1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * HID driver for ELO usb touchscreen 4000/4500
4 *
5 * Copyright (c) 2013 Jiri Slaby
6 *
7 * Data parsing taken from elousb driver by Vojtech Pavlik.
8 */
9
10#include <linux/hid.h>
11#include <linux/input.h>
12#include <linux/module.h>
13#include <linux/usb.h>
14#include <linux/workqueue.h>
15
16#include "hid-ids.h"
17
18#define ELO_PERIODIC_READ_INTERVAL	HZ
19#define ELO_SMARTSET_CMD_TIMEOUT	2000 /* msec */
20
21/* Elo SmartSet commands */
22#define ELO_FLUSH_SMARTSET_RESPONSES	0x02 /* Flush all pending smartset responses */
23#define ELO_SEND_SMARTSET_COMMAND	0x05 /* Send a smartset command */
24#define ELO_GET_SMARTSET_RESPONSE	0x06 /* Get a smartset response */
25#define ELO_DIAG			0x64 /* Diagnostics command */
26#define ELO_SMARTSET_PACKET_SIZE	8
27
28struct elo_priv {
29	struct usb_device *usbdev;
30	struct delayed_work work;
31	unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
32};
33
34static struct workqueue_struct *wq;
35static bool use_fw_quirk = true;
36module_param(use_fw_quirk, bool, S_IRUGO);
37MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
38
39static int elo_input_configured(struct hid_device *hdev,
40		struct hid_input *hidinput)
41{
42	struct input_dev *input = hidinput->input;
43
44	/*
45	 * ELO devices have one Button usage in GenDesk field, which makes
46	 * hid-input map it to BTN_LEFT; that confuses userspace, which then
47	 * considers the device to be a mouse/touchpad instead of touchscreen.
48	 */
49	clear_bit(BTN_LEFT, input->keybit);
50	set_bit(BTN_TOUCH, input->keybit);
51	set_bit(ABS_PRESSURE, input->absbit);
52	input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
53
54	return 0;
55}
56
57static void elo_process_data(struct input_dev *input, const u8 *data, int size)
58{
59	int press;
60
61	input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
62	input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
63
64	press = 0;
65	if (data[1] & 0x80)
66		press = (data[7] << 8) | data[6];
67	input_report_abs(input, ABS_PRESSURE, press);
68
69	if (data[1] & 0x03) {
70		input_report_key(input, BTN_TOUCH, 1);
71		input_sync(input);
72	}
73
74	if (data[1] & 0x04)
75		input_report_key(input, BTN_TOUCH, 0);
76
77	input_sync(input);
78}
79
80static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
81	 u8 *data, int size)
82{
83	struct hid_input *hidinput;
84
85	if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
86		return 0;
87
88	hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
89
90	switch (report->id) {
91	case 0:
92		if (data[0] == 'T') {	/* Mandatory ELO packet marker */
93			elo_process_data(hidinput->input, data, size);
94			return 1;
95		}
96		break;
97	default:	/* unknown report */
98		/* Unknown report type; pass upstream */
99		hid_info(hdev, "unknown report type %d\n", report->id);
100		break;
101	}
102
103	return 0;
104}
105
106static int elo_smartset_send_get(struct usb_device *dev, u8 command,
107		void *data)
108{
109	unsigned int pipe;
110	u8 dir;
111
112	if (command == ELO_SEND_SMARTSET_COMMAND) {
113		pipe = usb_sndctrlpipe(dev, 0);
114		dir = USB_DIR_OUT;
115	} else if (command == ELO_GET_SMARTSET_RESPONSE) {
116		pipe = usb_rcvctrlpipe(dev, 0);
117		dir = USB_DIR_IN;
118	} else
119		return -EINVAL;
120
121	return usb_control_msg(dev, pipe, command,
122			dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
123			0, 0, data, ELO_SMARTSET_PACKET_SIZE,
124			ELO_SMARTSET_CMD_TIMEOUT);
125}
126
127static int elo_flush_smartset_responses(struct usb_device *dev)
128{
129	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
130			ELO_FLUSH_SMARTSET_RESPONSES,
131			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
132			0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
133}
134
135static void elo_work(struct work_struct *work)
136{
137	struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
138	struct usb_device *dev = priv->usbdev;
139	unsigned char *buffer = priv->buffer;
140	int ret;
141
142	ret = elo_flush_smartset_responses(dev);
143	if (ret < 0) {
144		dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
145				ret);
146		goto fail;
147	}
148
149	/* send Diagnostics command */
150	*buffer = ELO_DIAG;
151	ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
152	if (ret < 0) {
153		dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
154				ret);
155		goto fail;
156	}
157
158	/* get the result */
159	ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
160	if (ret < 0) {
161		dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
162				ret);
163		goto fail;
164	}
165
166	/* read the ack */
167	if (*buffer != 'A') {
168		ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
169				buffer);
170		if (ret < 0) {
171			dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
172					ret);
173			goto fail;
174		}
175	}
176
177fail:
178	ret = elo_flush_smartset_responses(dev);
179	if (ret < 0)
180		dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
181				ret);
182	queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
183}
184
185/*
186 * Not all Elo devices need the periodic HID descriptor reads.
