Re: [RFC, PATCH 1/2] gspca: add input support for interrupt endpoints

["Németh Márton" <nm127@freemail.hu>]

Hi,

first of all: Hans and Jef, thank you for your helping guidance with
this patchset.

Jean-Francois Moine wrote:
> Hi,
> On Fri, 20 Nov 2009 08:14:10 +0100
> Németh Márton <nm127@freemail.hu> wrote:
>> Hans de Goede wrote:
> 	[snip]
>>> I'm personally not a big fan of adding more configuration options,
>>> what should be done instead is make the compilation dependent on the
>>> CONFIG_INPUT kernel config option, I see no reason not to enable
>>> this when CONFIG_INPUT is enabled.  
>> I added dependency on CONFIG_INPUT.
> 
> The option USB_GSPCA_SN9C20X_EVDEV should be removed too.

This one is a bit difficult for me because I don't have access
to device like that thus I would not be able to test the changes.

>>> Some other remarks, you are using:
>>> printk(KERN_DEBUG
>>> In various places, please use
>>> PDEBUG(D_FOO
>>> instead so that the output can be controlled using the gspca
>>> module's debug parameter.  
>> I created a PDEBUG_INPUT() for this otherwise there is a circular
>> dependency between gspca_main and gspca_input because of the variable
>> gspca_debug.
> 
> That is because you created a separate module.
> 
>>> And in gspca_input_connect() you are setting name to "pac7302", this
>>> needs to be generalized somehow,  
>> I use now gspca_dev->sd_desc->name.
> 
> OK for me.
> 
>>> and also you are not setting the
>>> input device's parent there, I think we need to fix that too
>>> (although I'm not sure what it should be set to).  
>> I don't know what to use there, maybe somebody on the linux-input
>> mailing list could tell.
> 
> sn9c20x sets it to &gspca_dev->dev->dev.
> 
>> Also, I am not sure about setting of input_dev->id.version.
> 
> It seems it can be EV_VERSION only.

The right solution is to use usb_to_input_id() from linux/usb/input.h ,
I think.

>> Unfortunately I still get the following error when I start streaming,
>> stop streaming or unplug the device:
>>
>> [ 6876.780726] uhci_hcd 0000:00:10.1: dma_pool_free buffer-32,
>> de0ad168/1e0ad168 (bad dma)
> 
> As there is no 'break' in gspca_input_create_urb(), many URBs are
> created.

I added 'break' in the loop, which makes no real difference because
my device have only one interrupt in endpoint. The error message is
printed when the usb_buffer_free() is called in gspca_input_destroy_urb():

[ 6362.113264] gspca_input: Freeing buffer
[ 6362.113284] uhci_hcd 0000:00:1d.1: dma_pool_free buffer-32, f5ada948/35ada948 (bad dma)
[ 6362.113296] gspca_input: Freeing URB

>> Please find the new version of this patch later in this mail.
> 
> Here are some other remarks:
> 
> - As the input functions are called from the gspca main only, and as
>   they cannot be used by other drivers, there is no need to have a
>   separate module.

The input.c is now part of the gspca_main.ko.

> - Almost all other webcams who have buttons ask for polling. So, the
>   'int_urb' should be pac7302 dependent (in 'struct sd' and not in
>   'struct gspca_dev').

I have the problem with this point that 'int_urb' has to be accessed by
gspca_main. This means that the 'int_urb' cannot be pac7302 dependent, I
think.

I ran checkpatch.pl to eliminate coding style problems.

Regards,

	Márton Németh
---
From: Márton Németh <nm127@freemail.hu>

Add helper functions for interrupt endpoint based input handling.

