Re: [PATCH v3 1/3] HID: hid-sensor-custom: Add custom sensor iio support

From: Jonathan Cameron
Date: Sat Dec 05 2020 - 14:20:14 EST

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In reply to: Ye Xiang: "[PATCH v3 1/3] HID: hid-sensor-custom: Add custom sensor iio support"
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On Thu, 3 Dec 2020 11:53:50 +0800
Ye Xiang <xiang.ye@xxxxxxxxx> wrote:

> Currently custom sensors properties are not decoded and it is up to
> user space to interpret.
>
> Some manufacturers already standardized the meaning of some custom sensors.
> They can be presented as a proper IIO sensor. We can identify these sensors
> based on manufacturer and serial number property in the report.
>
> This change is identifying hinge sensor when the manufacturer is "INTEL".
> This creates a platform device so that a sensor driver can be loaded to
> process these sensors.
>
> Signed-off-by: Ye Xiang <xiang.ye@xxxxxxxxx>
Hi,

A few little comments inline.

Others are much more familiar with this code than I am though so I'm sure
they will give a more in depth review!

> ---
> drivers/hid/hid-sensor-custom.c | 181 ++++++++++++++++++++++++++++++++
> include/linux/hid-sensor-ids.h | 14 +++
> 2 files changed, 195 insertions(+)
>
> diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-sensor-custom.c
> index 4d25577a8573..b8e59021c6a8 100644
> --- a/drivers/hid/hid-sensor-custom.c
> +++ b/drivers/hid/hid-sensor-custom.c
> @@ -4,6 +4,7 @@
> * Copyright (c) 2015, Intel Corporation.
> */
>
> +#include <linux/ctype.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/init.h>
> @@ -21,6 +22,7 @@
> #define HID_CUSTOM_TOTAL_ATTRS (HID_CUSTOM_MAX_CORE_ATTRS + 1)
> #define HID_CUSTOM_FIFO_SIZE 4096
> #define HID_CUSTOM_MAX_FEATURE_BYTES 64
> +#define HID_SENSOR_USAGE_LENGTH (4 + 1)
>
> struct hid_sensor_custom_field {
> int report_id;
> @@ -50,6 +52,8 @@ struct hid_sensor_custom {
> struct kfifo data_fifo;
> unsigned long misc_opened;
> wait_queue_head_t wait;
> + struct platform_device *custom_pdev;
> + bool custom_pdev_exposed;

Note on this below. I'm not sure the boolean brings us any advantages.

> };
>
> /* Header for each sample to user space via dev interface */
> @@ -746,11 +750,164 @@ static void hid_sensor_custom_dev_if_remove(struct hid_sensor_custom
>
> }
>
> +/*
> + * use sensors luid which is defined in FW, such as ISH,
> + * to identify sensor.
Perhaps rephrase as

luid defined in FW (e.g. ISH). May be used to identify sensor.

