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ASoC: fsl_spdif: Add sysclk df support to derive txclk from sysclk 

The sysclk is one the clock sources that could be selected to derive
tx clock. But the route for sysclk is a bit different that it does
not only contain txclk df divider but also have an extra sysclk df.

So this patch mainly adds syclk df configuration support so as to
let the driver be able to get clock from sysclk.

Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Nicolin Chen 2014-04-30 18:54:07 +08:00 committed by Mark Brown
parent e41a4a79af
commit 27c647bff2
1 changed files with 48 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
sound/soc/fsl/fsl_spdif.c
View File

@ -76,6 +76,7 @@ struct fsl_spdif_priv {
struct regmap *regmap;
bool dpll_locked;
u8 txclk_df[SPDIF_TXRATE_MAX];
u8 sysclk_df[SPDIF_TXRATE_MAX];
u8 txclk_src[SPDIF_TXRATE_MAX];
u8 rxclk_src;
struct clk *txclk[SPDIF_TXRATE_MAX];
@ -351,7 +352,7 @@ static int spdif_set_sample_rate(struct snd_pcm_substream *substream,
struct platform_device *pdev = spdif_priv->pdev;
unsigned long csfs = 0;
u32 stc, mask, rate;
u8 clk, txclk_df;
u8 clk, txclk_df, sysclk_df;
int ret;
switch (sample_rate) {
@ -384,6 +385,8 @@ static int spdif_set_sample_rate(struct snd_pcm_substream *substream,
return -EINVAL;
}
sysclk_df = spdif_priv->sysclk_df[rate];
/* Don't mess up the clocks from other modules */
if (clk != STC_TXCLK_SPDIF_ROOT)
goto clk_set_bypass;
@ -400,7 +403,7 @@ static int spdif_set_sample_rate(struct snd_pcm_substream *substream,
clk_set_bypass:
dev_dbg(&pdev->dev, "expected clock rate = %d\n",
(64 * sample_rate * txclk_df));
(64 * sample_rate * txclk_df * sysclk_df));
dev_dbg(&pdev->dev, "actual clock rate = %ld\n",
clk_get_rate(spdif_priv->txclk[rate]));
@ -412,6 +415,9 @@ clk_set_bypass:
mask = STC_TXCLK_ALL_EN_MASK | STC_TXCLK_SRC_MASK | STC_TXCLK_DF_MASK;
regmap_update_bits(regmap, REG_SPDIF_STC, mask, stc);
regmap_update_bits(regmap, REG_SPDIF_STC,
STC_SYSCLK_DF_MASK, STC_SYSCLK_DF(sysclk_df));
dev_dbg(&pdev->dev, "set sample rate to %d\n", sample_rate);
return 0;
@ -1018,9 +1024,16 @@ static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
enum spdif_txrate index, bool round)
{
const u32 rate[] = { 32000, 44100, 48000 };
bool is_sysclk = clk == spdif_priv->sysclk;
u64 rate_ideal, rate_actual, sub;
u32 txclk_df, arate;
u32 sysclk_dfmin, sysclk_dfmax;
u32 txclk_df, sysclk_df, arate;
/* The sysclk has an extra divisor [2, 512] */
sysclk_dfmin = is_sysclk ? 2 : 1;
sysclk_dfmax = is_sysclk ? 512 : 1;
for (sysclk_df = sysclk_dfmin; sysclk_df <= sysclk_dfmax; sysclk_df++) {
for (txclk_df = 1; txclk_df <= 128; txclk_df++) {
rate_ideal = rate[index] * (txclk_df + 1) * 64;
if (round)
@ -1029,32 +1042,37 @@ static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
rate_actual = clk_get_rate(clk);
arate = rate_actual / 64;
arate /= txclk_df;
arate /= txclk_df * sysclk_df;
if (arate == rate[index]) {
/* We are lucky */
savesub = 0;
spdif_priv->txclk_df[index] = txclk_df;
break;
spdif_priv->sysclk_df[index] = sysclk_df;
goto out;
} else if (arate / rate[index] == 1) {
/* A little bigger than expect */
sub = (arate - rate[index]) * 100000;
do_div(sub, rate[index]);
if (sub < savesub) {
if (sub >= savesub)
continue;
savesub = sub;
spdif_priv->txclk_df[index] = txclk_df;
}
spdif_priv->sysclk_df[index] = sysclk_df;
} else if (rate[index] / arate == 1) {
/* A little smaller than expect */
sub = (rate[index] - arate) * 100000;
do_div(sub, rate[index]);
if (sub < savesub) {
if (sub >= savesub)
continue;
savesub = sub;
spdif_priv->txclk_df[index] = txclk_df;
spdif_priv->sysclk_df[index] = sysclk_df;
}
}
}
out:
return savesub;
}
@ -1097,6 +1115,9 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
spdif_priv->txclk_src[index], rate[index]);
dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
spdif_priv->txclk_df[index], rate[index]);
if (spdif_priv->txclk[index] == spdif_priv->sysclk)
dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
spdif_priv->sysclk_df[index], rate[index]);
return 0;
}