diff options
Diffstat (limited to 'drivers/media/radio/si470x/radio-si470x-common.c')
-rw-r--r-- | drivers/media/radio/si470x/radio-si470x-common.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/media/radio/si470x/radio-si470x-common.c b/drivers/media/radio/si470x/radio-si470x-common.c index f33315f..4da0f15 100644 --- a/drivers/media/radio/si470x/radio-si470x-common.c +++ b/drivers/media/radio/si470x/radio-si470x-common.c @@ -426,6 +426,104 @@ int si470x_rds_on(struct si470x_device *radio) /************************************************************************** + * File Operations Interface + **************************************************************************/ + +/* + * si470x_fops_read - read RDS data + */ +static ssize_t si470x_fops_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct si470x_device *radio = video_drvdata(file); + int retval = 0; + unsigned int block_count = 0; + + /* switch on rds reception */ + if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0) + si470x_rds_on(radio); + + /* block if no new data available */ + while (radio->wr_index == radio->rd_index) { + if (file->f_flags & O_NONBLOCK) { + retval = -EWOULDBLOCK; + goto done; + } + if (wait_event_interruptible(radio->read_queue, + radio->wr_index != radio->rd_index) < 0) { + retval = -EINTR; + goto done; + } + } + + /* calculate block count from byte count */ + count /= 3; + + /* copy RDS block out of internal buffer and to user buffer */ + mutex_lock(&radio->lock); + while (block_count < count) { + if (radio->rd_index == radio->wr_index) + break; + + /* always transfer rds complete blocks */ + if (copy_to_user(buf, &radio->buffer[radio->rd_index], 3)) + /* retval = -EFAULT; */ + break; + + /* increment and wrap read pointer */ + radio->rd_index += 3; + if (radio->rd_index >= radio->buf_size) + radio->rd_index = 0; + + /* increment counters */ + block_count++; + buf += 3; + retval += 3; + } + mutex_unlock(&radio->lock); + +done: + return retval; +} + + +/* + * si470x_fops_poll - poll RDS data + */ +static unsigned int si470x_fops_poll(struct file *file, + struct poll_table_struct *pts) +{ + struct si470x_device *radio = video_drvdata(file); + int retval = 0; + + /* switch on rds reception */ + if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0) + si470x_rds_on(radio); + + poll_wait(file, &radio->read_queue, pts); + + if (radio->rd_index != radio->wr_index) + retval = POLLIN | POLLRDNORM; + + return retval; +} + + +/* + * si470x_fops - file operations interface + */ +static const struct v4l2_file_operations si470x_fops = { + .owner = THIS_MODULE, + .read = si470x_fops_read, + .poll = si470x_fops_poll, + .ioctl = video_ioctl2, + .open = si470x_fops_open, + .release = si470x_fops_release, +}; + + + +/************************************************************************** * Video4Linux Interface **************************************************************************/ |