xref: /openbmc/linux/drivers/usb/misc/usbsevseg.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB 7 Segment Driver
4  *
5  * Copyright (C) 2008 Harrison Metzger <harrisonmetz@gmail.com>
6  * Based on usbled.c by Greg Kroah-Hartman (greg@kroah.com)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/string.h>
14 #include <linux/usb.h>
15 
16 
17 #define DRIVER_AUTHOR "Harrison Metzger <harrisonmetz@gmail.com>"
18 #define DRIVER_DESC "USB 7 Segment Driver"
19 
20 #define VENDOR_ID	0x0fc5
21 #define PRODUCT_ID	0x1227
22 #define MAXLEN		8
23 
24 /* table of devices that work with this driver */
25 static const struct usb_device_id id_table[] = {
26 	{ USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
27 	{ },
28 };
29 MODULE_DEVICE_TABLE(usb, id_table);
30 
31 /* the different text display modes the device is capable of */
32 static const char *display_textmodes[] = {"raw", "hex", "ascii"};
33 
34 struct usb_sevsegdev {
35 	struct usb_device *udev;
36 	struct usb_interface *intf;
37 
38 	u8 powered;
39 	u8 mode_msb;
40 	u8 mode_lsb;
41 	u8 decimals[MAXLEN];
42 	u8 textmode;
43 	u8 text[MAXLEN];
44 	u16 textlength;
45 
46 	u8 shadow_power; /* for PM */
47 	u8 has_interface_pm;
48 };
49 
50 /* sysfs_streq can't replace this completely
51  * If the device was in hex mode, and the user wanted a 0,
52  * if str commands are used, we would assume the end of string
53  * so mem commands are used.
54  */
55 static inline size_t my_memlen(const char *buf, size_t count)
56 {
57 	if (count > 0 && buf[count-1] == '\n')
58 		return count - 1;
59 	else
60 		return count;
61 }
62 
63 static void update_display_powered(struct usb_sevsegdev *mydev)
64 {
65 	int rc;
66 
67 	if (mydev->powered && !mydev->has_interface_pm) {
68 		rc = usb_autopm_get_interface(mydev->intf);
69 		if (rc < 0)
70 			return;
71 		mydev->has_interface_pm = 1;
72 	}
73 
74 	if (mydev->shadow_power != 1)
75 		return;
76 
77 	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
78 				  (80 * 0x100) + 10, /*  (power mode) */
79 				  (0x00 * 0x100) + (mydev->powered ? 1 : 0),
80 				  NULL, 0, 2000, GFP_KERNEL);
81 	if (rc < 0)
82 		dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
83 
84 	if (!mydev->powered && mydev->has_interface_pm) {
85 		usb_autopm_put_interface(mydev->intf);
86 		mydev->has_interface_pm = 0;
87 	}
88 }
89 
90 static void update_display_mode(struct usb_sevsegdev *mydev)
91 {
92 	int rc;
93 
94 	if(mydev->shadow_power != 1)
95 		return;
96 
97 	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
98 				  (82 * 0x100) + 10, /* (set mode) */
99 				  (mydev->mode_msb * 0x100) + mydev->mode_lsb,
100 				  NULL, 0, 2000, GFP_NOIO);
101 
102 	if (rc < 0)
103 		dev_dbg(&mydev->udev->dev, "mode retval = %d\n", rc);
104 }
105 
106 static void update_display_visual(struct usb_sevsegdev *mydev, gfp_t mf)
107 {
108 	int rc;
109 	int i;
110 	unsigned char buffer[MAXLEN] = {0};
111 	u8 decimals = 0;
112 
113 	if(mydev->shadow_power != 1)
114 		return;
115 
116 	/* The device is right to left, where as you write left to right */
117 	for (i = 0; i < mydev->textlength; i++)
118 		buffer[i] = mydev->text[mydev->textlength-1-i];
119 
120 	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
121 				  (85 * 0x100) + 10, /* (write text) */
122 				  (0 * 0x100) + mydev->textmode, /* mode  */
123 				  &buffer, mydev->textlength, 2000, mf);
124 
125 	if (rc < 0)
126 		dev_dbg(&mydev->udev->dev, "write retval = %d\n", rc);
127 
128 	/* The device is right to left, where as you write left to right */
129 	for (i = 0; i < sizeof(mydev->decimals); i++)
130 		decimals |= mydev->decimals[i] << i;
131 
132 	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
