1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/kernel.h>
3#include <linux/slab.h>
4#include <linux/module.h>
5#include <linux/usb/input.h>
6#include <asm/unaligned.h>
7
8/*
9 * Pressure-threshold modules param code from Alex Perry <alex.perry@ieee.org>
10 */
11
12MODULE_AUTHOR("Josh Myer <josh@joshisanerd.com>");
13MODULE_DESCRIPTION("USB KB Gear JamStudio Tablet driver");
14MODULE_LICENSE("GPL");
15
16#define USB_VENDOR_ID_KBGEAR 0x084e
17
18static int kb_pressure_click = 0x10;
19module_param(kb_pressure_click, int, 0);
20MODULE_PARM_DESC(kb_pressure_click, "pressure threshold for clicks");
21
22struct kbtab {
23 unsigned char *data;
24 dma_addr_t data_dma;
25 struct input_dev *dev;
26 struct usb_interface *intf;
27 struct urb *irq;
28 char phys[32];
29};
30
31static void kbtab_irq(struct urb *urb)
32{
33 struct kbtab *kbtab = urb->context;
34 unsigned char *data = kbtab->data;
35 struct input_dev *dev = kbtab->dev;
36 int pressure;
37 int retval;
38
39 switch (urb->status) {
40 case 0:
41 /* success */
42 break;
43 case -ECONNRESET:
44 case -ENOENT:
45 case -ESHUTDOWN:
46 /* this urb is terminated, clean up */
47 dev_dbg(&kbtab->intf->dev,
48 "%s - urb shutting down with status: %d\n",
49 __func__, urb->status);
50 return;
51 default:
52 dev_dbg(&kbtab->intf->dev,
53 "%s - nonzero urb status received: %d\n",
54 __func__, urb->status);
55 goto exit;
56 }
57
58
59 input_report_key(dev, BTN_TOOL_PEN, value: 1);
60
61 input_report_abs(dev, ABS_X, value: get_unaligned_le16(p: &data[1]));
62 input_report_abs(dev, ABS_Y, value: get_unaligned_le16(p: &data[3]));
63
64 /*input_report_key(dev, BTN_TOUCH , data[0] & 0x01);*/
65 input_report_key(dev, BTN_RIGHT, value: data[0] & 0x02);
66
67 pressure = data[5];
68 if (kb_pressure_click == -1)
69 input_report_abs(dev, ABS_PRESSURE, value: pressure);
70 else
71 input_report_key(dev, BTN_LEFT, value: pressure > kb_pressure_click ? 1 : 0);
72
73 input_sync(dev);
74
75 exit:
76 retval = usb_submit_urb(urb, GFP_ATOMIC);
77 if (retval)
78 dev_err(&kbtab->intf->dev,
79 "%s - usb_submit_urb failed with result %d\n",
80 __func__, retval);
81}
82
83static const struct usb_device_id kbtab_ids[] = {
84 { USB_DEVICE(USB_VENDOR_ID_KBGEAR, 0x1001), .driver_info = 0 },
85 { }
86};
87
88MODULE_DEVICE_TABLE(usb, kbtab_ids);
89
90static int kbtab_open(struct input_dev *dev)
91{
92 struct kbtab *kbtab = input_get_drvdata(dev);
93 struct usb_device *udev = interface_to_usbdev(kbtab->intf);
94
95 kbtab->irq->dev = udev;
96 if (usb_submit_urb(urb: kbtab->irq, GFP_KERNEL))
97 return -EIO;
98
99 return 0;
100}
101
102static void kbtab_close(struct input_dev *dev)
103{
104 struct kbtab *kbtab = input_get_drvdata(dev);
105
106 usb_kill_urb(urb: kbtab->irq);
107}
108
109static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *id)
110{
111 struct usb_device *dev = interface_to_usbdev(intf);
112 struct usb_endpoint_descriptor *endpoint;
113 struct kbtab *kbtab;
114 struct input_dev *input_dev;
115 int error = -ENOMEM;
116
