From: Jörg Krause jk@lintech.de
The SAIF base oversample rates are either 512*fs or 384*fs. An additional divider exists within the SAIF to generate sub-multiples of these two base rates if MCLK is required by the codec.
* The sub-rates for the 512x base rate are: 256x, 128x, 64x, and 32x. * The sub-rates for the 384x base rate are: 192x, 96x, and 48x.
Setting the base rate depending on the modulo operation with 32 and 48 give wrong results for some mclk.
If mclk=18.432MHz both modulo operations results in 0. As testing the result with 32 is done first, a wrong base rate of 512*fs is set instead of the correct 384*fs.
Fix this by setting the base rate depending on the calculated sub-rate.
Signed-off-by: Jörg Krause joerg.krause@embedded.rocks --- sound/soc/mxs/mxs-saif.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c index 13631003cb7c..1e724533dc6e 100644 --- a/sound/soc/mxs/mxs-saif.c +++ b/sound/soc/mxs/mxs-saif.c @@ -119,23 +119,33 @@ static int mxs_saif_set_clk(struct mxs_saif *saif, * Set SAIF clock * * The SAIF clock should be either 384*fs or 512*fs. - * If MCLK is used, the SAIF clk ratio need to match mclk ratio. - * For 32x mclk, set saif clk as 512*fs. - * For 48x mclk, set saif clk as 384*fs. + * If MCLK is used, the SAIF clk ratio needs to match mclk ratio. + * For 256x, 128x, 64x, and 32x sub-rates, set saif clk as 512*fs. + * For 192x, 96x, and 48x sub-rates, set saif clk as 384*fs. * * If MCLK is not used, we just set saif clk to 512*fs. */ clk_prepare_enable(master_saif->clk);
if (master_saif->mclk_in_use) { - if (mclk % 32 == 0) { + switch (mclk / rate) { + case 32: + case 64: + case 128: + case 256: + case 512: scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE; ret = clk_set_rate(master_saif->clk, 512 * rate); - } else if (mclk % 48 == 0) { + break; + case 48: + case 96: + case 192: + case 384: scr |= BM_SAIF_CTRL_BITCLK_BASE_RATE; ret = clk_set_rate(master_saif->clk, 384 * rate); - } else { - /* SAIF MCLK should be either 32x or 48x */ + break; + default: + /* SAIF MCLK should be a sub-rate of 512x or 384x */ clk_disable_unprepare(master_saif->clk); return -EINVAL; }