1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
|
/* -*- linux-c -*-
* Cypress USB Thermometer driver
*
* Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com>
*
* This driver works with Elektor magazine USB Interface as published in
* issue #291. It should also work with the original starter kit/demo board
* from Cypress.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2.
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#define DRIVER_VERSION "v1.0"
#define DRIVER_AUTHOR "Erik Rigtorp"
#define DRIVER_DESC "Cypress USB Thermometer driver"
#define USB_SKEL_VENDOR_ID 0x04b4
#define USB_SKEL_PRODUCT_ID 0x0002
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
{ }
};
MODULE_DEVICE_TABLE (usb, id_table);
/* Structure to hold all of our device specific stuff */
struct usb_cytherm {
struct usb_device *udev; /* save off the usb device pointer */
struct usb_interface *interface; /* the interface for this device */
int brightness;
};
/* local function prototypes */
static int cytherm_probe(struct usb_interface *interface,
const struct usb_device_id *id);
static void cytherm_disconnect(struct usb_interface *interface);
/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver cytherm_driver = {
.name = "cytherm",
.probe = cytherm_probe,
.disconnect = cytherm_disconnect,
.id_table = id_table,
};
/* Vendor requests */
/* They all operate on one byte at a time */
#define PING 0x00
#define READ_ROM 0x01 /* Reads form ROM, value = address */
#define READ_RAM 0x02 /* Reads form RAM, value = address */
#define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */
#define READ_PORT 0x04 /* Reads from port, value = address */
#define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
/* Send a vendor command to device */
static int vendor_command(struct usb_device *dev, unsigned char request,
unsigned char value, unsigned char index,
void *buf, int size)
{
return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
request,
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
value,
index, buf, size,
USB_CTRL_GET_TIMEOUT);
}
#define BRIGHTNESS 0x2c /* RAM location for brightness value */
#define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_cytherm *cytherm = usb_get_intfdata(intf);
return sprintf(buf, "%i", cytherm->brightness);
}
static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf,
size_t count)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_cytherm *cytherm = usb_get_intfdata(intf);
unsigned char *buffer;
int retval;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer) {
dev_err(&cytherm->udev->dev, "out of memory\n");
return 0;
}
cytherm->brightness = simple_strtoul(buf, NULL, 10);
if (cytherm->brightness > 0xFF)
cytherm->brightness = 0xFF;
else if (cytherm->brightness < 0)
cytherm->brightness = 0;
/* Set brightness */
retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
cytherm->brightness, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
/* Inform µC that we have changed the brightness setting */
retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
0x01, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
kfree(buffer);
return count;
}
static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP,
show_brightness, set_brightness);
#define TEMP 0x33 /* RAM location for temperature */
#define SIGN 0x34 /* RAM location for temperature sign */
static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_cytherm *cytherm = usb_get_intfdata(intf);
int retval;
unsigned char *buffer;
int temp, sign;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer) {
dev_err(&cytherm->udev->dev, "out of memory\n");
return 0;
}
/* read temperature */
retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
temp = buffer[1];
/* read sign */
retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
sign = buffer[1];
kfree(buffer);
return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
5*(temp - ((temp >> 1) << 1)));
}
static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
return count;
}
static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp);
#define BUTTON 0x7a
static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_cytherm *cytherm = usb_get_intfdata(intf);
int retval;
unsigned char *buffer;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer) {
dev_err(&cytherm->udev->dev, "out of memory\n");
return 0;
}
/* check button */
retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
retval = buffer[1];
kfree(buffer);
if (retval)
return sprintf(buf, "1");
else
return sprintf(buf, "0");
}
static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
return count;
}
static DEVICE_ATTR(button, S_IRUGO, show_button, set_button);
static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_cytherm *cytherm = usb_get_intfdata(intf);
int retval;
unsigned char *buffer;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer) {
dev_err(&cytherm->udev->dev, "out of memory\n");
return 0;
}
retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
if (retval)
dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
retval = buffer[1];
k
|