1/*
2 * USB PhidgetServo driver 1.0
3 *
4 * Copyright (C) 2004, 2006 Sean Young <sean@mess.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This is a driver for the USB PhidgetServo version 2.0 and 3.0 servo
12 * controllers available at: http://www.phidgets.com/
13 *
14 * Note that the driver takes input as: degrees.minutes
15 *
16 * CAUTION: Generally you should use 0 < degrees < 180 as anything else
17 * is probably beyond the range of your servo and may damage it.
18 */
19
20#include <linux/kernel.h>
21#include <linux/errno.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/module.h>
25#include <linux/usb.h>
26
27#include "phidget.h"
28
29#define DRIVER_AUTHOR "Sean Young <sean@mess.org>"
30#define DRIVER_DESC "USB PhidgetServo Driver"
31
32#define VENDOR_ID_GLAB				0x06c2
33#define DEVICE_ID_GLAB_PHIDGETSERVO_QUAD	0x0038
34#define DEVICE_ID_GLAB_PHIDGETSERVO_UNI		0x0039
35
36#define VENDOR_ID_WISEGROUP			0x0925
37#define VENDOR_ID_WISEGROUP_PHIDGETSERVO_QUAD	0x8101
38#define VENDOR_ID_WISEGROUP_PHIDGETSERVO_UNI	0x8104
39
40#define SERVO_VERSION_30			0x01
41#define SERVO_COUNT_QUAD			0x02
42
43static struct usb_device_id id_table[] = {
44	{
45		USB_DEVICE(VENDOR_ID_GLAB, DEVICE_ID_GLAB_PHIDGETSERVO_QUAD),
46		.driver_info = SERVO_VERSION_30 | SERVO_COUNT_QUAD
47	},
48	{
49		USB_DEVICE(VENDOR_ID_GLAB, DEVICE_ID_GLAB_PHIDGETSERVO_UNI),
50		.driver_info = SERVO_VERSION_30
51	},
52	{
53		USB_DEVICE(VENDOR_ID_WISEGROUP,
54				VENDOR_ID_WISEGROUP_PHIDGETSERVO_QUAD),
55		.driver_info = SERVO_COUNT_QUAD
56	},
57	{
58		USB_DEVICE(VENDOR_ID_WISEGROUP,
59				VENDOR_ID_WISEGROUP_PHIDGETSERVO_UNI),
60		.driver_info = 0
61	},
62	{}
63};
64
65MODULE_DEVICE_TABLE(usb, id_table);
66
67static int unsigned long device_no;
68
69struct phidget_servo {
70	struct usb_device *udev;
71	struct device *dev;
72	int dev_no;
73	ulong type;
74	int pulse[4];
75	int degrees[4];
76	int minutes[4];
77};
78
79static int
80change_position_v30(struct phidget_servo *servo, int servo_no, int degrees,
81								int minutes)
82{
83	int retval;
84	unsigned char *buffer;
85
86	if (degrees < -23 || degrees > 362)
87		return -EINVAL;
88
89	buffer = kmalloc(6, GFP_KERNEL);
90	if (!buffer) {
91		dev_err(&servo->udev->dev, "%s - out of memory\n",
92			__FUNCTION__);
93		return -ENOMEM;
94	}
95
96	/*
97	 * pulse = 0 - 4095
98	 * angle = 0 - 180 degrees
99	 *
100	 * pulse = angle * 10.6 + 243.8
101	 */
102	servo->pulse[servo_no] = ((degrees*60 + minutes)*106 + 2438*60)/600;
103	servo->degrees[servo_no]= degrees;
104	servo->minutes[servo_no]= minutes;
105
106	/*
107	 * The PhidgetServo v3.0 is controlled by sending 6 bytes,
108	 * 4 * 12 bits for each servo.
