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 #include <linux/uaccess.h>
20
21 #include "picvue.h"
22
23 static DEFINE_MUTEX(pvc_mutex);
24 static char pvc_lines[PVC_NLINES][PVC_LINELEN+1];
25 static int pvc_linedata[PVC_NLINES];
26 static char *pvc_linename[PVC_NLINES] = {"line1", "line2"};
27 #define DISPLAY_DIR_NAME "display"
28 static int scroll_dir, scroll_interval;
29
30 static struct timer_list timer;
31
pvc_display(unsigned long data)32 static void pvc_display(unsigned long data)
33 {
34 int i;
35
36 pvc_clear();
37 for (i = 0; i < PVC_NLINES; i++)
38 pvc_write_string(pvc_lines[i], 0, i);
39 }
40
41 static DECLARE_TASKLET(pvc_display_tasklet, &pvc_display, 0);
42
pvc_line_proc_show(struct seq_file * m,void * v)43 static int pvc_line_proc_show(struct seq_file *m, void *v)
44 {
45 int lineno = *(int *)m->private;
46
47 if (lineno < 0 || lineno >= PVC_NLINES) {
48 printk(KERN_WARNING "proc_read_line: invalid lineno %d\n", lineno);
49 return 0;
50 }
51
52 mutex_lock(&pvc_mutex);
53 seq_printf(m, "%s\n", pvc_lines[lineno]);
54 mutex_unlock(&pvc_mutex);
55
56 return 0;
57 }
58
pvc_line_proc_open(struct inode * inode,struct file * file)59 static int pvc_line_proc_open(struct inode *inode, struct file *file)
60 {
61 return single_open(file, pvc_line_proc_show, PDE_DATA(inode));
62 }
63
pvc_line_proc_write(struct file * file,const char __user * buf,size_t count,loff_t * pos)64 static ssize_t pvc_line_proc_write(struct file *file, const char __user *buf,
65 size_t count, loff_t *pos)
66 {
67 int lineno = *(int *)PDE_DATA(file_inode(file));
68 char kbuf[PVC_LINELEN];
69 size_t len;
70
71 BUG_ON(lineno < 0 || lineno >= PVC_NLINES);
72
73 len = min(count, sizeof(kbuf) - 1);
74 if (copy_from_user(kbuf, buf, len))
75 return -EFAULT;
76 kbuf[len] = '\0';
77
78 if (len > 0 && kbuf[len - 1] == '\n')
79 len--;
80
81 mutex_lock(&pvc_mutex);
82 strncpy(pvc_lines[lineno], kbuf, len);
83 pvc_lines[lineno][len] = '\0';
84 mutex_unlock(&pvc_mutex);
85
86 tasklet_schedule(&pvc_display_tasklet);
87
88 return count;
89 }
90
91 static const struct file_operations pvc_line_proc_fops = {
92 .owner = THIS_MODULE,
93 .open = pvc_line_proc_open,
94 .read = seq_read,
95 .llseek = seq_lseek,
96 .release = single_release,
97 .write = pvc_line_proc_write,
98 };
99
pvc_scroll_proc_write(struct file * file,const char __user * buf,size_t count,loff_t * pos)100 static ssize_t pvc_scroll_proc_write(struct file *file, const char __user *buf,
101 size_t count, loff_t *pos)
102 {
103 char kbuf[42];
104 size_t len;
105 int cmd;
106
107 len = min(count, sizeof(kbuf) - 1);
108 if (copy_from_user(kbuf, buf, len))
109 return -EFAULT;
110 kbuf[len] = '\0';
111
112 cmd = simple_strtol(kbuf, NULL, 10);
113
114 mutex_lock(&pvc_mutex);
115 if (scroll_interval != 0)
116 del_timer(&timer);
117
118 if (cmd == 0) {
119 scroll_dir = 0;
120 scroll_interval = 0;
121 } else {
122 if (cmd < 0) {
123 scroll_dir = -1;
124 scroll_interval = -cmd;
125 } else {
126 scroll_dir = 1;
127 scroll_interval = cmd;
128 }
129 add_timer(&timer);
130 }
131 mutex_unlock(&pvc_mutex);
132
133 return count;
134 }
135
pvc_scroll_proc_show(struct seq_file * m,void * v)136 static int pvc_scroll_proc_show(struct seq_file *m, void *v)
137 {
138 mutex_lock(&pvc_mutex);
139 seq_printf(m, "%d\n", scroll_dir * scroll_interval);
140 mutex_unlock(&pvc_mutex);
141
142 return 0;
143 }
144
pvc_scroll_proc_open(struct inode * inode,struct file * file)145 static int pvc_scroll_proc_open(struct inode *inode, struct file *file)
146 {
147 return single_open(file, pvc_scroll_proc_show, NULL);
148 }
149
150 static const struct file_operations pvc_scroll_proc_fops = {
151 .owner = THIS_MODULE,
152 .open = pvc_scroll_proc_open,
153 .read = seq_read,
154 .llseek = seq_lseek,
155 .release = single_release,
156 .write = pvc_scroll_proc_write,
157 };
158
pvc_proc_timerfunc(unsigned long data)159 void pvc_proc_timerfunc(unsigned long data)
160 {
161 if (scroll_dir < 0)
162 pvc_move(DISPLAY|RIGHT);
163 else if (scroll_dir > 0)
164 pvc_move(DISPLAY|LEFT);
165
166 timer.expires = jiffies + scroll_interval;
167 add_timer(&timer);
168 }
169
pvc_proc_cleanup(void)170 static void pvc_proc_cleanup(void)
171 {
172 remove_proc_subtree(DISPLAY_DIR_NAME, NULL);
173 del_timer_sync(&timer);
174 }
175
pvc_proc_init(void)176 static int __init pvc_proc_init(void)
177 {
178 struct proc_dir_entry *dir, *proc_entry;
179 int i;
180
181 dir = proc_mkdir(DISPLAY_DIR_NAME, NULL);
182 if (dir == NULL)
183 goto error;
184
185 for (i = 0; i < PVC_NLINES; i++) {
186 strcpy(pvc_lines[i], "");
187 pvc_linedata[i] = i;
188 }
189 for (i = 0; i < PVC_NLINES; i++) {
190 proc_entry = proc_create_data(pvc_linename[i], 0644, dir,
191 &pvc_line_proc_fops, &pvc_linedata[i]);
192 if (proc_entry == NULL)
193 goto error;
194 }
195 proc_entry = proc_create("scroll", 0644, dir,
196 &pvc_scroll_proc_fops);
197 if (proc_entry == NULL)
198 goto error;
199
200 init_timer(&timer);
201 timer.function = pvc_proc_timerfunc;
202
203 return 0;
204 error:
205 pvc_proc_cleanup();
206 return -ENOMEM;
207 }
208
209 module_init(pvc_proc_init);
210 module_exit(pvc_proc_cleanup);
211 MODULE_LICENSE("GPL");
212