187 * Only firmware version M needs this.
188 */
189static bool elo_broken_firmware(struct usb_device *dev)
190{
191	struct usb_device *hub = dev->parent;
192	struct usb_device *child = NULL;
193	u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
194	u16 child_vid, child_pid;
195	int i;
196
197	if (!use_fw_quirk)
198		return false;
199	if (fw_lvl != 0x10d)
200		return false;
201
202	/* iterate sibling devices of the touch controller */
203	usb_hub_for_each_child(hub, i, child) {
204		child_vid = le16_to_cpu(child->descriptor.idVendor);
205		child_pid = le16_to_cpu(child->descriptor.idProduct);
206
207		/*
208		 * If one of the devices below is present attached as a sibling of
209		 * the touch controller then  this is a newer IBM 4820 monitor that
210		 * does not need the IBM-requested workaround if fw level is
211		 * 0x010d - aka 'M'.
212		 * No other HW can have this combination.
213		 */
214		if (child_vid==0x04b3) {
215			switch (child_pid) {
216			case 0x4676: /* 4820 21x Video */
217			case 0x4677: /* 4820 51x Video */
218			case 0x4678: /* 4820 2Lx Video */
219			case 0x4679: /* 4820 5Lx Video */
220				return false;
221			}
222		}
223	}
224	return true;
225}
226
227static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
228{
229	struct elo_priv *priv;
230	int ret;
231
232	if (!hid_is_usb(hdev))
233		return -EINVAL;
234
235	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
236	if (!priv)
237		return -ENOMEM;
238
239	INIT_DELAYED_WORK(&priv->work, elo_work);
240	priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
241
242	hid_set_drvdata(hdev, priv);
243
244	ret = hid_parse(hdev);
245	if (ret) {
246		hid_err(hdev, "parse failed\n");
247		goto err_free;
248	}
249
250	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
251	if (ret) {
252		hid_err(hdev, "hw start failed\n");
253		goto err_free;
254	}
255
256	if (elo_broken_firmware(priv->usbdev)) {
257		hid_info(hdev, "broken firmware found, installing workaround\n");
258		queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
259	}
260
261	return 0;
262err_free:
263	kfree(priv);
264	return ret;
265}
266
267static void elo_remove(struct hid_device *hdev)
268{
269	struct elo_priv *priv = hid_get_drvdata(hdev);
270
271	hid_hw_stop(hdev);
272	cancel_delayed_work_sync(&priv->work);
273	kfree(priv);
274}
275
276static const struct hid_device_id elo_devices[] = {
277	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
278	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
279	{ }
280};
281MODULE_DEVICE_TABLE(hid, elo_devices);
282
283static struct hid_driver elo_driver = {
284	.name = "elo",
285	.id_table = elo_devices,
286	.probe = elo_probe,
287	.remove = elo_remove,
288	.raw_event = elo_raw_event,
289	.input_configured = elo_input_configured,
290};
291
292static int __init elo_driver_init(void)
293{
294	int ret;
295
296	wq = create_singlethread_workqueue("elousb");
297	if (!wq)
298		return -ENOMEM;
299
300	ret = hid_register_driver(&elo_driver);
301	if (ret)
302		destroy_workqueue(wq);
303
304	return ret;
305}
306module_init(elo_driver_init);
307
308static void __exit elo_driver_exit(void)
309{
310	hid_unregister_driver(&elo_driver);
311	destroy_workqueue(wq);
312}
313module_exit(elo_driver_exit);
314
315MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
316MODULE_LICENSE("GPL");
317