xref: /openbmc/linux/drivers/hid/hid-elo.c (revision 588b48ca)
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 void 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 
50 static void elo_process_data(struct input_dev *input, const u8 *data, int size)
51 {
52 	int press;
53 
54 	input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
55 	input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
56 
57 	press = 0;
58 	if (data[1] & 0x80)
59 		press = (data[7] << 8) | data[6];
60 	input_report_abs(input, ABS_PRESSURE, press);
61 
62 	if (data[1] & 0x03) {
63 		input_report_key(input, BTN_TOUCH, 1);
64 		input_sync(input);
65 	}
66 
67 	if (data[1] & 0x04)
68 		input_report_key(input, BTN_TOUCH, 0);
69 
70 	input_sync(input);
71 }
72 
73 static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
74 	 u8 *data, int size)
75 {
76 	struct hid_input *hidinput;
77 
78 	if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
79 		return 0;
80 
81 	hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
82 
83 	switch (report->id) {
84 	case 0:
85 		if (data[0] == 'T') {	/* Mandatory ELO packet marker */
86 			elo_process_data(hidinput->input, data, size);
87 			return 1;
88 		}
89 		break;
90 	default:	/* unknown report */
91 		/* Unknown report type; pass upstream */
92 		hid_info(hdev, "unknown report type %d\n", report->id);
93 		break;
94 	}
95 
96 	return 0;
97 }
98 
99 static int elo_smartset_send_get(struct usb_device *dev, u8 command,
100 		void *data)
101 {
102 	unsigned int pipe;
103 	u8 dir;
104 
105 	if (command == ELO_SEND_SMARTSET_COMMAND) {
106 		pipe = usb_sndctrlpipe(dev, 0);
107 		dir = USB_DIR_OUT;
108 	} else if (command == ELO_GET_SMARTSET_RESPONSE) {
109 		pipe = usb_rcvctrlpipe(dev, 0);
110 		dir = USB_DIR_IN;
111 	} else
112 		return -EINVAL;
113 
114 	return usb_control_msg(dev, pipe, command,
115 			dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
116 			0, 0, data, ELO_SMARTSET_PACKET_SIZE,
117 			ELO_SMARTSET_CMD_TIMEOUT);
118 }
119 
120 static int elo_flush_smartset_responses(struct usb_device *dev)
121 {
122 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
123 			ELO_FLUSH_SMARTSET_RESPONSES,
124 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
125 			0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
126 }
127 
128 static void elo_work(struct work_struct *work)
129 {
130 	struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
131 	struct usb_device *dev = priv->usbdev;
132 	unsigned char *buffer = priv->buffer;
133 	int ret;
134 
135 	ret = elo_flush_smartset_responses(dev);
136 	if (ret < 0) {
137 		dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
138 				ret);
139 		goto fail;
140 	}
141 
142 	/* send Diagnostics command */
143 	*buffer = ELO_DIAG;
144 	ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
145 	if (ret < 0) {
146 		dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
147 				ret);
148 		goto fail;
149 	}
150 
151 	/* get the result */
152 	ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
153 	if (ret < 0) {
154 		dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
155 				ret);
156 		goto fail;
157 	}
158 
159 	/* read the ack */
160 	if (*buffer != 'A') {
161 		ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
162 				buffer);
163 		if (ret < 0) {
164 			dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
165 					ret);
166 			goto fail;
167 		}
168 	}
169 
170 fail:
171 	ret = elo_flush_smartset_responses(dev);
172 	if (ret < 0)
173 		dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
174 				ret);
175 	queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
176 }
177 
178 /*
179  * Not all Elo devices need the periodic HID descriptor reads.
180  * Only firmware version M needs this.
181  */
182 static bool elo_broken_firmware(struct usb_device *dev)
183 {
184 	struct usb_device *hub = dev->parent;
185 	struct usb_device *child = NULL;
186 	u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
187 	u16 child_vid, child_pid;
188 	int i;
189 
190 	if (!use_fw_quirk)
191 		return false;
192 	if (fw_lvl != 0x10d)
193 		return false;
194 
195 	/* iterate sibling devices of the touch controller */
196 	usb_hub_for_each_child(hub, i, child) {
197 		child_vid = le16_to_cpu(child->descriptor.idVendor);
198 		child_pid = le16_to_cpu(child->descriptor.idProduct);
199 
200 		/*
201 		 * If one of the devices below is present attached as a sibling of
202 		 * the touch controller then  this is a newer IBM 4820 monitor that
203 		 * does not need the IBM-requested workaround if fw level is
204 		 * 0x010d - aka 'M'.
205 		 * No other HW can have this combination.
206 		 */
207 		if (child_vid==0x04b3) {
208 			switch (child_pid) {
209 			case 0x4676: /* 4820 21x Video */
210 			case 0x4677: /* 4820 51x Video */
211 			case 0x4678: /* 4820 2Lx Video */
212 			case 0x4679: /* 4820 5Lx Video */
213 				return false;
214 			}
215 		}
216 	}
217 	return true;
218 }
219 
220 static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
221 {
222 	struct elo_priv *priv;
223 	int ret;
224 
225 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
226 	if (!priv)
227 		return -ENOMEM;
228 
229 	INIT_DELAYED_WORK(&priv->work, elo_work);
230 	priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
231 
232 	hid_set_drvdata(hdev, priv);
233 
234 	ret = hid_parse(hdev);
235 	if (ret) {
236 		hid_err(hdev, "parse failed\n");
237 		goto err_free;
238 	}
239 
240 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
241 	if (ret) {
242 		hid_err(hdev, "hw start failed\n");
243 		goto err_free;
244 	}
245 
246 	if (elo_broken_firmware(priv->usbdev)) {
247 		hid_info(hdev, "broken firmware found, installing workaround\n");
248 		queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
249 	}
250 
251 	return 0;
252 err_free:
253 	kfree(priv);
254 	return ret;
255 }
256 
257 static void elo_remove(struct hid_device *hdev)
258 {
259 	struct elo_priv *priv = hid_get_drvdata(hdev);
260 
261 	hid_hw_stop(hdev);
262 	flush_workqueue(wq);
263 	kfree(priv);
264 }
265 
266 static const struct hid_device_id elo_devices[] = {
267 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
268 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
269 	{ }
270 };
271 MODULE_DEVICE_TABLE(hid, elo_devices);
272 
273 static struct hid_driver elo_driver = {
274 	.name = "elo",
275 	.id_table = elo_devices,
276 	.probe = elo_probe,
277 	.remove = elo_remove,
278 	.raw_event = elo_raw_event,
279 	.input_configured = elo_input_configured,
280 };
281 
282 static int __init elo_driver_init(void)
283 {
284 	int ret;
285 
286 	wq = create_singlethread_workqueue("elousb");
287 	if (!wq)
288 		return -ENOMEM;
289 
290 	ret = hid_register_driver(&elo_driver);
291 	if (ret)
292 		destroy_workqueue(wq);
293 
294 	return ret;
295 }
296 module_init(elo_driver_init);
297 
298 static void __exit elo_driver_exit(void)
299 {
300 	hid_unregister_driver(&elo_driver);
301 	destroy_workqueue(wq);
302 }
303 module_exit(elo_driver_exit);
304 
305 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
306 MODULE_LICENSE("GPL");
307