xref: /openbmc/linux/drivers/hid/hid-elo.c (revision 1c2dd16a)
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 	set_bit(BTN_TOUCH, input->keybit);
46 	set_bit(ABS_PRESSURE, input->absbit);
47 	input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
48 
49 	return 0;
50 }
51 
52 static void elo_process_data(struct input_dev *input, const u8 *data, int size)
53 {
54 	int press;
55 
56 	input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
57 	input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
58 
59 	press = 0;
60 	if (data[1] & 0x80)
61 		press = (data[7] << 8) | data[6];
62 	input_report_abs(input, ABS_PRESSURE, press);
63 
64 	if (data[1] & 0x03) {
65 		input_report_key(input, BTN_TOUCH, 1);
66 		input_sync(input);
67 	}
68 
69 	if (data[1] & 0x04)
70 		input_report_key(input, BTN_TOUCH, 0);
71 
72 	input_sync(input);
73 }
74 
75 static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
76 	 u8 *data, int size)
77 {
78 	struct hid_input *hidinput;
79 
80 	if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
81 		return 0;
82 
83 	hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
84 
85 	switch (report->id) {
86 	case 0:
87 		if (data[0] == 'T') {	/* Mandatory ELO packet marker */
88 			elo_process_data(hidinput->input, data, size);
89 			return 1;
90 		}
91 		break;
92 	default:	/* unknown report */
93 		/* Unknown report type; pass upstream */
94 		hid_info(hdev, "unknown report type %d\n", report->id);
95 		break;
96 	}
97 
98 	return 0;
99 }
100 
101 static int elo_smartset_send_get(struct usb_device *dev, u8 command,
102 		void *data)
103 {
104 	unsigned int pipe;
105 	u8 dir;
106 
107 	if (command == ELO_SEND_SMARTSET_COMMAND) {
108 		pipe = usb_sndctrlpipe(dev, 0);
109 		dir = USB_DIR_OUT;
110 	} else if (command == ELO_GET_SMARTSET_RESPONSE) {
111 		pipe = usb_rcvctrlpipe(dev, 0);
112 		dir = USB_DIR_IN;
113 	} else
114 		return -EINVAL;
115 
116 	return usb_control_msg(dev, pipe, command,
117 			dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
118 			0, 0, data, ELO_SMARTSET_PACKET_SIZE,
119 			ELO_SMARTSET_CMD_TIMEOUT);
120 }
121 
122 static int elo_flush_smartset_responses(struct usb_device *dev)
123 {
124 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
125 			ELO_FLUSH_SMARTSET_RESPONSES,
126 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
127 			0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
128 }
129 
130 static void elo_work(struct work_struct *work)
131 {
132 	struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
133 	struct usb_device *dev = priv->usbdev;
134 	unsigned char *buffer = priv->buffer;
135 	int ret;
136 
137 	ret = elo_flush_smartset_responses(dev);
138 	if (ret < 0) {
139 		dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
140 				ret);
141 		goto fail;
142 	}
143 
144 	/* send Diagnostics command */
145 	*buffer = ELO_DIAG;
146 	ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
147 	if (ret < 0) {
148 		dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
149 				ret);
150 		goto fail;
151 	}
152 
153 	/* get the result */
154 	ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
155 	if (ret < 0) {
156 		dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
157 				ret);
158 		goto fail;
159 	}
160 
161 	/* read the ack */
162 	if (*buffer != 'A') {
163 		ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
164 				buffer);
165 		if (ret < 0) {
166 			dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
167 					ret);
168 			goto fail;
169 		}
170 	}
171 
172 fail:
173 	ret = elo_flush_smartset_responses(dev);
174 	if (ret < 0)
175 		dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
176 				ret);
177 	queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
178 }
179 
180 /*
181  * Not all Elo devices need the periodic HID descriptor reads.
182  * Only firmware version M needs this.
183  */
184 static bool elo_broken_firmware(struct usb_device *dev)
185 {
186 	struct usb_device *hub = dev->parent;
187 	struct usb_device *child = NULL;
188 	u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
189 	u16 child_vid, child_pid;
190 	int i;
191 
192 	if (!use_fw_quirk)
193 		return false;
194 	if (fw_lvl != 0x10d)
195 		return false;
196 
197 	/* iterate sibling devices of the touch controller */
198 	usb_hub_for_each_child(hub, i, child) {
199 		child_vid = le16_to_cpu(child->descriptor.idVendor);
200 		child_pid = le16_to_cpu(child->descriptor.idProduct);
201 
202 		/*
203 		 * If one of the devices below is present attached as a sibling of
204 		 * the touch controller then  this is a newer IBM 4820 monitor that
205 		 * does not need the IBM-requested workaround if fw level is
206 		 * 0x010d - aka 'M'.
207 		 * No other HW can have this combination.
208 		 */
209 		if (child_vid==0x04b3) {
210 			switch (child_pid) {
211 			case 0x4676: /* 4820 21x Video */
212 			case 0x4677: /* 4820 51x Video */
213 			case 0x4678: /* 4820 2Lx Video */
214 			case 0x4679: /* 4820 5Lx Video */
215 				return false;
216 			}
217 		}
218 	}
219 	return true;
220 }
221 
222 static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
223 {
224 	struct elo_priv *priv;
225 	int ret;
226 
227 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
228 	if (!priv)
229 		return -ENOMEM;
230 
231 	INIT_DELAYED_WORK(&priv->work, elo_work);
232 	priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
233 
234 	hid_set_drvdata(hdev, priv);
235 
236 	ret = hid_parse(hdev);
237 	if (ret) {
238 		hid_err(hdev, "parse failed\n");
239 		goto err_free;
240 	}
241 
242 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
243 	if (ret) {
244 		hid_err(hdev, "hw start failed\n");
245 		goto err_free;
246 	}
247 
248 	if (elo_broken_firmware(priv->usbdev)) {
249 		hid_info(hdev, "broken firmware found, installing workaround\n");
250 		queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
251 	}
252 
253 	return 0;
254 err_free:
255 	kfree(priv);
256 	return ret;
257 }
258 
259 static void elo_remove(struct hid_device *hdev)
260 {
261 	struct elo_priv *priv = hid_get_drvdata(hdev);
262 
263 	hid_hw_stop(hdev);
264 	cancel_delayed_work_sync(&priv->work);
265 	kfree(priv);
266 }
267 
268 static const struct hid_device_id elo_devices[] = {
269 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
270 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
271 	{ }
272 };
273 MODULE_DEVICE_TABLE(hid, elo_devices);
274 
275 static struct hid_driver elo_driver = {
276 	.name = "elo",
277 	.id_table = elo_devices,
278 	.probe = elo_probe,
279 	.remove = elo_remove,
280 	.raw_event = elo_raw_event,
281 	.input_configured = elo_input_configured,
282 };
283 
284 static int __init elo_driver_init(void)
285 {
286 	int ret;
287 
288 	wq = create_singlethread_workqueue("elousb");
289 	if (!wq)
290 		return -ENOMEM;
291 
292 	ret = hid_register_driver(&elo_driver);
293 	if (ret)
294 		destroy_workqueue(wq);
295 
296 	return ret;
297 }
298 module_init(elo_driver_init);
299 
300 static void __exit elo_driver_exit(void)
301 {
302 	hid_unregister_driver(&elo_driver);
303 	destroy_workqueue(wq);
304 }
305 module_exit(elo_driver_exit);
306 
307 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
308 MODULE_LICENSE("GPL");
309