/*
Driver for SAA6588 RDS decoder
(c) 2005 Hans J. Koch
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/types.h>
#include <linux/videodev.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <asm/uaccess.h>
#include <media/rds.h>
/* Addresses to scan */
static unsigned short normal_i2c[] = {
0x20 >> 1,
0x22 >> 1,
I2C_CLIENT_END,
};
I2C_CLIENT_INSMOD;
/* insmod options */
static unsigned int debug = 0;
static unsigned int xtal = 0;
static unsigned int rbds = 0;
static unsigned int plvl = 0;
static unsigned int bufblocks = 100;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "enable debug messages");
module_param(xtal, int, 0);
MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
module_param(rbds, int, 0);
MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
module_param(plvl, int, 0);
MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
module_param(bufblocks, int, 0);
MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
MODULE_LICENSE("GPL");
/* ---------------------------------------------------------------------- */
#define UNSET (-1U)
#define PREFIX "saa6588: "
#define dprintk if (debug) printk
struct saa6588 {
struct i2c_client client;
struct work_struct work;
struct timer_list timer;
spinlock_t lock;
unsigned char *buffer;
unsigned int buf_size;
unsigned int rd_index;
unsigned int wr_index;
unsigned int block_count;
unsigned char last_blocknum;
wait_queue_head_t read_queue;
int data_available_for_read;
};
static struct i2c_driver driver;
static struct i2c_client client_template;
/* ---------------------------------------------------------------------- */
/*
* SAA6588 defines
*/
/* Initialization and mode control byte (0w) */
/* bit 0+1 (DAC0/DAC1) */
#define cModeStandard 0x00
#define cModeFastPI 0x01
#define cModeReducedRequest 0x02
#define cModeInvalid 0x03
/* bit 2 (RBDS) */
#define cProcessingModeRDS 0x00
#define cProcessingModeRBDS 0x04
/* bit 3+4 (SYM0/SYM1) */
#define cErrCorrectionNone 0x00
#define cErrCorrection2Bits 0x08
#define cErrCorrection5Bits 0x10
#define cErrCorrectionNoneRBDS 0x18
/* bit 5 (NWSY) */
#define cSyncNormal 0x00
#define cSyncRestart 0x20
/* bit 6 (TSQD) */
#define cSigQualityDetectOFF 0x00
#define cSigQualityDetectON 0x40
/* bit 7 (SQCM) */
#define cSigQualityTriggered 0x00
#define cSigQualityContinous 0x80
/* Pause level and flywheel control byte (1w) */
/* bits 0..5 (FEB0..FEB5) */
#define cFlywheelMaxBlocksMask 0x3F
#define cFlywheelDefault 0x20
/* bits 6+7 (PL0/PL1) */
#define cPauseLevel_11mV 0x00
#define cPauseLevel_17mV 0x40
#define cPauseLevel_27mV 0x80
#define cPauseLevel_43mV 0xC0
/* Pause time/oscillator frequency/quality detector control byte (1w) */
/* bits 0..4 (SQS0..SQS4) */
#define cQualityDetectSensMask 0x1F
#define cQualityDetectDefault 0x0F
/* bit 5 (SOSC) */
#define cSelectOscFreqOFF 0x00
#define cSelectOscFreqON 0x20
/* bit 6+7 (PTF0/PTF1) */
#define cOscFreq_4332kHz 0x00
#define cOscFreq_8664kHz 0x40
#define cOscFreq_12996kHz 0x80
#define cOscFreq_17328kHz 0xC0
/* ---------------------------------------------------------------------- */
static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
{
int i;
if (s->rd_index == s->wr_index) {
if (debug > 2)
dprintk(PREFIX "Read: buffer empty.\n");
return 0;
}
if (debug > 2) {
dprintk(PREFIX "Read: ");
for (i = s->rd_index; i < s->rd_index + 3; i++)
dprintk("0x%02x ", s->buffer[i]);
}
if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
return -EFAULT;
s->rd_index += 3;
if (s->rd_index >= s->buf_size)
s->rd_index = 0;
s->block_count--;
