diff options
Diffstat (limited to 'sound/soc')
| -rw-r--r-- | sound/soc/fsl/fsl_ssi.c | 190 |
1 files changed, 96 insertions, 94 deletions
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index c6dcdb88b2b9..e5d8819cf19f 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -519,6 +519,102 @@ static int fsl_ssi_startup(struct snd_pcm_substream *substream, } /** + * fsl_ssi_set_dai_sysclk - configure Digital Audio Interface bit clock + * + * Note: This function can be only called when using SSI as DAI master + * + * Quick instruction for parameters: + * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels + * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK. + */ +static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai, + int clk_id, unsigned int freq, int dir) +{ + struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai); + struct ccsr_ssi __iomem *ssi = ssi_private->ssi; + int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret; + u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i; + unsigned long flags, clkrate, baudrate, tmprate; + u64 sub, savesub = 100000; + + /* Don't apply it to any non-baudclk circumstance */ + if (IS_ERR(ssi_private->baudclk)) + return -EINVAL; + + /* It should be already enough to divide clock by setting pm alone */ + psr = 0; + div2 = 0; + + factor = (div2 + 1) * (7 * psr + 1) * 2; + + for (i = 0; i < 255; i++) { + /* The bclk rate must be smaller than 1/5 sysclk rate */ + if (factor * (i + 1) < 5) + continue; + + tmprate = freq * factor * (i + 2); + clkrate = clk_round_rate(ssi_private->baudclk, tmprate); + + do_div(clkrate, factor); + afreq = (u32)clkrate / (i + 1); + + if (freq == afreq) + sub = 0; + else if (freq / afreq == 1) + sub = freq - afreq; + else if (afreq / freq == 1) + sub = afreq - freq; + else + continue; + + /* Calculate the fraction */ + sub *= 100000; + do_div(sub, freq); + + if (sub < savesub) { + baudrate = tmprate; + savesub = sub; + pm = i; + } + + /* We are lucky */ + if (savesub == 0) + break; + } + + /* No proper pm found if it is still remaining the initial value */ + if (pm == 999) { + dev_err(cpu_dai->dev, "failed to handle the required sysclk\n"); + return -EINVAL; + } + + stccr = CCSR_SSI_SxCCR_PM(pm + 1) | (div2 ? CCSR_SSI_SxCCR_DIV2 : 0) | + (psr ? CCSR_SSI_SxCCR_PSR : 0); + mask = CCSR_SSI_SxCCR_PM_MASK | CCSR_SSI_SxCCR_DIV2 | + CCSR_SSI_SxCCR_PSR; + + if (dir == SND_SOC_CLOCK_OUT || synchronous) + write_ssi_mask(&ssi->stccr, mask, stccr); + else + write_ssi_mask(&ssi->srccr, mask, stccr); + + spin_lock_irqsave(&ssi_private->baudclk_lock, flags); + if (!ssi_private->baudclk_locked) { + ret = clk_set_rate(ssi_private->baudclk, baudrate); + if (ret) { + spin_unlock_irqrestore(&ssi_private->baudclk_lock, + flags); + dev_err(cpu_dai->dev, "failed to set baudclk rate\n"); + return -EINVAL; + } + ssi_private->baudclk_locked = true; + } + spin_unlock_irqrestore(&ssi_private->baudclk_lock, flags); + + return 0; +} + +/** * fsl_ssi_hw_params - program the sample size * * Most of the SSI registers have been programmed in the startup function, @@ -721,100 +817,6 @@ static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt) } /** - * fsl_ssi_set_dai_sysclk - configure Digital Audio Interface bit clock - * - * Note: This function can be only called when using SSI as DAI master - * - * Quick instruction for parameters: - * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels - * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK. - */ -static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai, - int clk_id, unsigned int freq, int dir) -{ - struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai); - struct ccsr_ssi __iomem *ssi = ssi_private->ssi; - int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret; - u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i; - unsigned long flags, clkrate, baudrate, tmprate; - u64 sub, savesub = 100000; - - /* Don't apply it to any non-baudclk circumstance */ - if (IS_ERR(ssi_private->baudclk)) - return -EINVAL; - - /* It should be already enough to divide clock by setting pm alone */ - psr = 0; - div2 = 0; - - factor = (div2 + 1) * (7 * psr + 1) * 2; - - for (i = 0; i < 255; i++) { - /* The bclk rate must be smaller than 1/5 sysclk rate */ - if (factor * (i + 1) < 5) - continue; - - tmprate = freq * factor * (i + 2); - clkrate = clk_round_rate(ssi_private->baudclk, tmprate); - - do_div(clkrate, factor); - afreq = (u32)clkrate / (i + 1); - - if (freq == afreq) - sub = 0; - else if (freq / afreq == 1) - sub = freq - afreq; - else if (afreq / freq == 1) - sub = afreq - freq; - else - continue; - - /* Calculate the fraction */ - sub *= 100000; - do_div(sub, freq); - - if (sub < savesub) { - baudrate = tmprate; - savesub = sub; - pm = i; - } - - /* We are lucky */ - if (savesub == 0) - break; - } - - /* No proper pm found if it is still remaining the initial value */ - if (pm == 999) { - dev_err(cpu_dai->dev, "failed to handle the required sysclk\n"); - return -EINVAL; - } - - stccr = CCSR_SSI_SxCCR_PM(pm + 1) | (div2 ? CCSR_SSI_SxCCR_DIV2 : 0) | - (psr ? CCSR_SSI_SxCCR_PSR : 0); - mask = CCSR_SSI_SxCCR_PM_MASK | CCSR_SSI_SxCCR_DIV2 | CCSR_SSI_SxCCR_PSR; - - if (dir == SND_SOC_CLOCK_OUT || synchronous) - write_ssi_mask(&ssi->stccr, mask, stccr); - else - write_ssi_mask(&ssi->srccr, mask, stccr); - - spin_lock_irqsave(&ssi_private->baudclk_lock, flags); - if (!ssi_private->baudclk_locked) { - ret = clk_set_rate(ssi_private->baudclk, baudrate); - if (ret) { - spin_unlock_irqrestore(&ssi_private->baudclk_lock, flags); - dev_err(cpu_dai->dev, "failed to set baudclk rate\n"); - return -EINVAL; - } - ssi_private->baudclk_locked = true; - } - spin_unlock_irqrestore(&ssi_private->baudclk_lock, flags); - - return 0; -} - -/** * fsl_ssi_set_dai_tdm_slot - set TDM slot number * * Note: This function can be only called when using SSI as DAI master |
