xref: /openbmc/linux/drivers/usb/misc/cytherm.c (revision f87ba66a)
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