109	 *
110	 * low = lower 8 bits pulse
111	 * high = higher 4 bits pulse
112	 *
113	 * offset     bits
114	 * +---+-----------------+
115	 * | 0 |      low 0      |
116	 * +---+--------+--------+
117	 * | 1 | high 1 | high 0 |
118	 * +---+--------+--------+
119	 * | 2 |      low 1      |
120	 * +---+-----------------+
121	 * | 3 |      low 2      |
122	 * +---+--------+--------+
123	 * | 4 | high 3 | high 2 |
124	 * +---+--------+--------+
125	 * | 5 |      low 3      |
126	 * +---+-----------------+
127	 */
128
129	buffer[0] = servo->pulse[0] & 0xff;
130	buffer[1] = (servo->pulse[0] >> 8 & 0x0f)
131	    | (servo->pulse[1] >> 4 & 0xf0);
132	buffer[2] = servo->pulse[1] & 0xff;
133	buffer[3] = servo->pulse[2] & 0xff;
134	buffer[4] = (servo->pulse[2] >> 8 & 0x0f)
135	    | (servo->pulse[3] >> 4 & 0xf0);
136	buffer[5] = servo->pulse[3] & 0xff;
137
138	dev_dbg(&servo->udev->dev,
139		"data: %02x %02x %02x %02x %02x %02x\n",
140		buffer[0], buffer[1], buffer[2],
141		buffer[3], buffer[4], buffer[5]);
142
143	retval = usb_control_msg(servo->udev,
144				 usb_sndctrlpipe(servo->udev, 0),
145				 0x09, 0x21, 0x0200, 0x0000, buffer, 6, 2000);
146
147	kfree(buffer);
148
149	return retval;
150}
151
152static int
153change_position_v20(struct phidget_servo *servo, int servo_no, int degrees,
154								int minutes)
155{
156	int retval;
157	unsigned char *buffer;
158
159	if (degrees < -23 || degrees > 278)
160		return -EINVAL;
161
162	buffer = kmalloc(2, GFP_KERNEL);
163	if (!buffer) {
164		dev_err(&servo->udev->dev, "%s - out of memory\n",
165			__FUNCTION__);
166		return -ENOMEM;
167	}
168
169	/*
170	 * angle = 0 - 180 degrees
171	 * pulse = angle + 23
172	 */
173	servo->pulse[servo_no]= degrees + 23;
174	servo->degrees[servo_no]= degrees;
175	servo->minutes[servo_no]= 0;
176
177	/*
178	 * The PhidgetServo v2.0 is controlled by sending two bytes. The
179	 * first byte is the servo number xor'ed with 2:
180	 *
181	 * servo 0 = 2
182	 * servo 1 = 3
183	 * servo 2 = 0
184	 * servo 3 = 1
185	 *
186	 * The second byte is the position.
187	 */
188
189	buffer[0] = servo_no ^ 2;
190	buffer[1] = servo->pulse[servo_no];
191
192	dev_dbg(&servo->udev->dev, "data: %02x %02x\n", buffer[0], buffer[1]);
193
194	retval = usb_control_msg(servo->udev,
195				 usb_sndctrlpipe(servo->udev, 0),
196				 0x09, 0x21, 0x0200, 0x0000, buffer, 2, 2000);
197
198	kfree(buffer);
199
200	return retval;
201}
202
203#define show_set(value)	\
204static ssize_t set_servo##value (struct device *dev, 			\
205					struct device_attribute *attr,	\
206					const char *buf, size_t count)	\
207{									\
208	int degrees, minutes, retval;					\
209	struct phidget_servo *servo = dev_get_drvdata(dev);		\
210									\
211	minutes = 0;							\
212	/* must at least convert degrees */				\
213	if (sscanf(buf, "%d.%d", &degrees, &minutes) < 1) {		\
214		return -EINVAL;						\
215	}								\
216									\
217	if (minutes < 0 || minutes > 59) 				\
218		return -EINVAL;						\
219									\
220	if (servo->type & SERVO_VERSION_30)				\
221		retval = change_position_v30(servo, value, degrees, 	\
222							minutes);	\
223	else 								\
224		retval = change_position_v20(servo, value, degrees, 	\
225							minutes);	\
226									\
227	return retval < 0 ? retval : count;				\
228}									\
229									\
230static ssize_t show_servo##value (struct device *dev,			\
231					struct device_attribute *attr,	\
232					char *buf) 			\
233{									\
234	struct phidget_servo *servo = dev_get_drvdata(dev);		\
235									\
