Re: [RFC, PATCH] gspca pac7302: add support for camera button

["Németh Márton" <nm127@freemail.hu>]

Hi,
Hans de Goede wrote:
> Hi,
> 
> Thanks for working on this! I think it would be great if we could
> get support for camera buttons in general into gspca.
> 
> I've not looked closely at your code yet, have you looked at
> the camera button code in the gspca sn9c20x.c driver? Also I would really

As you proposed I had a look on sn9c20x. It seems that sn9c20x uses register read
via USB control message. The pac7302 uses interrupt endpoint. So it looks like
quite different to me. Currently I see the common point in the connection
to input subsystem only.

> like to see as much of the button handling code as possible go into
> the gspca core. AFAIK many many camera's use an usb interrupt ep for this, so
> I would like to see the setting up and cleanup of this interrupt ep be in
> the core (as said before see the sn9c20x driver for another driver which
> does such things).

Unfortunately I do not know how the USB descriptors of other webcams look like.
I have access to two webcams which are handled by gspca:

 1. Labtec Webcam 2200 (USB ID 093a:2626):

	Interface Number: 0
		Name: (none)
		Alternate Number: 0
		Class: ff(vend.)
		Sub Class: ff
		Protocol: ff
		Number of Endpoints: 6

			[...]

			Endpoint Address: 83
			Direction: in
			Attribute: 3
			Type: Int.
			Max Packet Size: 2
			Interval: 50ms

    This endpoint handles the capture button.

 2. Trust 610 LCD PowerC@m Zoom (USB ID 06d6:0031)

	Interface Number: 1
		Name: (none)
		Alternate Number: 0
		Class: ff(vend.)
		Sub Class: 00
		Protocol: 00
		Number of Endpoints: 3

			[...]

			Endpoint Address: 84
			Direction: in
			Attribute: 3
			Type: Int.
			Max Packet Size: 1
			Interval: 1ms

    I don't know what this interrupt endpoint is useful for.

Comparing these two endpoints shows the common and different points:
Common: interface class, endpoint direction, endpoint type.
Different: interface number, sub class, protocol, endpoint address, max
           packet size, interval.

Maybe the second example is not a good one because I don't know whether
the interrupt endpoint is used for buttons or not.

Do you have access to webcams equipped with button? Could you please
send the device descriptor (lsusb -v) about these devices in order
the common points can be identified for interrupt endpoints?

