tjh.dev
Linux kernel mirror (for testing)
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linux
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
25static const struct usb_device_id id_table[] = {
26 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
27 { }
28};
29MODULE_DEVICE_TABLE (usb, id_table);
30
31/* Structure to hold all of our device specific stuff */
32struct 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/* local function prototypes */
40static int cytherm_probe(struct usb_interface *interface,
41 const struct usb_device_id *id);
42static void cytherm_disconnect(struct usb_interface *interface);
43
44
45/* usb specific object needed to register this driver with the usb subsystem */
46static struct usb_driver cytherm_driver = {
47 .name = "cytherm",
48 .probe = cytherm_probe,
49 .disconnect = cytherm_disconnect,
50 .id_table = id_table,
51};
52
53/* Vendor requests */
54/* They all operate on one byte at a time */
55#define PING 0x00
56#define READ_ROM 0x01 /* Reads form ROM, value = address */
57#define READ_RAM 0x02 /* Reads form RAM, value = address */
58#define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */
59#define READ_PORT 0x04 /* Reads from port, value = address */
60#define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
61
62
63/* Send a vendor command to device */
64static int vendor_command(struct usb_device *dev, unsigned char request,
65 unsigned char value, unsigned char index,
66 void *buf, int size)
67{
68 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
69 request,
70 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
71 value,
72 index, buf, size,
73 USB_CTRL_GET_TIMEOUT);
74}
75
76
77
78#define BRIGHTNESS 0x2c /* RAM location for brightness value */
79#define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
80
81static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf)
82{
83 struct usb_interface *intf = to_usb_interface(dev);
84 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
85
86 return sprintf(buf, "%i", cytherm->brightness);
87}
88
89static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf,
90 size_t count)
91{
92 struct usb_interface *intf = to_usb_interface(dev);
93 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
94
95 unsigned char *buffer;
96 int retval;
97
98 buffer = kmalloc(8, GFP_KERNEL);
99 if (!buffer)
100 return 0;
101
102 cytherm->brightness = simple_strtoul(buf, NULL, 10);
103
104 if (cytherm->brightness > 0xFF)
105 cytherm->brightness = 0xFF;
106 else if (cytherm->brightness < 0)
107 cytherm->brightness = 0;
108
109 /* Set brightness */
110 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
111 cytherm->brightness, buffer, 8);
112 if (retval)
113 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
114 /* Inform µC that we have changed the brightness setting */
115 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
116 0x01, buffer, 8);
117 if (retval)
118 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
119
120 kfree(buffer);
121
122 return count;
123}
124static DEVICE_ATTR_RW(brightness);
125
126
127#define TEMP 0x33 /* RAM location for temperature */
128#define SIGN 0x34 /* RAM location for temperature sign */
129
130static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf)
131{
132
133 struct usb_interface *intf = to_usb_interface(dev);
134 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
135
136 int retval;
137 unsigned char *buffer;
138
139 int temp, sign;
140
141 buffer = kmalloc(8, GFP_KERNEL);
142 if (!buffer)
143 return 0;
144
145 /* read temperature */
146 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
147 if (retval)
148 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
149 temp = buffer[1];
150
151 /* read sign */
152 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
153 if (retval)
154 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
155 sign = buffer[1];
156
157 kfree(buffer);
158
159 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
160 5*(temp - ((temp >> 1) << 1)));
161}
162static DEVICE_ATTR_RO(temp);
163
164
165#define BUTTON 0x7a
166
167static ssize_t button_show(struct device *dev, struct device_attribute *attr, char *buf)
168{
169
170 struct usb_interface *intf = to_usb_interface(dev);
171 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
172
173 int retval;
174 unsigned char *buffer;
175
176 buffer = kmalloc(8, GFP_KERNEL);
177 if (!buffer)
178 return 0;
179
180 /* check button */
181 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
182 if (retval)
183 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
184
185 retval = buffer[1];
186
187 kfree(buffer);
188
189 if (retval)
190 return sprintf(buf, "1");
191 else
192 return sprintf(buf, "0");
193}
194static DEVICE_ATTR_RO(button);
195
196
