[alsa-devel] [PATCH v3] ASoC: davinci-mcasp: Set rule constraints if implicit BCLK divider is used
Peter Ujfalusi
peter.ujfalusi at ti.com
Tue Mar 24 10:17:47 CET 2015
On 03/20/2015 01:31 PM, Jyri Sarha wrote:
> Set rule constraints to allow only combinations of sample-rate,
> sample-format, and channels counts that can be played/captured with
> reasonable sample-rate accuracy.
>
> The logic with tdm-slots and serializers (=i2s data wires) goes like
> this: The first wire will take all channels up to number of tdm-slots,
> before following wires (if any) are used. If the first wire is used
> fully, the remaining wires share the same clocks and the divider can
> be calculated for the first wire.
>
> Also, takes the number of tdm-slots into account when implicitly
> selecting the BLCK divider.
Acked-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
>
> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> ---
> Previous version of the patch:
> http://mailman.alsa-project.org/pipermail/alsa-devel/2015-March/089319.html
>
> Since v2 I changed the SNDRV_PCM_HW_PARAM_SAMPLE_BITS rule in the to
> SNDRV_PCM_HW_PARAM_FORMAT rule.
>
> Somehow the constraints with a SNDRV_PCM_HW_PARAM_SAMPLE_BITS rule
> using snd_interval_list() converged to an empty set when ever I tried
> to play a format that could not pass the rule with any channel count
> or rate, resulting all too familiar assertion in alsa-lib. However,
> the direct tampering with SNDRV_PCM_HW_PARAM_FORMAT mask appears to
> work as it should.
>
> In addition to SAMPLE_BITS- to FORMAT-rule change I optimized the rate
> rule a bit so that it does not try the rates that are outside current
> range. According to my tests this does not affect the behavior in any
> other way but slightly speeds up the decision making.
>
> sound/soc/davinci/davinci-mcasp.c | 207 ++++++++++++++++++++++++++++++++++++--
> 1 file changed, 197 insertions(+), 10 deletions(-)
>
> diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
> index d40b392..76156d18 100644
> --- a/sound/soc/davinci/davinci-mcasp.c
> +++ b/sound/soc/davinci/davinci-mcasp.c
> @@ -27,6 +27,7 @@
> #include <linux/of_platform.h>
> #include <linux/of_device.h>
> #include <linux/platform_data/davinci_asp.h>
> +#include <linux/math64.h>
>
> #include <sound/asoundef.h>
> #include <sound/core.h>
> @@ -65,6 +66,11 @@ struct davinci_mcasp_context {
> bool pm_state;
> };
>
> +struct davinci_mcasp_ruledata {
> + struct davinci_mcasp *mcasp;
> + int serializers;
> +};
> +
> struct davinci_mcasp {
> struct snd_dmaengine_dai_dma_data dma_data[2];
> void __iomem *base;
> @@ -99,6 +105,8 @@ struct davinci_mcasp {
> #ifdef CONFIG_PM_SLEEP
> struct davinci_mcasp_context context;
> #endif
> +
> + struct davinci_mcasp_ruledata ruledata[2];
> };
>
> static inline void mcasp_set_bits(struct davinci_mcasp *mcasp, u32 offset,
> @@ -868,6 +876,30 @@ static int mcasp_dit_hw_param(struct davinci_mcasp *mcasp,
> return 0;
> }
>
> +static int davinci_mcasp_calc_clk_div(struct davinci_mcasp *mcasp,
> + unsigned int bclk_freq,
> + int *error_ppm)
> +{
> + int div = mcasp->sysclk_freq / bclk_freq;
> + int rem = mcasp->sysclk_freq % bclk_freq;
> +
> + if (rem != 0) {
> + if (div == 0 ||
> + ((mcasp->sysclk_freq / div) - bclk_freq) >
> + (bclk_freq - (mcasp->sysclk_freq / (div+1)))) {
> + div++;
> + rem = rem - bclk_freq;
> + }
> + }
> + if (error_ppm)
> + *error_ppm =
> + (div*1000000 + (int)div64_long(1000000LL*rem,
> + (int)bclk_freq))
> + /div - 1000000;
> +
> + return div;
> +}
> +
> static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
> struct snd_pcm_hw_params *params,
> struct snd_soc_dai *cpu_dai)
> @@ -883,16 +915,20 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
> * the machine driver, we need to calculate the ratio.
