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From:   "Sean O'Brien" <seobrien@chromium.org>
Date:   Tue, 2 Oct 2018 15:39:31 -0700
Message-ID: <CAOOzhkp6ChopAXxDFcbz1sT17EKTGysF5hdkMkM50LGdXcnyaQ@mail.gmail.com>
Subject: Re: [PATCH] [v3] HID: add support for Apple Magic Trackpad 2
To:     Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     peter.hutterer@redhat.com, marek.wyborski@emwesoft.com,
        linux-kernel@vger.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        linux-input@vger.kernel.org, rydberg@bitmath.org,
        Jiri Kosina <jikos@kernel.org>, claudio@ponyfleisch.ch
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Sender: linux-kernel-owner@vger.kernel.org
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On Mon, Oct 1, 2018 at 1:43 AM Benjamin Tissoires
<benjamin.tissoires@redhat.com> wrote:
>
> [adding Peter, for the libinput question]
>
> On Fri, Sep 21, 2018 at 1:13 AM Sean O'Brien <seobrien@chromium.org> wrote:
> >
> > USB device
> >         Vendor 05ac (Apple)
> >         Device 0265 (Magic Trackpad 2)
> > Bluetooth device
> >         Vendor 004c (Apple)
> >         Device 0265 (Magic Trackpad 2)
> >
> > Add support for Apple Magic Trackpad 2 over USB and bluetooth, putting
> > the device in multi-touch mode.
> >
> > Signed-off-by: Claudio Mettler <claudio@ponyfleisch.ch>
> > Signed-off-by: Marek Wyborski <marek.wyborski@emwesoft.com>
> > Signed-off-by: Sean O'Brien <seobrien@chromium.org>
> > ---
> >
>
> a few nitpcks:
>
> >  drivers/hid/hid-ids.h        |   1 +
> >  drivers/hid/hid-magicmouse.c | 149 +++++++++++++++++++++++++++++++----
> >  2 files changed, 134 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> > index 5146ee029db4..bb0cd212c7cc 100644
> > --- a/drivers/hid/hid-ids.h
> > +++ b/drivers/hid/hid-ids.h
> > @@ -92,6 +92,7 @@
> >  #define USB_DEVICE_ID_APPLE_MIGHTYMOUSE        0x0304
> >  #define USB_DEVICE_ID_APPLE_MAGICMOUSE 0x030d
> >  #define USB_DEVICE_ID_APPLE_MAGICTRACKPAD      0x030e
> > +#define USB_DEVICE_ID_APPLE_MAGICTRACKPAD2     0x0265
> >  #define USB_DEVICE_ID_APPLE_FOUNTAIN_ANSI      0x020e
> >  #define USB_DEVICE_ID_APPLE_FOUNTAIN_ISO       0x020f
> >  #define USB_DEVICE_ID_APPLE_GEYSER_ANSI        0x0214
> > diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
> > index b454c4386157..6a3a6c83e509 100644
> > --- a/drivers/hid/hid-magicmouse.c
> > +++ b/drivers/hid/hid-magicmouse.c
> > @@ -54,6 +54,8 @@ module_param(report_undeciphered, bool, 0644);
> >  MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state field using a MSC_RAW event");
> >
> >  #define TRACKPAD_REPORT_ID 0x28
> > +#define TRACKPAD2_USB_REPORT_ID 0x02
> > +#define TRACKPAD2_BT_REPORT_ID 0x31
> >  #define MOUSE_REPORT_ID    0x29
> >  #define DOUBLE_REPORT_ID   0xf7
> >  /* These definitions are not precise, but they're close enough.  (Bits
> > @@ -91,6 +93,17 @@ MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state fie
> >  #define TRACKPAD_RES_Y \
> >         ((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))
> >
> > +#define TRACKPAD2_DIMENSION_X (float)16000
> > +#define TRACKPAD2_MIN_X -3678
> > +#define TRACKPAD2_MAX_X 3934
> > +#define TRACKPAD2_RES_X \
> > +       ((TRACKPAD2_MAX_X - TRACKPAD2_MIN_X) / (TRACKPAD2_DIMENSION_X / 100))
> > +#define TRACKPAD2_DIMENSION_Y (float)11490
> > +#define TRACKPAD2_MIN_Y -2478
> > +#define TRACKPAD2_MAX_Y 2587
> > +#define TRACKPAD2_RES_Y \
> > +       ((TRACKPAD2_MAX_Y - TRACKPAD2_MIN_Y) / (TRACKPAD2_DIMENSION_Y / 100))
> > +
> >  /**
> >   * struct magicmouse_sc - Tracks Magic Mouse-specific data.
> >   * @input: Input device through which we report events.
