1 /* -*- linux-c -*-
2 * Cypress USB Thermometer driver
3 *
4 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com>
5 *
6 * This driver works with Elektor magazine USB Interface as published in
7 * issue #291. It should also work with the original starter kit/demo board
8 * from Cypress.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation, version 2.
13 *
14 */
15
16
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/usb.h>
22
23 #define DRIVER_AUTHOR "Erik Rigtorp"
24 #define DRIVER_DESC "Cypress USB Thermometer driver"
25
26 #define USB_SKEL_VENDOR_ID 0x04b4
27 #define USB_SKEL_PRODUCT_ID 0x0002
28
29 static const struct usb_device_id id_table[] = {
30 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
31 { }
32 };
33 MODULE_DEVICE_TABLE (usb, id_table);
34
35 /* Structure to hold all of our device specific stuff */
36 struct usb_cytherm {
37 struct usb_device *udev; /* save off the usb device pointer */
38 struct usb_interface *interface; /* the interface for this device */
39 int brightness;
40 };
41
42
43 /* local function prototypes */
44 static int cytherm_probe(struct usb_interface *interface,
45 const struct usb_device_id *id);
46 static void cytherm_disconnect(struct usb_interface *interface);
47
48
49 /* usb specific object needed to register this driver with the usb subsystem */
50 static struct usb_driver cytherm_driver = {
51 .name = "cytherm",
52 .probe = cytherm_probe,
53 .disconnect = cytherm_disconnect,
54 .id_table = id_table,
55 };
56
57 /* Vendor requests */
58 /* They all operate on one byte at a time */
59 #define PING 0x00
60 #define READ_ROM 0x01 /* Reads form ROM, value = address */
61 #define READ_RAM 0x02 /* Reads form RAM, value = address */
62 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */
63 #define READ_PORT 0x04 /* Reads from port, value = address */
64 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
65
66
67 /* Send a vendor command to device */
vendor_command(struct usb_device * dev,unsigned char request,unsigned char value,unsigned char index,void * buf,int size)68 static int vendor_command(struct usb_device *dev, unsigned char request,
69 unsigned char value, unsigned char index,
70 void *buf, int size)
71 {
72 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
73 request,
74 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
75 value,
76 index, buf, size,
77 USB_CTRL_GET_TIMEOUT);
78 }
79
80
81
82 #define BRIGHTNESS 0x2c /* RAM location for brightness value */
83 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
84
show_brightness(struct device * dev,struct device_attribute * attr,char * buf)85 static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf)
86 {
87 struct usb_interface *intf = to_usb_interface(dev);
88 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
89
90 return sprintf(buf, "%i", cytherm->brightness);
91 }
92
set_brightness(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)93 static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf,
94 size_t count)
95 {
96 struct usb_interface *intf = to_usb_interface(dev);
97 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
98
99 unsigned char *buffer;
100 int retval;
101
102 buffer = kmalloc(8, GFP_KERNEL);
103 if (!buffer)
104 return 0;
105
106 cytherm->brightness = simple_strtoul(buf, NULL, 10);
107
108 if (cytherm->brightness > 0xFF)
109 cytherm->brightness = 0xFF;
110 else if (cytherm->brightness < 0)
111 cytherm->brightness = 0;
112
113 /* Set brightness */
114 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
115 cytherm->brightness, buffer, 8);
116 if (retval)
117 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
118 /* Inform µC that we have changed the brightness setting */
119 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
120 0x01, buffer, 8);
121 if (retval)
122 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
123
124 kfree(buffer);
125
126 return count;
127 }
128
129 static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP,
130 show_brightness, set_brightness);
131
132
133 #define TEMP 0x33 /* RAM location for temperature */
134 #define SIGN 0x34 /* RAM location for temperature sign */
135
show_temp(struct device * dev,struct device_attribute * attr,char * buf)136 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf)
137 {
138
139 struct usb_interface *intf = to_usb_interface(dev);
140 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
141
142 int retval;
143 unsigned char *buffer;
144
145 int temp, sign;
146
147 buffer = kmalloc(8, GFP_KERNEL);
148 if (!buffer)
149 return 0;
150
151 /* read temperature */
152 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
153 if (retval)
154 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
155 temp = buffer[1];
156
157 /* read sign */
158 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
159 if (retval)
160 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
161 sign = buffer[1];
162
163 kfree(buffer);
164
165 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
166 5*(temp - ((temp >> 1) << 1)));
167 }
168
169
set_temp(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)170 static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
171 {
172 return count;
173 }
174
175 static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp);
176
177
178 #define BUTTON 0x7a
179
show_button(struct device * dev,struct device_attribute * attr,char * buf)180 static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf)
181 {
182
183 struct usb_interface *intf = to_usb_interface(dev);
184 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
185
186 int retval;
187 unsigned char *buffer;
188
189 buffer = kmalloc(8, GFP_KERNEL);
190 if (!buffer)
191 return 0;
192
193 /* check button */
