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 #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
  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
  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
  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
  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
 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
 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
 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
 159 void pvc_proc_timerfunc(struct timer_list *unused)
 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
 170 static void pvc_proc_cleanup(void)
 171 {
 172         remove_proc_subtree(DISPLAY_DIR_NAME, NULL);
 173         del_timer_sync(&timer);
 174 }
 175
 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         timer_setup(&timer, pvc_proc_timerfunc, 0);
 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");