Re: [PATCH] [RFC] HID: udraw: Add support for the uDraw tablet for PS3

[Bastien Nocera <hadess@hadess.net>]

On Wed, 2016-09-14 at 08:50 +1000, Peter Hutterer wrote:
> On Sun, Sep 11, 2016 at 06:48:24PM +0200, Bastien Nocera wrote:
> > 
> > This adds support for the THQ uDraw tablet for the PS3, as
> > 4 separate device nodes, so that user-space can easily consume
> > events coming from the hardware.
> > 
> > Tested-by: Bastien Nocera <hadess@hadess.net>
> > Signed-off-by: Bastien Nocera <hadess@hadess.net>
> > 
> > ---
> > 
> > I didn't compile it in-tree yet, only out-of-tree, and I'm still
> > investigating support for LEDs, battery and better two-finger tap
> > support.
> > 
> > Comments welcome
> > 
> >  MAINTAINERS             |   6 +
> >  drivers/hid/Kconfig     |   7 +
> >  drivers/hid/Makefile    |   1 +
> >  drivers/hid/hid-core.c  |   1 +
> >  drivers/hid/hid-ids.h   |   3 +
> >  drivers/hid/hid-udraw.c | 434
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> >  6 files changed, 452 insertions(+)
> >  create mode 100644 drivers/hid/hid-udraw.c
> > 
> 
> [...]
> 
> > 
> > diff --git a/drivers/hid/hid-udraw.c b/drivers/hid/hid-udraw.c
> > new file mode 100644
> > index 0000000..6728cae
> > --- /dev/null
> > +++ b/drivers/hid/hid-udraw.c
> > @@ -0,0 +1,434 @@
> > +/*
> > + * HID driver for THQ PS3 uDraw tablet
> > + *
> > + * Copyright (C) 2016 Red Hat Inc. All Rights Reserved
> > + *
> > + * This software is licensed under the terms of the GNU General
> > Public
> > + * License version 2, as published by the Free Software
> > Foundation,
> > and
> > + * may be copied, distributed, and modified under those terms.
> > + *
> > + * This program is distributed in the hope that 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.
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/hid.h>
> > +#include <linux/module.h>
> > +#include "hid-ids.h"
> > +
> > +MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
> > +MODULE_DESCRIPTION("PS3 uDraw tablet driver");
> > +MODULE_LICENSE("GPL");
> > +
> > +/*
> > + * Protocol information from:
> > + * http://brandonw.net/udraw/
> > + * and the source code of:
> > + * https://vvvv.org/contribution/udraw-hid
> > + */
> > +
> > +/*
> > + * The device is setup with multiple input devices to make it
> > easier
> > + * to handle in user-space:
> > + * - the touch area which works as a touchpad
> > + * - the tablet area which works as a touchpad/drawing tablet
> > + * - a joypad with a d-pad, and 7 buttons
> > + * - an optional, disabled by default, accelerometer device
> > + */
> > +
> > +static const unsigned short udraw_joy_key_table[] = {
> > +	BTN_SOUTH,
> > +	BTN_NORTH,
> > +	BTN_EAST,
> > +	BTN_WEST,
> > +	BTN_SELECT,
> > +	BTN_START,
> > +	BTN_MODE
> > +};
> > +
> > +enum {
> > +	TOUCH_NONE,
> > +	TOUCH_PEN,
> > +	TOUCH_FINGER,
> > +	TOUCH_FINGERS
> 
> FINGER and FINGERS is easy to confuse on a quick read, better rename
> to
> MULTIFINGER or TWOFINGER, depending what you can detect.

Done.