if (debug > 2)
dprintk("%d blocks total.\n", s->block_count);
return 1;
}
static void read_from_buf(struct saa6588 *s, struct rds_command *a)
{
unsigned long flags;
unsigned char __user *buf_ptr = a->buffer;
unsigned int i;
unsigned int rd_blocks;
a->result = 0;
if (!a->buffer)
return;
while (!s->data_available_for_read) {
int ret = wait_event_interruptible(s->read_queue,
s->data_available_for_read);
if (ret == -ERESTARTSYS) {
a->result = -EINTR;
return;
}
}
spin_lock_irqsave(&s->lock, flags);
rd_blocks = a->block_count;
if (rd_blocks > s->block_count)
rd_blocks = s->block_count;
if (!rd_blocks) {
spin_unlock_irqrestore(&s->lock, flags);
return;
}
for (i = 0; i < rd_blocks; i++) {
if (block_to_user_buf(s, buf_ptr)) {
buf_ptr += 3;
a->result++;
} else
break;
}
a->result *= 3;
s->data_available_for_read = (s->block_count > 0);
spin_unlock_irqrestore(&s->lock, flags);
}
static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
{
unsigned int i;
if (debug > 3)
dprintk(PREFIX "New block: ");
for (i = 0; i < 3; ++i) {
if (debug > 3)
dprintk("0x%02x ", blockbuf[i]);
s->buffer[s->wr_index] = blockbuf[i];
s->wr_index++;
}
if (s->wr_index >= s->buf_size)
s->wr_index = 0;
if (s->wr_index == s->rd_index) {
s->rd_index += 3;
if (s->rd_index >= s->buf_size)
s->rd_index = 0;
} else
s->block_count++;
if (debug > 3)
dprintk("%d blocks total.\n", s->block_count);
}
static void saa6588_i2c_poll(struct saa6588 *s)
{
unsigned long flags;
unsigned char tmpbuf[6];
unsigned char blocknum;
unsigned char tmp;
/* Although we only need 3 bytes, we have to read at least 6.
SAA6588 returns garbage otherwise */
if (6 != i2c_master_recv(&s->client, &tmpbuf[0], 6)) {
if (debug > 1)
dprintk(PREFIX "read error!\n");
return;
}
blocknum = tmpbuf[0] >> 5;
if (blocknum == s->last_blocknum) {
if (debug > 3)
dprintk("Saw block %d again.\n", blocknum);
return;
}
s->last_blocknum = blocknum;
/*
Byte order according to v4l2 specification:
Byte 0: Least Significant Byte of RDS Block
Byte 1: Most Significant Byte of RDS Block
Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
occurred during reception of this block.
Bit 6: Corrected bit. Indicates that an error was
corrected for this data block.
Bits 5-3: Received Offset. Indicates the offset received
by the sync system.
Bits 2-0: Offset Name. Indicates the offset applied to this data.
SAA6588 byte order is Status-MSB-LSB, so we have to swap the
first and the last of the 3 bytes block.
*/
tmp = tmpbuf[2];
tmpbuf[2] = tmpbuf[0];
tmpbuf[0] = tmp;
tmp = blocknum;
tmp |= blocknum << 3; /* Received offset == Offset Name (OK ?) */
if ((tmpbuf[2] & 0x03) == 0x03)
tmp |= 0x80; /* uncorrectable error */
else if ((tmpbuf[2] & 0x03) != 0x00)
tmp |= 0x40; /* corrected error */
tmpbuf[2] = tmp; /* Is this enough ? Should we also check other bits ? */
spin_lock_irqsave(&s->lock, flags);
block_to_buf(s, tmpbuf);
spin_unlock_irqrestore(&s->lock, flags);
s->data_available_for_read = 1;
wake_up_interruptible(&s->read_queue);
}
static void saa6588_timer(unsigned long data)
{
struct saa6588 *s = (struct saa6588 *)data;
schedule_work(&s->work);
}
static void saa6588_work(struct work_struct *work)
{
struct saa6588 *s = container_of(work, struct saa6588, work);
saa6588_i2c_poll(s);
mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
}
static int saa6588_configure(struct saa6588 *s)
{
unsigned char buf[3];
int rc;
buf[0] = cSyncRestart;
if (rbds)
buf[0] |= cProcessingModeRBDS;
buf[1] = cFlywheelDefault;
switch (plvl) {
case 0:
buf[1] |= cPauseLevel_11mV;
break;
case 1:
buf[1] |= cPauseLevel_17mV;
break;
case 2:
buf[1] |= cPauseLevel_27mV;
break;
case 3:
buf[1] |= cPauseLevel_43mV;
break;
default: /* nothing */
break;
}
buf[2] = cQualityDetectDefault | cSelectOscFreqON;
switch (xtal) {
case 0:
buf[2] |= cOscFreq_4332kHz;
break;
case 1:
buf[2] |= cOscFreq_8664kHz;
break;
case 2:
buf[2] |= cOscFreq_12996kHz;
break;
case 3:
buf[2] |= cOscFreq_17328kHz;
break;
default: /* nothing */
break;
}
dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
buf[0], buf[1], buf[2]);
if (3 != (rc = i2c_master_send(&s->client, buf, 3)))
printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
return 0;
}
/* ---------------------------------------------------------------------- */
static int saa6588_attach(struct i2c_adapter *adap, int addr, int kind)
{
struct saa6588 *s;
client_template.adapter = adap;
client_template.addr = addr;
printk(PREFIX "chip found @ 0x%x\n", addr << 1);
if (NULL == (s = kmalloc(sizeof(*s), GFP_KERNEL)))
return -ENOMEM;
s->buf_size = bufblocks * 3;
if (NULL == (s->buffer = kmalloc(s->buf_size, GFP_KERNEL))) {
kfree(s);
return -ENOMEM;
}
spin_lock_init(&s->lock);
s->client = client_template;
s->block_count = 0;
s->wr_index = 0;
s->rd_index = 0;
s->last_blocknum = 0xff;
init_waitqueue_head(&s->read_queue);
s->data_available_for_read = 0;
i2c_set_clientdata(&s->client, s);
i2c_attach_client(&s->client);
saa6588_configure(s);
/* start polling via eventd */
INIT_WORK(&s->work, saa6588_work);
init_timer(&s->timer);
s->timer.function = saa6588_timer;
s->timer.data = (unsigned long)s;
schedule_work(&s->work);
return 0;
}
static int saa6588_probe(struct i2c_adapter *adap)
{
if (adap->class & I2C_CLASS_TV_ANALOG)
return i2c_probe(adap, &addr_data, saa6588_attach);
return 0;
}
static int saa6588_detach(struct i2c_client *client)
{
struct saa6588 *s = i2c_get_clientdata(client);
del_timer_sync(&s->timer);
flush_scheduled_work();
i2c_detach_client(client);
kfree(s->buffer);
kfree(s);
return 0;
}
static int saa6588_command(struct i2c_client *client, unsigned int cmd,
void *arg)
{
struct saa6588 *s = i2c_get_clientdata(client);
struct rds_command *a = (struct rds_command *)arg;
switch (cmd) {
/* --- open() for /dev/radio --- */
case RDS_CMD_OPEN:
a->result = 0; /* return error if chip doesn't work ??? */
break;
/* --- close() for /dev/radio --- */
case RDS_CMD_CLOSE:
s->data_available_for_read = 1;
wake_up_interruptible(&s->read_queue);
a->result = 0;
break;
/* --- read() for /dev/radio --- */
case RDS_CMD_READ:
read_from_buf(s, a);
break;
/* --- poll() for /dev/radio --- */
case RDS_CMD_POLL:
a->result = 0;
if (s->data_available_for_read) {
a->result |= POLLIN | POLLRDNORM;
}
poll_wait(a->instance, &s->read_queue, a->event_list);
break;
default:
/* nothing */
break;
}
return 0;
}
/* ----------------------------------------------------------------------- */
static struct i2c_driver driver = {
.driver = {
.name = "saa6588",
},
.id = -1, /* FIXME */
.attach_adapter = saa6588_probe,
.detach_client = saa6588_detach,
.command = saa6588_command,
};
static struct i2c_client client_template = {
.name = "saa6588",
.driver = &driver,
};
static int __init saa6588_init_module(void)
{
return i2c_add_driver(&driver);
}
static void __exit saa6588_cleanup_module(void)
{
i2c_del_driver(&driver);
}
module_init(saa6588_init_module);
module_exit(saa6588_cleanup_module);
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* ---------------------------------------------------------------------------
* Local variables:
* c-basic-offset: 8
* End:
*/
