1 // SPDX-License-Identifier: GPL-2.0
2 /* -*- linux-c -*-
3 * Cypress USB Thermometer driver
4 *
5 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com>
6 *
7 * This driver works with Elektor magazine USB Interface as published in
8 * issue #291. It should also work with the original starter kit/demo board
9 * from Cypress.
10 */
11
12
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/usb.h>
18
19 #define DRIVER_AUTHOR "Erik Rigtorp"
20 #define DRIVER_DESC "Cypress USB Thermometer driver"
21
22 #define USB_SKEL_VENDOR_ID 0x04b4
23 #define USB_SKEL_PRODUCT_ID 0x0002
24
25 static const struct usb_device_id id_table[] = {
26 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
27 { }
28 };
29 MODULE_DEVICE_TABLE (usb, id_table);
30
31 /* Structure to hold all of our device specific stuff */
32 struct usb_cytherm {
33 struct usb_device *udev; /* save off the usb device pointer */
34 struct usb_interface *interface; /* the interface for this device */
35 int brightness;
36 };
37
38
39 /* Vendor requests */
40 /* They all operate on one byte at a time */
41 #define PING 0x00
42 #define READ_ROM 0x01 /* Reads form ROM, value = address */
43 #define READ_RAM 0x02 /* Reads form RAM, value = address */
44 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */
45 #define READ_PORT 0x04 /* Reads from port, value = address */
46 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
47
48
49 /* 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)50 static int vendor_command(struct usb_device *dev, unsigned char request,
51 unsigned char value, unsigned char index,
52 void *buf, int size)
53 {
54 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
55 request,
56 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
57 value,
58 index, buf, size,
59 USB_CTRL_GET_TIMEOUT);
60 }
61
62
63
64 #define BRIGHTNESS 0x2c /* RAM location for brightness value */
65 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
66
brightness_show(struct device * dev,struct device_attribute * attr,char * buf)67 static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf)
68 {
69 struct usb_interface *intf = to_usb_interface(dev);
70 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
71
72 return sprintf(buf, "%i", cytherm->brightness);
73 }
74
brightness_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)75 static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf,
76 size_t count)
77 {
78 struct usb_interface *intf = to_usb_interface(dev);
79 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
80
81 unsigned char *buffer;
82 int retval;
83
84 buffer = kmalloc(8, GFP_KERNEL);
85 if (!buffer)
86 return 0;
87
88 cytherm->brightness = simple_strtoul(buf, NULL, 10);
89
90 if (cytherm->brightness > 0xFF)
91 cytherm->brightness = 0xFF;
92 else if (cytherm->brightness < 0)
93 cytherm->brightness = 0;
94
95 /* Set brightness */
96 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
97 cytherm->brightness, buffer, 8);
98 if (retval)
99 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
100 /* Inform µC that we have changed the brightness setting */
101 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
102 0x01, buffer, 8);
103 if (retval)
104 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
105
106 kfree(buffer);
107
108 return count;
109 }
110 static DEVICE_ATTR_RW(brightness);
111
112
113 #define TEMP 0x33 /* RAM location for temperature */
114 #define SIGN 0x34 /* RAM location for temperature sign */
115
temp_show(struct device * dev,struct device_attribute * attr,char * buf)116 static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf)
117 {
118
119 struct usb_interface *intf = to_usb_interface(dev);
120 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
121
122 int retval;
123 unsigned char *buffer;
124
125 int temp, sign;
126
127 buffer = kmalloc(8, GFP_KERNEL);
128 if (!buffer)
129 return 0;
130
131 /* read temperature */
132 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
133 if (retval)
134 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
135 temp = buffer[1];
136
137 /* read sign */
138 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
139 if (retval)
140 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
141 sign = buffer[1];
142
143 kfree(buffer);
144
145 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
146 5*(temp - ((temp >> 1) << 1)));
147 }
148 static DEVICE_ATTR_RO(temp);
149
150
151 #define BUTTON 0x7a
152
button_show(struct device * dev,struct device_attribute * attr,char * buf)153 static ssize_t button_show(struct device *dev, struct device_attribute *attr, char *buf)
154 {
155
156 struct usb_interface *intf = to_usb_interface(dev);
157 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
158
159 int retval;
160 unsigned char *buffer;
161
162 buffer = kmalloc(8, GFP_KERNEL);
163 if (!buffer)
164 return 0;
165
166 /* check button */