> > 
> > +};
> > +
> > +/* Accelerometer min/max values
> > + * in order, X, Y and Z
> > + */
> > +struct {
> > +	int min;
> > +	int max;
> > +} accel_limits[] = {
> > +	{ 0x1EA, 0x216 },
> > +	{ 0x1EA, 0x216 },
> > +	{ 0x1EC, 0x218 }
> > +};
> > +
> > +#define DEVICE_NAME "THQ uDraw Game Tablet for PS3"
> > +/* resolution in pixels */
> > +#define RES_X 1920
> > +#define RES_Y 1080
> > +/* size in mm */
> > +#define WIDTH  160
> > +#define HEIGHT 90
> > +#define PRESSURE_OFFSET 0x71
> > +#define MAX_PRESSURE (0xFF - PRESSURE_OFFSET)
> > +
> > +struct udraw {
> > +	struct input_dev *joy_input_dev;
> > +	struct input_dev *touch_input_dev;
> > +	struct input_dev *pen_input_dev;
> > +	struct input_dev *accel_input_dev;
> > +	struct hid_device *hdev;
> > +};
> > +
> > +static int clamp_accel(int axis, int offset)
> > +{
> > +	axis = clamp(axis,
> > +			accel_limits[offset].min,
> > +			accel_limits[offset].max);
> > +	axis = (axis - accel_limits[offset].min) /
> > +			((accel_limits[offset].max -
> > +			  accel_limits[offset].min) * 0xFF);
> > +	return axis;
> > +}
> > +
> > +static int udraw_raw_event(struct hid_device *hdev, struct
> > hid_report
> > *report,
> > +	 u8 *data, int len)
> > +{
> > +	struct udraw *udraw = hid_get_drvdata(hdev);
> > +	int touch;
> > +	int x, y, z;
> > +
> > +	if (len != 0x1B)
> > +		return 0;
> > +
> > +	if (data[11] == 0x00)
> > +		touch = TOUCH_NONE;
> > +	else if (data[11] == 0x40)
> > +		touch = TOUCH_PEN;
> > +	else if (data[11] == 0x80)
> > +		touch = TOUCH_FINGER;
> > +	else
> > +		touch = TOUCH_FINGERS;
> > +
> > +	/* joypad */
> > +	input_report_key(udraw->joy_input_dev, BTN_WEST, data[0] &
> > 1);
> > +	input_report_key(udraw->joy_input_dev, BTN_SOUTH, data[0]
> > &
> > 2);
> > +	input_report_key(udraw->joy_input_dev, BTN_EAST, data[0] &
> > 4);
> > +	input_report_key(udraw->joy_input_dev, BTN_NORTH, data[0]
> > &
> > 8);
> > +
> > +	input_report_key(udraw->joy_input_dev, BTN_SELECT, data[1]
> > &
> > 1);
> > +	input_report_key(udraw->joy_input_dev, BTN_START, data[1]
> > &
> > 2);
> > +	input_report_key(udraw->joy_input_dev, BTN_MODE, data[1] &
> > 16);
> > +
> > +	x = y = 0;
> > +	switch (data[2]) {
> > +	case 0x0:
> > +		y = -127;
> > +		break;
> > +	case 0x1:
> > +		y = -127;
> > +		x = 127;
> > +		break;
> > +	case 0x2:
> > +		x = 127;
> > +		break;
> > +	case 0x3:
> > +		y = 127;
> > +		x = 127;
> > +		break;
