On Wed, 27 Jan 2010, Mark Brown wrote:
On Wed, Jan 27, 2010 at 06:56:23PM +0100, Guennadi Liakhovetski wrote:
[snip]
- if (f_opclk) {
...
if (16 * f_opclk < 3 * f_mclk || 4 * f_opclk >= 13 * f_mclk)return -EINVAL;if (4 * f_opclk < 3 * f_mclk)/* Have to use OPCLKDIV */opclk_div = (3 * f_mclk / 4 + f_opclk - 1) / f_opclk;elseopclk_div = 1;I'm fairly sure this and the similar logic for SYSCLK can be squashed together with some suitable local variables. Might be more legible since this requires some staring at. I didn't actually go so far as to work out what the relevant code is, though.
Well, not really. In one case f_PLLOUT can be derived directly, because OPCLKDIV covers the whole its value range 1-4, whereas MCLKDIV takes values 1, 3/2, 2, 3, 4, 6, 8, 12, so, you have to apply an iterative process to select the best match. I've just sent a patch, that improves these calculations. It should be the last patch for my SIU / wm8978 / migor support so far.
Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/