linux/drivers/media/radio/miropcm20-rds.c
Arjan van de Ven fa027c2a0a [PATCH] mark struct file_operations const 4
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@sdl.org: dvb fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00

134 lines
2.8 KiB
C

/* MiroSOUND PCM20 radio rds interface driver
* (c) 2001 Robert Siemer <Robert.Siemer@gmx.de>
* Thanks to Fred Seidel. See miropcm20-rds-core.c for further information.
*/
/* Revision history:
*
* 2001-04-18 Robert Siemer <Robert.Siemer@gmx.de>
* separate file for user interface driver
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/sched.h> /* current, TASK_*, schedule_timeout() */
#include <linux/delay.h>
#include <asm/uaccess.h>
#include "miropcm20-rds-core.h"
static char * text_buffer;
static int rds_users = 0;
static int rds_f_open(struct inode *in, struct file *fi)
{
if (rds_users)
return -EBUSY;
rds_users++;
if ((text_buffer=kmalloc(66, GFP_KERNEL)) == 0) {
rds_users--;
printk(KERN_NOTICE "aci-rds: Out of memory by open()...\n");
return -ENOMEM;
}
return 0;
}
static int rds_f_release(struct inode *in, struct file *fi)
{
kfree(text_buffer);
rds_users--;
return 0;
}
static void print_matrix(char *ch, char out[])
{
int j;
for (j=7; j>=0; j--) {
out[7-j] = ((*ch >> j) & 0x1) + '0';
}
}
static ssize_t rds_f_read(struct file *file, char __user *buffer, size_t length, loff_t *offset)
{
// i = sprintf(text_buffer, "length: %d, offset: %d\n", length, *offset);
char c;
char bits[8];
msleep(2000);
aci_rds_cmd(RDS_STATUS, &c, 1);
print_matrix(&c, bits);
if (copy_to_user(buffer, bits, 8))
return -EFAULT;
/* if ((c >> 3) & 1) {
aci_rds_cmd(RDS_STATIONNAME, text_buffer+1, 8);
text_buffer[0] = ' ' ;
text_buffer[9] = '\n';
return copy_to_user(buffer+8, text_buffer, 10) ? -EFAULT: 18;
}
*/
/* if ((c >> 6) & 1) {
aci_rds_cmd(RDS_PTYTATP, &c, 1);
if ( c & 1)
sprintf(text_buffer, " M");
else
sprintf(text_buffer, " S");
if ((c >> 1) & 1)
sprintf(text_buffer+2, " TA");
else
sprintf(text_buffer+2, " --");
if ((c >> 7) & 1)
sprintf(text_buffer+5, " TP");
else
sprintf(text_buffer+5, " --");
sprintf(text_buffer+8, " %2d\n", (c >> 2) & 0x1f);
return copy_to_user(buffer+8, text_buffer, 12) ? -EFAULT: 20;
}
*/
if ((c >> 4) & 1) {
aci_rds_cmd(RDS_TEXT, text_buffer, 65);
text_buffer[0] = ' ' ;
text_buffer[65] = '\n';
return copy_to_user(buffer+8, text_buffer,66) ? -EFAULT : 66+8;
} else {
put_user('\n', buffer+8);
return 9;
}
}
static const struct file_operations rds_fops = {
.owner = THIS_MODULE,
.read = rds_f_read,
.open = rds_f_open,
.release = rds_f_release
};
static struct miscdevice rds_miscdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "radiotext",
.fops = &rds_fops,
};
static int __init miropcm20_rds_init(void)
{
return misc_register(&rds_miscdev);
}
static void __exit miropcm20_rds_cleanup(void)
{
misc_deregister(&rds_miscdev);
}
module_init(miropcm20_rds_init);
module_exit(miropcm20_rds_cleanup);
MODULE_LICENSE("GPL");