arch/mips/lasat/picvue_proc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Picvue PVC160206 display driver
   4  *
   5  * Brian Murphy <brian.murphy@eicon.com>
   6  *
   7  */
   8 #include <linux/bug.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13
  14 #include <linux/proc_fs.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/interrupt.h>
  17
  18 #include <linux/timer.h>
  19 #include <linux/mutex.h>
  20 #include <linux/uaccess.h>
  21
  22 #include "picvue.h"
  23
  24 static DEFINE_MUTEX(pvc_mutex);
  25 static char pvc_lines[PVC_NLINES][PVC_LINELEN+1];
  26 static int pvc_linedata[PVC_NLINES];
  27 static char *pvc_linename[PVC_NLINES] = {"line1", "line2"};
  28 #define DISPLAY_DIR_NAME "display"
  29 static int scroll_dir, scroll_interval;
  30
  31 static struct timer_list timer;
  32
  33 static void pvc_display(unsigned long data)
  34 {
  35         int i;
  36
  37         pvc_clear();
  38         for (i = 0; i < PVC_NLINES; i++)
  39                 pvc_write_string(pvc_lines[i], 0, i);
  40 }
  41
  42 static DECLARE_TASKLET(pvc_display_tasklet, &pvc_display, 0);
  43
  44 static int pvc_line_proc_show(struct seq_file *m, void *v)
  45 {
  46         int lineno = *(int *)m->private;
  47
  48         if (lineno < 0 || lineno >= PVC_NLINES) {
  49                 printk(KERN_WARNING "proc_read_line: invalid lineno %d\n", lineno);
  50                 return 0;
  51         }
  52
  53         mutex_lock(&pvc_mutex);
  54         seq_printf(m, "%s\n", pvc_lines[lineno]);
  55         mutex_unlock(&pvc_mutex);
  56
  57         return 0;
  58 }
  59
  60 static int pvc_line_proc_open(struct inode *inode, struct file *file)
  61 {
  62         return single_open(file, pvc_line_proc_show, PDE_DATA(inode));
  63 }
  64
  65 static ssize_t pvc_line_proc_write(struct file *file, const char __user *buf,
  66                                    size_t count, loff_t *pos)
  67 {
  68         int lineno = *(int *)PDE_DATA(file_inode(file));
  69         char kbuf[PVC_LINELEN];
  70         size_t len;
  71
  72         BUG_ON(lineno < 0 || lineno >= PVC_NLINES);
  73
  74         len = min(count, sizeof(kbuf) - 1);
  75         if (copy_from_user(kbuf, buf, len))
  76                 return -EFAULT;
  77         kbuf[len] = '\0';
  78
  79         if (len > 0 && kbuf[len - 1] == '\n')
  80                 len--;
  81
  82         mutex_lock(&pvc_mutex);
  83         strncpy(pvc_lines[lineno], kbuf, len);
  84         pvc_lines[lineno][len] = '\0';
  85         mutex_unlock(&pvc_mutex);
  86
  87         tasklet_schedule(&pvc_display_tasklet);
  88
  89         return count;
  90 }
  91
  92 static const struct proc_ops pvc_line_proc_ops = {
  93         .proc_open      = pvc_line_proc_open,
  94         .proc_read      = seq_read,
  95         .proc_lseek     = seq_lseek,
  96         .proc_release   = single_release,
  97         .proc_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 proc_ops pvc_scroll_proc_ops = {
 151         .proc_open      = pvc_scroll_proc_open,
 152         .proc_read      = seq_read,
 153         .proc_lseek     = seq_lseek,
 154         .proc_release   = single_release,
 155         .proc_write     = pvc_scroll_proc_write,
 156 };
 157
 158 void pvc_proc_timerfunc(struct timer_list *unused)
 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_ops, &pvc_linedata[i]);
 191                 if (proc_entry == NULL)
 192                         goto error;
 193         }
 194         proc_entry = proc_create("scroll", 0644, dir, &pvc_scroll_proc_ops);
 195         if (proc_entry == NULL)
 196                 goto error;
 197
 198         timer_setup(&timer, pvc_proc_timerfunc, 0);
 199
 200         return 0;
 201 error:
 202         pvc_proc_cleanup();
 203         return -ENOMEM;
 204 }
 205
 206 module_init(pvc_proc_init);
 207 module_exit(pvc_proc_cleanup);
 208 MODULE_LICENSE("GPL");