> > +	case 0x4:
> > +		y = 127;
> > +		break;
> > +	case 0x5:
> > +		y = 127;
> > +		x = -127;
> > +		break;
> > +	case 0x6:
> > +		x = -127;
> > +		break;
> > +	case 0x7:
> > +		y = -127;
> > +		x = -127;
> > +		break;
> > +	default:
> > +		break;
> > +	}
> > +
> > +	input_report_abs(udraw->joy_input_dev, ABS_X, x);
> > +	input_report_abs(udraw->joy_input_dev, ABS_Y, y);
> > +
> > +	input_sync(udraw->joy_input_dev);
> > +
> > +	/* For pen and touchpad */
> > +	x = y = 0;
> > +	if (touch != TOUCH_NONE) {
> > +		if (data[15] != 0x0F)
> > +			x = data[15] * 256 + data[17];
> > +		if (data[16] != 0x0F)
> > +			y = data[16] * 256 + data[18];
> > +	}
> > +
> > +	/* touchpad */
> > +	if (touch == TOUCH_FINGER || touch == TOUCH_FINGERS) {
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOUCH,
> > 1);
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOOL_FINGER,
> > +				touch == TOUCH_FINGER);
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOOL_DOUBLETAP,
> > +				touch == TOUCH_FINGERS);
> > +
> > +		input_report_abs(udraw->touch_input_dev, ABS_X,
> > x);
> > +		input_report_abs(udraw->touch_input_dev, ABS_Y,
> > y);
> > +	} else {
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOUCH,
> > 0);
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOOL_FINGER, 0);
> > +		input_report_key(udraw->touch_input_dev,
> > BTN_TOOL_DOUBLETAP, 0);
> > +	}
> > +	input_sync(udraw->touch_input_dev);
> > +
> > +	/* pen */
> > +	if (touch == TOUCH_PEN) {
> > +		int level;
> > +
> > +		level = clamp(data[13] - PRESSURE_OFFSET,
> > +				0, MAX_PRESSURE);
> > +
> > +		input_report_key(udraw->pen_input_dev, BTN_TOUCH,
> > (level != 0));
> > +		input_report_key(udraw->pen_input_dev,
> > BTN_TOOL_PEN,
> > 1);
> > +		input_report_abs(udraw->pen_input_dev,
> > ABS_PRESSURE,
> > level);
> > +		input_report_abs(udraw->pen_input_dev, ABS_X, x);
> > +		input_report_abs(udraw->pen_input_dev, ABS_Y, y);
> > +	} else {
> > +		input_report_key(udraw->pen_input_dev, BTN_TOUCH,
> > 0);
> > +		input_report_abs(udraw->pen_input_dev,
> > ABS_PRESSURE,
> > 0);
> > +		input_report_key(udraw->pen_input_dev,
> > BTN_TOOL_PEN,
> > 0);
> > +	}
> > +	input_sync(udraw->pen_input_dev);
> 
> do me a favour and group the reports by type. it makes no difference
> to this
> driver but event recordings are much easier to read this way.
> so all EV_ABS first, then EV_KEY (or the other way round, don't
> care).

