1/*
2 * HID driver for ELO usb touchscreen 4000/4500
3 *
4 * Copyright (c) 2013 Jiri Slaby
5 *
6 * Data parsing taken from elousb driver by Vojtech Pavlik.
7 *
8 * This driver is licensed under the terms of GPLv2.
9 */
10
11#include <linux/hid.h>
12#include <linux/input.h>
13#include <linux/module.h>
14#include <linux/usb.h>
15#include <linux/workqueue.h>
16
17#include "hid-ids.h"
18
19#define ELO_PERIODIC_READ_INTERVAL HZ
20#define ELO_SMARTSET_CMD_TIMEOUT 2000 /* msec */
21
22/* Elo SmartSet commands */
23#define ELO_FLUSH_SMARTSET_RESPONSES 0x02 /* Flush all pending smartset responses */
24#define ELO_SEND_SMARTSET_COMMAND 0x05 /* Send a smartset command */
25#define ELO_GET_SMARTSET_RESPONSE 0x06 /* Get a smartset response */
26#define ELO_DIAG 0x64 /* Diagnostics command */
27#define ELO_SMARTSET_PACKET_SIZE 8
28
29struct elo_priv {
30 struct usb_device *usbdev;
31 struct delayed_work work;
32 unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
33};
34
35static struct workqueue_struct *wq;
36static bool use_fw_quirk = true;
37module_param(use_fw_quirk, bool, S_IRUGO);
38MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
39
40static int elo_input_configured(struct hid_device *hdev,
41 struct hid_input *hidinput)
42{
43 struct input_dev *input = hidinput->input;
44
45 /*
46 * ELO devices have one Button usage in GenDesk field, which makes
47 * hid-input map it to BTN_LEFT; that confuses userspace, which then
48 * considers the device to be a mouse/touchpad instead of touchscreen.
49 */
50 clear_bit(BTN_LEFT, input->keybit);
51 set_bit(BTN_TOUCH, input->keybit);
52 set_bit(ABS_PRESSURE, input->absbit);
53 input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
54
55 return 0;
56}
57
58static void elo_process_data(struct input_dev *input, const u8 *data, int size)
59{
60 int press;
61
62 input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
63 input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
64
65 press = 0;
66 if (data[1] & 0x80)
67 press = (data[7] << 8) | data[6];
68 input_report_abs(input, ABS_PRESSURE, press);
69
70 if (data[1] & 0x03) {
71 input_report_key(input, BTN_TOUCH, 1);
72 input_sync(input);
73 }
74
75 if (data[1] & 0x04)
76 input_report_key(input, BTN_TOUCH, 0);
77
78 input_sync(input);
79}
80
81static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
82 u8 *data, int size)
83{
84 struct hid_input *hidinput;
85
86 if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
87 return 0;
88
89 hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
90
91 switch (report->id) {
92 case 0:
93 if (data[0] == 'T') { /* Mandatory ELO packet marker */
94 elo_process_data(hidinput->input, data, size);
95 return 1;
96 }
97 break;
98 default: /* unknown report */
99 /* Unknown report type; pass upstream */
100 hid_info(hdev, "unknown report type %d\n", report->id);
101 break;
102 }
103
104 return 0;
105}
106
107static int elo_smartset_send_get(struct usb_device *dev, u8 command,
108 void *data)
109{
110 unsigned int pipe;
111 u8 dir;
112
113 if (command == ELO_SEND_SMARTSET_COMMAND) {
114 pipe = usb_sndctrlpipe(dev, 0);
115 dir = USB_DIR_OUT;
116 } else if (command == ELO_GET_SMARTSET_RESPONSE) {
117 pipe = usb_rcvctrlpipe(dev, 0);
118 dir = USB_DIR_IN;
119 } else
120 return -EINVAL;
121
122 return usb_control_msg(dev, pipe, command,
123 dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
124 0, 0, data, ELO_SMARTSET_PACKET_SIZE,
125 ELO_SMARTSET_CMD_TIMEOUT);
126}
127
128static int elo_flush_smartset_responses(struct usb_device *dev)
129{
130 return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
131 ELO_FLUSH_SMARTSET_RESPONSES,
132 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
133 0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
134}
135
136static void elo_work(struct work_struct *work)
137{
138 struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
139 struct usb_device *dev = priv->usbdev;
140 unsigned char *buffer = priv->buffer;
141 int ret;
142
143 ret = elo_flush_smartset_responses(dev);
144 if (ret < 0) {
145 dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
146 ret);
147 goto fail;
148 }
149
150 /* send Diagnostics command */
151 *buffer = ELO_DIAG;
152 ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
153 if (ret < 0) {
154 dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
155 ret);
156 goto fail;
157 }
158
159 /* get the result */
160 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
161 if (ret < 0) {
162 dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
163 ret);
164 goto fail;
165 }
166
167 /* read the ack */
168 if (*buffer != 'A') {
169 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
170 buffer);
171 if (ret < 0) {
172 dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
173 ret);
174 goto fail;
175 }
176 }
177
178fail:
179 ret = elo_flush_smartset_responses(dev);
180 if (ret < 0)
181 dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
182 ret);
183 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
184}
185
186/*
187 * Not all Elo devices need the periodic HID descriptor reads.
