arch/mips/lasat/picvue_proc.c

   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
  22 static DEFINE_MUTEX(pvc_mutex);
  23 static char pvc_lines[PVC_NLINES][PVC_LINELEN+1];
  24 static int pvc_linedata[PVC_NLINES];
  25 static char *pvc_linename[PVC_NLINES] = {"line1", "line2"};
  26 #define DISPLAY_DIR_NAME "display"
  27 static int scroll_dir, scroll_interval;
  28
  29 static struct timer_list timer;
  30
  31 static 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
  40 static DECLARE_TASKLET(pvc_display_tasklet, &pvc_display, 0);
  41
  42 static 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
  58 static 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
  63 static 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
  90 static 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
  99 static 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
 135 static 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
 144 static int pvc_scroll_proc_open(struct inode *inode, struct file *file)
 145 {
 146         return single_open(file, pvc_scroll_proc_show, NULL);
 147 }
 148
 149 static 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
 158 void 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
 169 static void pvc_proc_cleanup(void)
 170 {
 171         remove_proc_subtree(DISPLAY_DIR_NAME, NULL);
 172         del_timer_sync(&timer);
 173 }
 174
 175 static 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;
 203 error:
 204         pvc_proc_cleanup();
 205         return -ENOMEM;
 206 }
 207
 208 module_init(pvc_proc_init);
 209 module_exit(pvc_proc_cleanup);
 210 MODULE_LICENSE("GPL");