Re: [PATCH v7] drm/rockchip: rk3066_hdmi: add sound support

[Johan Jonker <jbx6244@xxxxxxxxx>]

Hi Andy, thanks.

On 6/28/24 15:08, Andy Yan wrote:
> 
> Hi Johan,
> 
> At 2024-06-28 17:23:39, "Johan Jonker" <jbx6244@xxxxxxxxx> wrote:
>> Add sound support to the RK3066 HDMI driver.
>> The HDMI TX audio source is connected to I2S_8CH.
>>
>> Signed-off-by: Zheng Yang <zhengyang@xxxxxxxxxxxxxx>
>> Signed-off-by: Johan Jonker <jbx6244@xxxxxxxxx>
>> ---
>>
>> Changed V7:
>>  rebase
>> ---
>> drivers/gpu/drm/rockchip/Kconfig       |   2 +
>> drivers/gpu/drm/rockchip/rk3066_hdmi.c | 274 ++++++++++++++++++++++++-
>> 2 files changed, 275 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
>> index 1bf3e2829cd0..a32ee558408c 100644
>> --- a/drivers/gpu/drm/rockchip/Kconfig
>> +++ b/drivers/gpu/drm/rockchip/Kconfig
>> @@ -102,6 +102,8 @@ config ROCKCHIP_RGB
>> config ROCKCHIP_RK3066_HDMI
>> 	bool "Rockchip specific extensions for RK3066 HDMI"
>> 	depends on DRM_ROCKCHIP
>> +	select SND_SOC_HDMI_CODEC if SND_SOC
>> +	select SND_SOC_ROCKCHIP_I2S if SND_SOC
>> 	help
>> 	  This selects support for Rockchip SoC specific extensions
>> 	  for the RK3066 HDMI driver. If you want to enable
>> diff --git a/drivers/gpu/drm/rockchip/rk3066_hdmi.c b/drivers/gpu/drm/rockchip/rk3066_hdmi.c
>> index 784de990da1b..d3128b787629 100644
>> --- a/drivers/gpu/drm/rockchip/rk3066_hdmi.c
>> +++ b/drivers/gpu/drm/rockchip/rk3066_hdmi.c
>> @@ -15,12 +15,20 @@
>> #include <linux/platform_device.h>
>> #include <linux/regmap.h>
>>
>> +#include <sound/hdmi-codec.h>
>> +
>> #include "rk3066_hdmi.h"
>>
>> #include "rockchip_drm_drv.h"
>>
>> #define DEFAULT_PLLA_RATE 30000000
>>
>> +struct audio_info {
>> +	int channels;
>> +	int sample_rate;
>> +	int sample_width;
>> +};
>> +
>> struct hdmi_data_info {
>> 	int vic; /* The CEA Video ID (VIC) of the current drm display mode. */
>> 	unsigned int enc_out_format;
>> @@ -54,9 +62,16 @@ struct rk3066_hdmi {
>>
>> 	unsigned int tmdsclk;
>>
>> +	struct platform_device *audio_pdev;
>> +	stru
> 
> ......
> 
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct hdmi_codec_ops audio_codec_ops = {
>> +	.hw_params = rk3066_hdmi_audio_hw_params,
>> +	.audio_shutdown = rk3066_hdmi_audio_shutdown,
>> +	.mute_stream = rk3066_hdmi_audio_mute_stream,
>> +	.get_eld = rk3066_hdmi_audio_get_eld,
>> +	.no_capture_mute = 1,
>> +};
>> +
>> +static int rk3066_hdmi_audio_codec_init(struct rk3066_hdmi *hdmi,
>> +					struct device *dev)
>> +{
>> +	struct hdmi_codec_pdata codec_data = {
>> +		.i2s = 1,
>> +		.ops = &audio_codec_ops,
>> +		.max_i2s_channels = 8,
>> +	};
>> +
>> +	hdmi->audio.channels = 2;
>> +	hdmi->audio.sample_rate = 48000;
>> +	hdmi->audio.sample_width = 16;
>> +	hdmi->audio_enable = false;
>> +	hdmi->audio_pdev =
>> +		platform_device_register_data(dev,
>> +					      HDMI_CODEC_DRV_NAME,
>> +					      PLATFORM_DEVID_NONE,
>> +					      &codec_data,
>> +					      sizeof(codec_data));
>> +
>> +	return PTR_ERR_OR_ZERO(hdmi->audio_pdev);
>> +}
>> +
>> static int
>> rk3066_hdmi_register(struct drm_device *drm, struct rk3066_hdmi *hdmi)
>> {
>> @@ -566,6 +834,8 @@ rk3066_hdmi_register(struct drm_device *drm, struct rk3066_hdmi *hdmi)
>>
>> 	drm_connector_attach_encoder(&hdmi->connector, encoder);
>>
>> +	rk3066_hdmi_audio_codec_init(hdmi, dev);
> 
> 
> According to Documentation/driver-api/driver-model/driver.rst,
> 

> It is best not to register at the bind callback：

Question for the DRM experts:
What would be the correct location/level for the rk3066_hdmi_audio_codec_init() function?
Is that at the rk3066_hdmi_encoder_enable() function?
Are there other functions/examples for sound in the DRM toolbox?

Johan
> 
> .. warning::
>       -EPROBE_DEFER must not be returned if probe() has already created
>       child devices, even if those child devices are removed again
>       in a cleanup path. If -EPROBE_DEFER is returned after a child
>       device has been registered, it may result in an infinite loop of
>       .probe() calls to the same driver.
> 
> For example：
> vop_probe --》component_add--》rk3066_hdmi_bind--》rk3066_hdmi_audio_codec_init--》hdmi_codec_probe--》rockchip_rgb_init（DEFER when panel not ready）
> 
> This  may result in an infinite loop of probe
> 
> 
>> +
>> 	return 0;
>> }
>>
>> @@ -813,6 +1083,7 @@ static int rk3066_hdmi_bind(struct device *dev, struct device *master,
>> 	return 0;
>>
>> err_cleanup_hdmi:
>> +	platform_device_unregister(hdmi->audio_pdev);
>> 	hdmi->connector.funcs->destroy(&hdmi->connector);
>> 	hdmi->encoder.encoder.funcs->destroy(&hdmi->encoder.encoder);
>> err_disable_i2c:
>> @@ -828,6 +1099,7 @@ static void rk3066_hdmi_unbind(struct device *dev, struct device *master,
>> {
>> 	struct rk3066_hdmi *hdmi = dev_get_drvdata(dev);
>>
>> +	platform_device_unregister(hdmi->audio_pdev);
>> 	hdmi->connector.funcs->destroy(&hdmi->connector);
>> 	hdmi->encoder.encoder.funcs->destroy(&hdmi->encoder.encoder);
>>
>> --
>> 2.39.2
>>