Re: [PATCH 1/3] HID: apple-ibridge: Add Apple iBridge HID driver for T1 chip.

[Aditya Garg]

> On 10-Feb-2023, at 10:26 AM, Thomas Weißschuh <thomas@xxxxxxxx> wrote:
> 
> Hi,
> 
> some comments inline.
> 
> On Fri, Feb 10, 2023 at 03:43:24AM +0000, Aditya Garg wrote:
>> From: Ronald Tschalär <ronald@xxxxxxxxxxxxx>
>> 
>> The iBridge device provides access to several devices, including:
>> - the Touch Bar
>> - the iSight webcam
>> - the light sensor
>> - the fingerprint sensor
>> 
>> This driver provides the core support for managing the iBridge device
>> and the access to the underlying devices. In particular, the
>> functionality for the touch bar and light sensor is exposed via USB HID
>> interfaces, and on devices with the T1 chip one of the HID devices is
>> used for both functions. So this driver creates virtual HID devices, one
>> per top-level report collection on each HID device (for a total of 3
>> virtual HID devices). The sub-drivers then bind to these virtual HID
>> devices.
>> 
>> This way the Touch Bar and ALS drivers can be kept in their own modules,
>> while at the same time making them look very much like as if they were
>> connected to the real HID devices. And those drivers then work (mostly)
>> without further changes on MacBooks with the T2 chip that don't need
>> this driver.
>> 
>> Signed-off-by: Ronald Tschalär <ronald@xxxxxxxxxxxxx>
>> [Kerem Karabay: convert to a platform driver]
>> [Kerem Karabay: fix appleib_forward_int_op]
>> [Kerem Karabay: rely on HID core's parsing in appleib_add_device]
>> Signed-off-by: Kerem Karabay <kekrby@xxxxxxxxx>
>> Signed-off-by: Aditya Garg <gargaditya08@xxxxxxxx>
>> ---
>> drivers/hid/Kconfig         |  15 +
>> drivers/hid/Makefile        |   1 +
>> drivers/hid/apple-ibridge.c | 610 ++++++++++++++++++++++++++++++++++++
>> drivers/hid/apple-ibridge.h |  15 +
>> drivers/hid/hid-ids.h       |   1 +
>> drivers/hid/hid-quirks.c    |   3 +
>> 6 files changed, 645 insertions(+)
>> create mode 100644 drivers/hid/apple-ibridge.c
>> create mode 100644 drivers/hid/apple-ibridge.h
>> 
> 
>> 
>> +}
>> +
>> +static int appleib_ll_raw_request(struct hid_device *hdev,
>> +   unsigned char reportnum, __u8 *buf,
>> +   size_t len, unsigned char rtype, int reqtype)
>> +{
>> + struct appleib_hid_dev_info *hdev_info = hdev->driver_data;
>> +
>> + return hid_hw_raw_request(hdev_info->hdev, reportnum, buf, len, rtype,
>> +   reqtype);
>> +}
>> +
>> +static int appleib_ll_output_report(struct hid_device *hdev, __u8 *buf,
>> +     size_t len)
>> +{
>> + struct appleib_hid_dev_info *hdev_info = hdev->driver_data;
>> +
>> + return hid_hw_output_report(hdev_info->hdev, buf, len);
>> +}
>> +
>> +static struct hid_ll_driver appleib_ll_driver = {
>> + .start = appleib_ll_start,
>> + .stop = appleib_ll_stop,
>> + .open = appleib_ll_open,
>> + .close = appleib_ll_close,
>> + .power = appleib_ll_power,
>> + .parse = appleib_ll_parse,
>> + .request = appleib_ll_request,
>> + .wait = appleib_ll_wait,
>> + .raw_request = appleib_ll_raw_request,
>> + .output_report = appleib_ll_output_report,
>> +};
> 
> const

Are you sure about const here?

> 
>> +
>> + if (udev->actconfig->desc.bConfigurationValue != APPLEIB_BASIC_CONFIG) {
>> + rc = usb_driver_set_configuration(udev, APPLEIB_BASIC_CONFIG);
>> + return rc ? rc : -ENODEV;
>> + }
>> +
>> + rc = hid_parse(hdev);
>> + if (rc) {
>> + hid_err(hdev, "ib: hid parse failed (%d)\n", rc);
>> + goto error;
>> + }
>> +
>> + rc = hid_hw_start(hdev, HID_CONNECT_DRIVER);
>> + if (rc) {
>> + hid_err(hdev, "ib: hw start failed (%d)\n", rc);
>> + goto error;
>> + }
>> +
>> + hdev_info = appleib_add_device(hdev);
>> + if (IS_ERR(hdev_info)) {
>> + rc = PTR_ERR(hdev_info);
>> + goto stop_hw;
>> + }
>> +
>> + hid_set_drvdata(hdev, hdev_info);
>> +
>> + rc = hid_hw_open(hdev);
>> + if (rc) {
>> + hid_err(hdev, "ib: failed to open hid: %d\n", rc);
>> + goto remove_dev;
>> + }
>> +
>> + return 0;
>> +
>> +remove_dev:
>> + appleib_remove_device(hdev);
>> +stop_hw:
>> + hid_hw_stop(hdev);
>> +error:
>> + return rc;
>> +}
>> +
>> +static void appleib_hid_remove(struct hid_device *hdev)
>> +{
>> + hid_hw_close(hdev);
>> + appleib_remove_device(hdev);
>> + hid_hw_stop(hdev);
>> +}
>> +
>> +static const struct hid_device_id appleib_hid_ids[] = {
>> + { HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IBRIDGE) },
>> + { },
>> +};
>> +
>> +static struct hid_driver appleib_hid_driver = {
>> + .name = "apple-ibridge-hid",
>> + .id_table = appleib_hid_ids,
>> + .probe = appleib_hid_probe,
>> + .remove = appleib_hid_remove,
>> + .raw_event = appleib_hid_raw_event,
>> + .report_fixup = appleib_report_fixup,
>> +#ifdef CONFIG_PM
>> + .suspend = appleib_hid_suspend,
>> + .resume = appleib_hid_resume,
>> + .reset_resume = appleib_hid_reset_resume,
>> +#endif
>> +};
> 
> const

Are you sure you want to do const here, cause other hid-drivers are NOT using const.

>> +
>> +static struct appleib_device *appleib_alloc_device(struct platform_device *pdev)
>> +{
>> + struct appleib_device *ib_dev;
>> + acpi_status sts;