Signed-off-by: Márton Németh <nm127@freemail.hu>
---

diff -r abfdd03b800d linux/drivers/media/video/gspca/Makefile
--- a/linux/drivers/media/video/gspca/Makefile	Thu Nov 19 10:34:21 2009 +0100
+++ b/linux/drivers/media/video/gspca/Makefile	Sat Nov 21 13:02:41 2009 +0100
@@ -30,6 +30,9 @@
 obj-$(CONFIG_USB_GSPCA_ZC3XX)    += gspca_zc3xx.o

 gspca_main-objs     := gspca.o
+ifeq ($(CONFIG_INPUT),y)
+    gspca_main-objs += input.o
+endif
 gspca_conex-objs    := conex.o
 gspca_etoms-objs    := etoms.o
 gspca_finepix-objs  := finepix.o
diff -r abfdd03b800d linux/drivers/media/video/gspca/gspca.c
--- a/linux/drivers/media/video/gspca/gspca.c	Thu Nov 19 10:34:21 2009 +0100
+++ b/linux/drivers/media/video/gspca/gspca.c	Sat Nov 21 13:02:41 2009 +0100
@@ -41,6 +41,9 @@

 #include "gspca.h"

+#include <linux/input.h>
+#include "input.h"
+
 /* global values */
 #define DEF_NURBS 3		/* default number of URBs */
 #if DEF_NURBS > MAX_NURBS
@@ -499,11 +502,13 @@
 			i, ep->desc.bEndpointAddress);
 	gspca_dev->alt = i;		/* memorize the current alt setting */
 	if (gspca_dev->nbalt > 1) {
+		gspca_input_destroy_urb(gspca_dev);
 		ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, i);
 		if (ret < 0) {
 			err("set alt %d err %d", i, ret);
-			return NULL;
+			ep = NULL;
 		}
+		gspca_input_create_urb(gspca_dev);
 	}
 	return ep;
 }
@@ -707,7 +712,9 @@
 		if (gspca_dev->sd_desc->stopN)
 			gspca_dev->sd_desc->stopN(gspca_dev);
 		destroy_urbs(gspca_dev);
+		gspca_input_destroy_urb(gspca_dev);
 		gspca_set_alt0(gspca_dev);
+		gspca_input_create_urb(gspca_dev);
 	}

 	/* always call stop0 to free the subdriver's resources */
@@ -2088,6 +2095,11 @@

 	usb_set_intfdata(intf, gspca_dev);
 	PDEBUG(D_PROBE, "/dev/video%d created", gspca_dev->vdev.num);
+
+	ret = gspca_input_connect(gspca_dev);
+	if (0 <= ret)
+		ret = gspca_input_create_urb(gspca_dev);
+
 	return 0;
 out:
 	kfree(gspca_dev->usb_buf);
@@ -2105,6 +2117,7 @@
 void gspca_disconnect(struct usb_interface *intf)
 {
 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
+	struct input_dev *input_dev;

 	PDEBUG(D_PROBE, "/dev/video%d disconnect", gspca_dev->vdev.num);
 	mutex_lock(&gspca_dev->usb_lock);
@@ -2115,6 +2128,13 @@
 		wake_up_interruptible(&gspca_dev->wq);
 	}

+	gspca_input_destroy_urb(gspca_dev);
+	input_dev = gspca_dev->input_dev;
+	if (input_dev) {
+		gspca_dev->input_dev = NULL;
+		input_unregister_device(input_dev);
+	}
+
 	/* the device is freed at exit of this function */
 	gspca_dev->dev = NULL;
 	mutex_unlock(&gspca_dev->usb_lock);
@@ -2140,6 +2160,7 @@
 	if (gspca_dev->sd_desc->stopN)
 		gspca_dev->sd_desc->stopN(gspca_dev);
 	destroy_urbs(gspca_dev);
+	gspca_input_destroy_urb(gspca_dev);
 	gspca_set_alt0(gspca_dev);
 	if (gspca_dev->sd_desc->stop0)
 		gspca_dev->sd_desc->stop0(gspca_dev);
@@ -2153,6 +2174,7 @@