> */
> if (mcasp->bclk_master && mcasp->bclk_div == 0 && mcasp->sysclk_freq) {
> - unsigned int bclk_freq = snd_soc_params_to_bclk(params);
> - unsigned int div = mcasp->sysclk_freq / bclk_freq;
> - if (mcasp->sysclk_freq % bclk_freq != 0) {
> - if (((mcasp->sysclk_freq / div) - bclk_freq) >
> - (bclk_freq - (mcasp->sysclk_freq / (div+1))))
> - div++;
> - dev_warn(mcasp->dev,
> - "Inaccurate BCLK: %u Hz / %u != %u Hz\n",
> - mcasp->sysclk_freq, div, bclk_freq);
> - }
> + int channels = params_channels(params);
> + int rate = params_rate(params);
> + int sbits = params_width(params);
> + int ppm, div;
> +
> + if (channels > mcasp->tdm_slots)
> + channels = mcasp->tdm_slots;
> +
> + div = davinci_mcasp_calc_clk_div(mcasp, rate*sbits*channels,
> + &ppm);
> + if (ppm)
> + dev_info(mcasp->dev, "Sample-rate is off by %d PPM\n",
> + ppm);
> +
> __davinci_mcasp_set_clkdiv(cpu_dai, 1, div, 0);
> }
>
> @@ -974,6 +1010,120 @@ static int davinci_mcasp_trigger(struct snd_pcm_substream *substream,
> return ret;
> }
>
> +static const unsigned int davinci_mcasp_dai_rates[] = {
> + 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
> + 88200, 96000, 176400, 192000,
> +};
> +
> +#define DAVINCI_MAX_RATE_ERROR_PPM 1000
> +
> +static int davinci_mcasp_hw_rule_rate(struct snd_pcm_hw_params *params,
> + struct snd_pcm_hw_rule *rule)
> +{
> + struct davinci_mcasp_ruledata *rd = rule->private;
> + struct snd_interval *ri =
> + hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
> + int sbits = params_width(params);
> + int channels = params_channels(params);
> + unsigned int list[ARRAY_SIZE(davinci_mcasp_dai_rates)];
> + int i, count = 0;
> +
> + if (channels > rd->mcasp->tdm_slots)
> + channels = rd->mcasp->tdm_slots;
> +
> + for (i = 0; i < ARRAY_SIZE(davinci_mcasp_dai_rates); i++) {
> + if (ri->min <= davinci_mcasp_dai_rates[i] &&
> + ri->max >= davinci_mcasp_dai_rates[i]) {
> + uint bclk_freq = sbits*channels*
> + davinci_mcasp_dai_rates[i];
> + int ppm;
> +
> + davinci_mcasp_calc_clk_div(rd->mcasp, bclk_freq, &ppm);
> + if (abs(ppm) < DAVINCI_MAX_RATE_ERROR_PPM)
> + list[count++] = davinci_mcasp_dai_rates[i];
> + }
> + }
> + dev_dbg(rd->mcasp->dev,
> + "%d frequencies (%d-%d) for %d sbits and %d channels\n",
> + count, ri->min, ri->max, sbits, channels);
> +
> + return snd_interval_list(hw_param_interval(params, rule->var),
> + count, list, 0);
> +}
> +
> +static int davinci_mcasp_hw_rule_format(struct snd_pcm_hw_params *params,
> + struct snd_pcm_hw_rule *rule)
> +{
> + struct davinci_mcasp_ruledata *rd = rule->private;
> + struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
> + struct snd_mask nfmt;
> + int rate = params_rate(params);
> + int channels = params_channels(params);
> + int i, count = 0;
> +
> + snd_mask_none(&nfmt);
> +
> + if (channels > rd->mcasp->tdm_slots)
> + channels = rd->mcasp->tdm_slots;
> +
> + for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
> + if (snd_mask_test(fmt, i)) {
> + uint bclk_freq = snd_pcm_format_width(i)*channels*rate;
> + int ppm;
> +
> + davinci_mcasp_calc_clk_div(rd->mcasp, bclk_freq, &ppm);
> + if (abs(ppm) < DAVINCI_MAX_RATE_ERROR_PPM) {
> + snd_mask_set(&nfmt, i);
> + count++;
> + }
> + }
> + }
> + dev_dbg(rd->mcasp->dev,
> + "%d possible sample format for %d Hz and %d channels\n",
> + count, rate, channels);
> +
> + return snd_mask_refine(fmt, &nfmt);
> +}
> +
> +static int davinci_mcasp_hw_rule_channels(struct snd_pcm_hw_params *params,
> + struct snd_pcm_hw_rule *rule)
> +{
> + struct davinci_mcasp_ruledata *rd = rule->private;
> + struct snd_interval *ci =
> + hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
> + int sbits = params_width(params);
> + int rate = params_rate(params);
> + int max_chan_per_wire = rd->mcasp->tdm_slots < ci->max ?
> + rd->mcasp->tdm_slots : ci->max;
> + unsigned int list[ci->max - ci->min + 1];
> + int c1, c, count = 0;
> +
> + for (c1 = ci->min; c1 <= max_chan_per_wire; c1++) {
> + uint bclk_freq = c1*sbits*rate;
> + int ppm;
> +
> + davinci_mcasp_calc_clk_div(rd->mcasp, bclk_freq, &ppm);
> + if (abs(ppm) < DAVINCI_MAX_RATE_ERROR_PPM) {
> + /* If we can use all tdm_slots, we can put any
> + amount of channels to remaining wires as
> + long as they fit in. */
> + if (c1 == rd->mcasp->tdm_slots) {
> + for (c = c1; c <= rd->serializers*c1 &&
> + c <= ci->max; c++)
> + list[count++] = c;
> + } else {
> + list[count++] = c1;
> + }
> + }
> + }
> + dev_dbg(rd->mcasp->dev,
> + "%d possible channel counts (%d-%d) for %d Hz and %d sbits\n",
> + count, ci->min, ci->max, rate, sbits);
> +
> + return snd_interval_list(hw_param_interval(params, rule->var),
> + count, list, 0);
> +}
> +
> static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
> struct snd_soc_dai *cpu_dai)
> {
> @@ -999,6 +1149,7 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
> if (mcasp->serial_dir[i] == dir)
> max_channels++;
> }
> + mcasp->ruledata[dir].serializers = max_channels;
> max_channels *= mcasp->tdm_slots;
> /*
> * If the already active stream has less channels than the calculated
> @@ -1013,6 +1164,42 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
> snd_pcm_hw_constraint_minmax(substream->runtime,
> SNDRV_PCM_HW_PARAM_CHANNELS,
> 2, max_channels);
> +
> + /*
> + * If we rely on implicit BCLK divider setting we should
> + * set constraints based on what we can provide.
> + */
> + if (mcasp->bclk_master && mcasp->bclk_div == 0 && mcasp->sysclk_freq) {
> + int ret;
> +
> + mcasp->ruledata[dir].mcasp = mcasp;
> +
> + ret = snd_pcm_hw_rule_add(substream->runtime, 0,
> + SNDRV_PCM_HW_PARAM_RATE,
> + davinci_mcasp_hw_rule_rate,
> + &mcasp->ruledata[dir],
> + SNDRV_PCM_HW_PARAM_FORMAT,
> + SNDRV_PCM_HW_PARAM_CHANNELS, -1);
> + if (ret)
> + return ret;
> + ret = snd_pcm_hw_rule_add(substream->runtime, 0,
> + SNDRV_PCM_HW_PARAM_FORMAT,
> + davinci_mcasp_hw_rule_format,
> + &mcasp->ruledata[dir],
> + SNDRV_PCM_HW_PARAM_RATE,
> + SNDRV_PCM_HW_PARAM_CHANNELS, -1);
> + if (ret)
> + return ret;
> + ret = snd_pcm_hw_rule_add(substream->runtime, 0,
> + SNDRV_PCM_HW_PARAM_CHANNELS,
> + davinci_mcasp_hw_rule_channels,
> + &mcasp->ruledata[dir],
> + SNDRV_PCM_HW_PARAM_RATE,
> + SNDRV_PCM_HW_PARAM_FORMAT, -1);
> + if (ret)
> + return ret;
> + }
> +
> return 0;
> }
>
>
--
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