I've not got time to review this patch right now, but Sergey and Steven, you both posted MPMC drivers on the same day; Steven on the microblaze list and Sergey on the powerpc list. Can you two please coordinate and figure out how to mork toward a single driver that will meet both your needs? I don't want to have 2 drivers (3 if you count the ll_temac driver) in mainline for the same hardware interface.
Thanks, g. On Wed, Mar 17, 2010 at 12:18 PM, Sergey Temerkhanov <temerkha...@cifronik.ru> wrote: > This patch adds generic support for Xilinx MPMC SoftDMA channels which are > used by, e.g., LLTEMAC and other IP cores (including custom cores). So, the > implemented functions include only SDMA channels enumeration and control > (finding device by phandle property, channel reset, initialization of RX/TX > links, enabling/disabling IRQs, IRQ coalescing control and submission of > descriptors (struct sdma_desc). > > The users of this subsystem are supposed to get the pointer to the struct > sdma_device by phandle (using sdma_find_device() function), fill the struct > sdma_client with pointers to the callback functions which are called on rx/tx > completion, on error, and when sdma_reset is called by any client and then > register the client with add_client() (sdma_del_client can be used to > unregister the struct sdma_client) > > Also, some auxiliary functions are provided to check the status of descriptors > (busy, done, start of packet, end of packet). > > The user is also responsible for maintenance of linked descriptors queue, > proper initialization of their fields, and submission of the descriptors list > to SDMA channel. IRQ acknowledge must be performed by user too (calling > sdma_[rx|tx]_irq_ack respectively in [rx|tx]_complete callbacks). Also on RX > side user must check the __be32 user[4] fields of descriptors to get the > information supplied by SDMA channel. > > This code uses SDMA channels in "Tail pointer fashion", i.e. the call to > sdma_[rx|tx]_init is performed only once after reset and then only sdma_[rx| > tx]_submit calls are used to update the pointer to the last descriptor in SDMA > channel. > > Simple bus driver for MPMC is also added by this patch. > > This code is in production use with our internal LLTEMAC driver implementation > since 2008 and with a few custom cores drivers since 2009. > > This code currently supports only soft MPMCs, i.e., only SDMA channels with > memory-mapped registers. In order to support channels with DCR, a few > modifications are needed. > > Any comments and suggestions are appreciated. > > Regards, Sergey Temerkhanov, Cifronic ZAO > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
