On 27/02/17 10:31, Arnaud Pouliquen wrote: > > > On 02/19/2017 03:56 PM, Jonathan Cameron wrote: >> On 14/02/17 17:45, Mark Brown wrote: >>> On Mon, Feb 13, 2017 at 05:38:27PM +0100, Arnaud Pouliquen wrote: >>> >>> This looks basically fine as a system specific driver but as some of the >>> comments in here say there's bits of it could perhaps be genericised but >>> I'm not sure we need to do that right now. I'm not sure the abstraction >>> is exactly comfortable but having another bit of hardware doing a bridge >>> to IIO might be the best way to figure out something better. >> Agreed. To an extent we are fishing around in the dark at the moment. >> Lets wait until we have a few more cases of similar hardware before trying >> too much generalization. This is acting as a good exploration of what >> is needed. > > So for now i keep like this the API between ASOC and IIO, means not > generic API, and DMA handled in ASOC? > > Then when some other hardwares come with same kind of requirements, we > will re-discuss a more generic way to do it... Exactly what I was thinking. > >> >> Ideally Lars might upstream some of the other bits he has in his tree >> to do with DSP processing on ADC streams and that might provide us with >> more clues on generality (at least at the lowest layers) >> (Apparently he's busy - though he always makes that excuse :) >> Joking aside, the exploration Analog and in particular Lars does around >> pushing the limits of how things interact is always useful!) >> >>> >>>> + .period_bytes_min = 40, /* 8 khz 5 ms */ >>>> + .period_bytes_max = 4 * PAGE_SIZE, >>>> + .buffer_bytes_max = 16 * PAGE_SIZE >>> >>> What's the physical minimum period limit? The comment makes this sound >>> like it's just made up. >>> >>>> + unsigned int shift = 24 -priv->max_scaling; >>>> + >>> >>> Missing space after -. >>> >>>> + dev_dbg(dai->dev, "%s: enter\n", __func__); >>>> + return 0; >>>> + return snd_pcm_hw_constraint_list(substream->runtime, 0, >>>> + SNDRV_PCM_HW_PARAM_RATE, >>>> + &priv->rates_const); >>> >>> Looks like debug changes got left in? >>> >>>> +static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id, >>>> + unsigned int freq, int dir) >>>> +{ >>>> + struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai); >>>> + struct stm32_adfsdm_pdata *pdata = priv->pdata; >>>> + >>>> + dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id); >>>> + if (dir == SND_SOC_CLOCK_IN) { >>>> + pdata->ops->set_sysclk(pdata->adc, freq); >>>> + priv->dmic_clk = freq; >>>> + } >>>> + >>>> + /* Determine supported rate which depends on SPI/manchester clock */ >>>> + return stm32_adfsdm_get_supported_rates(dai, &priv->rates_const.mask); >>> >>> Since the DAI is unidirectional it doesn't matter but obviously if it >>> weren't then the fact that getting the supported rates involves setting >>> the hwparams means this could become disruptive. If we're going to >>> genericise this to be a more general IIO/ASoC bridge that could matter. >>> >>>> +static int stm32_adfsdm_dai_remove(struct snd_soc_dai *dai) >>>> +{ >>>> + dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id); >>>> + >>>> + return 0; >>>> +} >>> >>> Remove empty functions, though in this case I think you want to add >>> something to disconnect the XRUN callback just in order to be sure it >>> can't be mistakenly called. >>> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html