> + */
> +static const char *const known_sensor_luid[] = { "020B000000000000" };
> +
> +static int get_luid_table_index(unsigned char *usage_str)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(known_sensor_luid); i++) {
> + if (!strncmp(usage_str, known_sensor_luid[i],
> + strlen(known_sensor_luid[i])))
> + return i;
> + }
> +
> + return -1;
> +}
> +
> +static int get_known_custom_sensor_index(struct hid_sensor_hub_device *hsdev)
> +{
> + struct hid_sensor_hub_attribute_info sensor_manufacturer = { 0 };
> + struct hid_sensor_hub_attribute_info sensor_luid_info = { 0 };
> + int report_size;
> + int ret;
> + u16 *w_buf;
> + char *buf;
> + int w_buf_len = sizeof(u16) * HID_CUSTOM_MAX_FEATURE_BYTES;
> + int buf_len = sizeof(char) * HID_CUSTOM_MAX_FEATURE_BYTES;
> + int i;
> + int index;
> +
> + w_buf = kzalloc(w_buf_len, GFP_KERNEL);
> + if (!w_buf) {
> + ret = -ENOMEM;
> + goto error_out2;
> + }
> +
> + buf = kzalloc(buf_len, GFP_KERNEL);
> + if (!buf) {
> + ret = -ENOMEM;
> + goto error_out1;
> + }
> + /* get manufacturer info */
> + ret = sensor_hub_input_get_attribute_info(
> + hsdev, HID_FEATURE_REPORT, hsdev->usage,
> + HID_USAGE_SENSOR_PROP_MANUFACTURER, &sensor_manufacturer);
> + if (ret < 0) {
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + report_size =
> + sensor_hub_get_feature(hsdev, sensor_manufacturer.report_id,
> + sensor_manufacturer.index, w_buf_len,
> + w_buf);
> + if (report_size <= 0) {
> + hid_err(hsdev->hdev,
> + "Failed to get sensor manufacturer info %d\n",
> + report_size);
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + /* convert from wide char to char */
> + for (i = 0; i < buf_len - 1 && w_buf[i]; i++)
> + buf[i] = (char)w_buf[i];
> +
> + /* ensure it's ISH sensor */
> + if (strncmp(buf, "INTEL", strlen("INTEL"))) {
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + memset(w_buf, 0, w_buf_len);
> + memset(buf, 0, buf_len);
> +
> + /* get real usage id */
> + ret = sensor_hub_input_get_attribute_info(
> + hsdev, HID_FEATURE_REPORT, hsdev->usage,
> + HID_USAGE_SENSOR_PROP_SERIAL_NUM, &sensor_luid_info);
> + if (ret < 0) {
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + report_size = sensor_hub_get_feature(hsdev, sensor_luid_info.report_id,
> + sensor_luid_info.index, w_buf_len,
> + w_buf);
> + if (report_size <= 0) {
> + hid_err(hsdev->hdev, "Failed to get real usage info %d\n",
> + report_size);
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + /* convert from wide char to char */
> + for (i = 0; i < buf_len - 1 && w_buf[i]; i++)
> + buf[i] = (char)w_buf[i];
> +
> + if (strlen(buf) != strlen(known_sensor_luid[0]) + 5) {
> + hid_err(hsdev->hdev,
> + "%s luid length not match %zu != (%zu + 5)\n", __func__,
> + strlen(buf), strlen(known_sensor_luid[0]));
> + ret = -ENODEV;
> + goto error_out;
> + }
> +
> + /* get table index with luid (not matching 'LUID: ' in luid) */
> + index = get_luid_table_index(&buf[5]);
> + if (index >= 0)
> + ret = index;
> + else
> + ret = -ENODEV;
> +
> +error_out:
> + kfree(buf);
> +error_out1:
> + kfree(w_buf);
> +error_out2:
> + return ret;
> +}
> +
> +static struct platform_device *
> +hid_sensor_register_platform_device(struct platform_device *pdev,
> + struct hid_sensor_hub_device *hsdev,
> + int index)
> +{
> + char real_usage[HID_SENSOR_USAGE_LENGTH] = { 0 };
> + struct platform_device *custom_pdev;
> + const char *dev_name;
> + char *c;
> +
> + /* copy real usage id */
> + memcpy(real_usage, known_sensor_luid[index], 4);
> +
> + /* usage id are all lowcase */
> + for (c = real_usage; *c != '\0'; c++)
> + *c = tolower(*c);
> +
> + /* HID-SENSOR-INT-REAL_USAGE_ID */
> + dev_name = kasprintf(GFP_KERNEL, "HID-SENSOR-INT-%s", real_usage);
> + if (!dev_name)
> + return NULL;
> +
> + custom_pdev = platform_device_register_data(pdev->dev.parent, dev_name,
> + PLATFORM_DEVID_NONE, hsdev,
> + sizeof(*hsdev));
> + kfree(dev_name);
> + return custom_pdev;
> +}
> +
> static int hid_sensor_custom_probe(struct platform_device *pdev)
> {
> struct hid_sensor_custom *sensor_inst;
> struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> int ret;
> + int index;
>
> sensor_inst = devm_kzalloc(&pdev->dev, sizeof(*sensor_inst),
> GFP_KERNEL);
> @@ -764,6 +921,25 @@ static int hid_sensor_custom_probe(struct platform_device *pdev)
> sensor_inst->pdev = pdev;
> mutex_init(&sensor_inst->mutex);
> platform_set_drvdata(pdev, sensor_inst);
> +
> + index = get_known_custom_sensor_index(hsdev);
> + if (index >= 0 && index < ARRAY_SIZE(known_sensor_luid)) {
> + sensor_inst->custom_pdev =
> + hid_sensor_register_platform_device(pdev, hsdev, index);
> +
> + ret = PTR_ERR_OR_ZERO(sensor_inst->custom_pdev);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "register_platform_device failed\n");
> + return ret;
> + }
> +
> + sensor_inst->custom_pdev_exposed = true;

