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Merge tag 'gadget-for-v3.6' of git://git.kernel.org/pub/scm/linux/ker…
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…nel/git/balbi/usb into usb-next

usb: gadget: patches for v3.6 merge window

This is quite a big pull request and contains patches
all over the place.

omap_udc is now a bit cleaner after removing omap2 support,
fixing some checkpatch.pl warnings and errors, switching over
to generic map/unmap routines and preventing a NULL pointer
de-reference.

s3c-hsotg has been switched over to devm_* API, got some
locking fixes and improvements and it also got an implementation
for the pullup() method.

the mass storage gadgets changed default value of the removable
parameter, dropped some unused options and made "file" and "ro"
module_parameters read-only in some cases.

ffs function got support for HID descriptor.

Some UDCs have been converted to clk_prepare_enable() and
clk_disable_unprepare().

Marvell now got support for its USB3 controller in mainline
after introducing its mv_u3d_core.c driver.
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Greg Kroah-Hartman committed Jul 5, 2012
2 parents 979eef3 + 65c84ea commit 94ff447
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226 changes: 226 additions & 0 deletions Documentation/usb/mass-storage.txt
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* Overview

Mass Storage Gadget (or MSG) acts as a USB Mass Storage device,
appearing to the host as a disk or a CD-ROM drive. It supports
multiple logical units (LUNs). Backing storage for each LUN is
provided by a regular file or a block device, access can be limited
to read-only, and gadget can indicate that it is removable and/or
CD-ROM (the latter implies read-only access).

Its requirements are modest; only a bulk-in and a bulk-out endpoint
are needed. The memory requirement amounts to two 16K buffers.
Support is included for full-speed, high-speed and SuperSpeed
operation.

Note that the driver is slightly non-portable in that it assumes
a single memory/DMA buffer will be useable for bulk-in and bulk-out
endpoints. With most device controllers this is not an issue, but
there may be some with hardware restrictions that prevent a buffer
from being used by more than one endpoint.

This document describes how to use the gadget from user space, its
relation to mass storage function (or MSF) and different gadgets
using it, and how it differs from File Storage Gadget (or FSG). It
will talk only briefly about how to use MSF within composite
gadgets.

* Module parameters

The mass storage gadget accepts the following mass storage specific
module parameters:

- file=filename[,filename...]

This parameter lists paths to files or block devices used for
backing storage for each logical unit. There may be at most
FSG_MAX_LUNS (8) LUNs set. If more files are specified, they will
be silently ignored. See also “luns” parameter.

*BEWARE* that if a file is used as a backing storage, it may not
be modified by any other process. This is because the host
assumes the data does not change without its knowledge. It may be
read, but (if the logical unit is writable) due to buffering on
the host side, the contents are not well defined.

The size of the logical unit will be rounded down to a full
logical block. The logical block size is 2048 bytes for LUNs
simulating CD-ROM, block size of the device if the backing file is
a block device, or 512 bytes otherwise.

- removable=b[,b...]

This parameter specifies whether each logical unit should be
removable. “b” here is either “y”, “Y” or “1” for true or “n”,
“N” or “0” for false.

If this option is set for a logical unit, gadget will accept an
“eject” SCSI request (Start/Stop Unit). When it is sent, the
backing file will be closed to simulate ejection and the logical
unit will not be mountable by the host until a new backing file is
specified by userspace on the device (see “sysfs entries”
section).

If a logical unit is not removable (the default), a backing file
must be specified for it with the “file” parameter as the module
is loaded. The same applies if the module is built in, no
exceptions.

The default value of the flag is false, *HOWEVER* it used to be
true. This has been changed to better match File Storage Gadget
and because it seems like a saner default after all. Thus to
maintain compatibility with older kernels, it's best to specify
the default values. Also, if one relied on old default, explicit
“n” needs to be specified now.

Note that “removable” means the logical unit's media can be
ejected or removed (as is true for a CD-ROM drive or a card
reader). It does *not* mean that the entire gadget can be
unplugged from the host; the proper term for that is
“hot-unpluggable”.

- cdrom=b[,b...]

This parameter specifies whether each logical unit should simulate
CD-ROM. The default is false.

- ro=b[,b...]

This parameter specifies whether each logical unit should be
reported as read only. This will prevent host from modifying the
backing files.

Note that if this flag for given logical unit is false but the
backing file could not be opened in read/write mode, the gadget
will fall back to read only mode anyway.

