[PATCH v7 0/2] usb: gadget: f_fs: userspace API fixes and improvements

[PATCH v7 0/2] usb: gadget: f_fs: userspace API fixes and improvements

[Robert Baldyga]

This patchset contains changes in FunctionFS making it easier and
safer to use. It fixes bug in endpoint files handling code, adds new
ioctl allowing to obtain endpoint descriptor, and introduces virtual
address mapping which allows to separate endpoint address space in
function from physical endpoint addresses, and introduces new endpoint
files naming convention.

Changelog:

v7:
- return proper value from ffs_epfile_ioctl() function
- remove patch "usb: gadget: f_fs: fix the redundant ep files problem"
  from this patchset because it's already in Gregs tree

v6: https://lkml.org/lkml/2014/8/25/101
- unlock spinlock before copy_to_user() call 
- remove duplicated eps_count value check
- few minor fixes

v5: https://lkml.org/lkml/2014/8/21/252
- fix typo pointed by Sergei Shtylyov

v4: https://lkml.org/lkml/2014/8/20/277
- change if() sequence into switch() statement
v3: https://lkml.org/lkml/2014/7/30/115
- move fix for the redundant ep files problem into sepatare patch
- merge user space API affecting changes into single patch
- add flag switching between old and new style API

v2: https://lkml.org/lkml/2014/7/25/296
- return proper endpont address in setup request handling
- add patch usb: gadget: f_fs: add ioctl returning ep descriptor
- add patch usb: gadget: f_fs: make numbers in ep file names the same
  as ep addresses

v1: https://lkml.org/lkml/2014/7/18/1010

Robert Baldyga (2):
  usb: gadget: f_fs: add ioctl returning ep descriptor
  usb: gadget: f_fs: virtual endpoint address mapping

 drivers/usb/gadget/function/f_fs.c  | 46 +++++++++++++++++++++++++++++++++++--
 drivers/usb/gadget/function/u_fs.h  |  2 ++
 include/uapi/linux/usb/functionfs.h |  7 ++++++
 3 files changed, 53 insertions(+), 2 deletions(-)

-- 
1.9.1

[PATCH v7 1/2] usb: gadget: f_fs: add ioctl returning ep descriptor

[Robert Baldyga]

This patch introduces ioctl named FUNCTIONFS_ENDPOINT_DESC, which
returns endpoint descriptor to userspace. It works only if function
is active.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
---
 drivers/usb/gadget/function/f_fs.c  | 23 +++++++++++++++++++++++
 include/uapi/linux/usb/functionfs.h |  6 ++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 0dc3552d..978a4c9 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1032,6 +1032,29 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code,
 		case FUNCTIONFS_ENDPOINT_REVMAP:
 			ret = epfile->ep->num;
 			break;
+		case FUNCTIONFS_ENDPOINT_DESC:
+		{
+			int desc_idx;
+			struct usb_endpoint_descriptor *desc;
+
+			switch (epfile->ffs->gadget->speed) {
+			case USB_SPEED_SUPER:
+				desc_idx = 2;
+				break;
+			case USB_SPEED_HIGH:
+				desc_idx = 1;
+				break;
+			default:
+				desc_idx = 0;
+			}
+			desc = epfile->ep->descs[desc_idx];
+
+			spin_unlock_irq(&epfile->ffs->eps_lock);
+			ret = copy_to_user((void *)value, desc, sizeof(*desc));
+			if (ret)
+				ret = -EFAULT;
+			return ret;
+		}
 		default:
 			ret = -ENOTTY;
 		}
diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index 0154b28..7677108 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -265,6 +265,12 @@ struct usb_functionfs_event {
  */
 #define	FUNCTIONFS_ENDPOINT_REVMAP	_IO('g', 129)
 
+/*
+ * Returns endpoint descriptor. If function is not active returns -ENODEV.
+ */
+#define	FUNCTIONFS_ENDPOINT_DESC	_IOR('g', 130, \
+					     struct usb_endpoint_descriptor)
+
 
 
 #endif /* _UAPI__LINUX_FUNCTIONFS_H__ */
-- 
1.9.1

[PATCH v7 2/2] usb: gadget: f_fs: virtual endpoint address mapping

[Robert Baldyga]

This patch introduces virtual endpoint address mapping. It separates
function logic form physical endpoint addresses making it more hardware
independent.

Following modifications changes user space API, so to enable them user
have to switch on the FUNCTIONFS_VIRTUAL_ADDR flag in descriptors.

Endpoints are now refered using virtual endpoint addresses chosen by
user in endpoint descpriptors. This applies to each context when endpoint
address can be used:
- when accessing endpoint files in FunctionFS filesystemi (in file name),
- in setup requests directed to specific endpoint (in wIndex field),
- in descriptors returned by FUNCTIONFS_ENDPOINT_DESC ioctl.

In endpoint file names the endpoint address number is formatted as
double-digit hexadecimal value ("ep%02x") which has few advantages -
it is easy to parse, allows to easly recognize endpoint direction basing
on its name (IN endpoint number starts with digit 8, and OUT with 0)
which can be useful for debugging purpose, and it makes easier to introduce
further features allowing to use each endpoint number in both directions
to have more endpoints available for function if hardware supports this
(for example we could have ep01 which is endpoint 1 with OUT direction,
and ep81 which is endpoint 1 with IN direction).

