Dear All, This series adds support to tcm usb gadget for composing it with configfs.
@target-devel folks: You might be wondering why add configfs for something which already supports configfs. In tcm_usb_gadget configfs has beeen used for configuring the SCSI target part, but the usb gadget part is considered a legacy gadget. A legacy gadget is a composite usb gadget whose composition is defined statically at compilation time. Composite gadgets can consist of a number of "functions" and configurations. In legacy gadgets the selection is hardcoded in a dedicated kernel module. But with configfs the selection can be made at runtime without writing any kernel code. The conversion process started almost three years ago. The series aims at integrating configfs into tcm, the way it has been done with 19 of 20 usb functions. In other words this concludes the process of conversion to configfs in usb gadgets. The series depends on the series from Chrisoph: http://www.spinics.net/lists/target-devel/msg10730.html @Nicholas: In order to use the series from Christoph (simplifying configfs attributes) I rebased my series on top of your for-next, which happens not to contain your patches which strip off nexus WWPN prefix, fix nexus leak and fix enabled attribute failure. I re-post them here. I have split one of them to separate unrelated changes. @Joel: I resend the patch which adds unlocked versions of configfs_(un)depend_item(). The purpose of configfs_(un)depend_item() is to allow other kernel subsystems to prohibit deletion of a config item until they can live without it. This is exactly the case with tcm usb gadget, but the other kernel subsystem happens to be another subsystem in configfs: the user must create an instance of the tcm function in usb_gadget subsystem in order to be able to create a tpg in target subsystem. But once a tpg goes live its corresponding tcm function must not be removed until the tpg is deleted. Even though these are two distinct configfs subsystems the configfs_(un)depend_item() will not work from a configfs callback. That is why there is a need to provide the "unlocked" variant. v1..v2: - added missing comments - used the next version of configfs_(un)depend_item_unlocked() - fixed bug: THIS_MODULE is NULL if a module is compiled-in, so we cannot rely on opts->dependent being non-NULL if a dependent module is present - added passing configfs subsystem to configfs_(un)depend_item_unlocked() BACKWARD COMPATIBILITY ====================== Please note that the old tcm_usb_gadget.ko is still available and works. USING THE NEW "GADGET" ====================== Please refer to this post: http://www.spinics.net/lists/linux-usb/msg76388.html for general information from Sebastian on how to use configfs-based gadgets (*). With configfs the procedure is as follows, compared to the information mentioned above (*): instead of mkdir functions/acm.ttyS1 do mkdir functions/tcm.<instance name> e.g. mkdir functions/tcm.usb0. In the tcm.usb0 directory there are no attributes, because all the configuration is performed with the target subsystem in configfs. Below is a script which creates a tcm gadget on a board with dwc3: # mount -t configfs none /sys/kernel/config # modprobe usb_f_tcm # cd /sys/kernel/config/usb_gadget # mkdir tcm # cd tcm # mkdir functions/tcm.0 # cd /sys/kernel/config/target/ # mkdir usb_gadget # cd usb_gadget # mkdir naa.0123456789abcdef # cd naa.0123456789abcdef # mkdir tpgt_1 # cd tpgt_1 # echo naa.01234567890abcdef > nexus # echo 1 > enable # cd /sys/kernel/config/usb_gadget/tcm # mkdir configs/c.1 # ln -s functions/tcm.0 configs/c.1 # echo $VENDOR_ID > idVendor # echo $PRODUCT_ID > idProduct # echo 12400000.dwc3 > UDC TESTING THE FUNCTION ==================== The most basic testing device: run the script above host: see the gadget enumerated Andrzej Pietrasiewicz (11): usb: gadget: tcm: split string definitions into function and device usb: gadget: tcm: follow naming conventions usb: gadget: tcm: use strtobool for a boolean value usb: gadget: tcm: simplify attribute store function usb: gadget: tcm: factor out f_tcm usb: gadget: f_tcm: convert to new function interface with backward compatibility usb: gadget: tcm: convert to use new function registration interface usb: gadget: f_tcm: remove compatibility layer usb: gadget: f_tcm: remove redundant singleton usb: gadget: f_tcm: use usb_gstrings_attach usb: gadget: f_tcm: add configfs support Krzysztof Opasiak (1): fs: configfs: Add unlocked version of configfs_depend_item() Nicholas Bellinger (3): tcm_usb_gadget: Don't strip off nexus WWPN prefix tcm_usb_gadget: Fix nexus leak tcm_usb_gadget: Fix enabled attribute failure Documentation/ABI/testing/configfs-usb-gadget-tcm | 6 + drivers/usb/gadget/Kconfig | 17 + drivers/usb/gadget/function/Makefile | 2 + drivers/usb/gadget/function/f_tcm.c | 2425 +++++++++++++++++++++ drivers/usb/gadget/function/tcm.h | 132 ++ drivers/usb/gadget/function/u_tcm.h | 50 + drivers/usb/gadget/legacy/Kconfig | 1 + drivers/usb/gadget/legacy/tcm_usb_gadget.c | 2183 +------------------ drivers/usb/gadget/legacy/tcm_usb_gadget.h | 133 -- fs/configfs/dir.c | 97 + include/linux/configfs.h | 12 + 11 files changed, 2791 insertions(+), 2267 deletions(-) create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-tcm create mode 100644 drivers/usb/gadget/function/f_tcm.c create mode 100644 drivers/usb/gadget/function/tcm.h create mode 100644 drivers/usb/gadget/function/u_tcm.h delete mode 100644 drivers/usb/gadget/legacy/tcm_usb_gadget.h -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
