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Subject[PATCH AUTOSEL 5.10 01/39] ASoC: max98088: fix ni clock divider calculation
Date
From: Marco Felsch <m.felsch@pengutronix.de>

[ Upstream commit 6c9762a78c325107dc37d20ee21002b841679209 ]

The ni1/ni2 ratio formula [1] uses the pclk which is the prescaled mclk.
The max98088 datasheet [2] has no such formula but table-12 equals so
we can assume that it is the same for both devices.

While on it make use of DIV_ROUND_CLOSEST_ULL().

[1] https://datasheets.maximintegrated.com/en/ds/MAX98089.pdf; page 86
[2] https://datasheets.maximintegrated.com/en/ds/MAX98088.pdf; page 82

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20210423135402.32105-1-m.felsch@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/codecs/max98088.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/max98088.c b/sound/soc/codecs/max98088.c
index 4be24e7f51c8..f8e49e45ce33 100644
--- a/sound/soc/codecs/max98088.c
+++ b/sound/soc/codecs/max98088.c
@@ -41,6 +41,7 @@ struct max98088_priv {
enum max98088_type devtype;
struct max98088_pdata *pdata;
struct clk *mclk;
+ unsigned char mclk_prescaler;
unsigned int sysclk;
struct max98088_cdata dai[2];
int eq_textcnt;
@@ -998,13 +999,16 @@ static int max98088_dai1_hw_params(struct snd_pcm_substream *substream,
/* Configure NI when operating as master */
if (snd_soc_component_read(component, M98088_REG_14_DAI1_FORMAT)
& M98088_DAI_MAS) {
+ unsigned long pclk;
+
if (max98088->sysclk == 0) {
dev_err(component->dev, "Invalid system clock frequency\n");
return -EINVAL;
}
ni = 65536ULL * (rate < 50000 ? 96ULL : 48ULL)
* (unsigned long long int)rate;
- do_div(ni, (unsigned long long int)max98088->sysclk);
+ pclk = DIV_ROUND_CLOSEST(max98088->sysclk, max98088->mclk_prescaler);
+ ni = DIV_ROUND_CLOSEST_ULL(ni, pclk);
snd_soc_component_write(component, M98088_REG_12_DAI1_CLKCFG_HI,
(ni >> 8) & 0x7F);
snd_soc_component_write(component, M98088_REG_13_DAI1_CLKCFG_LO,
@@ -1065,13 +1069,16 @@ static int max98088_dai2_hw_params(struct snd_pcm_substream *substream,
/* Configure NI when operating as master */
if (snd_soc_component_read(component, M98088_REG_1C_DAI2_FORMAT)
& M98088_DAI_MAS) {
+ unsigned long pclk;
+
if (max98088->sysclk == 0) {
dev_err(component->dev, "Invalid system clock frequency\n");
return -EINVAL;
}
ni = 65536ULL * (rate < 50000 ? 96ULL : 48ULL)
* (unsigned long long int)rate;
- do_div(ni, (unsigned long long int)max98088->sysclk);
+ pclk = DIV_ROUND_CLOSEST(max98088->sysclk, max98088->mclk_prescaler);
+ ni = DIV_ROUND_CLOSEST_ULL(ni, pclk);
snd_soc_component_write(component, M98088_REG_1A_DAI2_CLKCFG_HI,
(ni >> 8) & 0x7F);
snd_soc_component_write(component, M98088_REG_1B_DAI2_CLKCFG_LO,
@@ -1113,8 +1120,10 @@ static int max98088_dai_set_sysclk(struct snd_soc_dai *dai,
*/
if ((freq >= 10000000) && (freq < 20000000)) {
snd_soc_component_write(component, M98088_REG_10_SYS_CLK, 0x10);
+ max98088->mclk_prescaler = 1;
} else if ((freq >= 20000000) && (freq < 30000000)) {
snd_soc_component_write(component, M98088_REG_10_SYS_CLK, 0x20);
+ max98088->mclk_prescaler = 2;
} else {
dev_err(component->dev, "Invalid master clock frequency\n");
return -EINVAL;
--
2.30.2
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