[alsa-devel] [PATCH 4/4] ASoC: tegra: i2s: Add support for more than 2 channels

[Jon Hunter]

On 27/07/18 13:59, Jorge Sanjuan wrote:
> From: Edward Cragg <edward.cragg at codethink.co.uk>
> 
> The CIF configuration and clock setting is currently hard coded for 2
> channels. Since the hardware is capable of supporting 1-8 channels add
> support for reading the channel count from the supplied parameters to
> allow for better TDM support. It seems the original implementation of this
> driver was fixed at 2 channels for simplicity, and not implementing TDM.
> 
> Signed-off-by: Edward Cragg <edward.cragg at codethink.co.uk>
> Signed-off-by: Jorge Sanjuan <jorge.sanjuan at codethink.co.uk>
> ---
>  sound/soc/tegra/tegra30_i2s.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/sound/soc/tegra/tegra30_i2s.c b/sound/soc/tegra/tegra30_i2s.c
> index e26c19ef7439..0f240d7989d0 100644
> --- a/sound/soc/tegra/tegra30_i2s.c
> +++ b/sound/soc/tegra/tegra30_i2s.c
> @@ -138,16 +138,17 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
>  	struct device *dev = dai->dev;
>  	struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
>  	unsigned int mask, val, reg;
> -	int ret, sample_size, srate, i2sclock, bitcnt;
> +	int ret, sample_size, srate, i2sclock, bitcnt, audio_bits, channels;
>  	struct tegra30_ahub_cif_conf cif_conf;
>  
> -	if (params_channels(params) != 2)
> +	if (params_channels(params) > 8)
>  		return -EINVAL;

For normal I2S mode, channels should always be 2 and so it could be worth checking
if we are using TDM mode here or not.

>  
>  	mask = TEGRA30_I2S_CTRL_BIT_SIZE_MASK;
>  	switch (params_format(params)) {
>  	case SNDRV_PCM_FORMAT_S16_LE:
>  		val = TEGRA30_I2S_CTRL_BIT_SIZE_16;
> +		audio_bits = TEGRA30_AUDIOCIF_BITS_16;
>  		sample_size = 16;
>  		break;
>  	case SNDRV_PCM_FORMAT_S24_LE:
> @@ -157,6 +158,7 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
>  		break;
>  	case SNDRV_PCM_FORMAT_S32_LE:
>  		val = TEGRA30_I2S_CTRL_BIT_SIZE_32;
> +		audio_bits = TEGRA30_AUDIOCIF_BITS_32;
>  		sample_size = 32;
>  		break;
>  	default:
> @@ -166,9 +168,10 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
>  	regmap_update_bits(i2s->regmap, TEGRA30_I2S_CTRL, mask, val);
>  
>  	srate = params_rate(params);
> +	channels = params_channels(params);
>  
>  	/* Final "* 2" required by Tegra hardware */
> -	i2sclock = srate * params_channels(params) * sample_size * 2;
> +	i2sclock = srate * channels * sample_size * 2;
>  
>  	bitcnt = (i2sclock / (2 * srate)) - 1;
>  	if (bitcnt < 0 || bitcnt > TEGRA30_I2S_TIMING_CHANNEL_BIT_COUNT_MASK_US)
> @@ -188,10 +191,10 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
>  	regmap_write(i2s->regmap, TEGRA30_I2S_TIMING, val);
>  
>  	cif_conf.threshold = 0;
> -	cif_conf.audio_channels = 2;
> -	cif_conf.client_channels = 2;
> -	cif_conf.audio_bits = TEGRA30_AUDIOCIF_BITS_16;
> -	cif_conf.client_bits = TEGRA30_AUDIOCIF_BITS_16;
> +	cif_conf.audio_channels = channels;
> +	cif_conf.client_channels = channels;
> +	cif_conf.audio_bits = audio_bits;
> +	cif_conf.client_bits = audio_bits;
>  	cif_conf.expand = 0;
>  	cif_conf.stereo_conv = 0;
>  	cif_conf.replicate = 0;
> @@ -329,7 +332,7 @@ static const struct snd_soc_dai_driver tegra30_i2s_dai_template = {
>  	.playback = {
>  		.stream_name = "Playback",
>  		.channels_min = 2,
> -		.channels_max = 2,
> +		.channels_max = 8,
>  		.rates = SNDRV_PCM_RATE_8000_96000,
>  		.formats = SNDRV_PCM_FMTBIT_S32_LE |
>  			   SNDRV_PCM_FMTBIT_S24_LE |
> @@ -338,7 +341,7 @@ static const struct snd_soc_dai_driver tegra30_i2s_dai_template = {
>  	.capture = {
>  		.stream_name = "Capture",
>  		.channels_min = 2,
> -		.channels_max = 2,
> +		.channels_max = 8,
>  		.rates = SNDRV_PCM_RATE_8000_96000,
>  		.formats = SNDRV_PCM_FMTBIT_S32_LE |
>  			   SNDRV_PCM_FMTBIT_S24_LE |
> 

Otherwise, assuming that you fix patch 3/4 and rebase this one, looks good to me.

Cheers
Jon

-- 
nvpublic