 	gspca_dev->frozen = 0;
 	gspca_dev->sd_desc->init(gspca_dev);
+	gspca_input_create_urb(gspca_dev);
 	if (gspca_dev->streaming)
 		return gspca_init_transfer(gspca_dev);
 	return 0;
diff -r abfdd03b800d linux/drivers/media/video/gspca/gspca.h
--- a/linux/drivers/media/video/gspca/gspca.h	Thu Nov 19 10:34:21 2009 +0100
+++ b/linux/drivers/media/video/gspca/gspca.h	Sat Nov 21 13:02:41 2009 +0100
@@ -81,6 +81,9 @@
 typedef void (*cam_pkt_op) (struct gspca_dev *gspca_dev,
 				u8 *data,
 				int len);
+typedef int (*cam_int_pkt_op) (struct gspca_dev *gspca_dev,
+				u8 *data,
+				int len);

 struct ctrl {
 	struct v4l2_queryctrl qctrl;
@@ -116,6 +119,9 @@
 	cam_reg_op get_register;
 #endif
 	cam_ident_op get_chip_ident;
+#ifdef CONFIG_INPUT
+	cam_int_pkt_op int_pkt_scan;
+#endif
 };

 /* packet types when moving from iso buf to frame buf */
@@ -138,6 +144,10 @@
 	struct module *module;		/* subdriver handling the device */
 	struct usb_device *dev;
 	struct file *capt_file;		/* file doing video capture */
+#ifdef CONFIG_INPUT
+	struct input_dev *input_dev;
+	char phys[64];			/* physical device path */
+#endif

 	struct cam cam;				/* device information */
 	const struct sd_desc *sd_desc;		/* subdriver description */
@@ -147,6 +157,9 @@
 #define USB_BUF_SZ 64
 	__u8 *usb_buf;				/* buffer for USB exchanges */
 	struct urb *urb[MAX_NURBS];
+#ifdef CONFIG_INPUT
+	struct urb *int_urb;
+#endif

