Re: [v4l-dvb-maintainer] [PATCH] v4l2: add hardware frequency seek ioctl interface
- Date: Sun, 23 Mar 2008 15:36:45 +0100
- From: Tobias Lorenz <tobias.lorenz@xxxxxxx>
- Subject: Re: [v4l-dvb-maintainer] [PATCH] v4l2: add hardware frequency seek ioctl interface
Hi Keith,
> I have already submit the patch to the group but we need an example
> patch/code also for the patch to be applied. I attached the previous
> submit patch here again.
Sorry, I have not found it on the v4l mailing list.
> Such as different chipset vendor may have different seek tuning
> parameters and limits.
Therefore I would not implement this as ioctls, but using VIDIOC_[G/S/ENUM]_CTRL.
#define V4L2_CID_SEEKTH (V4L2_CID_BASE+24) /* RSSI Seek Threshold */
#define V4L2_CID_SKSNR (V4L2_CID_BASE+25) /* Seek SNR Threshold */
#define V4L2_CID_SKCNT (V4L2_CID_BASE+26) /* Seek FM Impulse Detection Threshold */
But this is not done in the current implementation of the driver radio-si470x.
The device is currently just initialized using the default/recommended parameters.
> Signed-off-by: Keith Mok <ek9852@xxxxxxxxx>
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
I guess that there is also a patch to linux/include/media/v4l2-dev.h containing at least:
--- linux-2.6.23/include/media/v4l2-dev.h 2007-10-09 22:31:38.000000000 +0200
+++ linux-2.6.23.new/include/media/v4l2-dev.h 2008-03-23 14:39:16.000000000 +0100
@@ -301,6 +301,8 @@
struct v4l2_frequency *a);
int (*vidioc_s_frequency) (struct file *file, void *fh,
struct v4l2_frequency *a);
+ int (*vidioc_s_hw_freq_seek) (struct file *file, void *fh,
+ struct v4l2_hw_freq_seek *a);
/* Sliced VBI cap */
int (*vidioc_g_sliced_vbi_cap) (struct file *file, void *fh,
Is there also a function, that indicated if seek is in progress, completed or failed, propably named vidioc_g_hw_freq_seek?
Okay, I made a patch to my driver radio-si470x to implement the functionality as your patch currently needs it.
Implementing it, I found some remaining questions/issues:
1. When does seeking finish? Should the ioctl wait and return after a timeout, as currently implemented?
Where and how is it indicated else?
=> I would suggest to have a vidioc_g_hw_freq_seek to indicate that seek is in progress, completed or failed.
2. At least my device does not support wrap around at the end of the frequency band.
=> I suggest to remove that parameter. The application has to handle seek failures anyway.
3. Do we need a start_freq parameter? The usual case for the application is to start seeking at the current frequency.
And we have a vidioc_s_frequency for it, that applications can use, if they want to start seeking somewhere else.
=> I suggest to remove that parameter too.
Here is my patch. I have not modified any application yet to test the functionality. But the driver compiles cleanly.
May I update your patch using my three suggestions above?
So for my ToDo list, I have:
- modify the seek patch and the radio-si470x driver.
- add code to change the seek parameters using VIDIOC_[G/S/ENUM]_CTRL.
- patch an application to test everything.
Bye,
Toby
Signed-off-by: Tobias Lorenz <tobias.lorenz@xxxxxxx>
--- 1.0.7c_unplug_patch/radio-si470x.c 2008-03-23 11:12:07.000000000 +0100
+++ 1.0.8_hw_seek/radio-si470x.c 2008-03-23 14:40:53.000000000 +0100
@@ -86,9 +86,11 @@
* Version 1.0.7
* - usb autosuspend support
* - unplugging fixed
+ * 2008-03-17 Tobias Lorenz <tobias.lorenz@xxxxxxx
+ * Version 1.0.8
+ * - hardware frequency seek
*
* ToDo:
- * - add seeking support
* - add firmware download/update support
* - RDS support: interrupt mode, instead of polling
* - add LED status output (check if that's not already done in firmware)
@@ -98,10 +100,10 @@
/* driver definitions */
#define DRIVER_AUTHOR "Tobias Lorenz <tobias.lorenz@xxxxxxx>"
#define DRIVER_NAME "radio-si470x"
-#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 7)
+#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 8)
#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
