Re: [PATCH v2 3/7] dmaengine: Add driver for TI DMA crossbar on DRA7x

From: Tony Lindgren
Date: Thu Mar 26 2015 - 11:26:30 EST


* Peter Ujfalusi <peter.ujfalusi@xxxxxx> [150326 05:32]:
> On 03/26/2015 12:56 PM, Vinod Koul wrote:
> >> +
> >> +static void ti_dma_xbar_free(struct device *dev, void *route_data)
> >> +{
> >> + struct ti_dma_xbar_data *xbar = dev_get_drvdata(dev);
> >> + struct ti_dma_xbar_map *map = route_data;
> >> +
> >> + dev_dbg(dev, "Unmapping XBAR%d (was routed to %d)\n",
> >> + map->xbar_in, map->xbar_out);
> >> +
> >> + regmap_write(xbar->regmap, map->xbar_out * 2, 0);
> > just out of curiosity how much do you save using regmap :)
>
> good point, not much I guess. I had it implemented w/o regmap as well, but
> thought why not use regmap if it is available.

Regmap is nice for slow devices and devices in a shared register
range like the omap syscon general area. For normal use, there's
quite a bit of overhead with regmap compared to just read/write :)

Regards,

Tony
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