Physical endpoint address can be still obtained using ioctl named
FUNCTIONFS_ENDPOINT_REVMAP, but now it's not neccesary to handle
USB transactions properly.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
---
 drivers/usb/gadget/function/f_fs.c  | 23 +++++++++++++++++++++--
 drivers/usb/gadget/function/u_fs.h  |  2 ++
 include/uapi/linux/usb/functionfs.h |  1 +
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 978a4c9..4d3a0d5 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1557,7 +1557,10 @@ static int ffs_epfiles_create(struct ffs_data *ffs)
 		epfile->ffs = ffs;
 		mutex_init(&epfile->mutex);
 		init_waitqueue_head(&epfile->wait);
-		sprintf(epfiles->name, "ep%u",  i);
+		if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
+			sprintf(epfiles->name, "ep%02x", ffs->eps_addrmap[i]);
+		else
+			sprintf(epfiles->name, "ep%u", i);
 		if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
 						 &ffs_epfile_operations,
 						 &epfile->dentry))) {
@@ -2106,10 +2109,12 @@ static int __ffs_data_got_descs(struct ffs_data *ffs,
 		break;
 	case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
 		flags = get_unaligned_le32(data + 8);
+		ffs->user_flags = flags;
 		if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
 			      FUNCTIONFS_HAS_HS_DESC |
 			      FUNCTIONFS_HAS_SS_DESC |
-			      FUNCTIONFS_HAS_MS_OS_DESC)) {
+			      FUNCTIONFS_HAS_MS_OS_DESC |
+			      FUNCTIONFS_VIRTUAL_ADDR)) {
 			ret = -ENOSYS;
 			goto error;
 		}
@@ -2464,7 +2469,13 @@ static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
 	} else {
 		struct usb_request *req;
 		struct usb_ep *ep;
+		u8 bEndpointAddress;
 
+		/*
+		 * We back up bEndpointAddress because autoconfig overwrites
+		 * it with physical endpoint address.
+		 */
+		bEndpointAddress = ds->bEndpointAddress;
 		pr_vdebug("autoconfig\n");
 		ep = usb_ep_autoconfig(func->gadget, ds);
 		if (unlikely(!ep))
@@ -2479,6 +2490,12 @@ static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
 		ffs_ep->req = req;
 		func->eps_revmap[ds->bEndpointAddress &
 				 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
+		/*
+		 * If we use virtual address mapping, we restore
+		 * original bEndpointAddress value.
+		 */
+		if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
+			ds->bEndpointAddress = bEndpointAddress;
 	}
 	ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
 
@@ -2923,6 +2940,8 @@ static int ffs_func_setup(struct usb_function *f,
 		ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
 		if (unlikely(ret < 0))
 			return ret;
+		if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
+			ret = func->ffs->eps_addrmap[ret];
 		break;
 
 	default:
diff --git a/drivers/usb/gadget/function/u_fs.h b/drivers/usb/gadget/function/u_fs.h
index d48897e..cd128e3 100644
--- a/drivers/usb/gadget/function/u_fs.h
+++ b/drivers/usb/gadget/function/u_fs.h
@@ -224,6 +224,8 @@ struct ffs_data {
 	void				*ms_os_descs_ext_prop_name_avail;
 	void				*ms_os_descs_ext_prop_data_avail;
 
+	unsigned			user_flags;
+
 	u8				eps_addrmap[15];
 
 	unsigned short			strings_count;
diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index 7677108..d2ca92e 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -19,6 +19,7 @@ enum functionfs_flags {
 	FUNCTIONFS_HAS_HS_DESC = 2,
 	FUNCTIONFS_HAS_SS_DESC = 4,
 	FUNCTIONFS_HAS_MS_OS_DESC = 8,
+	FUNCTIONFS_VIRTUAL_ADDR = 16,
 };
 
 /* Descriptor of an non-audio endpoint */
-- 
1.9.1

Re: [PATCH v7 2/2] usb: gadget: f_fs: virtual endpoint address mapping

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 1783 bytes --]

On Thu, Sep 04, 2014 at 08:32:18AM +0200, Robert Baldyga wrote:
> This patch introduces virtual endpoint address mapping. It separates
> function logic form physical endpoint addresses making it more hardware
> independent.
> 
> Following modifications changes user space API, so to enable them user
> have to switch on the FUNCTIONFS_VIRTUAL_ADDR flag in descriptors.
> 
> Endpoints are now refered using virtual endpoint addresses chosen by
> user in endpoint descpriptors. This applies to each context when endpoint
> address can be used:
> - when accessing endpoint files in FunctionFS filesystemi (in file name),
> - in setup requests directed to specific endpoint (in wIndex field),
> - in descriptors returned by FUNCTIONFS_ENDPOINT_DESC ioctl.
> 
> In endpoint file names the endpoint address number is formatted as
> double-digit hexadecimal value ("ep%02x") which has few advantages -
> it is easy to parse, allows to easly recognize endpoint direction basing
> on its name (IN endpoint number starts with digit 8, and OUT with 0)
> which can be useful for debugging purpose, and it makes easier to introduce
> further features allowing to use each endpoint number in both directions
> to have more endpoints available for function if hardware supports this
> (for example we could have ep01 which is endpoint 1 with OUT direction,
> and ep81 which is endpoint 1 with IN direction).
> 
> Physical endpoint address can be still obtained using ioctl named
> FUNCTIONFS_ENDPOINT_REVMAP, but now it's not neccesary to handle
> USB transactions properly.
> 
> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
> Acked-by: Michal Nazarewicz <mina86@mina86.com>

this one does't apply to my testing/next. Can you please rebase ?

-- 
balbi

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]