Regards,

	Márton Németh

> On 11/15/2009 09:47 AM, Németh Márton wrote:
>> From: Márton Németh<nm127@freemail.hu>
>>
>> Add support for snapshot button found on Labtec Webcam 2200.
>>
>> Signed-off-by: Márton Németh<nm127@freemail.hu>
>> ---
>> Hi,
>>
>> this is the first trial to add support for the snapshot button. This
>> code is working only before the streaming is started. When the streaming
>> is started the alternate number of the interface 0 is changed and the
>> interrupt URB is no longer usable. I guess the interrupt URB is to
>> be reconstructed every time when the alternate number is changed.
>>
>> When I disconnect the device I get the following error:
>>
>> uhci_hcd 0000:00:1d.1: dma_pool_free buffer-32, f58ba168/358ba168 (bad dma)
>>
>> I guess something is wrong in this patch with the cleanup routine.
>>
>> Regards,
>>
>> 	Márton Németh
>>
>> ---
>> diff -r 09c1284de47d linux/drivers/media/video/gspca/gspca.h
>> --- a/linux/drivers/media/video/gspca/gspca.h	Sat Nov 14 08:58:12 2009 +0100
>> +++ b/linux/drivers/media/video/gspca/gspca.h	Sun Nov 15 10:40:54 2009 +0100
>> @@ -138,6 +138,7 @@
>>   	struct module *module;		/* subdriver handling the device */
>>   	struct usb_device *dev;
>>   	struct file *capt_file;		/* file doing video capture */
>> +	struct input_dev *input_dev;
>>
>>   	struct cam cam;				/* device information */
>>   	const struct sd_desc *sd_desc;		/* subdriver description */
>> @@ -147,6 +148,7 @@
>>   #define USB_BUF_SZ 64
>>   	__u8 *usb_buf;				/* buffer for USB exchanges */
>>   	struct urb *urb[MAX_NURBS];
>> +	struct urb *int_urb;
>>
>>   	__u8 *frbuf;				/* buffer for nframes */
>>   	struct gspca_frame frame[GSPCA_MAX_FRAMES];
>> diff -r 09c1284de47d linux/drivers/media/video/gspca/pac7302.c
>> --- a/linux/drivers/media/video/gspca/pac7302.c	Sat Nov 14 08:58:12 2009 +0100
>> +++ b/linux/drivers/media/video/gspca/pac7302.c	Sun Nov 15 10:40:54 2009 +0100
>> @@ -68,6 +68,7 @@
>>
>>   #define MODULE_NAME "pac7302"
>>
>> +#include<linux/input.h>
>>   #include<media/v4l2-chip-ident.h>
>>   #include "gspca.h"
>>
>> @@ -1220,6 +1221,50 @@
>>   }
>>   #endif
>>
>> +#if LINUX_VERSION_CODE<  KERNEL_VERSION(2, 6, 19)
>> +static void int_irq(struct urb *urb, struct pt_regs *regs)
>> +#else
>> +static void int_irq(struct urb *urb)
>> +#endif
>> +{
>> +	struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
>> +	int ret;
>> +	int i;
>> +	__u8 data0, data1;
>> +
>> +	printk(KERN_DEBUG "int_irq()\n");
>> +	printk(KERN_DEBUG "urb->status: %i\n", urb->status);
>> +	if (urb->status == 0) {
>> +		printk(KERN_DEBUG "urb->actual_length: %u\n", urb->actual_length);
>> +		for (i = 0; i<  urb->actual_length; i++) {
>> +			printk(KERN_DEBUG "urb->transfer_buffer[%i]=0x%x\n",
>> +				i, ((__u8*)urb->transfer_buffer)[i]);
>> +		}
>> +		if (urb->actual_length == 2) {
>> +			data0 = ((__u8*)urb->transfer_buffer)[0];
>> +			data1 = ((__u8*)urb->transfer_buffer)[1];
>> +			if ((data0 == 0x00&&  data1 == 0x11) ||
>> +			    (data0 == 0x22&&  data1 == 0x33) ||
>> +			    (data0 == 0x44&&  data1 == 0x55) ||
>> +			    (data0 == 0x66&&  data1 == 0x77) ||
>> +			    (data0 == 0x88&&  data1 == 0x99) ||
>> +			    (data0 == 0xaa&&  data1 == 0xbb) ||
>> +			    (data0 == 0xcc&&  data1 == 0xdd) ||
>> +			    (data0 == 0xee&&  data1 == 0xff)) {
>> +				input_report_key(gspca_dev->input_dev, KEY_CAMERA, 1);
>> +				input_sync(gspca_dev->input_dev);
>> +				input_report_key(gspca_dev->input_dev, KEY_CAMERA, 0);
>> +				input_sync(gspca_dev->input_dev);
>> +			} else
>> +				printk(KERN_DEBUG "Unknown packet received\n");
>> +		}
>> +		ret = usb_submit_urb(urb, GFP_ATOMIC);
>> +		printk(KERN_DEBUG "resubmit urb: %i\n", ret);
>> +	}
>> +
>> +}
>> +
>> +
>>   /* sub-driver description for pac7302 */
>>   static struct sd_desc sd_desc = {
>>   	.name = MODULE_NAME,
>> @@ -1254,19 +1299,132 @@
>>   };
>>   MODULE_DEVICE_TABLE(usb, device_table);
>>
