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/* 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 */
50static 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, data: 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
67static 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, fmt: "%i", cytherm->brightness);
73}
74
75static 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(size: 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(dev: cytherm->udev, WRITE_RAM, BRIGHTNESS,
97 index: cytherm->brightness, buf: buffer, size: 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(dev: cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
102 index: 0x01, buf: buffer, size: 8);
103 if (retval)
104 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
105
106 kfree(objp: buffer);
107
108 return count;
109}
110static DEVICE_ATTR_RW(brightness);
111
112
113#define TEMP 0x33 /* RAM location for temperature */
114#define SIGN 0x34 /* RAM location for temperature sign */
115
116static 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(size: 8, GFP_KERNEL);
128 if (!buffer)
129 return 0;
130
131 /* read temperature */
132 retval = vendor_command(dev: cytherm->udev, READ_RAM, TEMP, index: 0, buf: buffer, size: 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(dev: cytherm->udev, READ_RAM, SIGN, index: 0, buf: buffer, size: 8);
139 if (retval)
140 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
141 sign = buffer[1];
142
143 kfree(objp: buffer);
144
145 return sprintf(buf, fmt: "%c%i.%i", sign ? '-' : '+', temp >> 1,
146 5*(temp - ((temp >> 1) << 1)));
147}
148static DEVICE_ATTR_RO(temp);
149
150
151#define BUTTON 0x7a
152
153static 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(size: 8, GFP_KERNEL);
163 if (!buffer)
164 return 0;
165
166 /* check button */
167 retval = vendor_command(dev: cytherm->udev, READ_RAM, BUTTON, index: 0, buf: buffer, size: 8);
168 if (retval)
169 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
170
171 retval = buffer[1];
172
173 kfree(objp: buffer);
174
175 if (retval)
176 return sprintf(buf, fmt: "1");
177 else
178 return sprintf(buf, fmt: "0");
179}
180static DEVICE_ATTR_RO(button);
181
182
183static 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(size: 8, GFP_KERNEL);
192 if (!buffer)
193 return 0;
194
195 retval = vendor_command(dev: cytherm->udev, READ_PORT, value: 0, index: 0, buf: buffer, size: 8);
196 if (retval)
197 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
198
199 retval = buffer[1];
200
201 kfree(objp: buffer);
202
203 return sprintf(buf, fmt: "%d", retval);
204}
205
206
207static 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(size: 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(dev: cytherm->udev, WRITE_PORT, value: 0,
228 index: tmp, buf: buffer, size: 8);
229 if (retval)
230 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
231
232 kfree(objp: buffer);
233
234 return count;
235}
236static DEVICE_ATTR_RW(port0);
237
238static 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(size: 8, GFP_KERNEL);
247 if (!buffer)
248 return 0;
249
250 retval = vendor_command(dev: cytherm->udev, READ_PORT, value: 1, index: 0, buf: buffer, size: 8);
251 if (retval)
252 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
253
254 retval = buffer[1];
255
256 kfree(objp: buffer);
257
258 return sprintf(buf, fmt: "%d", retval);
259}
260
261
262static 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(size: 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(dev: cytherm->udev, WRITE_PORT, value: 1,
283 index: tmp, buf: buffer, size: 8);
284 if (retval)
285 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
286
287 kfree(objp: buffer);
288
289 return count;
290}
291static DEVICE_ATTR_RW(port1);
292
293static 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};
301ATTRIBUTE_GROUPS(cytherm);
302
303static 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(size: sizeof(struct usb_cytherm), GFP_KERNEL);
311 if (!dev)
312 goto error_mem;
313
314 dev->udev = usb_get_dev(dev: udev);
315
316 usb_set_intfdata(intf: interface, data: dev);
317
318 dev->brightness = 0xFF;
319
320 dev_info(&interface->dev,
321 "Cypress thermometer device now attached\n");
322 return 0;
323
324error_mem:
325 return retval;
326}
327
328static void cytherm_disconnect(struct usb_interface *interface)
329{
330 struct usb_cytherm *dev;
331
332 dev = usb_get_intfdata(intf: interface);
333
334 /* first remove the files, then NULL the pointer */
335 usb_set_intfdata(intf: interface, NULL);
336
337 usb_put_dev(dev: dev->udev);
338
339 kfree(objp: 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 */
345static 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
353module_usb_driver(cytherm_driver);
354
355MODULE_AUTHOR(DRIVER_AUTHOR);
356MODULE_DESCRIPTION(DRIVER_DESC);
357MODULE_LICENSE("GPL");
358

source code of linux/drivers/usb/misc/cytherm.c