xref: /openbmc/linux/drivers/usb/misc/usbsevseg.c (revision ecba1060)
1 /*
2  * USB 7 Segment Driver
3  *
4  * Copyright (C) 2008 Harrison Metzger <harrisonmetz@gmail.com>
5  * Based on usbled.c by Greg Kroah-Hartman (greg@kroah.com)
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License as
9  *	published by the Free Software Foundation, version 2.
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/string.h>
19 #include <linux/usb.h>
20 
21 
22 #define DRIVER_AUTHOR "Harrison Metzger <harrisonmetz@gmail.com>"
23 #define DRIVER_DESC "USB 7 Segment Driver"
24 
25 #define VENDOR_ID	0x0fc5
26 #define PRODUCT_ID	0x1227
27 #define MAXLEN		6
28 
29 /* table of devices that work with this driver */
30 static struct usb_device_id id_table[] = {
31 	{ USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
32 	{ },
33 };
34 MODULE_DEVICE_TABLE(usb, id_table);
35 
36 /* the different text display modes the device is capable of */
37 static char *display_textmodes[] = {"raw", "hex", "ascii", NULL};
38 
39 struct usb_sevsegdev {
40 	struct usb_device *udev;
41 
42 	u8 powered;
43 	u8 mode_msb;
44 	u8 mode_lsb;
45 	u8 decimals[MAXLEN];
46 	u8 textmode;
47 	u8 text[MAXLEN];
48 	u16 textlength;
49 };
50 
51 /* sysfs_streq can't replace this completely
52  * If the device was in hex mode, and the user wanted a 0,
53  * if str commands are used, we would assume the end of string
54  * so mem commands are used.
55  */
56 inline size_t my_memlen(const char *buf, size_t count)
57 {
58 	if (count > 0 && buf[count-1] == '\n')
59 		return count - 1;
60 	else
61 		return count;
62 }
63 
64 static void update_display_powered(struct usb_sevsegdev *mydev)
65 {
66 	int rc;
67 
68 	rc = usb_control_msg(mydev->udev,
69 			usb_sndctrlpipe(mydev->udev, 0),
70 			0x12,
71 			0x48,
72 			(80 * 0x100) + 10, /*  (power mode) */
73 			(0x00 * 0x100) + (mydev->powered ? 1 : 0),
74 			NULL,
75 			0,
76 			2000);
77 	if (rc < 0)
78 		dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
79 }
80 
81 static void update_display_mode(struct usb_sevsegdev *mydev)
82 {
83 	int rc;
84 
85 	rc = usb_control_msg(mydev->udev,
86 			usb_sndctrlpipe(mydev->udev, 0),
87 			0x12,
88 			0x48,
89 			(82 * 0x100) + 10, /* (set mode) */
90 			(mydev->mode_msb * 0x100) + mydev->mode_lsb,
91 			NULL,
92 			0,
93 			2000);
94 
95 	if (rc < 0)
96 		dev_dbg(&mydev->udev->dev, "mode retval = %d\n", rc);
97 }
98 
99 static void update_display_visual(struct usb_sevsegdev *mydev)
100 {
101 	int rc;
102 	int i;
103 	unsigned char *buffer;
104 	u8 decimals = 0;
105 
106 	buffer = kzalloc(MAXLEN, GFP_KERNEL);
107 	if (!buffer) {
108 		dev_err(&mydev->udev->dev, "out of memory\n");
109 		return;
110 	}
111 
112 	/* The device is right to left, where as you write left to right */
113 	for (i = 0; i < mydev->textlength; i++)
114 		buffer[i] = mydev->text[mydev->textlength-1-i];
115 
116 	rc = usb_control_msg(mydev->udev,
117 			usb_sndctrlpipe(mydev->udev, 0),
118 			0x12,
119 			0x48,
120 			(85 * 0x100) + 10, /* (write text) */
121 			(0 * 0x100) + mydev->textmode, /* mode  */
122 			buffer,
123 			mydev->textlength,
124 			2000);
125 
126 	if (rc < 0)
127 		dev_dbg(&mydev->udev->dev, "write retval = %d\n", rc);
128 
129 	kfree(buffer);
130 
131 	/* The device is right to left, where as you write left to right */
132 	for (i = 0; i < sizeof(mydev->decimals); i++)
133 		decimals |= mydev->decimals[i] << i;
134 
135 	rc = usb_control_msg(mydev->udev,
136 			usb_sndctrlpipe(mydev->udev, 0),
137 			0x12,
138 			0x48,
139 			(86 * 0x100) + 10, /* (set decimal) */
140 			(0 * 0x100) + decimals, /* decimals */