>> +static int init_camera_input(struct gspca_dev *gspca_dev, const struct usb_device_id *id)
>> +{
>> +	struct input_dev *input_dev;
>> +	int err;
>> +
>> +	printk(KERN_DEBUG "allocating input device\n");
>> +	input_dev = input_allocate_device();
>> +	if (!input_dev)
>> +		return -ENOMEM;
>> +
>> +	//input_dev->name = "Camera capture button";
>> +	//input_dev->phys = "camera";
>> +	input_dev->id.bustype = BUS_USB;
>> +	input_dev->id.vendor = id->idVendor;
>> +	input_dev->id.product = id->idProduct;
>> +	input_dev->id.version = id->bcdDevice_hi;
>> +	//input_dev->id.version = id->bcdDevice_lo;
>> +
>> +	input_dev->evbit[0] = BIT_MASK(EV_KEY);
>> +	input_dev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);
>> +	//input_dev->dev.parent = ;
>> +
>> +	printk(KERN_DEBUG "registering input device\n");
>> +	err = input_register_device(input_dev);
>> +	if (err) {
>> +		input_dev->dev.parent = NULL;
>> +		input_free_device(input_dev);
>> +	} else {
>> +		gspca_dev->input_dev = input_dev;
>> +	}
>> +
>> +	return err;
>> +}
>> +
>>   /* -- device connect -- */
>>   static int sd_probe(struct usb_interface *intf,
>>   			const struct usb_device_id *id)
>>   {
>> -	return gspca_dev_probe(intf, id,&sd_desc, sizeof(struct sd),
>> +	int ret;
>> +	struct usb_host_interface *intf_desc;
>> +	struct usb_endpoint_descriptor *ep;
>> +	int i;
>> +
>> +	struct urb *urb;
>> +	void* buffer = NULL;
>> +	unsigned int buffer_len;
>> +	int interval;
>> +	struct gspca_dev *gspca_dev;
>> +	struct usb_device *dev;
>> +
>> +	ret = gspca_dev_probe(intf, id,&sd_desc, sizeof(struct sd),
>>   				THIS_MODULE);
>> +	if (0<= ret) {
>> +		intf_desc = intf->cur_altsetting;
>> +		for (i = 0; i<  intf_desc->desc.bNumEndpoints; i++) {
>> +			ep =&intf_desc->endpoint[i].desc;
>> +			if ((ep->bEndpointAddress&  USB_DIR_IN)&&
>> +			    ((ep->bmAttributes&  USB_ENDPOINT_XFERTYPE_MASK)
>> +				== USB_ENDPOINT_XFER_INT)) {
>> +
>> +				buffer_len = ep->wMaxPacketSize;
>> +				interval = ep->bInterval;
>> +				printk(KERN_DEBUG "found int in endpoint: 0x%x\n", ep->bEndpointAddress);
>> +				printk(KERN_DEBUG " - buffer_len = %u\n", buffer_len);
>> +				printk(KERN_DEBUG " - interval = %u\n", interval);
>> +
>> +				gspca_dev = usb_get_intfdata(intf);
>> +				dev = gspca_dev->dev;
>> +				gspca_dev->int_urb = NULL;
>> +				gspca_dev->input_dev = NULL;
>> +
>> +				buffer = kmalloc(ep->wMaxPacketSize, GFP_KERNEL);
>> +				if (buffer)
>> +					urb = usb_alloc_urb(0, GFP_KERNEL);
>> +				else {
>> +					kfree(buffer);
>> +					urb = NULL;
>> +				}
>> +				if (buffer&&  urb) {
>> +					usb_fill_int_urb(urb, dev,
>> +						usb_rcvintpipe(dev, ep->bEndpointAddress),
>> +						buffer, buffer_len,
>> +						int_irq, (void*)gspca_dev, interval);
>> +					ret = init_camera_input(gspca_dev, id);
>> +					if (0<= ret) {
>> +						gspca_dev->int_urb = urb;
>> +						ret = usb_submit_urb(urb, GFP_KERNEL);
>> +						printk(KERN_DEBUG "usb_submit_urb() returns %i\n", ret);
>> +					}
>> +				}
>> +			}
>> +
>> +		}
>> +	}
>> +	return ret;
>> +}
>> +
>> +static void sd_disconnect(struct usb_interface *intf)
>> +{
>> +	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
>> +	struct urb *urb;
>> +	struct input_dev *input_dev;
>> +
>> +	urb = gspca_dev->int_urb;
>> +	if (urb != NULL) {
>> +		gspca_dev->int_urb = NULL;
>> +		usb_kill_urb(urb);
>> +		usb_buffer_free(gspca_dev->dev,
>> +				urb->transfer_buffer_length,
>> +				urb->transfer_buffer,
>> +				urb->transfer_dma);
>> +		usb_free_urb(urb);
>> +	}
>> +	input_dev = gspca_dev->input_dev;
>> +	if (input_dev) {
>> +		gspca_dev->input_dev = NULL;
>> +		input_unregister_device(input_dev);
>> +	}
>> +	gspca_disconnect(intf);
>>   }
>>
>>   static struct usb_driver sd_driver = {
>>   	.name = MODULE_NAME,
>>   	.id_table = device_table,
>>   	.probe = sd_probe,
>> -	.disconnect = gspca_disconnect,
>> +	.disconnect = sd_disconnect,
>>   #ifdef CONFIG_PM
>>   	.suspend = gspca_suspend,
>>   	.resume = gspca_resume,