194 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
195 if (retval)
196 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
197
198 retval = buffer[1];
199
200 kfree(buffer);
201
202 if (retval)
203 return sprintf(buf, "1");
204 else
205 return sprintf(buf, "0");
206 }
207
208
set_button(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)209 static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
210 {
211 return count;
212 }
213
214 static DEVICE_ATTR(button, S_IRUGO, show_button, set_button);
215
216
show_port0(struct device * dev,struct device_attribute * attr,char * buf)217 static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf)
218 {
219 struct usb_interface *intf = to_usb_interface(dev);
220 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
221
222 int retval;
223 unsigned char *buffer;
224
225 buffer = kmalloc(8, GFP_KERNEL);
226 if (!buffer)
227 return 0;
228
229 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
230 if (retval)
231 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
232
233 retval = buffer[1];
234
235 kfree(buffer);
236
237 return sprintf(buf, "%d", retval);
238 }
239
240
set_port0(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)241 static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
242 {
243 struct usb_interface *intf = to_usb_interface(dev);
244 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
245
246 unsigned char *buffer;
247 int retval;
248 int tmp;
249
250 buffer = kmalloc(8, GFP_KERNEL);
251 if (!buffer)
252 return 0;
253
254 tmp = simple_strtoul(buf, NULL, 10);
255
256 if (tmp > 0xFF)
257 tmp = 0xFF;
258 else if (tmp < 0)
259 tmp = 0;
260
261 retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
262 tmp, buffer, 8);
263 if (retval)
264 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
265
266 kfree(buffer);
267
268 return count;
269 }
270
271 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0);
272
show_port1(struct device * dev,struct device_attribute * attr,char * buf)273 static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf)
274 {
275 struct usb_interface *intf = to_usb_interface(dev);
276 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
277
278 int retval;
279 unsigned char *buffer;
280
281 buffer = kmalloc(8, GFP_KERNEL);
282 if (!buffer)
283 return 0;
284
285 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
286 if (retval)
287 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
288
289 retval = buffer[1];
290
291 kfree(buffer);
292
293 return sprintf(buf, "%d", retval);
294 }
295
296
set_port1(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)297 static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
298 {
299 struct usb_interface *intf = to_usb_interface(dev);
300 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
301
302 unsigned char *buffer;
303 int retval;
304 int tmp;
305
306 buffer = kmalloc(8, GFP_KERNEL);
307 if (!buffer)
308 return 0;
309
310 tmp = simple_strtoul(buf, NULL, 10);
311
312 if (tmp > 0xFF)
313 tmp = 0xFF;
314 else if (tmp < 0)
315 tmp = 0;
316
317 retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
318 tmp, buffer, 8);
319 if (retval)
320 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
321
322 kfree(buffer);
323
324 return count;
325 }
326
327 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1);
328
329
330
cytherm_probe(struct usb_interface * interface,const struct usb_device_id * id)331 static int cytherm_probe(struct usb_interface *interface,
332 const struct usb_device_id *id)
333 {
334 struct usb_device *udev = interface_to_usbdev(interface);
335 struct usb_cytherm *dev = NULL;
336 int retval = -ENOMEM;
337
338 dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
339 if (!dev)
340 goto error_mem;
341
342 dev->udev = usb_get_dev(udev);
343
344 usb_set_intfdata (interface, dev);
345
346 dev->brightness = 0xFF;
347
348 retval = device_create_file(&interface->dev, &dev_attr_brightness);
349 if (retval)
350 goto error;
351 retval = device_create_file(&interface->dev, &dev_attr_temp);
352 if (retval)
353 goto error;
354 retval = device_create_file(&interface->dev, &dev_attr_button);
355 if (retval)
356 goto error;
357 retval = device_create_file(&interface->dev, &dev_attr_port0);
358 if (retval)
359 goto error;
360 retval = device_create_file(&interface->dev, &dev_attr_port1);
361 if (retval)
362 goto error;
363
364 dev_info (&interface->dev,
365 "Cypress thermometer device now attached\n");
366 return 0;
367 error:
368 device_remove_file(&interface->dev, &dev_attr_brightness);
369 device_remove_file(&interface->dev, &dev_attr_temp);
370 device_remove_file(&interface->dev, &dev_attr_button);
371 device_remove_file(&interface->dev, &dev_attr_port0);
372 device_remove_file(&interface->dev, &dev_attr_port1);
373 usb_set_intfdata (interface, NULL);
374 usb_put_dev(dev->udev);
375 kfree(dev);
376 error_mem:
377 return retval;
378 }
379
cytherm_disconnect(struct usb_interface * interface)380 static void cytherm_disconnect(struct usb_interface *interface)
381 {
382 struct usb_cytherm *dev;
383
384 dev = usb_get_intfdata (interface);
385
386 device_remove_file(&interface->dev, &dev_attr_brightness);
387 device_remove_file(&interface->dev, &dev_attr_temp);
388 device_remove_file(&interface->dev, &dev_attr_button);
389 device_remove_file(&interface->dev, &dev_attr_port0);
390 device_remove_file(&interface->dev, &dev_attr_port1);
391
392 /* first remove the files, then NULL the pointer */
393 usb_set_intfdata (interface, NULL);
394
395 usb_put_dev(dev->udev);
396
397 kfree(dev);
398
399 dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
400 }
401
402 module_usb_driver(cytherm_driver);
403
404 MODULE_AUTHOR(DRIVER_AUTHOR);
405 MODULE_DESCRIPTION(DRIVER_DESC);
406 MODULE_LICENSE("GPL");
407