141 			NULL,
142 			0,
143 			2000);
144 
145 	if (rc < 0)
146 		dev_dbg(&mydev->udev->dev, "decimal retval = %d\n", rc);
147 }
148 
149 #define MYDEV_ATTR_SIMPLE_UNSIGNED(name, update_fcn)		\
150 static ssize_t show_attr_##name(struct device *dev, 		\
151 	struct device_attribute *attr, char *buf) 		\
152 {								\
153 	struct usb_interface *intf = to_usb_interface(dev);	\
154 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
155 								\
156 	return sprintf(buf, "%u\n", mydev->name);		\
157 }								\
158 								\
159 static ssize_t set_attr_##name(struct device *dev, 		\
160 	struct device_attribute *attr, const char *buf, size_t count) \
161 {								\
162 	struct usb_interface *intf = to_usb_interface(dev);	\
163 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
164 								\
165 	mydev->name = simple_strtoul(buf, NULL, 10);		\
166 	update_fcn(mydev); \
167 								\
168 	return count;						\
169 }								\
170 static DEVICE_ATTR(name, S_IWUGO | S_IRUGO, show_attr_##name, set_attr_##name);
171 
172 static ssize_t show_attr_text(struct device *dev,
173 	struct device_attribute *attr, char *buf)
174 {
175 	struct usb_interface *intf = to_usb_interface(dev);
176 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
177 
178 	return snprintf(buf, mydev->textlength, "%s\n", mydev->text);
179 }
180 
181 static ssize_t set_attr_text(struct device *dev,
182 	struct device_attribute *attr, const char *buf, size_t count)
183 {
184 	struct usb_interface *intf = to_usb_interface(dev);
185 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
186 	size_t end = my_memlen(buf, count);
187 
188 	if (end > sizeof(mydev->text))
189 		return -EINVAL;
190 
191 	memset(mydev->text, 0, sizeof(mydev->text));
192 	mydev->textlength = end;
193 
194 	if (end > 0)
195 		memcpy(mydev->text, buf, end);
196 
197 	update_display_visual(mydev);
198 	return count;
199 }
200 
201 static DEVICE_ATTR(text, S_IWUGO | S_IRUGO, show_attr_text, set_attr_text);
202 
203 static ssize_t show_attr_decimals(struct device *dev,
204 	struct device_attribute *attr, char *buf)
205 {
206 	struct usb_interface *intf = to_usb_interface(dev);
207 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
208 	int i;
209 	int pos;
210 
211 	for (i = 0; i < sizeof(mydev->decimals); i++) {
212 		pos = sizeof(mydev->decimals) - 1 - i;
213 		if (mydev->decimals[i] == 0)
214 			buf[pos] = '0';
215 		else if (mydev->decimals[i] == 1)
216 			buf[pos] = '1';
217 		else
218 			buf[pos] = 'x';
219 	}
220 
221 	buf[sizeof(mydev->decimals)] = '\n';
222 	return sizeof(mydev->decimals) + 1;
223 }
224 
225 static ssize_t set_attr_decimals(struct device *dev,
226 	struct device_attribute *attr, const char *buf, size_t count)
227 {
228 	struct usb_interface *intf = to_usb_interface(dev);
229 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
230 	size_t end = my_memlen(buf, count);
231 	int i;
232 
233 	if (end > sizeof(mydev->decimals))
234 		return -EINVAL;
235 
236 	for (i = 0; i < end; i++)
237 		if (buf[i] != '0' && buf[i] != '1')
238 			return -EINVAL;
239 
240 	memset(mydev->decimals, 0, sizeof(mydev->decimals));
241 	for (i = 0; i < end; i++)
242 		if (buf[i] == '1')
243 			mydev->decimals[end-1-i] = 1;
244 
245 	update_display_visual(mydev);
246 
247 	return count;
248 }
249 
250 static DEVICE_ATTR(decimals, S_IWUGO | S_IRUGO,
251 	show_attr_decimals, set_attr_decimals);
252 
253 static ssize_t show_attr_textmode(struct device *dev,
254 	struct device_attribute *attr, char *buf)
255 {
256 	struct usb_interface *intf = to_usb_interface(dev);
257 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
