[alsa-devel] [PATCH v2 2/2] ASoC: omap-mcpdm: Replace legacy driver

[Lars-Peter Clausen]

On 08/19/2011 09:41 AM, Peter Ujfalusi wrote:
> From: Misael Lopez Cruz <misael.lopez at ti.com>
> 
> Reasons for the replacement:
> The current driver for McPDM was developed to support the legacy mode only.
> In preparation for the ABE support the current driver stack need the be
> replaced.
> The new driver is much simpler, easier to extend, and it also fixes some of the
> issues with the old stack.
> 
> Main changes:
> - single file for omap-mcpdm (mcpdm.c/h removed)
> - Define names for registers, bits cleaned up, prefixed
> - Full-duplex audio operation (arecord | aplay) has been fixed
> - Less code
> 
> McPDM need to be turned off _after_ the codec's DAC/ADC has been powered down.
> The solution for this without extensive change in core:
> Use DAPM_SUPPLY to turn off the McPDM interface.
> The machine driver connects the "OMAP McPDM Interface" to the codec's DAC/ADC,
> so after audio activity we can be sure that the host side McPDM is turned off
> at the correct time.
> 
> Signed-off-by: Misael Lopez Cruz <misael.lopez at ti.com>
> Signed-off-by: Liam Girdwood <lrg at ti.com>
> Signed-off-by: Sebastien Guiriec <s-guiriec at ti.com>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> ---
>  sound/soc/omap/Makefile     |    2 +-
>  sound/soc/omap/mcpdm.c      |  472 -------------------------
>  sound/soc/omap/mcpdm.h      |  152 --------
>  sound/soc/omap/omap-mcpdm.c |  823 ++++++++++++++++++++++++++++---------------
>  sound/soc/omap/omap-mcpdm.h |   97 +++++
>  sound/soc/omap/sdp4430.c    |   14 +-
>  6 files changed, 655 insertions(+), 905 deletions(-)
>  delete mode 100644 sound/soc/omap/mcpdm.c
>  delete mode 100644 sound/soc/omap/mcpdm.h
>  rewrite sound/soc/omap/omap-mcpdm.c (46%)
>  create mode 100644 sound/soc/omap/omap-mcpdm.h
> 
> diff --git a/sound/soc/omap/Makefile b/sound/soc/omap/Makefile
> index 59e2c8d..052fd75 100644
> --- a/sound/soc/omap/Makefile
> +++ b/sound/soc/omap/Makefile
> @@ -1,7 +1,7 @@
>  # OMAP Platform Support
>  snd-soc-omap-objs := omap-pcm.o
>  snd-soc-omap-mcbsp-objs := omap-mcbsp.o
> -snd-soc-omap-mcpdm-objs := omap-mcpdm.o mcpdm.o
> +snd-soc-omap-mcpdm-objs := omap-mcpdm.o
>  snd-soc-omap-hdmi-objs := omap-hdmi.o
>  
>  obj-$(CONFIG_SND_OMAP_SOC) += snd-soc-omap.o
> diff --git a/sound/soc/omap/mcpdm.c b/sound/soc/omap/mcpdm.c
> deleted file mode 100644
> index 9746a49..0000000
> --- a/sound/soc/omap/mcpdm.c
> +++ /dev/null
> @@ -1,472 +0,0 @@
> [...]
> +static int omap_mcpdm_interface_event(struct snd_soc_dapm_widget *w,
> +		struct snd_kcontrol *kcontrol, int event)
> +{
> +	struct omap_mcpdm *mcpdm = w->private_data;

Can't you use
struct omap_mcpdm *mcpdm = snd_soc_codec_get_drvdata(codec)?

This would avoid having to add the private_data field to the widget struct. In
it's current form it will only really work, if there is just one instance of
the driver using the widget. And if that's the case you can use a global
variable directly anyway.

- Lars