> > @@ -183,6 +196,7 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
> >  {
> >         struct input_dev *input = msc->input;
> >         int id, x, y, size, orientation, touch_major, touch_minor, state, down;
> > +       int pressure = 0;
> >
> >         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
> >                 id = (tdata[6] << 2 | tdata[5] >> 6) & 0xf;
> > @@ -194,6 +208,20 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
> >                 touch_minor = tdata[4];
> >                 state = tdata[7] & TOUCH_STATE_MASK;
> >                 down = state != TOUCH_STATE_NONE;
> > +       } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               id = tdata[8] & 0xf;
> > +               x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
> > +               y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
> > +               size = tdata[6];
> > +               orientation = (tdata[8] >> 5) - 4;
> > +               touch_major = tdata[4];
> > +               touch_minor = tdata[5];
> > +               /* Add to pressure to prevent libraries such as libinput
> > +                * from ignoring low pressure touches
> > +                */
> > +               pressure = tdata[7] + 30;
>
> Peter, can you have a look?
>
> To me, while adding this threshold, you are basically fooling
> userspace, and we might want to come back to the raw values at some
> point.
> If there is a userspace problem, it has to be solved in userspace.
>

I'm fine with removing the offset.  I haven't personally tested using
libinput, but the chromium OS gesture detector I've been using can
handle pressure values of 0.

> > +               state = tdata[3] & 0xC0;
> > +               down = state == 0x80;
> >         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> >                 id = (tdata[7] << 2 | tdata[6] >> 6) & 0xf;
> >                 x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
> > @@ -215,7 +243,8 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
> >         /* If requested, emulate a scroll wheel by detecting small
> >          * vertical touch motions.
> >          */
> > -       if (emulate_scroll_wheel) {
> > +       if (emulate_scroll_wheel && (input->id.product !=
> > +                       USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)) {
> >                 unsigned long now = jiffies;
> >                 int step_x = msc->touches[id].scroll_x - x;
> >                 int step_y = msc->touches[id].scroll_y - y;
> > @@ -269,10 +298,14 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
> >                 input_report_abs(input, ABS_MT_POSITION_X, x);
> >                 input_report_abs(input, ABS_MT_POSITION_Y, y);
> >
> > +               if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)
> > +                       input_report_abs(input, ABS_MT_PRESSURE, pressure);
> > +
> >                 if (report_undeciphered) {
> >                         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
> >                                 input_event(input, EV_MSC, MSC_RAW, tdata[7]);
> > -                       else /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> > +                       else if (input->id.product !=
> > +                                       USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)
> >                                 input_event(input, EV_MSC, MSC_RAW, tdata[8]);
> >                 }
> >         }
> > @@ -287,6 +320,7 @@ static int magicmouse_raw_event(struct hid_device *hdev,
> >
> >         switch (data[0]) {
> >         case TRACKPAD_REPORT_ID:
> > +       case TRACKPAD2_BT_REPORT_ID:
> >                 /* Expect four bytes of prefix, and N*9 bytes of touch data. */
> >                 if (size < 4 || ((size - 4) % 9) != 0)
> >                         return 0;
> > @@ -301,12 +335,22 @@ static int magicmouse_raw_event(struct hid_device *hdev,
> >                         magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);
> >
> >                 clicks = data[1];
> > +               break;
> > +       case TRACKPAD2_USB_REPORT_ID:
> > +               /* Expect twelve bytes of prefix and N*9 bytes of touch data. */
> > +               if (size < 12 || ((size - 12) % 9) != 0)
> > +                       return 0;
> > +               npoints = (size - 12) / 9;
> > +               if (npoints > 15) {
> > +                       hid_warn(hdev, "invalid size value (%d) for TRACKPAD2_USB_REPORT_ID\n",
> > +                                       size);
> > +                       return 0;
> > +               }
> > +               msc->ntouches = 0;
> > +               for (ii = 0; ii < npoints; ii++)
> > +                       magicmouse_emit_touch(msc, ii, data + ii * 9 + 12);
> >
> > -               /* The following bits provide a device specific timestamp. They
> > -                * are unused here.
> > -                *
> > -                * ts = data[1] >> 6 | data[2] << 2 | data[3] << 10;
> > -                */
>
> Can you keep this comment from the original version? If your touchpad
> doesn't have the timestamp bit, the old ones still have them, and
> having the decoded information might help in the future.
>

Will do.