Do we need an additional boolean or can we just use the existence of
custom_pdev?

> + return 0;
> + } else if (index < 0 && index != -ENODEV) {
> + return index;
> + }
> +
> ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> &sensor_inst->callbacks);
> if (ret < 0) {
> @@ -802,6 +978,11 @@ static int hid_sensor_custom_remove(struct platform_device *pdev)
> struct hid_sensor_custom *sensor_inst = platform_get_drvdata(pdev);
> struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
>
> + if (sensor_inst->custom_pdev_exposed) {
> + platform_device_unregister(sensor_inst->custom_pdev);
> + return 0;
> + }
> +
> hid_sensor_custom_dev_if_remove(sensor_inst);
> hid_sensor_custom_remove_attributes(sensor_inst);
> sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
> diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
> index 530c09f3e64a..ac631159403a 100644
> --- a/include/linux/hid-sensor-ids.h
> +++ b/include/linux/hid-sensor-ids.h
> @@ -128,6 +128,10 @@
> #define HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND 0x15
>
> /* Common selectors */
> +#define HID_USAGE_SENSOR_PROP_DESC 0x200300
> +#define HID_USAGE_SENSOR_PROP_FRIENDLY_NAME 0x200301
> +#define HID_USAGE_SENSOR_PROP_SERIAL_NUM 0x200307
> +#define HID_USAGE_SENSOR_PROP_MANUFACTURER 0x200305
> #define HID_USAGE_SENSOR_PROP_REPORT_INTERVAL 0x20030E
> #define HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS 0x20030F
> #define HID_USAGE_SENSOR_PROP_SENSITIVITY_RANGE_PCT 0x200310
> @@ -159,4 +163,14 @@
> #define HID_USAGE_SENSOR_PROP_REPORTING_STATE_NO_EVENTS_ENUM 0x200840
> #define HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM 0x200841
>
> +/* Custom Sensor (2000e1) */
> +#define HID_USAGE_SENSOR_HINGE 0x20020B
> +#define HID_USAGE_SENSOR_DATA_FIELD_LOCATION 0x200400
> +#define HID_USAGE_SENSOR_DATA_FIELE_TIME_SINCE_SYS_BOOT 0x20052B
> +#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_USAGE 0x200541
> +#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_BASE 0x200543
> +/* Custom Sensor data 28=>x>=0 */
> +#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x) \
> + (HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_BASE + (x))
> +
> #endif

Next message: Rasmus Villemoes: "[PATCH 06/20] soc: fsl: qe: add cpm_muram_free_addr() helper"
Previous message: Rasmus Villemoes: "[PATCH 04/20] soc: fsl: qe: make cpm_muram_offset take a const void* argument"
In reply to: Ye Xiang: "[PATCH v3 1/3] HID: hid-sensor-custom: Add custom sensor iio support"
Next in thread: Ye Xiang: "[PATCH v3 2/3] iio: hid-sensors: Add hinge sensor driver"
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