From 1b0bf88fd8b845aef4300c7c0feca774265dd1c4 Mon Sep 17 00:00:00 2001 From: Robert Baldyga Date: Tue, 9 Sep 2014 08:23:17 +0200 Subject: [PATCH] usb: gadget: f_fs: virtual endpoint address mapping 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 Acked-by: Michal Nazarewicz Signed-off-by: Felipe Balbi --- 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 e4afe8df5553..4ad11e03cf54 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; } @@ -2466,7 +2471,13 @@ 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)) @@ -2481,6 +2492,12 @@ 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); @@ -2925,6 +2942,8 @@ 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 d48897e8ffeb..cd128e31f808 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 7c7a2feb0e6e..295ba299e7bd 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 */ -- 2.34.1