I put the EV_KEYs first, then EV_ABS. That was the only place where I
did this...

> > 
> > +
> > +	/* accel */
> > +	x = (data[19] + (data[20] << 8));
> > +	x = clamp_accel(x, 0);
> > +	y = (data[21] + (data[22] << 8));
> > +	y = clamp_accel(y, 1);
> > +	z = (data[23] + (data[24] << 8));
> > +	z = clamp_accel(z, 2);
> 
> this may not be kernel style, but any reason you can't use an enum
> here
> instead of 0, 1, 2? clamp_accel(x, ACCEL_AXIS_X) would be more
> obvious to
> read.

Done.

> > 
> > +	input_report_abs(udraw->accel_input_dev, ABS_X, x);
> > +	input_report_abs(udraw->accel_input_dev, ABS_Y, y);
> > +	input_report_abs(udraw->accel_input_dev, ABS_Z, z);
> > +	input_sync(udraw->accel_input_dev);
> > +
> > +	/* let hidraw and hiddev handle the report */
> > +	return 0;
> > +}
> > +
> > +static int udraw_open(struct input_dev *dev)
> > +{
> > +	struct udraw *udraw = input_get_drvdata(dev);
> > +
> > +	return hid_hw_open(udraw->hdev);
> > +}
> > +
> > +static void udraw_close(struct input_dev *dev)
> > +{
> > +	struct udraw *udraw = input_get_drvdata(dev);
> > +
> > +	hid_hw_close(udraw->hdev);
> > +}
> > +
> > +static struct input_dev *allocate_and_setup(struct hid_device
> > *hdev,
> > +		const char *name)
> > +{
> > +	struct input_dev *input_dev;
> > +
> > +	input_dev = devm_input_allocate_device(&hdev->dev);
> > +	if (!input_dev)
> > +		return NULL;
> > +
> > +	input_dev->name = name;
> > +	input_dev->phys = hdev->phys;
> > +	input_dev->dev.parent = &hdev->dev;
> > +	input_dev->open = udraw_open;
> > +	input_dev->close = udraw_close;
> > +	input_dev->uniq = hdev->uniq;
> > +	input_dev->id.bustype = hdev->bus;
> > +	input_dev->id.vendor  = hdev->vendor;
> > +	input_dev->id.product = hdev->product;
> > +	input_dev->id.version = hdev->version;
> > +	input_set_drvdata(input_dev, hid_get_drvdata(hdev));
> > +
> > +	return input_dev;
> > +}
> > +
> > +static bool udraw_setup_touch(struct udraw *udraw,
> > +		struct hid_device *hdev)
> > +{
> > +	struct input_dev *input_dev;
> > +
> > +	input_dev = allocate_and_setup(hdev, DEVICE_NAME "
> > (touchpad)");
> 
> no need to use () here. wacom device names are "foo Pen", "foo
> Finger", etc.
> would be nice to continue that naming scheme.

Renamed.

> > 
> > +	if (!input_dev)
> > +		return false;
> > +
> > +	input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
> > +
> > +	set_bit(ABS_X, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_X, 0, RES_X, 1, 0);
> > +	input_abs_set_res(input_dev, ABS_X, RES_X / WIDTH);
> > +	set_bit(ABS_Y, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_Y, 0, RES_Y, 1, 0);
> > +	input_abs_set_res(input_dev, ABS_Y, RES_Y / HEIGHT);
> > +
> > +	set_bit(BTN_TOUCH, input_dev->keybit);
> > +	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
> > +	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
> > +
> > +	set_bit(INPUT_PROP_POINTER, input_dev->propbit);
> > +
> > +	udraw->touch_input_dev = input_dev;
> > +
> > +	return true;
> > +}
> > +
> > +static bool udraw_setup_pen(struct udraw *udraw,
> > +		struct hid_device *hdev)
> > +{
> > +	struct input_dev *input_dev;
> > +
> > +	input_dev = allocate_and_setup(hdev, DEVICE_NAME "
> > (pen)");
> 
> see above for naming scheme

Done.

> > 
> > +	if (!input_dev)
> > +		return false;
> > +
> > +	input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
> > +
> > +	set_bit(ABS_X, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_X, 0, RES_X, 1, 0);
> > +	input_abs_set_res(input_dev, ABS_X, RES_X / WIDTH);
> > +	set_bit(ABS_Y, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_Y, 0, RES_Y, 1, 0);
> > +	input_abs_set_res(input_dev, ABS_Y, RES_Y / HEIGHT);
> > +	set_bit(ABS_PRESSURE, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_PRESSURE,
> > +			0, MAX_PRESSURE, 0, 0);
> > +
> > +	set_bit(BTN_TOUCH, input_dev->keybit);
> > +	set_bit(BTN_TOOL_PEN, input_dev->keybit);
> > +
> > +	set_bit(INPUT_PROP_POINTER, input_dev->propbit);
> > +
> > +	udraw->pen_input_dev = input_dev;
> > +
> > +	return true;
> > +}
> > +
> > +static bool udraw_setup_accel(struct udraw *udraw,
> > +		struct hid_device *hdev)
> > +{
> > +	struct input_dev *input_dev;
> > +
> > +	input_dev = allocate_and_setup(hdev, DEVICE_NAME "
> > (accelerometer)");
> 
> see above for naming scheme

Done.