117 if (intf->cur_altsetting->desc.bNumEndpoints < 1)
118 return -ENODEV;
119
120 endpoint = &intf->cur_altsetting->endpoint[0].desc;
121 if (!usb_endpoint_is_int_in(epd: endpoint))
122 return -ENODEV;
123
124 kbtab = kzalloc(size: sizeof(struct kbtab), GFP_KERNEL);
125 input_dev = input_allocate_device();
126 if (!kbtab || !input_dev)
127 goto fail1;
128
129 kbtab->data = usb_alloc_coherent(dev, size: 8, GFP_KERNEL, dma: &kbtab->data_dma);
130 if (!kbtab->data)
131 goto fail1;
132
133 kbtab->irq = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
134 if (!kbtab->irq)
135 goto fail2;
136
137 kbtab->intf = intf;
138 kbtab->dev = input_dev;
139
140 usb_make_path(dev, buf: kbtab->phys, size: sizeof(kbtab->phys));
141 strlcat(p: kbtab->phys, q: "/input0", avail: sizeof(kbtab->phys));
142
143 input_dev->name = "KB Gear Tablet";
144 input_dev->phys = kbtab->phys;
145 usb_to_input_id(dev, id: &input_dev->id);
146 input_dev->dev.parent = &intf->dev;
147
148 input_set_drvdata(dev: input_dev, data: kbtab);
149
150 input_dev->open = kbtab_open;
151 input_dev->close = kbtab_close;
152
153 input_dev->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
154 input_dev->keybit[BIT_WORD(BTN_LEFT)] |=
155 BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT);
156 input_dev->keybit[BIT_WORD(BTN_DIGI)] |=
157 BIT_MASK(BTN_TOOL_PEN) | BIT_MASK(BTN_TOUCH);
158 input_set_abs_params(dev: input_dev, ABS_X, min: 0, max: 0x2000, fuzz: 4, flat: 0);
159 input_set_abs_params(dev: input_dev, ABS_Y, min: 0, max: 0x1750, fuzz: 4, flat: 0);
160 input_set_abs_params(dev: input_dev, ABS_PRESSURE, min: 0, max: 0xff, fuzz: 0, flat: 0);
161
162 usb_fill_int_urb(urb: kbtab->irq, dev,
163 usb_rcvintpipe(dev, endpoint->bEndpointAddress),
164 transfer_buffer: kbtab->data, buffer_length: 8,
165 complete_fn: kbtab_irq, context: kbtab, interval: endpoint->bInterval);
166 kbtab->irq->transfer_dma = kbtab->data_dma;
167 kbtab->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
168
169 error = input_register_device(kbtab->dev);
170 if (error)
171 goto fail3;
172
173 usb_set_intfdata(intf, data: kbtab);
174
175 return 0;
176
177 fail3: usb_free_urb(urb: kbtab->irq);
178 fail2: usb_free_coherent(dev, size: 8, addr: kbtab->data, dma: kbtab->data_dma);
179 fail1: input_free_device(dev: input_dev);
180 kfree(objp: kbtab);
181 return error;
182}
183
184static void kbtab_disconnect(struct usb_interface *intf)
185{
186 struct kbtab *kbtab = usb_get_intfdata(intf);
187 struct usb_device *udev = interface_to_usbdev(intf);
188
189 usb_set_intfdata(intf, NULL);
190
191 input_unregister_device(kbtab->dev);
192 usb_free_urb(urb: kbtab->irq);
193 usb_free_coherent(dev: udev, size: 8, addr: kbtab->data, dma: kbtab->data_dma);
194 kfree(objp: kbtab);
195}
196
197static struct usb_driver kbtab_driver = {
198 .name = "kbtab",
199 .probe = kbtab_probe,
200 .disconnect = kbtab_disconnect,
201 .id_table = kbtab_ids,
202};
203
204module_usb_driver(kbtab_driver);
205

source code of linux/drivers/input/tablet/kbtab.c