133 				  (86 * 0x100) + 10, /* (set decimal) */
134 				  (0 * 0x100) + decimals, /* decimals */
135 				  NULL, 0, 2000, mf);
136 
137 	if (rc < 0)
138 		dev_dbg(&mydev->udev->dev, "decimal retval = %d\n", rc);
139 }
140 
141 #define MYDEV_ATTR_SIMPLE_UNSIGNED(name, update_fcn)		\
142 static ssize_t name##_show(struct device *dev,			\
143 	struct device_attribute *attr, char *buf) 		\
144 {								\
145 	struct usb_interface *intf = to_usb_interface(dev);	\
146 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
147 								\
148 	return sprintf(buf, "%u\n", mydev->name);		\
149 }								\
150 								\
151 static ssize_t name##_store(struct device *dev,			\
152 	struct device_attribute *attr, const char *buf, size_t count) \
153 {								\
154 	struct usb_interface *intf = to_usb_interface(dev);	\
155 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
156 								\
157 	mydev->name = simple_strtoul(buf, NULL, 10);		\
158 	update_fcn(mydev); 					\
159 								\
160 	return count;						\
161 }								\
162 static DEVICE_ATTR_RW(name);
163 
164 static ssize_t text_show(struct device *dev,
165 	struct device_attribute *attr, char *buf)
166 {
167 	struct usb_interface *intf = to_usb_interface(dev);
168 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
169 
170 	return sysfs_emit(buf, "%s\n", mydev->text);
171 }
172 
173 static ssize_t text_store(struct device *dev,
174 	struct device_attribute *attr, const char *buf, size_t count)
175 {
176 	struct usb_interface *intf = to_usb_interface(dev);
177 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
178 	size_t end = my_memlen(buf, count);
179 
180 	if (end > sizeof(mydev->text))
181 		return -EINVAL;
182 
183 	memset(mydev->text, 0, sizeof(mydev->text));
184 	mydev->textlength = end;
185 
186 	if (end > 0)
187 		memcpy(mydev->text, buf, end);
188 
189 	update_display_visual(mydev, GFP_KERNEL);
190 	return count;
191 }
192 
193 static DEVICE_ATTR_RW(text);
194 
195 static ssize_t decimals_show(struct device *dev,
196 	struct device_attribute *attr, char *buf)
197 {
198 	struct usb_interface *intf = to_usb_interface(dev);
199 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
200 	int i;
201 	int pos;
202 
203 	for (i = 0; i < sizeof(mydev->decimals); i++) {
204 		pos = sizeof(mydev->decimals) - 1 - i;
205 		if (mydev->decimals[i] == 0)
206 			buf[pos] = '0';
207 		else if (mydev->decimals[i] == 1)
208 			buf[pos] = '1';
209 		else
210 			buf[pos] = 'x';
211 	}
212 
213 	buf[sizeof(mydev->decimals)] = '\n';
214 	return sizeof(mydev->decimals) + 1;
215 }
216 
217 static ssize_t decimals_store(struct device *dev,
218 	struct device_attribute *attr, const char *buf, size_t count)
219 {
220 	struct usb_interface *intf = to_usb_interface(dev);
221 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
222 	size_t end = my_memlen(buf, count);
223 	int i;
224 
225 	if (end > sizeof(mydev->decimals))
226 		return -EINVAL;
227 
228 	for (i = 0; i < end; i++)
229 		if (buf[i] != '0' && buf[i] != '1')
230 			return -EINVAL;
231 
232 	memset(mydev->decimals, 0, sizeof(mydev->decimals));
233 	for (i = 0; i < end; i++)
234 		if (buf[i] == '1')
235 			mydev->decimals[end-1-i] = 1;
236 
237 	update_display_visual(mydev, GFP_KERNEL);
238 
239 	return count;
240 }
241 
242 static DEVICE_ATTR_RW(decimals);
243 
244 static ssize_t textmode_show(struct device *dev,
245 	struct device_attribute *attr, char *buf)
246 {
247 	struct usb_interface *intf = to_usb_interface(dev);
248 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
249 	int i;
250 
251 	buf[0] = 0;
252 
253 	for (i = 0; i < ARRAY_SIZE(display_textmodes); i++) {
254 		if (mydev->textmode == i) {
255 			strcat(buf, " [");
256 			strcat(buf, display_textmodes[i]);