188 * Only firmware version M needs this.
189 */
190static bool elo_broken_firmware(struct usb_device *dev)
191{
192 struct usb_device *hub = dev->parent;
193 struct usb_device *child = NULL;
194 u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
195 u16 child_vid, child_pid;
196 int i;
197
198 if (!use_fw_quirk)
199 return false;
200 if (fw_lvl != 0x10d)
201 return false;
202
203 /* iterate sibling devices of the touch controller */
204 usb_hub_for_each_child(hub, i, child) {
205 child_vid = le16_to_cpu(child->descriptor.idVendor);
206 child_pid = le16_to_cpu(child->descriptor.idProduct);
207
208 /*
209 * If one of the devices below is present attached as a sibling of
210 * the touch controller then this is a newer IBM 4820 monitor that
211 * does not need the IBM-requested workaround if fw level is
212 * 0x010d - aka 'M'.
213 * No other HW can have this combination.
214 */
215 if (child_vid==0x04b3) {
216 switch (child_pid) {
217 case 0x4676: /* 4820 21x Video */
218 case 0x4677: /* 4820 51x Video */
219 case 0x4678: /* 4820 2Lx Video */
220 case 0x4679: /* 4820 5Lx Video */
221 return false;
222 }
223 }
224 }
225 return true;
226}
227
228static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
229{
230 struct elo_priv *priv;
231 int ret;
232
233 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
234 if (!priv)
235 return -ENOMEM;
236
237 INIT_DELAYED_WORK(&priv->work, elo_work);
238 priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
239
240 hid_set_drvdata(hdev, priv);
241
242 ret = hid_parse(hdev);
243 if (ret) {
244 hid_err(hdev, "parse failed\n");
245 goto err_free;
246 }
247
248 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
249 if (ret) {
250 hid_err(hdev, "hw start failed\n");
251 goto err_free;
252 }
253
254 if (elo_broken_firmware(priv->usbdev)) {
255 hid_info(hdev, "broken firmware found, installing workaround\n");
256 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
257 }
258
259 return 0;
260err_free:
261 kfree(priv);
262 return ret;
263}
264
265static void elo_remove(struct hid_device *hdev)
266{
267 struct elo_priv *priv = hid_get_drvdata(hdev);
268
269 hid_hw_stop(hdev);
270 cancel_delayed_work_sync(&priv->work);
271 kfree(priv);
272}
273
274static const struct hid_device_id elo_devices[] = {
275 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
276 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
277 { }
278};
279MODULE_DEVICE_TABLE(hid, elo_devices);
280
281static struct hid_driver elo_driver = {
282 .name = "elo",
283 .id_table = elo_devices,
284 .probe = elo_probe,
285 .remove = elo_remove,
286 .raw_event = elo_raw_event,
287 .input_configured = elo_input_configured,
288};
289
290static int __init elo_driver_init(void)
291{
292 int ret;
293
294 wq = create_singlethread_workqueue("elousb");
295 if (!wq)
296 return -ENOMEM;
297
298 ret = hid_register_driver(&elo_driver);
299 if (ret)
300 destroy_workqueue(wq);
301
302 return ret;
303}
304module_init(elo_driver_init);
305
306static void __exit elo_driver_exit(void)
307{
308 hid_unregister_driver(&elo_driver);
309 destroy_workqueue(wq);
310}
311module_exit(elo_driver_exit);
312
313MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
314MODULE_LICENSE("GPL");
315