 	__u8 *frbuf;				/* buffer for nframes */
 	struct gspca_frame frame[GSPCA_MAX_FRAMES];
diff -r abfdd03b800d linux/drivers/media/video/gspca/input.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/linux/drivers/media/video/gspca/input.c	Sat Nov 21 13:02:41 2009 +0100
@@ -0,0 +1,174 @@
+/*
+ * Input handling for gspca USB camera drivers
+ *
+ * Copyright (C) 2009 Márton Németh <nm127@freemail.hu>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/input.h>
+#include <linux/usb/input.h>
+
+#include "gspca.h"
+#include "input.h"
+
+#define MODULE_NAME "gspca_input"
+
+
+#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;
+
+	if (urb->status == 0) {
+		if (gspca_dev->sd_desc->int_pkt_scan(gspca_dev,
+		    urb->transfer_buffer, urb->actual_length) < 0) {
+			PDEBUG(D_ERR, "Unknown packet received");
+		}
+
+		ret = usb_submit_urb(urb, GFP_ATOMIC);
+		if (ret < 0)
+			PDEBUG(D_ERR, "Resubmit URB failed with error %i", ret);
+	}
+}
+
+int gspca_input_connect(struct gspca_dev *dev)
+{
+	struct input_dev *input_dev;
+	int err = 0;
+
+	dev->input_dev = NULL;
+	if (dev->sd_desc->int_pkt_scan)  {
+		input_dev = input_allocate_device();
+		if (!input_dev)
+			return -ENOMEM;
+
+		usb_make_path(dev->dev, dev->phys, sizeof(dev->phys));
+		strlcat(dev->phys, "/input0", sizeof(dev->phys));
+
+		input_dev->name = dev->sd_desc->name;
+		input_dev->phys = dev->phys;
+
+		usb_to_input_id(dev->dev, &input_dev->id);
+
+		input_dev->evbit[0] = BIT_MASK(EV_KEY);
+		input_dev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);
+		input_dev->dev.parent = &dev->dev->dev;
+
+		err = input_register_device(input_dev);
+		if (err) {
+			PDEBUG(D_ERR, "Input device registration failed "
+				"with error %i", err);
+			input_dev->dev.parent = NULL;
+			input_free_device(input_dev);
+		} else {
+			dev->input_dev = input_dev;
+		}
+	} else
+		err = -EINVAL;
+
+	return err;
+}
+EXPORT_SYMBOL(gspca_input_connect);
+
+static int alloc_and_submit_int_urb(struct gspca_dev *gspca_dev,
+			  struct usb_endpoint_descriptor *ep)
+{
+	unsigned int buffer_len;
+	int interval;
+	struct urb *urb;
+	struct usb_device *dev;
+	void *buffer = NULL;
+	int ret = -EINVAL;
+
+	buffer_len = ep->wMaxPacketSize;
+	interval = ep->bInterval;
+	PDEBUG(D_PROBE, "found int in endpoint: 0x%x, "
+		"buffer_len=%u, interval=%u",
+		ep->bEndpointAddress, buffer_len, interval);
+
+	dev = gspca_dev->dev;
+	gspca_dev->int_urb = NULL;
+
+	buffer = kmalloc(ep->wMaxPacketSize, GFP_KERNEL);
+	if (buffer)
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+	else {
+		PDEBUG(D_ERR, "buffer allocation failed\n");
+		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);
+		gspca_dev->int_urb = urb;
+		ret = usb_submit_urb(urb, GFP_KERNEL);
+		if (ret < 0)
+			PDEBUG(D_ERR, "submit URB failed with error %i", ret);
+	} else
+		PDEBUG(D_ERR, "URB allocation failed");
+	return ret;
+}
+
+int gspca_input_create_urb(struct gspca_dev *gspca_dev)
+{
+	int ret = -EINVAL;
+	struct usb_interface *intf;
+	struct usb_host_interface *intf_desc;
+	struct usb_endpoint_descriptor *ep;
+	int i;
+
+	if (gspca_dev->sd_desc->int_pkt_scan)  {
+		intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
+		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)) {
+
+				ret = alloc_and_submit_int_urb(gspca_dev, ep);
+				break;
+			}
+		}
+	}
+	return ret;
+}
+EXPORT_SYMBOL(gspca_input_create_urb);
+
+void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
+{
+	struct urb *urb;
+
+	urb = gspca_dev->int_urb;
+	if (urb) {
+		gspca_dev->int_urb = NULL;
+		usb_kill_urb(urb);
+		PDEBUG(D_PROBE, "Freeing buffer");
+		usb_buffer_free(gspca_dev->dev,
+				urb->transfer_buffer_length,
+				urb->transfer_buffer,
+				urb->transfer_dma);
+		PDEBUG(D_PROBE, "Freeing URB");
+		usb_free_urb(urb);
+	}
+}
+EXPORT_SYMBOL(gspca_input_destroy_urb);
diff -r abfdd03b800d linux/drivers/media/video/gspca/input.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/linux/drivers/media/video/gspca/input.h	Sat Nov 21 13:02:41 2009 +0100
@@ -0,0 +1,36 @@
+/*
+ * Input handling for gspca USB camera drivers
+ *
+ * Copyright (C) 2009 Márton Németh <nm127@freemail.hu>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef GSPCA_INPUT_H
+#define GSPCA_INPUT_H
+
+#include "gspca.h"
+
+#ifdef CONFIG_INPUT
+int gspca_input_connect(struct gspca_dev *gspca_dev);
+int gspca_input_create_urb(struct gspca_dev *gspca_dev);
+void gspca_input_destroy_urb(struct gspca_dev *gspca_dev);
+#else
+#define gspca_input_connect(gspca_dev)		0
+#define gspca_input_create_urb(gspca_dev)	0
+#define gspca_input_destroy_urb(gspca_dev)
+#endif
+
+#endif
--
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