[media] radio-cadet: fix RDS handling

The current RDS code suffered from bit rot. Clean it up and make it work again.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 39 insertions, 17 deletions

diff --git a/drivers/media/radio/radio-cadet.c b/drivers/media/radio/radio-cadet.c
index 93536b7e75c7..d1fb42746fc2 100644
--- a/drivers/media/radio/radio-cadet.c
+++ b/drivers/media/radio/radio-cadet.c
@@ -71,7 +71,7 @@ struct cadet {
         int sigstrength;
         wait_queue_head_t read_queue;
         struct timer_list readtimer;
-        __u8 rdsin, rdsout, rdsstat;
+        u8 rdsin, rdsout, rdsstat;
         unsigned char rdsbuf[RDS_BUFFER];
         struct mutex lock;
         int reading;
@@ -85,8 +85,8 @@ static struct cadet cadet_card;
  * strength value.  These values are in microvolts of RF at the tuner's input.
  */
 static __u16 sigtable[2][4] = {
-        {  5, 10, 30,  150 },
-        { 28, 40, 63, 1000 }
+        { 2185, 4369, 13107, 65535 },
+        { 1835, 2621,  4128, 65535 }
 };
 
 
@@ -240,10 +240,13 @@ static void cadet_setfreq(struct cadet *dev, unsigned freq)
                 cadet_gettune(dev);
                 if ((dev->tunestat & 0x40) == 0) {   /* Tuned */
                         dev->sigstrength = sigtable[dev->curtuner][j];
-                        return;
+                        goto reset_rds;
                 }
         }
         dev->sigstrength = 0;
+reset_rds:
+        outb(3, dev->io);
+        outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
 }
 
 
@@ -259,7 +262,7 @@ static void cadet_handler(unsigned long data)
                 outb(0x80, dev->io);      /* Select RDS fifo */
                 while ((inb(dev->io) & 0x80) != 0) {
                         dev->rdsbuf[dev->rdsin] = inb(dev->io + 1);
-                        if (dev->rdsin == dev->rdsout)
+                        if (dev->rdsin + 1 == dev->rdsout)
                                 printk(KERN_WARNING "cadet: RDS buffer overflow\n");
                         else
                                 dev->rdsin++;
@@ -278,11 +281,21 @@ static void cadet_handler(unsigned long data)
          */
         init_timer(&dev->readtimer);
         dev->readtimer.function = cadet_handler;
-        dev->readtimer.data = (unsigned long)0;
+        dev->readtimer.data = data;
         dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
         add_timer(&dev->readtimer);
 }
 
+static void cadet_start_rds(struct cadet *dev)
+{
+        dev->rdsstat = 1;
+        outb(0x80, dev->io);        /* Select RDS fifo */
+        init_timer(&dev->readtimer);
+        dev->readtimer.function = cadet_handler;
+        dev->readtimer.data = (unsigned long)dev;
+        dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
+        add_timer(&dev->readtimer);
+}
 
 static ssize_t cadet_read(struct file *file, char __user *data, size_t count, loff_t *ppos)
 {
@@ -291,26 +304,21 @@ static ssize_t cadet_read(struct file *file, char __user *data, size_t count, lo
         int i = 0;
 
         mutex_lock(&dev->lock);
-        if (dev->rdsstat == 0) {
-                dev->rdsstat = 1;
-                outb(0x80, dev->io);        /* Select RDS fifo */
-                init_timer(&dev->readtimer);
-                dev->readtimer.function = cadet_handler;
-                dev->readtimer.data = (unsigned long)dev;
-                dev->readtimer.expires = jiffies + msecs_to_jiffies(50);
-                add_timer(&dev->readtimer);
-        }
+        if (dev->rdsstat == 0)
+                cadet_start_rds(dev);
         if (dev->rdsin == dev->rdsout) {
                 if (file->f_flags & O_NONBLOCK) {
                         i = -EWOULDBLOCK;
                         goto unlock;
                 }
+                mutex_unlock(&dev->lock);
                 interruptible_sleep_on(&dev->read_queue);
+                mutex_lock(&dev->lock);
         }
         while (i < count && dev->rdsin != dev->rdsout)
                 readbuf[i++] = dev->rdsbuf[dev->rdsout++];
 
-        if (copy_to_user(data, readbuf, i))
+        if (i && copy_to_user(data, readbuf, i))
                 i = -EFAULT;
 unlock:
         mutex_unlock(&dev->lock);
@@ -345,7 +353,12 @@ static int vidioc_g_tuner(struct file *file, void *priv,
                 v->rangehigh = 1728000;    /* 108.0 MHz */
                 v->rxsubchans = cadet_getstereo(dev);
                 v->audmode = V4L2_TUNER_MODE_STEREO;
-                v->rxsubchans |= V4L2_TUNER_SUB_RDS;
+                outb(3, dev->io);
+                outb(inb(dev->io + 1) & 0x7f, dev->io + 1);
+                mdelay(100);
+                outb(3, dev->io);
+                if (inb(dev->io + 1) & 0x80)
+                        v->rxsubchans |= V4L2_TUNER_SUB_RDS;
                 break;
         case 1:
                 strlcpy(v->name, "AM", sizeof(v->name));
@@ -455,9 +468,16 @@ static int cadet_release(struct file *file)
 static unsigned int cadet_poll(struct file *file, struct poll_table_struct *wait)
 {
         struct cadet *dev = video_drvdata(file);
+        unsigned long req_events = poll_requested_events(wait);
         unsigned int res = v4l2_ctrl_poll(file, wait);
 
         poll_wait(file, &dev->read_queue, wait);
+        if (dev->rdsstat == 0 && (req_events & (POLLIN | POLLRDNORM))) {
+                mutex_lock(&dev->lock);
+                if (dev->rdsstat == 0)
+                        cadet_start_rds(dev);
+                mutex_unlock(&dev->lock);
+        }
         if (dev->rdsin != dev->rdsout)
                 res |= POLLIN | POLLRDNORM;
         return res;
@@ -628,6 +648,8 @@ static void __exit cadet_exit(void)
         video_unregister_device(&dev->vdev);
         v4l2_ctrl_handler_free(&dev->ctrl_handler);
         v4l2_device_unregister(&dev->v4l2_dev);
+        outb(7, dev->io);       /* Mute */
+        outb(0x00, dev->io + 1);
         release_region(dev->io, 2);
         pnp_unregister_driver(&cadet_pnp_driver);
 }