tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Picvue PVC160206 display driver
3 *
4 * Brian Murphy <brian.murphy@eicon.com>
5 *
6 */
7#include <linux/bug.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12
13#include <linux/proc_fs.h>
14#include <linux/seq_file.h>
15#include <linux/interrupt.h>
16
17#include <linux/timer.h>
18#include <linux/mutex.h>
19
20#include "picvue.h"
21
22static DEFINE_MUTEX(pvc_mutex);
23static char pvc_lines[PVC_NLINES][PVC_LINELEN+1];
24static int pvc_linedata[PVC_NLINES];
25static char *pvc_linename[PVC_NLINES] = {"line1", "line2"};
26#define DISPLAY_DIR_NAME "display"
27static int scroll_dir, scroll_interval;
28
29static struct timer_list timer;
30
31static void pvc_display(unsigned long data)
32{
33 int i;
34
35 pvc_clear();
36 for (i = 0; i < PVC_NLINES; i++)
37 pvc_write_string(pvc_lines[i], 0, i);
38}
39
40static DECLARE_TASKLET(pvc_display_tasklet, &pvc_display, 0);
41
42static int pvc_line_proc_show(struct seq_file *m, void *v)
43{
44 int lineno = *(int *)m->private;
45
46 if (lineno < 0 || lineno > PVC_NLINES) {
47 printk(KERN_WARNING "proc_read_line: invalid lineno %d\n", lineno);
48 return 0;
49 }
50
51 mutex_lock(&pvc_mutex);
52 seq_printf(m, "%s\n", pvc_lines[lineno]);
53 mutex_unlock(&pvc_mutex);
54
55 return 0;
56}
57
58static int pvc_line_proc_open(struct inode *inode, struct file *file)
59{
60 return single_open(file, pvc_line_proc_show, PDE_DATA(inode));
61}
62
63static ssize_t pvc_line_proc_write(struct file *file, const char __user *buf,
64 size_t count, loff_t *pos)
65{
66 int lineno = *(int *)PDE_DATA(file_inode(file));
67 char kbuf[PVC_LINELEN];
68 size_t len;
69
70 BUG_ON(lineno < 0 || lineno > PVC_NLINES);
71
72 len = min(count, sizeof(kbuf) - 1);
73 if (copy_from_user(kbuf, buf, len))
74 return -EFAULT;
75 kbuf[len] = '\0';
76
77 if (len > 0 && kbuf[len - 1] == '\n')
78 len--;
79
80 mutex_lock(&pvc_mutex);
81 strncpy(pvc_lines[lineno], kbuf, len);
82 pvc_lines[lineno][len] = '\0';
83 mutex_unlock(&pvc_mutex);
84
85 tasklet_schedule(&pvc_display_tasklet);
86
87 return count;
88}
89
90static const struct file_operations pvc_line_proc_fops = {
91 .owner = THIS_MODULE,
92 .open = pvc_line_proc_open,
93 .read = seq_read,
94 .llseek = seq_lseek,
95 .release = single_release,
96 .write = pvc_line_proc_write,
97};
98
99static ssize_t pvc_scroll_proc_write(struct file *file, const char __user *buf,
100 size_t count, loff_t *pos)
101{
102 char kbuf[42];
103 size_t len;
104 int cmd;
105
106 len = min(count, sizeof(kbuf) - 1);
107 if (copy_from_user(kbuf, buf, len))
108 return -EFAULT;
109 kbuf[len] = '\0';
110
111 cmd = simple_strtol(kbuf, NULL, 10);
112
113 mutex_lock(&pvc_mutex);
114 if (scroll_interval != 0)
115 del_timer(&timer);
116
117 if (cmd == 0) {
118 scroll_dir = 0;
119 scroll_interval = 0;
120 } else {
121 if (cmd < 0) {
122 scroll_dir = -1;
123 scroll_interval = -cmd;
124 } else {
125 scroll_dir = 1;
126 scroll_interval = cmd;
127 }
128 add_timer(&timer);
129 }
130 mutex_unlock(&pvc_mutex);
131
132 return count;
133}
134
135static int pvc_scroll_proc_show(struct seq_file *m, void *v)
136{
137 mutex_lock(&pvc_mutex);
138 seq_printf(m, "%d\n", scroll_dir * scroll_interval);
139 mutex_unlock(&pvc_mutex);
140
141 return 0;
142}
143
144static int pvc_scroll_proc_open(struct inode *inode, struct file *file)
145{
146 return single_open(file, pvc_scroll_proc_show, NULL);
147}
148
149static const struct file_operations pvc_scroll_proc_fops = {
150 .owner = THIS_MODULE,
151 .open = pvc_scroll_proc_open,
152 .read = seq_read,
153 .llseek = seq_lseek,
154 .release = single_release,
155 .write = pvc_scroll_proc_write,
156};
157
158void pvc_proc_timerfunc(unsigned long data)
159{
160 if (scroll_dir < 0)
161 pvc_move(DISPLAY|RIGHT);
162 else if (scroll_dir > 0)
163 pvc_move(DISPLAY|LEFT);
164
165 timer.expires = jiffies + scroll_interval;
166 add_timer(&timer);
167}
168
169static void pvc_proc_cleanup(void)
170{
171 remove_proc_subtree(DISPLAY_DIR_NAME, NULL);
172 del_timer_sync(&timer);
173}
174
175static int __init pvc_proc_init(void)
176{
177 struct proc_dir_entry *dir, *proc_entry;
178 int i;
179
180 dir = proc_mkdir(DISPLAY_DIR_NAME, NULL);
181 if (dir == NULL)
182 goto error;
183
184 for (i = 0; i < PVC_NLINES; i++) {
185 strcpy(pvc_lines[i], "");
186 pvc_linedata[i] = i;
187 }
188 for (i = 0; i < PVC_NLINES; i++) {
189 proc_entry = proc_create_data(pvc_linename[i], 0644, dir,
190 &pvc_line_proc_fops, &pvc_linedata[i]);
191 if (proc_entry == NULL)
192 goto error;
193 }
194 proc_entry = proc_create("scroll", 0644, dir,
195 &pvc_scroll_proc_fops);
196 if (proc_entry == NULL)
197 goto error;
198
199 init_timer(&timer);
200 timer.function = pvc_proc_timerfunc;
201
202 return 0;
203error:
204 pvc_proc_cleanup();
205 return -ENOMEM;
206}
207
208module_init(pvc_proc_init);
209module_exit(pvc_proc_cleanup);
210MODULE_LICENSE("GPL");