mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![Michael Krufky](/assets/img/avatar_default.png)
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
211 lines
3.9 KiB
C
211 lines
3.9 KiB
C
/*
|
|
* Many thanks to Fred Seidel <seidel@metabox.de>, the
|
|
* designer of the RDS decoder hardware. With his help
|
|
* I was able to code this driver.
|
|
* Thanks also to Norberto Pellicci, Dominic Mounteney
|
|
* <DMounteney@pinnaclesys.com> and www.teleauskunft.de
|
|
* for good hints on finding Fred. It was somewhat hard
|
|
* to locate him here in Germany... [:
|
|
*
|
|
* Revision history:
|
|
*
|
|
* 2000-08-09 Robert Siemer <Robert.Siemer@gmx.de>
|
|
* RDS support for MiroSound PCM20 radio
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/string.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mutex.h>
|
|
|
|
#include <asm/io.h>
|
|
#include "oss/aci.h"
|
|
#include "miropcm20-rds-core.h"
|
|
|
|
#define DEBUG 0
|
|
|
|
static struct mutex aci_rds_mutex;
|
|
|
|
#define RDS_DATASHIFT 2 /* Bit 2 */
|
|
#define RDS_DATAMASK (1 << RDS_DATASHIFT)
|
|
#define RDS_BUSYMASK 0x10 /* Bit 4 */
|
|
#define RDS_CLOCKMASK 0x08 /* Bit 3 */
|
|
|
|
#define RDS_DATA(x) (((x) >> RDS_DATASHIFT) & 1)
|
|
|
|
|
|
#if DEBUG
|
|
static void print_matrix(char array[], unsigned int length)
|
|
{
|
|
int i, j;
|
|
|
|
for (i=0; i<length; i++) {
|
|
printk(KERN_DEBUG "aci-rds: ");
|
|
for (j=7; j>=0; j--) {
|
|
printk("%d", (array[i] >> j) & 0x1);
|
|
}
|
|
if (i%8 == 0)
|
|
printk(" byte-border\n");
|
|
else
|
|
printk("\n");
|
|
}
|
|
}
|
|
#endif /* DEBUG */
|
|
|
|
static int byte2trans(unsigned char byte, unsigned char sendbuffer[], int size)
|
|
{
|
|
int i;
|
|
|
|
if (size != 8)
|
|
return -1;
|
|
for (i = 7; i >= 0; i--)
|
|
sendbuffer[7-i] = (byte & (1 << i)) ? RDS_DATAMASK : 0;
|
|
sendbuffer[0] |= RDS_CLOCKMASK;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rds_waitread(void)
|
|
{
|
|
unsigned char byte;
|
|
int i=2000;
|
|
|
|
do {
|
|
byte=inb(RDS_REGISTER);
|
|
i--;
|
|
}
|
|
while ((byte & RDS_BUSYMASK) && i);
|
|
|
|
if (i) {
|
|
#if DEBUG
|
|
printk(KERN_DEBUG "rds_waitread()");
|
|
print_matrix(&byte, 1);
|
|
#endif
|
|
return (byte);
|
|
} else {
|
|
printk(KERN_WARNING "aci-rds: rds_waitread() timeout...\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* don't use any ..._nowait() function if you are not sure what you do... */
|
|
|
|
static inline void rds_rawwrite_nowait(unsigned char byte)
|
|
{
|
|
#if DEBUG
|
|
printk(KERN_DEBUG "rds_rawwrite()");
|
|
print_matrix(&byte, 1);
|
|
#endif
|
|
outb(byte, RDS_REGISTER);
|
|
}
|
|
|
|
static int rds_rawwrite(unsigned char byte)
|
|
{
|
|
if (rds_waitread() >= 0) {
|
|
rds_rawwrite_nowait(byte);
|
|
return 0;
|
|
} else
|
|
return -1;
|
|
}
|
|
|
|
static int rds_write(unsigned char cmd)
|
|
{
|
|
unsigned char sendbuffer[8];
|
|
int i;
|
|
|
|
if (byte2trans(cmd, sendbuffer, 8) != 0){
|
|
return -1;
|
|
} else {
|
|
for (i=0; i<8; i++) {
|
|
rds_rawwrite(sendbuffer[i]);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int rds_readcycle_nowait(void)
|
|
{
|
|
rds_rawwrite_nowait(0);
|
|
return rds_waitread();
|
|
}
|
|
|
|
static int rds_readcycle(void)
|
|
{
|
|
if (rds_rawwrite(0) < 0)
|
|
return -1;
|
|
return rds_waitread();
|
|
}
|
|
|
|
static int rds_read(unsigned char databuffer[], int datasize)
|
|
{
|
|
#define READSIZE (8*datasize)
|
|
|
|
int i,j;
|
|
|
|
if (datasize < 1) /* nothing to read */
|
|
return 0;
|
|
|
|
/* to be able to use rds_readcycle_nowait()
|
|
I have to waitread() here */
|
|
if (rds_waitread() < 0)
|
|
return -1;
|
|
|
|
memset(databuffer, 0, datasize);
|
|
|
|
for (i=0; i< READSIZE; i++)
|
|
if((j=rds_readcycle_nowait()) < 0) {
|
|
return -1;
|
|
} else {
|
|
databuffer[i/8]|=(RDS_DATA(j) << (7-(i%8)));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rds_ack(void)
|
|
{
|
|
int i=rds_readcycle();
|
|
|
|
if (i < 0)
|
|
return -1;
|
|
if (i & RDS_DATAMASK) {
|
|
return 0; /* ACK */
|
|
} else {
|
|
printk(KERN_DEBUG "aci-rds: NACK\n");
|
|
return 1; /* NACK */
|
|
}
|
|
}
|
|
|
|
int aci_rds_cmd(unsigned char cmd, unsigned char databuffer[], int datasize)
|
|
{
|
|
int ret;
|
|
|
|
if (mutex_lock_interruptible(&aci_rds_mutex))
|
|
return -EINTR;
|
|
|
|
rds_write(cmd);
|
|
|
|
/* RDS_RESET doesn't need further processing */
|
|
if (cmd!=RDS_RESET && (rds_ack() || rds_read(databuffer, datasize)))
|
|
ret = -1;
|
|
else
|
|
ret = 0;
|
|
|
|
mutex_unlock(&aci_rds_mutex);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(aci_rds_cmd);
|
|
|
|
int __init attach_aci_rds(void)
|
|
{
|
|
mutex_init(&aci_rds_mutex);
|
|
return 0;
|
|
}
|
|
|
|
void __exit unload_aci_rds(void)
|
|
{
|
|
}
|
|
MODULE_LICENSE("GPL");
|