236	return sprintf(buf, "%d.%02d\n", servo->degrees[value],		\
237				servo->minutes[value]);			\
238}
239
240#define servo_attr(value)						\
241	__ATTR(servo##value, S_IWUGO | S_IRUGO,				\
242		show_servo##value, set_servo##value)
243show_set(0);
244show_set(1);
245show_set(2);
246show_set(3);
247
248static struct device_attribute dev_attrs[] = {
249	servo_attr(0), servo_attr(1), servo_attr(2), servo_attr(3)
250};
251
252static int
253servo_probe(struct usb_interface *interface, const struct usb_device_id *id)
254{
255	struct usb_device *udev = interface_to_usbdev(interface);
256	struct phidget_servo *dev;
257	int bit, value, rc;
258	int servo_count, i;
259
260	dev = kzalloc(sizeof (struct phidget_servo), GFP_KERNEL);
261	if (dev == NULL) {
262		dev_err(&interface->dev, "%s - out of memory\n", __FUNCTION__);
263		rc = -ENOMEM;
264		goto out;
265	}
266
267	dev->udev = usb_get_dev(udev);
268	dev->type = id->driver_info;
269	dev->dev_no = -1;
270	usb_set_intfdata(interface, dev);
271
272        do {
273                bit = find_first_zero_bit(&device_no, sizeof(device_no));
274                value = test_and_set_bit(bit, &device_no);
275        } while (value);
276	dev->dev_no = bit;
277
278	dev->dev = device_create(phidget_class, &dev->udev->dev, 0,
279				 "servo%d", dev->dev_no);
280	if (IS_ERR(dev->dev)) {
281		rc = PTR_ERR(dev->dev);
282		dev->dev = NULL;
283		goto out;
284	}
285	dev_set_drvdata(dev->dev, dev);
286
287	servo_count = dev->type & SERVO_COUNT_QUAD ? 4 : 1;
288
289	for (i=0; i<servo_count; i++) {
290		rc = device_create_file(dev->dev, &dev_attrs[i]);
291		if (rc)
292			goto out2;
293	}
294
295	dev_info(&interface->dev, "USB %d-Motor PhidgetServo v%d.0 attached\n",
296		servo_count, dev->type & SERVO_VERSION_30 ? 3 : 2);
297
298	if (!(dev->type & SERVO_VERSION_30))
299		dev_info(&interface->dev,
300			 "WARNING: v2.0 not tested! Please report if it works.\n");
301
302	return 0;
303out2:
304	while (i-- > 0)
305		device_remove_file(dev->dev, &dev_attrs[i]);
306out:
307	if (dev) {
308		if (dev->dev)
309			device_unregister(dev->dev);
310		if (dev->dev_no >= 0)
311			clear_bit(dev->dev_no, &device_no);
312
313		kfree(dev);
314	}
315
316	return rc;
317}
318
319static void
320servo_disconnect(struct usb_interface *interface)
321{
322	struct phidget_servo *dev;
323	int servo_count, i;
324
325	dev = usb_get_intfdata(interface);
326	usb_set_intfdata(interface, NULL);
327
328	if (!dev)
329		return;
330
331	servo_count = dev->type & SERVO_COUNT_QUAD ? 4 : 1;
332
333	for (i=0; i<servo_count; i++)
334		device_remove_file(dev->dev, &dev_attrs[i]);
335
336	device_unregister(dev->dev);
337	usb_put_dev(dev->udev);
338
339	dev_info(&interface->dev, "USB %d-Motor PhidgetServo v%d.0 detached\n",
340		servo_count, dev->type & SERVO_VERSION_30 ? 3 : 2);
341
342	clear_bit(dev->dev_no, &device_no);
343	kfree(dev);
344}
345
346static struct usb_driver servo_driver = {
347	.name = "phidgetservo",
348	.probe = servo_probe,
349	.disconnect = servo_disconnect,
350	.id_table = id_table
351};
352
353static int __init
354phidget_servo_init(void)
355{
356	int retval;
357
358	retval = usb_register(&servo_driver);
359	if (retval)
360		err("usb_register failed. Error number %d", retval);
361
362	return retval;
363}
364
365static void __exit
366phidget_servo_exit(void)
367{
368	usb_deregister(&servo_driver);
369}
370
371module_init(phidget_servo_init);
372module_exit(phidget_servo_exit);
373
374MODULE_AUTHOR(DRIVER_AUTHOR);
375MODULE_DESCRIPTION(DRIVER_DESC);
376MODULE_LICENSE("GPL");
377