258 	int i;
259 
260 	buf[0] = 0;
261 
262 	for (i = 0; display_textmodes[i]; i++) {
263 		if (mydev->textmode == i) {
264 			strcat(buf, " [");
265 			strcat(buf, display_textmodes[i]);
266 			strcat(buf, "] ");
267 		} else {
268 			strcat(buf, " ");
269 			strcat(buf, display_textmodes[i]);
270 			strcat(buf, " ");
271 		}
272 	}
273 	strcat(buf, "\n");
274 
275 
276 	return strlen(buf);
277 }
278 
279 static ssize_t set_attr_textmode(struct device *dev,
280 	struct device_attribute *attr, const char *buf, size_t count)
281 {
282 	struct usb_interface *intf = to_usb_interface(dev);
283 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
284 	int i;
285 
286 	for (i = 0; display_textmodes[i]; i++) {
287 		if (sysfs_streq(display_textmodes[i], buf)) {
288 			mydev->textmode = i;
289 			update_display_visual(mydev);
290 			return count;
291 		}
292 	}
293 
294 	return -EINVAL;
295 }
296 
297 static DEVICE_ATTR(textmode, S_IWUGO | S_IRUGO,
298 	show_attr_textmode, set_attr_textmode);
299 
300 
301 MYDEV_ATTR_SIMPLE_UNSIGNED(powered, update_display_powered);
302 MYDEV_ATTR_SIMPLE_UNSIGNED(mode_msb, update_display_mode);
303 MYDEV_ATTR_SIMPLE_UNSIGNED(mode_lsb, update_display_mode);
304 
305 static struct attribute *dev_attrs[] = {
306 	&dev_attr_powered.attr,
307 	&dev_attr_text.attr,
308 	&dev_attr_textmode.attr,
309 	&dev_attr_decimals.attr,
310 	&dev_attr_mode_msb.attr,
311 	&dev_attr_mode_lsb.attr,
312 	NULL
313 };
314 
315 static struct attribute_group dev_attr_grp = {
316 	.attrs = dev_attrs,
317 };
318 
319 static int sevseg_probe(struct usb_interface *interface,
320 	const struct usb_device_id *id)
321 {
322 	struct usb_device *udev = interface_to_usbdev(interface);
323 	struct usb_sevsegdev *mydev = NULL;
324 	int rc = -ENOMEM;
325 
326 	mydev = kzalloc(sizeof(struct usb_sevsegdev), GFP_KERNEL);
327 	if (mydev == NULL) {
328 		dev_err(&interface->dev, "Out of memory\n");
329 		goto error_mem;
330 	}
331 
332 	mydev->udev = usb_get_dev(udev);
333 	usb_set_intfdata(interface, mydev);
334 
335 	/*set defaults */
336 	mydev->textmode = 0x02; /* ascii mode */
337 	mydev->mode_msb = 0x06; /* 6 characters */
338 	mydev->mode_lsb = 0x3f; /* scanmode for 6 chars */
339 
340 	rc = sysfs_create_group(&interface->dev.kobj, &dev_attr_grp);
341 	if (rc)
342 		goto error;
343 
344 	dev_info(&interface->dev, "USB 7 Segment device now attached\n");
345 	return 0;
346 
347 error:
348 	usb_set_intfdata(interface, NULL);
349 	usb_put_dev(mydev->udev);
350 	kfree(mydev);
351 error_mem:
352 	return rc;
353 }
354 
355 static void sevseg_disconnect(struct usb_interface *interface)
356 {
357 	struct usb_sevsegdev *mydev;
358 
359 	mydev = usb_get_intfdata(interface);
360 	sysfs_remove_group(&interface->dev.kobj, &dev_attr_grp);
361 	usb_set_intfdata(interface, NULL);
362 	usb_put_dev(mydev->udev);
363 	kfree(mydev);
364 	dev_info(&interface->dev, "USB 7 Segment now disconnected\n");
365 }
366 
367 static struct usb_driver sevseg_driver = {
368 	.name =		"usbsevseg",
369 	.probe =	sevseg_probe,
370 	.disconnect =	sevseg_disconnect,
371 	.id_table =	id_table,
372 };
373 
374 static int __init usb_sevseg_init(void)
375 {
376 	int rc = 0;
377 
378 	rc = usb_register(&sevseg_driver);
379 	if (rc)
380 		err("usb_register failed. Error number %d", rc);
381 	return rc;
382 }
383 
384 static void __exit usb_sevseg_exit(void)
385 {
386 	usb_deregister(&sevseg_driver);
387 }
388 
389 module_init(usb_sevseg_init);
390 module_exit(usb_sevseg_exit);
391 
392 MODULE_AUTHOR(DRIVER_AUTHOR);
393 MODULE_DESCRIPTION(DRIVER_DESC);
394 MODULE_LICENSE("GPL");
395