> > 
> > +	if (!input_dev)
> > +		return false;
> > +
> > +	input_dev->evbit[0] = BIT(EV_ABS);
> > +
> > +	/* 1G accel is reported as ~256, so clamp to 2G */
> > +	set_bit(ABS_X, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_X, -512, 512, 0, 0);
> > +	set_bit(ABS_Y, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_Y, -512, 512, 0, 0);
> > +	set_bit(ABS_Z, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_Z, -512, 512, 0, 0);
> > +
> > +	set_bit(INPUT_PROP_ACCELEROMETER, input_dev->propbit);
> > +
> > +	udraw->accel_input_dev = input_dev;
> > +
> > +	return true;
> > +}
> > +
> > +static bool udraw_setup_joypad(struct udraw *udraw,
> > +		struct hid_device *hdev)
> > +{
> > +	struct input_dev *input_dev;
> > +	int i;
> > +
> > +	input_dev = allocate_and_setup(hdev, DEVICE_NAME "
> > (joypad)");
> 
> see above for naming scheme

Done.

> > 
> > +	if (!input_dev)
> > +		return false;
> > +
> > +	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
> > +
> > +	set_bit(ABS_X, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_X, -127, 127, 0, 0);
> > +	set_bit(ABS_Y, input_dev->absbit);
> > +	input_set_abs_params(input_dev, ABS_Y, -127, 127, 0, 0);
> > +
> > +	for (i = 0; i < ARRAY_SIZE(udraw_joy_key_table); i++)
> > +		set_bit(udraw_joy_key_table[i], input_dev-
> > >keybit);
> 
> Personal opinion here: for the few buttons you have, the loop over an
> array
> doesn't really get you much benefit over just having 7 set_bit()
> calls. just
> hardcoding all set_bit calls (or moving joy_key_table to here) is
> that you
> have all the init bits in one place for quick analysis.
> 
> but I'm not going to argue this point too hard.

I moved all that to a flat list of calls.

All pushed to https://github.com/hadess/udraw until I get some more
comments, or some parts of the protocol mysteriously appear ;)

Cheers

> Cheers,
>    Peter
> 
> > 
> > +
> > +	udraw->joy_input_dev = input_dev;
> > +
> > +	return true;
> > +}
> > +
> > +static int udraw_probe(struct hid_device *hdev, const struct
> > hid_device_id *id)
> > +{
> > +	struct udraw *udraw;
> > +	int ret;
> > +
> > +	udraw = devm_kzalloc(&hdev->dev, sizeof(struct udraw),
> > GFP_KERNEL);
> > +	if (!udraw)
> > +		return -ENOMEM;
> > +
> > +	udraw->hdev = hdev;
> > +
> > +	hid_set_drvdata(hdev, udraw);
> > +
> > +	ret = hid_parse(hdev);
> > +	if (ret) {
> > +		hid_err(hdev, "parse failed\n");
> > +		return ret;
> > +	}
> > +
> > +	if (!udraw_setup_joypad(udraw, hdev) ||
> > +	    !udraw_setup_touch(udraw, hdev) ||
> > +	    !udraw_setup_pen(udraw, hdev) ||
> > +	    !udraw_setup_accel(udraw, hdev)) {
> > +		hid_err(hdev, "could not allocate interfaces\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	ret = input_register_device(udraw->joy_input_dev) ||
> > +		input_register_device(udraw->touch_input_dev) ||
> > +		input_register_device(udraw->pen_input_dev) ||
> > +		input_register_device(udraw->accel_input_dev);
> > +	if (ret) {
> > +		hid_err(hdev, "failed to register interfaces\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW |
> > HID_CONNECT_DRIVER);
> > +	if (ret) {
> > +		hid_err(hdev, "hw start failed\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct hid_device_id udraw_devices[] = {
> > +	{ HID_USB_DEVICE(USB_VENDOR_ID_THQ,
> > USB_DEVICE_ID_THQ_PS3_UDRAW) },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(hid, udraw_devices);
> > +
> > +static struct hid_driver udraw_driver = {
> > +	.name = "hid-udraw",
> > +	.id_table = udraw_devices,
> > +	.raw_event = udraw_raw_event,
> > +	.probe = udraw_probe,
> > +};
> > +module_hid_driver(udraw_driver);
> > -- 
> > 2.7.4
> > --
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