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 */
25static const struct usb_device_id id_table[] = {
26	{ USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
27	{ },
28};
29MODULE_DEVICE_TABLE(usb, id_table);
30
31/* the different text display modes the device is capable of */
32static const char *display_textmodes[] = {"raw", "hex", "ascii"};
33
34struct 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 */
55static 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
63static 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
90static 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
106static 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)		\
142static 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								\
151static 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}								\
162static DEVICE_ATTR_RW(name);
163
164static 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
173static 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
193static DEVICE_ATTR_RW(text);
194
195static 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
217static 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
242static DEVICE_ATTR_RW(decimals);
243
244static 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
270static 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
286static DEVICE_ATTR_RW(textmode);
287
288
289MYDEV_ATTR_SIMPLE_UNSIGNED(powered, update_display_powered);
290MYDEV_ATTR_SIMPLE_UNSIGNED(mode_msb, update_display_mode);
291MYDEV_ATTR_SIMPLE_UNSIGNED(mode_lsb, update_display_mode);
292
293static 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};
302ATTRIBUTE_GROUPS(sevseg);
303
304static 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;
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
331error_mem:
332	return rc;
333}
334
335static 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
346static 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
356static 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
368static 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
380static 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
392module_usb_driver(sevseg_driver);
393
394MODULE_AUTHOR(DRIVER_AUTHOR);
395MODULE_DESCRIPTION(DRIVER_DESC);
396MODULE_LICENSE("GPL");
397