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// SPDX-License-Identifier: GPL-2.0-only
/*
* Picvue PVC160206 display driver
*
* Brian Murphy <brian.murphy@eicon.com>
*
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include "picvue.h"
static DEFINE_MUTEX(pvc_mutex);
static char pvc_lines[PVC_NLINES][PVC_LINELEN+1];
static int pvc_linedata[PVC_NLINES];
static char *pvc_linename[PVC_NLINES] = {"line1", "line2"};
#define DISPLAY_DIR_NAME "display"
static int scroll_dir, scroll_interval;
static struct timer_list timer;
static void pvc_display(unsigned long data)
{
int i;
pvc_clear();
for (i = 0; i < PVC_NLINES; i++)
pvc_write_string(pvc_lines[i], 0, i);
}
static DECLARE_TASKLET(pvc_display_tasklet, &pvc_display, 0);
static int pvc_line_proc_show(struct seq_file *m, void *v)
{
int lineno = *(int *)m->private;
if (lineno < 0 || lineno >= PVC_NLINES) {
printk(KERN_WARNING "proc_read_line: invalid lineno %d\n", lineno);
return 0;
}
mutex_lock(&pvc_mutex);
seq_printf(m, "%s\n", pvc_lines[lineno]);
mutex_unlock(&pvc_mutex);
return 0;
}
static int pvc_line_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, pvc_line_proc_show, PDE_DATA(inode));
}
static ssize_t pvc_line_proc_write(struct file *file, const char __user *buf,
size_t count, loff_t *pos)
{
int lineno = *(int *)PDE_DATA(file_inode(file));
char kbuf[PVC_LINELEN];
size_t len;
BUG_ON(lineno < 0 || lineno >= PVC_NLINES);
len = min(count, sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, len))
return -EFAULT;
kbuf[len] = '\0';
if (len > 0 && kbuf[len - 1] == '\n')
len--;
mutex_lock(&pvc_mutex);
strncpy(pvc_lines[lineno], kbuf, len);
pvc_lines[lineno][len] = '\0';
mutex_unlock(&pvc_mutex);
tasklet_schedule(&pvc_display_tasklet);
return count;
}
static const struct file_operations pvc_line_proc_fops = {
.owner = THIS_MODULE,
.open = pvc_line_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = pvc_line_proc_write,
};
static ssize_t pvc_scroll_proc_write(struct file *file, const char __user *buf,
size_t count, loff_t *pos)
{
char kbuf[42];
size_t len;
int cmd;
len = min(count, sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, len))
return -EFAULT;
kbuf[len] = '\0';
cmd = simple_strtol(kbuf, NULL, 10);
mutex_lock(&pvc_mutex);
if (scroll_interval != 0)
del_timer(&timer);
if (cmd == 0) {
scroll_dir = 0;
scroll_interval = 0;
} else {
if (cmd < 0) {
scroll_dir = -1;
scroll_interval = -cmd;
} else {
scroll_dir = 1;
scroll_interval = cmd;
}
add_timer(&timer);
}
mutex_unlock(&pvc_mutex);
return count;
}
static int pvc_scroll_proc_show(struct seq_file *m, void *v)
{
mutex_lock(&pvc_mutex);
seq_printf(m, "%d\n", scroll_dir * scroll_interval);
mutex_unlock(&pvc_mutex);
return 0;
}
static int pvc_scroll_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, pvc_scroll_proc_show, NULL);
}
static const struct file_operations pvc_scroll_proc_fops = {
.owner = THIS_MODULE,
.open = pvc_scroll_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = pvc_scroll_proc_write,
};
void pvc_proc_timerfunc(struct timer_list *unused)
{
if (scroll_dir < 0)
pvc_move(DISPLAY|RIGHT);
else if (scroll_dir > 0)
pvc_move(DISPLAY|LEFT);
timer.expires = jiffies + scroll_interval;
add_timer(&timer);
}
static void pvc_proc_cleanup(void)
{
remove_proc_subtree(DISPLAY_DIR_NAME, NULL);
del_timer_sync(&timer);
}
static int __init pvc_proc_init(void)
{
struct proc_dir_entry *dir, *proc_entry;
int i;
dir = proc_mkdir(DISPLAY_DIR_NAME, NULL);
if (dir == NULL)
goto error;
for (i = 0; i < PVC_NLINES; i++) {
strcpy(pvc_lines[i], "");
pvc_linedata[i] = i;
}
for (i = 0; i < PVC_NLINES; i++) {
proc_entry = proc_create_data(pvc_linename[i], 0644, dir,
&pvc_line_proc_fops, &pvc_linedata[i]);
if (proc_entry == NULL)
goto error;
}
proc_entry = proc_create("scroll", 0644, dir,
&pvc_scroll_proc_fops);
if (proc_entry == NULL)
goto error;
timer_setup(&timer, pvc_proc_timerfunc, 0);
return 0;
error:
pvc_proc_cleanup();
return -ENOMEM;
}
module_init(pvc_proc_init);
module_exit(pvc_proc_cleanup);
MODULE_LICENSE("GPL");
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