#define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
-#define DRIVER_VERSION "1.0.7"
+#define DRIVER_VERSION "1.0.8"
/* kernel includes */
@@ -178,6 +180,11 @@ static unsigned int tune_timeout = 3000;
module_param(tune_timeout, uint, 0);
MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
+/* Seek timeout */
+static unsigned int seek_timeout = 5000;
+module_param(seek_timeout, uint, 0);
+MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
+
/* RDS buffer blocks */
static unsigned int rds_buf = 100;
module_param(rds_buf, uint, 0);
@@ -726,6 +733,71 @@ static int si470x_set_freq(struct si470x
/*
+ * si470x_set_seek - set seek
+ */
+static int si470x_set_seek(struct si470x_device *radio,
+ unsigned int wrap_around, unsigned int seek_upward)
+{
+ int retval;
+ unsigned long timeout;
+ bool timed_out = 0;
+
+ /* start seeking */
+ radio->registers[POWERCFG] |= POWERCFG_SEEK;
+ if (seek_upward)
+ radio->registers[POWERCFG] |= POWERCFG_SEEKUP;
+ retval = si470x_set_register(radio, POWERCFG);
+ if (retval < 0)
+ return retval;
+
+ /* wait till seek operation has completed */
+ timeout = jiffies + msecs_to_jiffies(seek_timeout);
+ do {
+ /* check for success */
+ do {
+ retval = si470x_get_register(radio, STATUSRSSI);
+ if (retval < 0)
+ return retval;
+ timed_out = time_after(jiffies, timeout);
+ } while (((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
+ && (!timed_out));
+
+ /* wrap around operation */
+ if ((radio->registers[STATUSRSSI] & STATUSRSSI_SF) &&
+ wrap_around) {
+ unsigned int freq;
+ /* Frequency Wrap Around (MHz) */
+ switch (band) {
+ /* 0: 87.5 - 108 MHz (USA, Europe) */
+ case 0 : freq = seek_upward ? 87.5 * FREQ_MUL
+ : 108 * FREQ_MUL; break;
+ /* 1: 76 - 108 MHz (Japan wide band) */
+ default: freq = seek_upward ? 76 * FREQ_MUL
+ : 108 * FREQ_MUL; break;
+ /* 2: 76 - 90 MHz (Japan) */
+ case 2 : freq = seek_upward ? 76 * FREQ_MUL
+ : 90 * FREQ_MUL; break;
+ };
+ si470x_set_freq(radio, freq);
+
+ /* restart seek */
+ retval = si470x_set_register(radio, POWERCFG);
+ if (retval < 0)
+ return retval;
+ }
+ } while (((radio->registers[STATUSRSSI] & STATUSRSSI_SF) == 1) &&
+ (!timed_out));
+ if (timed_out)
+ printk(KERN_WARNING DRIVER_NAME
+ ": seek does not finish after %u ms\n", seek_timeout);
+
+ /* stop seeking */
+ radio->registers[POWERCFG] &= ~POWERCFG_SEEK;
+ return si470x_set_register(radio, POWERCFG);
+}
+
+
+/*
* si470x_start - switch on radio
*/
static int si470x_start(struct si470x_device *radio)
@@ -1126,7 +1198,8 @@ static int si470x_vidioc_querycap(struct
strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
sprintf(capability->bus_info, "USB");
capability->version = DRIVER_KERNEL_VERSION;
- capability->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+ capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
+ V4L2_CAP_TUNER | V4L2_CAP_RADIO;
return 0;
}
@@ -1399,6 +1472,32 @@ static int si470x_vidioc_s_frequency(str
/*
+ * si470x_vidioc_s_hw_freq_seek - set hardware frequency seek
+ */
+static int si470x_vidioc_s_hw_freq_seek(struct file *file, void *priv,
+ struct v4l2_hw_freq_seek *seek)
+{
+ struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+ int retval;
+
+ if (seek->type != V4L2_TUNER_RADIO)
+ return -EINVAL;
+
+ retval = si470x_set_freq(radio, seek->start_freq);
+ if (retval < 0)
+ printk(KERN_WARNING DRIVER_NAME
+ ": set frequency failed with %d\n", retval);
+
+ retval = si470x_set_seek(radio, seek->wrap_around, seek->seek_upward);
+ if (retval < 0)
+ printk(KERN_WARNING DRIVER_NAME
+ ": set seek failed with %d\n", retval);
+
+ return 0;
+}
+
+
+/*
* si470x_viddev_tamples - video device interface
*/
static struct video_device si470x_viddev_template = {
@@ -1418,6 +1517,7 @@ static struct video_device si470x_viddev
.vidioc_s_tuner = si470x_vidioc_s_tuner,
.vidioc_g_frequency = si470x_vidioc_g_frequency,
.vidioc_s_frequency = si470x_vidioc_s_frequency,
+ .vidioc_s_hw_freq_seek = si470x_vidioc_s_hw_freq_seek,
.owner = THIS_MODULE,
};
--
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