197static ssize_t port0_show(struct device *dev, struct device_attribute *attr, char *buf)
198{
199 struct usb_interface *intf = to_usb_interface(dev);
200 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
201
202 int retval;
203 unsigned char *buffer;
204
205 buffer = kmalloc(8, GFP_KERNEL);
206 if (!buffer)
207 return 0;
208
209 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
210 if (retval)
211 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
212
213 retval = buffer[1];
214
215 kfree(buffer);
216
217 return sprintf(buf, "%d", retval);
218}
219
220
221static ssize_t port0_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
222{
223 struct usb_interface *intf = to_usb_interface(dev);
224 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
225
226 unsigned char *buffer;
227 int retval;
228 int tmp;
229
230 buffer = kmalloc(8, GFP_KERNEL);
231 if (!buffer)
232 return 0;
233
234 tmp = simple_strtoul(buf, NULL, 10);
235
236 if (tmp > 0xFF)
237 tmp = 0xFF;
238 else if (tmp < 0)
239 tmp = 0;
240
241 retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
242 tmp, buffer, 8);
243 if (retval)
244 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
245
246 kfree(buffer);
247
248 return count;
249}
250static DEVICE_ATTR_RW(port0);
251
252static ssize_t port1_show(struct device *dev, struct device_attribute *attr, char *buf)
253{
254 struct usb_interface *intf = to_usb_interface(dev);
255 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
256
257 int retval;
258 unsigned char *buffer;
259
260 buffer = kmalloc(8, GFP_KERNEL);
261 if (!buffer)
262 return 0;
263
264 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
265 if (retval)
266 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
267
268 retval = buffer[1];
269
270 kfree(buffer);
271
272 return sprintf(buf, "%d", retval);
273}
274
275
276static ssize_t port1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
277{
278 struct usb_interface *intf = to_usb_interface(dev);
279 struct usb_cytherm *cytherm = usb_get_intfdata(intf);
280
281 unsigned char *buffer;
282 int retval;
283 int tmp;
284
285 buffer = kmalloc(8, GFP_KERNEL);
286 if (!buffer)
287 return 0;
288
289 tmp = simple_strtoul(buf, NULL, 10);
290
291 if (tmp > 0xFF)
292 tmp = 0xFF;
293 else if (tmp < 0)
294 tmp = 0;
295
296 retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
297 tmp, buffer, 8);
298 if (retval)
299 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
300
301 kfree(buffer);
302
303 return count;
304}
305static DEVICE_ATTR_RW(port1);
306
307
308static int cytherm_probe(struct usb_interface *interface,
309 const struct usb_device_id *id)
310{
311 struct usb_device *udev = interface_to_usbdev(interface);
312 struct usb_cytherm *dev = NULL;
313 int retval = -ENOMEM;
314
315 dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
316 if (!dev)
317 goto error_mem;
318
319 dev->udev = usb_get_dev(udev);
320
321 usb_set_intfdata (interface, dev);
322
323 dev->brightness = 0xFF;
324
325 retval = device_create_file(&interface->dev, &dev_attr_brightness);
326 if (retval)
327 goto error;
328 retval = device_create_file(&interface->dev, &dev_attr_temp);
329 if (retval)
330 goto error;
331 retval = device_create_file(&interface->dev, &dev_attr_button);
332 if (retval)
333 goto error;
334 retval = device_create_file(&interface->dev, &dev_attr_port0);
335 if (retval)
336 goto error;
337 retval = device_create_file(&interface->dev, &dev_attr_port1);
338 if (retval)
339 goto error;
340
341 dev_info (&interface->dev,
342 "Cypress thermometer device now attached\n");
343 return 0;
344error:
345 device_remove_file(&interface->dev, &dev_attr_brightness);
346 device_remove_file(&interface->dev, &dev_attr_temp);
347 device_remove_file(&interface->dev, &dev_attr_button);
348 device_remove_file(&interface->dev, &dev_attr_port0);
349 device_remove_file(&interface->dev, &dev_attr_port1);
350 usb_set_intfdata (interface, NULL);
351 usb_put_dev(dev->udev);
352 kfree(dev);
353error_mem:
354 return retval;
355}
356
357static void cytherm_disconnect(struct usb_interface *interface)
358{
359 struct usb_cytherm *dev;
360
361 dev = usb_get_intfdata (interface);
362
363 device_remove_file(&interface->dev, &dev_attr_brightness);
364 device_remove_file(&interface->dev, &dev_attr_temp);
365 device_remove_file(&interface->dev, &dev_attr_button);
366 device_remove_file(&interface->dev, &dev_attr_port0);
367 device_remove_file(&interface->dev, &dev_attr_port1);
368
369 /* first remove the files, then NULL the pointer */
370 usb_set_intfdata (interface, NULL);
371
372 usb_put_dev(dev->udev);
373
374 kfree(dev);
375
376 dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
377}
378
379module_usb_driver(cytherm_driver);
380
381MODULE_AUTHOR(DRIVER_AUTHOR);
382MODULE_DESCRIPTION(DRIVER_DESC);
383MODULE_LICENSE("GPL");