to an usage id*/
> +static int temperature_parse_report(struct platform_device *pdev,
> +				struct hid_sensor_hub_device *hsdev,
> +				struct iio_chan_spec *channels,
> +				unsigned int usage_id,
> +				struct temperature_state *st)
> +{
> +	int ret;
> +
> +	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
> +			usage_id,
> +			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
> +			&st->temperature_attr);
> +	if (ret < 0)
> +		return ret;
> +
> +	temperature_adjust_channel_bit_mask(channels,
> +					CHANNEL_SCAN_INDEX_TEMPERATURE,
> +					st->temperature_attr.size);
> +
> +	st->scale_precision = hid_sensor_format_scale(
> +				HID_USAGE_SENSOR_TEMPERATURE,
> +				&st->temperature_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_DATA_ENVIRONMENTAL_TEMPERATURE,
> +			&st->common_attributes.sensitivity);
blank line here.
> +	return ret;
> +}
> +
> +/* Function to initialize the processing for usage id */
> +static int hid_temperature_probe(struct platform_device *pdev)
> +{
> +	static const char *name = "temperature";
> +	struct iio_dev *indio_dev;
> +	struct temperature_state *temperature_state;
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev,
> +				sizeof(struct temperature_state));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	temperature_state = iio_priv(indio_dev);
> +	temperature_state->common_attributes.hsdev = hsdev;
> +	temperature_state->common_attributes.pdev = pdev;
> +
> +	ret = hid_sensor_parse_common_attributes(hsdev,
> +					HID_USAGE_SENSOR_TEMPERATURE,
> +					&temperature_state->common_attributes);
> +	if (ret)
> +		return ret;
> +
> +	indio_dev->channels = devm_kmemdup(&indio_dev->dev,
> +					temperature_channels,
> +					sizeof(temperature_channels),
> +					GFP_KERNEL);
> +	if (!indio_dev->channels)
> +		return -ENOMEM;
> +
> +	ret = temperature_parse_report(pdev, hsdev,
> +				(struct iio_chan_spec *)indio_dev->channels,
> +				HID_USAGE_SENSOR_TEMPERATURE,
> +				temperature_state);
> +	if (ret)
> +		return ret;
> +
> +	indio_dev->num_channels = ARRAY_SIZE(temperature_channels);
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &temperature_info;
> +	indio_dev->name = name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
> +					NULL, NULL);
> +	if (ret)
> +		return ret;
If you are going all devm (which is fine) then use
devm_iio_triggered_buffer_setup.

> +
> +	atomic_set(&temperature_state->common_attributes.data_ready, 0);
> +	ret = hid_sensor_setup_trigger(indio_dev, name,
> +				&temperature_state->common_attributes);
I'd expect to see this unwound somewhere as well..
> +	if (ret)
> +		goto error_unreg_buffer_funcs;
> +
> +	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
> +	if (ret)
> +		goto error_unreg_buffer_funcs;
Is there a race here in that userspace interfaces are exposed, but the
hid system has no way to send answers to any queries?
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	temperature_state->callbacks.send_event = temperature_proc_event;
> +	temperature_state->callbacks.capture_sample =
> +						temperature_capture_sample;
> +	temperature_state->callbacks.pdev = pdev;
> +	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE,
> +					&temperature_state->callbacks); 
> +	return ret;
> +
> +error_unreg_buffer_funcs:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	return ret;
> +}
> +
> +/* Function to deinitialize the processing for usage id */
> +static int hid_temperature_remove(struct platform_device *pdev)
> +{
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +
> +	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
> +
> +	return 0;
> +}
> +
> +static const struct platform_device_id hid_temperature_ids[] = {
> +	{
> +		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
> +		.name = "HID-SENSOR-200033",
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, hid_temperature_ids);
> +
> +static struct platform_driver hid_temperature_platform_driver = {
> +	.id_table = hid_temperature_ids,
> +	.driver = {
> +		.name	= KBUILD_MODNAME,
> +		.pm	= &hid_sensor_pm_ops,
> +	},
> +	.probe		= hid_temperature_probe,
> +	.remove		= hid_temperature_remove,
> +};
> +module_platform_driver(hid_temperature_platform_driver);
> +
> +MODULE_DESCRIPTION("HID Environmental temperature sensor");
> +MODULE_AUTHOR("Song Hongyan <hongyan.song-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
> index bab8375..ecec978 100644
> --- a/include/linux/hid-sensor-ids.h
> +++ b/include/linux/hid-sensor-ids.h
> @@ -45,6 +45,10 @@
>  #define HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE              0x200430
>  #define HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE                   0x200431
>  
> +/* Tempreture (200033) */
> +#define	HID_USAGE_SENSOR_TEMPERATURE				0x200033
> +#define	HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE		0x200434
> +
>  /* Gyro 3D: (200076) */
>  #define HID_USAGE_SENSOR_GYRO_3D				0x200076
>  #define HID_USAGE_SENSOR_DATA_ANGL_VELOCITY			0x200456
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread