[RFC 1/2] ARM:Tegra: Device Tree Support: Initialize the audio card from the device tree.

[Barry Song]

2011/6/3 Grant Likely <grant.likely at secretlab.ca>
>
> On Thu, Jun 02, 2011 at 05:07:02PM +0800, Barry Song wrote:
> > 2011/6/2 Grant Likely <grant.likely at secretlab.ca>:
> > > On Wed, Jun 1, 2011 at 1:07 AM, Barry Song <21cnbao at gmail.com> wrote:
> > >> 2011/5/28 John Bonesio <bones at secretlab.ca>:
> > >>> This patch makes it so the top level audio card is initialized from the device
> > >>> tree. This is just the first step getting the audio complex of devices
> > >>> iniialized from device tree nodes.
> > >>>
> > >>> Signed-off-by: John Bonesio<bones at secretlab.ca>
> > >>> ---
> > >>>
> > >>>  arch/arm/boot/dts/tegra-harmony.dts |    4 +++
> > >>>  arch/arm/mach-tegra/board-dt.c      |    3 ++
> > >>>  sound/soc/tegra/harmony.c           |   45 ++++++++++++++++++++++++++++++++---
> > >>>  3 files changed, 48 insertions(+), 4 deletions(-)
> > >>>
> > >>> diff --git a/arch/arm/boot/dts/tegra-harmony.dts b/arch/arm/boot/dts/tegra-harmony.dts
> > >>> index 05521a5..217a7f0 100644
> > >>> --- a/arch/arm/boot/dts/tegra-harmony.dts
> > >>> +++ b/arch/arm/boot/dts/tegra-harmony.dts
> > >>> @@ -53,6 +53,10 @@
> > >>>                clock-frequency = <400000>;
> > >>>        };
> > >>>
> > >>> +       harmony_audio: audio_card {
> > >>> +               compatible = "nvidia,harmony-audio";
> > >>> +       };
> > >>> +
> > >>>        serial at 70006300 {
> > >>>                status = "ok";
> > >>>                clock-frequency = < 216000000 >;
> > >>> diff --git a/arch/arm/mach-tegra/board-dt.c b/arch/arm/mach-tegra/board-dt.c
> > >>> index c498e84..a569ad9 100644
> > >>> --- a/arch/arm/mach-tegra/board-dt.c
> > >>> +++ b/arch/arm/mach-tegra/board-dt.c
> > >>> @@ -56,6 +56,9 @@ static struct platform_device *tegra250_devices[] __initdata = {
> > >>>        &tegra_i2c_device2,
> > >>>        &tegra_i2c_device3,
> > >>>        &tegra_i2c_device4,
> > >>> +       &tegra_i2s_device1,
> > >>> +       &tegra_das_device,
> > >>> +       &tegra_pcm_device,
> > >>
> > >> i am thinking whether platform_device should be created by
> > >> of_platform_device_create after scanning device tree, but not by
> > >> hard-code? looks like the two patches are only trying to let device
> > >> tree deliver gpio to drivers?
> > >
> > > Can you please restate your question?  I don't think I understand what
> > > you are trying to ask.
> >
> > i mean we don't need to have this platform device registerred by the
> > old way here. we may get it by matching information in dts and delete
> > all platform_device and related codes in arch/arm. For example:
>
> Ah, I see what you mean.  Yes, it is ultimately the goal to register
> all the device from data in the device tree, but we're taking things
> one step at a time.  For this series, it is expedient to register the
> on-chip devices, and to move to dynamic registration later.
>
> Right now we can't do dynamic registration for on-chip devices in a
> lot of cases because we don't have the infrastructure to hook up the
> associated struct clks.
Arnd has required me to use device tree in our new SoC for the coming
upstream. so i am trying to define a property like clock = "uart" in
dts. then in drivers,
i get this  string by:
clk = of_get_property(np, "clock", NULL);
then request this clock by clk_get().

it does work for the moment, but maybe is not what you like :-)

>
> g.
>
>