167 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
168 if (retval)
169 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
170
171 retval = buffer[1];
172
173 kfree(buffer);
174
175 if (retval)
176 return sprintf(buf, "1");
177 else
178 return sprintf(buf, "0");
179 }
180 static DEVICE_ATTR_RO(button);
181
182
port0_show(struct device * dev,struct device_attribute * attr,char * buf)183 static ssize_t port0_show(struct device *dev, struct device_attribute *attr, char *buf)
184 {
185 struct usb_interface *intf = to_usb_interface(dev);
186 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
187
188 int retval;
189 unsigned char *buffer;
190
191 buffer = kmalloc(8, GFP_KERNEL);
192 if (!buffer)
193 return 0;
194
195 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
196 if (retval)
197 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
198
199 retval = buffer[1];
200
201 kfree(buffer);
202
203 return sprintf(buf, "%d", retval);
204 }
205
206
port0_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)207 static ssize_t port0_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
208 {
209 struct usb_interface *intf = to_usb_interface(dev);
210 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
211
212 unsigned char *buffer;
213 int retval;
214 int tmp;
215
216 buffer = kmalloc(8, GFP_KERNEL);
217 if (!buffer)
218 return 0;
219
220 tmp = simple_strtoul(buf, NULL, 10);
221
222 if (tmp > 0xFF)
223 tmp = 0xFF;
224 else if (tmp < 0)
225 tmp = 0;
226
227 retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
228 tmp, buffer, 8);
229 if (retval)
230 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
231
232 kfree(buffer);
233
234 return count;
235 }
236 static DEVICE_ATTR_RW(port0);
237
port1_show(struct device * dev,struct device_attribute * attr,char * buf)238 static ssize_t port1_show(struct device *dev, struct device_attribute *attr, char *buf)
239 {
240 struct usb_interface *intf = to_usb_interface(dev);
241 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
242
243 int retval;
244 unsigned char *buffer;
245
246 buffer = kmalloc(8, GFP_KERNEL);
247 if (!buffer)
248 return 0;
249
250 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
251 if (retval)
252 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
253
254 retval = buffer[1];
255
256 kfree(buffer);
257
258 return sprintf(buf, "%d", retval);
259 }
260
261
port1_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)262 static ssize_t port1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
263 {
264 struct usb_interface *intf = to_usb_interface(dev);
265 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
266
267 unsigned char *buffer;
268 int retval;
269 int tmp;
270
271 buffer = kmalloc(8, GFP_KERNEL);
272 if (!buffer)
273 return 0;
274
275 tmp = simple_strtoul(buf, NULL, 10);
276
277 if (tmp > 0xFF)
278 tmp = 0xFF;
279 else if (tmp < 0)
280 tmp = 0;
281
282 retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
283 tmp, buffer, 8);
284 if (retval)
285 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
286
287 kfree(buffer);
288
289 return count;
290 }
291 static DEVICE_ATTR_RW(port1);
292
293 static struct attribute *cytherm_attrs[] = {
294 &dev_attr_brightness.attr,
295 &dev_attr_temp.attr,
296 &dev_attr_button.attr,
297 &dev_attr_port0.attr,
298 &dev_attr_port1.attr,
299 NULL,
300 };
301 ATTRIBUTE_GROUPS(cytherm);
302
cytherm_probe(struct usb_interface * interface,const struct usb_device_id * id)303 static int cytherm_probe(struct usb_interface *interface,
304 const struct usb_device_id *id)
305 {
306 struct usb_device *udev = interface_to_usbdev(interface);
307 struct usb_cytherm *dev;
308 int retval = -ENOMEM;
309
310 dev = kzalloc(sizeof(struct usb_cytherm), GFP_KERNEL);
311 if (!dev)
312 goto error_mem;
313
314 dev->udev = usb_get_dev(udev);
315
316 usb_set_intfdata(interface, dev);
317
318 dev->brightness = 0xFF;
319
320 dev_info(&interface->dev,
321 "Cypress thermometer device now attached\n");
322 return 0;
323
324 error_mem:
325 return retval;
326 }
327
cytherm_disconnect(struct usb_interface * interface)328 static void cytherm_disconnect(struct usb_interface *interface)
329 {
330 struct usb_cytherm *dev;
331
332 dev = usb_get_intfdata(interface);
333
334 /* first remove the files, then NULL the pointer */
335 usb_set_intfdata(interface, NULL);
336
337 usb_put_dev(dev->udev);
338
339 kfree(dev);
340
341 dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
342 }
343
344 /* usb specific object needed to register this driver with the usb subsystem */
345 static struct usb_driver cytherm_driver = {
346 .name = "cytherm",
347 .probe = cytherm_probe,
348 .disconnect = cytherm_disconnect,
349 .id_table = id_table,
350 .dev_groups = cytherm_groups,
351 };
352
353 module_usb_driver(cytherm_driver);
354
355 MODULE_AUTHOR(DRIVER_AUTHOR);
356 MODULE_DESCRIPTION(DRIVER_DESC);
357 MODULE_LICENSE("GPL");
358