xref: /openbmc/linux/drivers/hid/hid-elo.c (revision e3b9f1e8)
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 
29 struct elo_priv {
30 	struct usb_device *usbdev;
31 	struct delayed_work work;
32 	unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
33 };
34 
35 static struct workqueue_struct *wq;
36 static bool use_fw_quirk = true;
37 module_param(use_fw_quirk, bool, S_IRUGO);
38 MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
39 
40 static 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 
58 static 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 
81 static 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 
107 static 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 
128 static 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 
136 static 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 
178 fail:
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  */
190 static 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 
228 static 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;
260 err_free:
261 	kfree(priv);
262 	return ret;
263 }
264 
265 static 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 
274 static 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 };
279 MODULE_DEVICE_TABLE(hid, elo_devices);
280 
281 static 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 
290 static 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 }
304 module_init(elo_driver_init);
305 
306 static void __exit elo_driver_exit(void)
307 {
308 	hid_unregister_driver(&elo_driver);
309 	destroy_workqueue(wq);
310 }
311 module_exit(elo_driver_exit);
312 
313 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
314 MODULE_LICENSE("GPL");
315