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
28 struct elo_priv {
29 struct usb_device *usbdev;
30 struct delayed_work work;
31 unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
32 };
33
34 static struct workqueue_struct *wq;
35 static bool use_fw_quirk = true;
36 module_param(use_fw_quirk, bool, S_IRUGO);
37 MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
38
elo_input_configured(struct hid_device * hdev,struct hid_input * hidinput)39 static 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
elo_process_data(struct input_dev * input,const u8 * data,int size)57 static 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
elo_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)80 static 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
elo_smartset_send_get(struct usb_device * dev,u8 command,void * data)106 static 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
elo_flush_smartset_responses(struct usb_device * dev)127 static 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
elo_work(struct work_struct * work)135 static 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
177 fail:
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 */
elo_broken_firmware(struct usb_device * dev)189 static 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
elo_probe(struct hid_device * hdev,const struct hid_device_id * id)227 static 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;
262 err_free:
263 kfree(priv);
264 return ret;
265 }
266
elo_remove(struct hid_device * hdev)267 static 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
276 static 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 };
281 MODULE_DEVICE_TABLE(hid, elo_devices);
282
283 static 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
elo_driver_init(void)292 static 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 }
306 module_init(elo_driver_init);
307
elo_driver_exit(void)308 static void __exit elo_driver_exit(void)
309 {
310 hid_unregister_driver(&elo_driver);
311 destroy_workqueue(wq);
312 }
313 module_exit(elo_driver_exit);
314
315 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
316 MODULE_DESCRIPTION("HID driver for ELO usb touchscreen 4000/4500");
317 MODULE_LICENSE("GPL");
318