On Sun, Jul 15, 2012 at 04:17:16PM +0800, Shawn Guo wrote: > On Fri, Jul 13, 2012 at 10:22:49AM +0200, Wolfram Sang wrote: > > > + /* > > > + * TODO: This is a temporary solution and should be changed > > > + * to use generic DMA binding later when the helpers get in. > > > + */ > > > > @Shawn: Any idea when this is going to happen? And why do we need this? > > See thread [1] for current statues. I'm not sure when it's going to > happen though. Phew, [1] is a bit too much too read. I will just assume there are still issues. > > AFAICT it will be always channel 6/7 on mx28? > > > Yes, but it might be a different channel on mx23. Just like we define > IO region and interrupt number in device tree, dma channel is just > another resource of hardware block that we choose to define in device > tree. What makes me wonder now that I come to think of it (not necessarily a question for Shawn but to all): If I have an I2C slave with an interrupt line tied to something, GPIO or external IRQ from the SoC, it makes perfect sense to define that in the devicetree. Yet, if I know the compatible property for the mxs I2C driver, and also know the CPU type (be it MX23 or MX28), I can deduce from that a lot of information, including DMA channel. That is fix. Why encode it? Regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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