> Cheers,
> Benjamin
>
> > +               clicks = data[1];
> >                 break;
> >         case MOUSE_REPORT_ID:
> >                 /* Expect six bytes of prefix, and N*8 bytes of touch data. */
> > @@ -352,6 +396,9 @@ static int magicmouse_raw_event(struct hid_device *hdev,
> >                 magicmouse_emit_buttons(msc, clicks & 3);
> >                 input_report_rel(input, REL_X, x);
> >                 input_report_rel(input, REL_Y, y);
> > +       } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               input_mt_sync_frame(input);
> > +               input_report_key(input, BTN_MOUSE, clicks & 1);
> >         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> >                 input_report_key(input, BTN_MOUSE, clicks & 1);
> >                 input_mt_report_pointer_emulation(input, true);
> > @@ -364,6 +411,7 @@ static int magicmouse_raw_event(struct hid_device *hdev,
> >  static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hdev)
> >  {
> >         int error;
> > +       int mt_flags = 0;
> >
> >         __set_bit(EV_KEY, input->evbit);
> >
> > @@ -380,6 +428,22 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
> >                         __set_bit(REL_WHEEL, input->relbit);
> >                         __set_bit(REL_HWHEEL, input->relbit);
> >                 }
> > +       } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               /* setting the device name to ensure the same driver settings
> > +                * get loaded, whether connected through bluetooth or USB
> > +                */
> > +               input->name = "Apple Inc. Magic Trackpad 2";
> > +
> > +               __clear_bit(EV_MSC, input->evbit);
> > +               __clear_bit(BTN_0, input->keybit);
> > +               __clear_bit(BTN_RIGHT, input->keybit);
> > +               __clear_bit(BTN_MIDDLE, input->keybit);
> > +               __set_bit(BTN_MOUSE, input->keybit);
> > +               __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
> > +               __set_bit(BTN_TOOL_FINGER, input->keybit);
> > +
> > +               mt_flags = INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
> > +                               INPUT_MT_TRACK;
> >         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> >                 /* input->keybit is initialized with incorrect button info
> >                  * for Magic Trackpad. There really is only one physical
> > @@ -402,14 +466,13 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
> >
> >         __set_bit(EV_ABS, input->evbit);
> >
> > -       error = input_mt_init_slots(input, 16, 0);
> > +       error = input_mt_init_slots(input, 16, mt_flags);
> >         if (error)
> >                 return error;
> >         input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255 << 2,
> >                              4, 0);
> >         input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 255 << 2,
> >                              4, 0);
> > -       input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
> >
> >         /* Note: Touch Y position from the device is inverted relative
> >          * to how pointer motion is reported (and relative to how USB
> > @@ -418,6 +481,7 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
> >          * inverse of the reported Y.
> >          */
> >         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
> > +               input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
> >                 input_set_abs_params(input, ABS_MT_POSITION_X,
> >                                      MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
> >                 input_set_abs_params(input, ABS_MT_POSITION_Y,
> > @@ -427,7 +491,25 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
> >                                   MOUSE_RES_X);
> >                 input_abs_set_res(input, ABS_MT_POSITION_Y,
> >                                   MOUSE_RES_Y);
> > +       } else if (input->id.product ==  USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               input_set_abs_params(input, ABS_MT_PRESSURE, 0, 283, 0, 0);
> > +               input_set_abs_params(input, ABS_PRESSURE, 0, 283, 0, 0);
> > +               input_set_abs_params(input, ABS_MT_ORIENTATION, -3, 4, 0, 0);
> > +               input_set_abs_params(input, ABS_X, TRACKPAD2_MIN_X,
> > +                                    TRACKPAD2_MAX_X, 0, 0);
> > +               input_set_abs_params(input, ABS_Y, TRACKPAD2_MIN_Y,
> > +                                    TRACKPAD2_MAX_Y, 0, 0);
> > +               input_set_abs_params(input, ABS_MT_POSITION_X,
> > +                                    TRACKPAD2_MIN_X, TRACKPAD2_MAX_X, 0, 0);
> > +               input_set_abs_params(input, ABS_MT_POSITION_Y,
> > +                                    TRACKPAD2_MIN_Y, TRACKPAD2_MAX_Y, 0, 0);
> > +
> > +               input_abs_set_res(input, ABS_X, TRACKPAD2_RES_X);
> > +               input_abs_set_res(input, ABS_Y, TRACKPAD2_RES_Y);
> > +               input_abs_set_res(input, ABS_MT_POSITION_X, TRACKPAD2_RES_X);
> > +               input_abs_set_res(input, ABS_MT_POSITION_Y, TRACKPAD2_RES_Y);
> >         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> > +               input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
> >                 input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
> >                                      TRACKPAD_MAX_X, 4, 0);
