Re: [PATCH 2/2] ASoC: axentia: tse850: add ASoC driver for the Axentia TSE-850

From: Peter Rosin
Date: Wed Nov 09 2016 - 11:43:43 EST


On 2016-11-09 14:38, Mark Brown wrote:
> On Tue, Nov 08, 2016 at 05:20:57PM +0100, Peter Rosin wrote:
>
>> +++ b/sound/soc/axentia/Kconfig
>> @@ -0,0 +1,10 @@
>> +config SND_SOC_AXENTIA_TSE850_PCM5142
>> + tristate "ASoC driver for the Axentia TSE-850"
>> + depends on ARCH_AT91 && OF
>> + select ATMEL_SSC
>> + select SND_ATMEL_SOC
>> + select SND_ATMEL_SOC_SSC_DMA
>> + select SND_SOC_PCM512x_I2C
>> + help
>> + Say Y if you want to add support for the ASoC driver for the
>> + Axentia TSE-850 with a PCM5142 codec.
>
> This just looks like a normal machine driver for an Atmel system which
> would usually go in the atemel directory - why is a new directory being
> created?

I thought atmel in this context meant that Atmel made the board, not that
the board was based on an Atmel cpu.

I'll move it for v2.

>> +static int tse850_get_mux2(struct snd_kcontrol *kctrl,
>> + struct snd_ctl_elem_value *ucontrol)
>> +{
>> + struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kctrl);
>> + struct snd_soc_card *card = dapm->card;
>> + struct tse850_priv *tse850 = snd_soc_card_get_drvdata(card);
>> + int ret;
>> +
>> + ret = gpiod_get_value(tse850->loop2);
>> + if (ret < 0)
>> + return ret;
>
> We can't reliably read the value of output GPIOs (though in practice the
> majority do support it) so it'd be better practice to use a state
> variable to remember what we set. I'd also expect this to use the
> _cansleep() GPIO calls as it's not in a context where sleeping would be
> a problem.

Ok, I'll add _cansleep and cached values for v2.

>> +int tse850_get_ana(struct snd_kcontrol *kctrl,
>> + struct snd_ctl_elem_value *ucontrol)
>> +{
>> + struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kctrl);
>> + struct snd_soc_card *card = dapm->card;
>> + struct tse850_priv *tse850 = snd_soc_card_get_drvdata(card);
>> + int ret;
>> +
>> + ret = regulator_get_voltage(tse850->ana);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (ret < 11000000)
>> + ret = 11000000;
>> + else if (ret > 20000000)
>> + ret = 20000000;
>
> This needs some comments...

Ok, I'll add some words...

>> + struct snd_soc_pcm_runtime *rtd = substream->private_data;
>> + struct device *dev = rtd->dev;
>> + struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
>> + int dir = substream->stream != SNDRV_PCM_STREAM_PLAYBACK;
>> + int div_id = dir ? ATMEL_SSC_RCMR_PERIOD : ATMEL_SSC_TCMR_PERIOD;
>> + int period = snd_soc_params_to_frame_size(params) / 2 - 1;
>
> Please write the logic out as normal if statements for legibility. It's
> a bit concerning that we even need this function, it looks like pretty
> basic stuff that I'd expect the CPU DAI to just be doing - why can't
> this be the default behaviour of the CPU DAI?

I don't know and obviously don't have all the relevant HW to test
changes. Do you want me to attempt such a change anyway?
Adding Cc: Nicolas Ferre

>> +static int tse850_init(struct snd_soc_pcm_runtime *rtd)
>> +{
>> + struct snd_soc_dapm_context *dapm = &rtd->card->dapm;
>> +
>> + return snd_soc_dapm_add_routes(dapm, tse850_intercon,
>> + ARRAY_SIZE(tse850_intercon));
>
> Set this up in the card data structure rather than open coding the call,
> you can register DAPM routes there too.

Right.

Thanks for looking!

Cheers,
Peter