The default value for non-CD-ROM logical units is false; for
logical units simulating CD-ROM it is forced to true.

- nofua=b[,b...]

This parameter specifies whether FUA flag should be ignored in SCSI
Write10 and Write12 commands sent to given logical units.

MS Windows mounts removable storage in “Removal optimised mode” by
default. All the writes to the media are synchronous, which is
achieved by setting the FUA (Force Unit Access) bit in SCSI
Write(10,12) commands. This forces each write to wait until the
data has actually been written out and prevents I/O requests
aggregation in block layer dramatically decreasing performance.

Note that this may mean that if the device is powered from USB and
the user unplugs the device without unmounting it first (which at
least some Windows users do), the data may be lost.

The default value is false.

- luns=N

This parameter specifies number of logical units the gadget will
have. It is limited by FSG_MAX_LUNS (8) and higher value will be
capped.

If this parameter is provided, and the number of files specified
in “file” argument is greater then the value of “luns”, all excess
files will be ignored.

If this parameter is not present, the number of logical units will
be deduced from the number of files specified in the “file”
parameter. If the file parameter is missing as well, one is
assumed.

- stall=b

Specifies whether the gadget is allowed to halt bulk endpoints.
The default is determined according to the type of USB device
controller, but usually true.

In addition to the above, the gadget also accepts the following
parameters defined by the composite framework (they are common to
all composite gadgets so just a quick listing):

- idVendor -- USB Vendor ID (16 bit integer)
- idProduct -- USB Product ID (16 bit integer)
- bcdDevice -- USB Device version (BCD) (16 bit integer)
- iManufacturer -- USB Manufacturer string (string)
- iProduct -- USB Product string (string)
- iSerialNumber -- SerialNumber string (sting)

* sysfs entries

For each logical unit, the gadget creates a directory in the sysfs
hierarchy. Inside of it the following three files are created:

- file

When read it returns the path to the backing file for the given
logical unit. If there is no backing file (possible only if the
logical unit is removable), the content is empty.

When written into, it changes the backing file for given logical
unit. This change can be performed even if given logical unit is
not specified as removable (but that may look strange to the
host). It may fail, however, if host disallowed medium removal
with the Prevent-Allow Medium Removal SCSI command.

- ro

Reflects the state of ro flag for the given logical unit. It can
be read any time, and written to when there is no backing file
open for given logical unit.

- nofua

Reflects the state of nofua flag for given logical unit. It can
be read and written.

Other then those, as usual, the values of module parameters can be
read from /sys/module/g_mass_storage/parameters/* files.

* Other gadgets using mass storage function

The Mass Storage Gadget uses the Mass Storage Function to handle
mass storage protocol. As a composite function, MSF may be used by
other gadgets as well (eg. g_multi and acm_ms).

All of the information in previous sections are valid for other
gadgets using MSF, except that support for mass storage related
module parameters may be missing, or the parameters may have
a prefix. To figure out whether any of this is true one needs to
consult the gadget's documentation or its source code.

For examples of how to include mass storage function in gadgets, one
may take a look at mass_storage.c, acm_ms.c and multi.c (sorted by
complexity).

* Relation to file storage gadget

The Mass Storage Function and thus the Mass Storage Gadget has been
based on the File Storage Gadget. The difference between the two is
that MSG is a composite gadget (ie. uses the composite framework)
while file storage gadget is a traditional gadget. From userspace
point of view this distinction does not really matter, but from
kernel hacker's point of view, this means that (i) MSG does not
duplicate code needed for handling basic USB protocol commands and
(ii) MSF can be used in any other composite gadget.

Because of that, File Storage Gadget has been deprecated and
scheduled to be removed in Linux 3.8. All users need to transition
to the Mass Storage Gadget by that time. The two gadgets behave
mostly the same from the outside except:

1. In FSG the “removable” and “cdrom” module parameters set the flag
for all logical units whereas in MSG they accept a list of y/n
values for each logical unit. If one uses only a single logical
unit this does not matter, but if there are more, the y/n value
needs to be repeated for each logical unit.

2. FSG's “serial”, “vendor”, “product” and “release” module
parameters are handled in MSG by the composite layer's parameters
named respectively: “iSerialnumber”, “idVendor”, “idProduct” and
“bcdDevice”.

