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Commit d7448a8d authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

V4L/DVB (6952): Add code for autoloading em28xx-alsa, if needed 



Older em28xx devices does implement standard Audio Class.

However, on newer devices, this were replaced by a Vendor Class. This
patch autodetects that an em28xx lacks Audio Class and auto-loads
em28xx-alsa, for the devices that implements only a Vendor Class.

For devices with Audio Class, snd-usb-audio module will provide an ALSA
interface.

This patch uses the request_module_async function as defined on cx88-mpeg.c, 
originally wrote by Markus Rechberger.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent 6d79468d

drivers/media/video/em28xx/em28xx-audio.c

+0 −1
Original line number Diff line number Diff line
@@ -472,7 +472,6 @@ static struct em28xx_ops audio_ops = { 


static int __init em28xx_alsa_register(void)

{

	request_module("em28xx");

	return em28xx_register_extension(&audio_ops);

}

drivers/media/video/em28xx/em28xx-video.c

+38 −0
Original line number Diff line number Diff line
@@ -1668,6 +1668,10 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev, 
	dev->em28xx_read_reg_req = em28xx_read_reg_req;

	dev->is_em2800 = em28xx_boards[dev->model].is_em2800;



	errCode = em28xx_read_reg(dev, CHIPID_REG);

	if (errCode >= 0)

		em28xx_info("em28xx chip ID = %d\n", errCode);



	em28xx_pre_card_setup(dev);



	errCode = em28xx_config(dev);
@@ -1794,6 +1798,25 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev, 
	return 0;

}



#if defined(CONFIG_MODULES) && defined(MODULE)

static void request_module_async(struct work_struct *work)

{

	struct em28xx *dev = container_of(work,

			     struct em28xx, request_module_wk);



	if (!dev->has_audio_class)

		request_module("em28xx-alsa");

}



static void request_modules(struct em28xx *dev)

{

	INIT_WORK(&dev->request_module_wk, request_module_async);

	schedule_work(&dev->request_module_wk);

}

#else

#define request_modules(dev)

#endif /* CONFIG_MODULES */



/*

 * em28xx_usb_probe()

 * checks for supported devices
@@ -1864,6 +1887,18 @@ static int em28xx_usb_probe(struct usb_interface *interface, 
	dev->devno = nr;

	dev->model = id->driver_info;



	/* Checks if audio is provided by some interface */

	for (i = 0; i < udev->config->desc.bNumInterfaces; i++) {

		uif = udev->config->interface[i];

		if (uif->altsetting[0].desc.bInterfaceClass == USB_CLASS_AUDIO) {

			dev->has_audio_class = 1;

			break;

		}

	}



	printk(KERN_INFO DRIVER_NAME " %s usb audio class\n",

		   dev->has_audio_class ? "Has" : "Doesn't have");



	/* compute alternate max packet sizes */

	uif = udev->actconfig->interface[0];
@@ -1900,6 +1935,9 @@ static int em28xx_usb_probe(struct usb_interface *interface, 


	/* save our data pointer in this interface device */

	usb_set_intfdata(interface, dev);



	request_modules(dev);



	return 0;

}

drivers/media/video/em28xx/em28xx.h

+3 −0
Original line number Diff line number Diff line
@@ -246,6 +246,7 @@ struct em28xx { 
	unsigned int has_msp34xx:1;

	unsigned int has_tda9887:1;

	unsigned int stream_on:1;	/* Locks streams */

	unsigned int has_audio_class:1;



	int video_inputs;	/* number of video inputs */

	struct list_head	devlist;
@@ -295,6 +296,8 @@ struct em28xx { 
	enum em28xx_stream_state stream;

	enum em28xx_io_method io;



	struct work_struct         request_module_wk;



	/* locks */

	struct mutex lock;

	spinlock_t queue_lock;