Messages in this thread | | | Date | Tue, 17 Aug 2010 07:36:12 +0300 | From | Baruch Siach <> | Subject | Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support |
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Hi Sascha,
On Mon, Aug 16, 2010 at 04:15:40PM +0200, Sascha Hauer wrote: > On Mon, Aug 16, 2010 at 02:21:06PM +0200, Linus Walleij wrote: > > 2010/8/16 Sascha Hauer <s.hauer@pengutronix.de>: > > > The SDMA engine is a scatter/gather DMA engine which is implemented > > > as a seperate coprocessor. SDMA needs its own firmware which is > > > requested using the standard request_firmware mechanism. The firmware > > > has different entry points for each peripheral type, so drivers > > > have to pass the peripheral type to the DMA engine which in turn > > > picks the correct firmware entry point from a table contained in > > > the firmware image itself. > > > > Quite fun, if the spec for the microcode is open this opens up > > for dynamic firmware generation for specific DMA jobs does it > > not? > > Unfortunately the specs are not open, so we are sticked to the binary > microcode from Freescale. I'm pretty sure though that the SDMA engine > could do at least a device_prep_dma_xor operation.
Chapter 38 in the i.MX25 Reference Manual seems to include almost everything there is to know about the SDMA. Isn't this enough for writing custom SDMA microcodes?
baruch
-- ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
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