patch-2.4.4 linux/drivers/media/radio/rds-miropcm20.c

• Lines: 250
• Date: Fri Apr 13 20:26:07 2001
• Orig file: v2.4.3/linux/drivers/media/radio/rds-miropcm20.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.3/linux/drivers/media/radio/rds-miropcm20.c linux/drivers/media/radio/rds-miropcm20.c
@@ -0,0 +1,249 @@
+/*
+ *  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
+ */
+
+#define _NO_VERSION_
+
+/* #include <linux/kernel.h> */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <asm/semaphore.h>
+#include <asm/io.h>
+#include "../../sound/aci.h"
+
+#define WATCHMASK       0352 /* 11101010 */
+
+#define DEBUG 0
+
+static struct semaphore aci_rds_sem;
+
+
+#define RDS_BUSYMASK        0x10   /* Bit 4 */
+#define RDS_CLOCKMASK       0x08   /* Bit 3 */
+#define RDS_DATAMASK        0x04   /* Bit 2 */
+
+
+static void print_matrix(char array[], unsigned int length)
+{
+        int i, j;
+
+        for (i=0; i<length; i++) {
+                printk("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");
+        }
+}
+
+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 trans2byte(unsigned char buffer[], int size)
+{
+	int i;
+	unsigned char byte=0;
+
+	if (size != 8)
+		return -1;
+	for (i = 7; i >= 0; i--)
+		byte |= ((buffer[7-i] & RDS_DATAMASK) ? 1 : 0) << i;
+
+	return byte;
+}
+
+static int trans2data(unsigned char readbuffer[], int readsize, unsigned char data[], int datasize)
+{
+	int i,j;
+
+	if (readsize != datasize*8)
+		return -1;
+	for (i = 0; i < datasize; i++)
+		if ((j=trans2byte(&readbuffer[i*8], 8)) < 0)
+			return -1;
+		else
+			data[i]=j;
+	return 0;
+}
+
+static int rds_waitread(void)
+{
+	unsigned char byte;
+	int i=2000;
+
+	do {
+		byte=inb(RDS_REGISTER);
+		if ((byte & WATCHMASK) != WATCHMASK)
+			printk("aci-rds: Hidden information discoverd!\n");
+		i--;
+	}
+	while ((byte & RDS_BUSYMASK) && i);
+
+	if (i) {
+#if DEBUG
+		printk("rds_waitread()");
+		print_matrix(&byte, 1);
+#endif
+		return (byte);
+	} else {
+		printk("aci-rds: rds_waitread() timeout...\n");
+		return -1;
+	}
+}
+
+/* dont use any ..._nowait() function if you are not sure what you do... */
+
+static inline void rds_rawwrite_nowait(unsigned char byte)
+{
+#if DEBUG
+	printk("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;
+	unsigned char* readbuffer;
+
+	if (!datasize)  /* nothing to read */
+		return 0;
+
+	/* to be able to use rds_readcycle_nowait()
+	   I have to readwait() here */
+	if (rds_waitread() < 0)
+		return -1;
+	
+	if ((readbuffer=kmalloc(READSIZE, GFP_KERNEL)) == 0) {
+		printk("aci-rds: Out of memory...\n");
+		return -ENOMEM;
+	} else {
+		if (signal_pending(current)) {
+			kfree(readbuffer);
+			return -EINTR;
+		}
+	}
+	
+	for (i=0; i< READSIZE; i++)
+		if((j=rds_readcycle_nowait()) < 0) {
+			kfree(readbuffer);
+			return -1;
+		} else
+			readbuffer[i]=j;
+	if (trans2data(readbuffer, READSIZE, databuffer, datasize) < 0) {
+		kfree(readbuffer);
+		return -1;
+	}
+	kfree(readbuffer);
+	return 0;
+}
+
+static int rds_ack(void)
+{
+	int i=rds_readcycle();
+
+	if (i < 0)
+		return -1;
+	if (i & RDS_DATAMASK) {
+		return 0;  /* ACK  */
+	} else {
+		return 1;  /* NACK */
+	}
+}
+
+int aci_rds_cmd(unsigned char cmd, unsigned char databuffer[], int datasize)
+{
+	int ret;
+
+	if (down_interruptible(&aci_rds_sem))
+		return -EINTR;
+
+	if (rds_write(cmd))
+		ret = -2;
+
+	/* RDS_RESET doesn't need further processing */
+	if (cmd!=RDS_RESET && (rds_ack() || rds_read(databuffer, datasize)))
+		ret = -1;
+	else
+		ret = 0;
+
+	up(&aci_rds_sem);
+	
+	return ret;
+}
+
+int __init attach_aci_rds(void)
+{
+	init_MUTEX(&aci_rds_sem);
+	return 0;
+}
+
+void __exit unload_aci_rds(void)
+{
+}