[alsa-devel] [PATCH 07/11] ASoC: omap-mcbsp: Sidetone: Use SIDLE bits in SYSCONFIG register to select noidle mode
Ricardo Neri
ricardo.neri at ti.com
Thu Aug 9 00:12:58 CEST 2012
On 08/08/2012 04:11 AM, Peter Ujfalusi wrote:
> Instead of the callback (which modifies control module register) use the
> McBSP module's SYSCONFIG register to disable smart-idle mode when the
> sidetone is enabled.
> Store the original SIDLEMODE configuration and restore it when the sidetone
> has been disabled.
Is this another case in which it is required to change the idle-mode on
a per-use-case basis? In the past I was trying to do the same with HDMI
[1]. In that case it was decided to add the HWMOD_SWSUP_SIDLE to hwmod
data with the drawback of using no-idle/force-idle rather than
smart-idle[2][3].
[1] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg60226.html
[2] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg70463.html
[3] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg70653.html
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> ---
> sound/soc/omap/mcbsp.c | 18 ++++++++++++++----
> sound/soc/omap/mcbsp.h | 1 +
> 2 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/sound/soc/omap/mcbsp.c b/sound/soc/omap/mcbsp.c
> index c870023..e008898 100644
> --- a/sound/soc/omap/mcbsp.c
> +++ b/sound/soc/omap/mcbsp.c
> @@ -257,8 +257,15 @@ static void omap_st_on(struct omap_mcbsp *mcbsp)
> {
> unsigned int w;
>
> - if (mcbsp->pdata->enable_st_clock)
> - mcbsp->pdata->enable_st_clock(mcbsp->id, 1);
> + /*
> + * Sidetone uses McBSP ICLK - which must not idle when sidetones
> + * are enabled or sidetones start sounding ugly.
> + */
> + w = MCBSP_READ(mcbsp, SYSCON);
> + mcbsp->st_data->mcbsp_sidle = (w >> 3) & 0x3;
> + w &= ~SIDLEMODE(0x3);
> + w |= SIDLEMODE(0x1);
> + MCBSP_WRITE(mcbsp, SYSCON, w);
Wouldn't this create a mismatch between the SYSCONFIG register and McBSP
omap_hwmod._sysc_cache? Perhaps this could be done with a future
omap_hwmod API?
Ricardo
>
> /* Enable McBSP Sidetone */
> w = MCBSP_READ(mcbsp, SSELCR);
> @@ -279,8 +286,11 @@ static void omap_st_off(struct omap_mcbsp *mcbsp)
> w = MCBSP_READ(mcbsp, SSELCR);
> MCBSP_WRITE(mcbsp, SSELCR, w & ~(SIDETONEEN));
>
> - if (mcbsp->pdata->enable_st_clock)
> - mcbsp->pdata->enable_st_clock(mcbsp->id, 0);
> + /* Restore the SIDLEMODE as it was before the ST has been started */
> + w = MCBSP_READ(mcbsp, SYSCON);
> + w &= ~SIDLEMODE(0x3);
> + w |= SIDLEMODE(mcbsp->st_data->mcbsp_sidle);
> + MCBSP_WRITE(mcbsp, SYSCON, w);
> }
>
> static void omap_st_fir_write(struct omap_mcbsp *mcbsp, s16 *fir)
> diff --git a/sound/soc/omap/mcbsp.h b/sound/soc/omap/mcbsp.h
> index 49a6725..ba82846 100644
> --- a/sound/soc/omap/mcbsp.h
> +++ b/sound/soc/omap/mcbsp.h
> @@ -280,6 +280,7 @@ struct omap_mcbsp_st_data {
> int nr_taps; /* Number of filter coefficients in use */
> s16 ch0gain;
> s16 ch1gain;
> + unsigned int mcbsp_sidle;
> };
>
> struct omap_mcbsp {
>
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