On Fri, Nov 20, 2015 at 02:47:10PM +0100, Hans de Goede wrote:
> Add support for PA gpio pin for controlling an external amplifier as used
> on some Allwinner boards.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> .../devicetree/bindings/sound/sun4i-codec.txt | 3 +++
> sound/soc/sunxi/sun4i-codec.c | 25 ++++++++++++++--------
> 2 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/sound/sun4i-codec.txt b/Documentation/devicetree/bindings/sound/sun4i-codec.txt
> index c92966b..974babe 100644
> --- a/Documentation/devicetree/bindings/sound/sun4i-codec.txt
> +++ b/Documentation/devicetree/bindings/sound/sun4i-codec.txt
> @@ -14,6 +14,9 @@ Required properties:
> - "apb": the parent APB clock for this controller
> - "codec": the parent module clock
>
> +Optional properties:
> +- pa-gpios: gpio to enable external amplifier
This is a custom property, it should be prefixed by the vendor name.
> +
> Example:
> codec: codec@01c22c00 {
> #sound-dai-cells = <0>;
> diff --git a/sound/soc/sunxi/sun4i-codec.c b/sound/soc/sunxi/sun4i-codec.c
> index bcbf4da..2aca9cd 100644
> --- a/sound/soc/sunxi/sun4i-codec.c
> +++ b/sound/soc/sunxi/sun4i-codec.c
> @@ -27,6 +27,7 @@
> #include <linux/of_address.h>
> #include <linux/clk.h>
> #include <linux/regmap.h>
> +#include <linux/gpio/consumer.h>
>
> #include <sound/core.h>
> #include <sound/pcm.h>
> @@ -101,16 +102,15 @@ struct sun4i_codec {
> struct regmap *regmap;
> struct clk *clk_apb;
> struct clk *clk_module;
> + struct gpio_desc *gpio_pa;
>
> struct snd_dmaengine_dai_dma_data playback_dma_data;
> };
>
> static void sun4i_codec_start_playback(struct sun4i_codec *scodec)
> {
> - /*
> - * FIXME: according to the BSP, we might need to drive a PA
> - * GPIO high here on some boards
> - */
> + if (scodec->gpio_pa)
> + gpiod_set_value_cansleep(scodec->gpio_pa, 1);
>
> /* Flush TX FIFO */
> regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
> @@ -125,15 +125,13 @@ static void sun4i_codec_start_playback(struct sun4i_codec *scodec)
>
> static void sun4i_codec_stop_playback(struct sun4i_codec *scodec)
> {
> - /*
> - * FIXME: according to the BSP, we might need to drive a PA
> - * GPIO low here on some boards
> - */
> -
> /* Disable DAC DRQ */
> regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
> BIT(SUN4I_CODEC_DAC_FIFOC_DAC_DRQ_EN),
> 0);
> +
> + if (scodec->gpio_pa)
> + gpiod_set_value_cansleep(scodec->gpio_pa, 0);
You should rather plug that into DAPM, using a speaker widget, and a
custom event function that will enable or disable the amplifier only
when this audio path is going to be used.
You can see such an example here:
http://lxr.free-electrons.com/source/sound/soc/jz4740/qi_lb60.c#L29
That will require to modify a bit sun4i_codec_create_card as well in
order to add the new widgets (and routes) when the DT property is
found.
Thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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