257 			strcat(buf, "] ");
258 		} else {
259 			strcat(buf, " ");
260 			strcat(buf, display_textmodes[i]);
261 			strcat(buf, " ");
262 		}
263 	}
264 	strcat(buf, "\n");
265 
266 
267 	return strlen(buf);
268 }
269 
270 static ssize_t textmode_store(struct device *dev,
271 	struct device_attribute *attr, const char *buf, size_t count)
272 {
273 	struct usb_interface *intf = to_usb_interface(dev);
274 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
275 	int i;
276 
277 	i = sysfs_match_string(display_textmodes, buf);
278 	if (i < 0)
279 		return i;
280 
281 	mydev->textmode = i;
282 	update_display_visual(mydev, GFP_KERNEL);
283 	return count;
284 }
285 
286 static DEVICE_ATTR_RW(textmode);
287 
288 
289 MYDEV_ATTR_SIMPLE_UNSIGNED(powered, update_display_powered);
290 MYDEV_ATTR_SIMPLE_UNSIGNED(mode_msb, update_display_mode);
291 MYDEV_ATTR_SIMPLE_UNSIGNED(mode_lsb, update_display_mode);
292 
293 static struct attribute *sevseg_attrs[] = {
294 	&dev_attr_powered.attr,
295 	&dev_attr_text.attr,
296 	&dev_attr_textmode.attr,
297 	&dev_attr_decimals.attr,
298 	&dev_attr_mode_msb.attr,
299 	&dev_attr_mode_lsb.attr,
300 	NULL
301 };
302 ATTRIBUTE_GROUPS(sevseg);
303 
304 static int sevseg_probe(struct usb_interface *interface,
305 	const struct usb_device_id *id)
306 {
307 	struct usb_device *udev = interface_to_usbdev(interface);
308 	struct usb_sevsegdev *mydev = NULL;
309 	int rc = -ENOMEM;
310 
311 	mydev = kzalloc(sizeof(struct usb_sevsegdev), GFP_KERNEL);
312 	if (!mydev)
313 		goto error_mem;
314 
315 	mydev->udev = usb_get_dev(udev);
316 	mydev->intf = interface;
317 	usb_set_intfdata(interface, mydev);
318 
319 	/* PM */
320 	mydev->shadow_power = 1; /* currently active */
321 	mydev->has_interface_pm = 0; /* have not issued autopm_get */
322 
323 	/*set defaults */
324 	mydev->textmode = 0x02; /* ascii mode */
325 	mydev->mode_msb = 0x06; /* 6 characters */
326 	mydev->mode_lsb = 0x3f; /* scanmode for 6 chars */
327 
328 	dev_info(&interface->dev, "USB 7 Segment device now attached\n");
329 	return 0;
330 
331 error_mem:
332 	return rc;
333 }
334 
335 static void sevseg_disconnect(struct usb_interface *interface)
336 {
337 	struct usb_sevsegdev *mydev;
338 
339 	mydev = usb_get_intfdata(interface);
340 	usb_set_intfdata(interface, NULL);
341 	usb_put_dev(mydev->udev);
342 	kfree(mydev);
343 	dev_info(&interface->dev, "USB 7 Segment now disconnected\n");
344 }
345 
346 static int sevseg_suspend(struct usb_interface *intf, pm_message_t message)
347 {
348 	struct usb_sevsegdev *mydev;
349 
350 	mydev = usb_get_intfdata(intf);
351 	mydev->shadow_power = 0;
352 
353 	return 0;
354 }
355 
356 static int sevseg_resume(struct usb_interface *intf)
357 {
358 	struct usb_sevsegdev *mydev;
359 
360 	mydev = usb_get_intfdata(intf);
361 	mydev->shadow_power = 1;
362 	update_display_mode(mydev);
363 	update_display_visual(mydev, GFP_NOIO);
364 
365 	return 0;
366 }
367 
368 static int sevseg_reset_resume(struct usb_interface *intf)
369 {
370 	struct usb_sevsegdev *mydev;
371 
372 	mydev = usb_get_intfdata(intf);
373 	mydev->shadow_power = 1;
374 	update_display_mode(mydev);
375 	update_display_visual(mydev, GFP_NOIO);
376 
377 	return 0;
378 }
379 
380 static struct usb_driver sevseg_driver = {
381 	.name =		"usbsevseg",
382 	.probe =	sevseg_probe,
383 	.disconnect =	sevseg_disconnect,
384 	.suspend =	sevseg_suspend,
385 	.resume =	sevseg_resume,
386 	.reset_resume =	sevseg_reset_resume,
387 	.id_table =	id_table,
388 	.dev_groups =	sevseg_groups,
389 	.supports_autosuspend = 1,
390 };
391 
392 module_usb_driver(sevseg_driver);
393 
394 MODULE_AUTHOR(DRIVER_AUTHOR);
395 MODULE_DESCRIPTION(DRIVER_DESC);
396 MODULE_LICENSE("GPL");
397