On Wed, Nov 04, 2009 at 05:53:55PM +0000, Liam Girdwood wrote:
> From: Graeme Gregory <gg@xxxxxxxxxxxxxxx>
>
> This patch increases the number of supported audio channels from 4
> to 16 and was sponsored by Shotspotter inc.
>
> Signed-off-by: Graeme Gregory <gg@xxxxxxxxxxxxxxx>
> Signed-off-by: Liam Girdwood <lrg@xxxxxxxxxxxxxxx>
> + /* Default div to 1 if it wasn't set by machine driver, otherwise
> + * use set div as the maximum clock value
> + */
> + div = mcbsp_data->clk_div ? mcbsp_data->clk_div : 1;
> +
> + /* calc best frame size for rate and clock divider */
> + do {
> + frame_size = (mcbsp_data->in_freq / div) / params_rate(params);
> + pr_debug("freq %d, rate %d, frame size %d, div %d\n",
> + mcbsp_data->in_freq, params_rate(params), frame_size, div);
> +
> + if (frame_size > 256)
> + div++;
> + } while (frame_size > 256);
> +
> + /* Check we can fit the requested number of channels into our
> + * calculated frame size
> + */
> + if ((channels * wlen) > frame_size) {
> + printk(KERN_ERR
> + "OMAP-MCBSP: cannot fit channels in frame size\n");
> + return -EINVAL;
> + }
> +
> + /* Set the actual clkdiv to use for this samplerate */
> + regs->srgr1 &= ~CLKGDV(0xFF);
> + regs->srgr1 |= CLKGDV(div - 1);
> +
This chunk changes the semantics of other devices which I have never tested.
I also dont know how much damage it does if it does to slave mode. In fact
I think it might break it in cases which are actually allowable as it uses
the omap as its clock constraint and not the clock source.
Graeme
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