usb: gadget: mass_storage: added sysfs entry for cdrom to LUNs

[FrozenCow]

This patch adds a "cdrom" sysfs entry for each mass_storage LUN, just
like "ro" sysfs entry. This allows switching between USB and CD-ROM
emulation without reinserting the module or recompiling the kernel.

As requested in: http://forum.xda-developers.com/showpost.php?p=45293017&postcount=1505

[FrozenCow]

I am not sure whether this actually works, because I don't have a Sony device nor do I have the required config to compile the kernel. However since the patch worked for various Samsung devices (and it applied without problems) it should just work.

[DooMLoRD]

@FrozenCow can u tell me how do i check if this is working? i will build test kernel and check it out

[FrozenCow]

The following file should exist:

/sys/devices/platform/msm_hsusb/gadget/lun0/cdrom

When you have USB Mass Storage enabled (and you can see a USB-drive on your PC) you should be able to unplug the phone and execute:

echo 1 > /sys/devices/platform/msm_hsusb/gadget/lun0/cdrom

Plug the phone back in and your phone should pop up as a CD-rom device.

Alternatively you can install DriveDroid (https://play.google.com/store/apps/details?id=com.softwarebakery.drivedroid). In DriveDroid follow the initial setup to see whether your phone pops up as USB-drive in Windows (you may skip rebooting your PC and trying to boot off of the phone). After that select 'drivedroid.img' (or any other image) and a dialog will pop up similar to this:
http://softwarebakery.com/using-rufus-to-create-bootable-usb-images/04-selectusbrw.png

In this dialog you should see the CD-rom icons in the right column (this is hidden when the device does not have the CD-rom patch). Just to be safe, unplug the phone and press the first CD-rom icon. A notification should pop up that the image was hosted succesfully. Now plug your phone back in and your phone should pop up on your PC as a CD-rom device. (the content will be unreadable when drivedroid.img is used, but this is normal, a real ISO file is needed to fully test the rest, but you can presume from here that everything works).

[DooMLoRD]

thanks working perfectly fine!

merged offline!

[FrozenCow]

Aah cool! Thanks for merging!