3. MSG does not support FSG's test mode, thus “transport”,
“protocol” and “buflen” FSG's module parameters are not
supported. MSG always uses SCSI protocol with bulk only
transport mode and 16 KiB buffers.
2 changes: 1 addition & 1 deletion drivers/usb/dwc3/gadget.c
Original file line number Diff line number Diff line change
Expand Up @@ -414,7 +414,7 @@ static int dwc3_gadget_set_ep_config(struct dwc3 *dwc, struct dwc3_ep *dep,

params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc))
| DWC3_DEPCFG_BURST_SIZE(dep->endpoint.maxburst);
| DWC3_DEPCFG_BURST_SIZE(dep->endpoint.maxburst - 1);

params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN
| DWC3_DEPCFG_XFER_NOT_READY_EN;
Expand Down
9 changes: 9 additions & 0 deletions drivers/usb/gadget/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -321,6 +321,15 @@ config USB_MV_UDC
USB2.0 OTG controller, which can be configured as high speed or
full speed USB peripheral.

config USB_MV_U3D
tristate "MARVELL PXA2128 USB 3.0 controller"
depends on CPU_MMP3
select USB_GADGET_DUALSPEED
select USB_GADGET_SUPERSPEED
help
MARVELL PXA2128 Processor series include a super speed USB3.0 device
controller, which support super speed USB peripheral.

#
# Controllers available in both integrated and discrete versions
#
Expand Down
1 change: 1 addition & 0 deletions drivers/usb/gadget/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@ obj-$(CONFIG_USB_EG20T) += pch_udc.o
obj-$(CONFIG_USB_MV_UDC) += mv_udc.o
mv_udc-y := mv_udc_core.o
obj-$(CONFIG_USB_FUSB300) += fusb300_udc.o
obj-$(CONFIG_USB_MV_U3D) += mv_u3d_core.o

#
# USB gadget drivers
Expand Down
1 change: 1 addition & 0 deletions drivers/usb/gadget/acm_ms.c
Original file line number Diff line number Diff line change
Expand Up @@ -235,6 +235,7 @@ static int __exit acm_ms_unbind(struct usb_composite_dev *cdev)
static struct usb_composite_driver acm_ms_driver = {
.name = "g_acm_ms",
.dev = &device_desc,
.max_speed = USB_SPEED_SUPER,
.strings = dev_strings,
.unbind = __exit_p(acm_ms_unbind),
};
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1 change: 1 addition & 0 deletions drivers/usb/gadget/at91_udc.c
Original file line number Diff line number Diff line change
Expand Up @@ -1634,6 +1634,7 @@ static int at91_start(struct usb_gadget *gadget,
udc = container_of(gadget, struct at91_udc, gadget);
udc->driver = driver;
udc->gadget.dev.driver = &driver->driver;
udc->gadget.dev.of_node = udc->pdev->dev.of_node;
dev_set_drvdata(&udc->gadget.dev, &driver->driver);
udc->enabled = 1;
udc->selfpowered = 1;
Expand Down
7 changes: 5 additions & 2 deletions drivers/usb/gadget/composite.c
Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,7 @@ int config_ep_by_speed(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep)
{
struct usb_composite_dev *cdev = get_gadget_data(g);
struct usb_endpoint_descriptor *chosen_desc = NULL;
struct usb_descriptor_header **speed_desc = NULL;

Expand Down Expand Up @@ -180,10 +181,12 @@ int config_ep_by_speed(struct usb_gadget *g,
_ep->mult = comp_desc->bmAttributes & 0x3;
case USB_ENDPOINT_XFER_BULK:
case USB_ENDPOINT_XFER_INT:
_ep->maxburst = comp_desc->bMaxBurst;
_ep->maxburst = comp_desc->bMaxBurst + 1;
break;
default:
/* Do nothing for control endpoints */
if (comp_desc->bMaxBurst != 0)
ERROR(cdev, "ep0 bMaxBurst must be 0\n");
_ep->maxburst = 1;
break;
}
}
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7 changes: 7 additions & 0 deletions drivers/usb/gadget/f_fs.c
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
#include <linux/blkdev.h>
#include <linux/pagemap.h>
#include <linux/export.h>
#include <linux/hid.h>
#include <asm/unaligned.h>

#include <linux/usb/composite.h>
Expand Down Expand Up @@ -1671,6 +1672,12 @@ static int __must_check ffs_do_desc(char *data, unsigned len,
}
break;

case HID_DT_HID:
pr_vdebug("hid descriptor\n");
if (length != sizeof(struct hid_descriptor))
goto inv_length;
break;

case USB_DT_OTG:
if (length != sizeof(struct usb_otg_descriptor))
goto inv_length;
Expand Down
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