> >                 input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
> > @@ -447,7 +529,8 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
> >
> >         input_set_events_per_packet(input, 60);
> >
> > -       if (report_undeciphered) {
> > +       if (report_undeciphered &&
> > +           input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> >                 __set_bit(EV_MSC, input->evbit);
> >                 __set_bit(MSC_RAW, input->mscbit);
> >         }
> > @@ -465,7 +548,8 @@ static int magicmouse_input_mapping(struct hid_device *hdev,
> >                 msc->input = hi->input;
> >
> >         /* Magic Trackpad does not give relative data after switching to MT */
> > -       if (hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD &&
> > +       if ((hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD ||
> > +            hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) &&
> >             field->flags & HID_MAIN_ITEM_RELATIVE)
> >                 return -1;
> >
> > @@ -494,11 +578,20 @@ static int magicmouse_input_configured(struct hid_device *hdev,
> >  static int magicmouse_probe(struct hid_device *hdev,
> >         const struct hid_device_id *id)
> >  {
> > -       const u8 feature[] = { 0xd7, 0x01 };
> > +       const u8 *feature;
> > +       const u8 feature_mt[] = { 0xD7, 0x01 };
> > +       const u8 feature_mt_trackpad2_usb[] = { 0x02, 0x01 };
> > +       const u8 feature_mt_trackpad2_bt[] = { 0xF1, 0x02, 0x01 };
> >         u8 *buf;
> >         struct magicmouse_sc *msc;
> >         struct hid_report *report;
> >         int ret;
> > +       int feature_size;
> > +
> > +       if (id->vendor == USB_VENDOR_ID_APPLE &&
> > +           id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
> > +           hdev->type != HID_TYPE_USBMOUSE)
> > +               return 0;
> >
> >         msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
> >         if (msc == NULL) {
> > @@ -532,7 +625,14 @@ static int magicmouse_probe(struct hid_device *hdev,
> >         if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
> >                 report = hid_register_report(hdev, HID_INPUT_REPORT,
> >                         MOUSE_REPORT_ID, 0);
> > -       else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> > +       else if (id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               if (id->vendor == BT_VENDOR_ID_APPLE)
> > +                       report = hid_register_report(hdev, HID_INPUT_REPORT,
> > +                               TRACKPAD2_BT_REPORT_ID, 0);
> > +               else /* USB_VENDOR_ID_APPLE */
> > +                       report = hid_register_report(hdev, HID_INPUT_REPORT,
> > +                               TRACKPAD2_USB_REPORT_ID, 0);
> > +       } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
> >                 report = hid_register_report(hdev, HID_INPUT_REPORT,
> >                         TRACKPAD_REPORT_ID, 0);
> >                 report = hid_register_report(hdev, HID_INPUT_REPORT,
> > @@ -546,7 +646,20 @@ static int magicmouse_probe(struct hid_device *hdev,
> >         }
> >         report->size = 6;
> >
> > -       buf = kmemdup(feature, sizeof(feature), GFP_KERNEL);
> > +       if (id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
> > +               if (id->vendor == BT_VENDOR_ID_APPLE) {
> > +                       feature_size = sizeof(feature_mt_trackpad2_bt);
> > +                       feature = feature_mt_trackpad2_bt;
> > +               } else { /* USB_VENDOR_ID_APPLE */
> > +                       feature_size = sizeof(feature_mt_trackpad2_usb);
> > +                       feature = feature_mt_trackpad2_usb;
> > +               }
> > +       } else {
> > +               feature_size = sizeof(feature_mt);
> > +               feature = feature_mt;
> > +       }
> > +
> > +       buf = kmemdup(feature, feature_size, GFP_KERNEL);
> >         if (!buf) {
> >                 ret = -ENOMEM;
> >                 goto err_stop_hw;
> > @@ -560,10 +673,10 @@ static int magicmouse_probe(struct hid_device *hdev,
> >          * but there seems to be no other way of switching the mode.
> >          * Thus the super-ugly hacky success check below.
> >          */
> > -       ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(feature),
> > +       ret = hid_hw_raw_request(hdev, buf[0], buf, feature_size,
> >                                 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
> >         kfree(buf);
> > -       if (ret != -EIO && ret != sizeof(feature)) {
> > +       if (ret != -EIO && ret != feature_size) {
> >                 hid_err(hdev, "unable to request touch data (%d)\n", ret);
> >                 goto err_stop_hw;
> >         }
> > @@ -579,6 +692,10 @@ static const struct hid_device_id magic_mice[] = {
> >                 USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
> >         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
> >                 USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .driver_data = 0 },
> > +       { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
> > +               USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
> > +       { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
> > +               USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
> >         { }
> >  };
> >  MODULE_DEVICE_TABLE(hid, magic_mice);
> > --
> > 2.19.0.444.g18242da7ef-goog
> >