[alsa-devel] [PATCH] ASoC: wm8804: Allow control of master clock divider in PLL generation
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower samples rates. By using an additional mclk_div divider, it is now possible to control the behaviour. This allows using 256xfs PLL frequency on all sample rates up to 96kHz. It should allow lower jitter and better signal quality. The behavior has to be controlled by the sound card driver, because some sample frequency share the same setting. e.g. 192kHz and 96kHz use 24.576MHz master clock. The only difference is the MCLK divider.
Signed-off-by: Daniel Matuschek daniel@matuschek.net
--- sound/soc/codecs/wm8804.c | 17 ++++++++++++++--- sound/soc/codecs/wm8804.h | 4 ++++ 2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/sound/soc/codecs/wm8804.c b/sound/soc/codecs/wm8804.c index 1704b1e..4619bf8 100644 --- a/sound/soc/codecs/wm8804.c +++ b/sound/soc/codecs/wm8804.c @@ -63,6 +63,7 @@ struct wm8804_priv { struct regmap *regmap; struct regulator_bulk_data supplies[WM8804_NUM_SUPPLIES]; struct notifier_block disable_nb[WM8804_NUM_SUPPLIES]; + int mclk_div; };
static int txsrc_get(struct snd_kcontrol *kcontrol, @@ -318,7 +319,7 @@ static struct {
#define FIXED_PLL_SIZE ((1ULL << 22) * 10) static int pll_factors(struct pll_div *pll_div, unsigned int target, - unsigned int source) + unsigned int source, unsigned int mclk_div) { u64 Kpart; unsigned long int K, Ndiv, Nmod, tmp; @@ -330,7 +331,8 @@ static int pll_factors(struct pll_div *pll_div, unsigned int target, */ for (i = 0; i < ARRAY_SIZE(post_table); i++) { tmp = target * post_table[i].div; - if (tmp >= 90000000 && tmp <= 100000000) { + if ((tmp >= 90000000 && tmp <= 100000000) && + (mclk_div == post_table[i].mclkdiv)) { pll_div->freqmode = post_table[i].freqmode; pll_div->mclkdiv = post_table[i].mclkdiv; target *= post_table[i].div; @@ -387,8 +389,12 @@ static int wm8804_set_pll(struct snd_soc_dai *dai, int pll_id, } else { int ret; struct pll_div pll_div; + struct wm8804_priv *wm8804;
- ret = pll_factors(&pll_div, freq_out, freq_in); + wm8804 = snd_soc_codec_get_drvdata(codec); + + ret = pll_factors(&pll_div, freq_out, freq_in, + wm8804->mclk_div); if (ret) return ret;
@@ -452,6 +458,7 @@ static int wm8804_set_clkdiv(struct snd_soc_dai *dai, int div_id, int div) { struct snd_soc_codec *codec; + struct wm8804_priv *wm8804;
codec = dai->codec; switch (div_id) { @@ -459,6 +466,10 @@ static int wm8804_set_clkdiv(struct snd_soc_dai *dai, snd_soc_update_bits(codec, WM8804_PLL5, 0x30, (div & 0x3) << 4); break; + case WM8804_MCLK_DIV: + wm8804 = snd_soc_codec_get_drvdata(codec); + wm8804->mclk_div = div; + break; default: dev_err(dai->dev, "Unknown clock divider: %d\n", div_id); return -EINVAL; diff --git a/sound/soc/codecs/wm8804.h b/sound/soc/codecs/wm8804.h index 8ec14f5..e72d4f4 100644 --- a/sound/soc/codecs/wm8804.h +++ b/sound/soc/codecs/wm8804.h @@ -57,5 +57,9 @@ #define WM8804_CLKOUT_SRC_OSCCLK 4
#define WM8804_CLKOUT_DIV 1 +#define WM8804_MCLK_DIV 2 + +#define WM8804_MCLKDIV_256FS 0 +#define WM8804_MCLKDIV_128FS 1
#endif /* _WM8804_H */
On Tue, Jan 14, 2014 at 08:34:10PM +0100, Daniel Matuschek wrote:
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower
Charles (or someone else from Wolfson), you commented on previous versions of this - are you still OK with it?
Charles (or someone else from Wolfson), you commented on previous versions of this - are you still OK with it?
Looks good to me.
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On Fri, Jan 17, 2014 at 10:35:10AM +0000, Dimitris Papastamos wrote:
Charles (or someone else from Wolfson), you commented on previous versions of this - are you still OK with it?
Looks good to me.
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Shouldn't be posting them to public lists then.
On Tue, Jan 14, 2014 at 08:34:10PM +0100, Daniel Matuschek wrote:
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower samples rates. By using an additional mclk_div divider, it is now possible to control the behaviour. This allows using 256xfs PLL frequency on all sample rates up to 96kHz. It should allow lower jitter and better signal quality. The behavior has to be controlled by the sound card driver, because some sample frequency share the same setting. e.g. 192kHz and 96kHz use 24.576MHz master clock. The only difference is the MCLK divider.
Signed-off-by: Daniel Matuschek daniel@matuschek.net
Acked-by: Charles Keepax ckeepax@opensource.wolfsonmicro.com
Sorry about the slight delay travelling with limited internet at the mo.
Thanks, Charles
On Tue, Jan 14, 2014 at 08:34:10PM +0100, Daniel Matuschek wrote:
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower
This patch doesn't apply against current code. Please check and resend, from MAINTAINERS:
SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEMENT (ASoC) M: Liam Girdwood lgirdwood@gmail.com M: Mark Brown broonie@kernel.org T: git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git L: alsa-devel@alsa-project.org (moderated for non-subscribers) W: http://alsa-project.org/main/index.php/ASoC S: Supported F: Documentation/sound/alsa/soc/ F: sound/soc/ F: include/sound/soc*
specifically the for-next branch (or ideally topic/wm8804 for wm8804 when it exists).
I'm sorry for this. Looks like I still had problems with some whitespaces. I will resend the patch and hope, it will work now.
Daniel
Am 17.01.2014 um 13:22 schrieb Mark Brown broonie@kernel.org:
On Tue, Jan 14, 2014 at 08:34:10PM +0100, Daniel Matuschek wrote:
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower
This patch doesn't apply against current code. Please check and resend, from MAINTAINERS:
SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEMENT (ASoC) M: Liam Girdwood lgirdwood@gmail.com M: Mark Brown broonie@kernel.org T: git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git L: alsa-devel@alsa-project.org (moderated for non-subscribers) W: http://alsa-project.org/main/index.php/ASoC S: Supported F: Documentation/sound/alsa/soc/ F: sound/soc/ F: include/sound/soc*
specifically the for-next branch (or ideally topic/wm8804 for wm8804 when it exists). _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
I have tested your patch. There is a (non blocking) error message regarding .idle_bias_off, but I assume that should not have something to do with your patch. Can we just set idle_bias_off to false here?
Otherwise, it looks good to me.
On 01/14/2014 08:34 PM, Daniel Matuschek wrote:
WM8804 can run with PLL frequencies of 256xfs and 128xfs for most sample rates. At 192kHz only 128xfs is supported. The existing driver selects 128xfs automatically for some lower samples rates. By using an additional mclk_div divider, it is now possible to control the behaviour. This allows using 256xfs PLL frequency on all sample rates up to 96kHz. It should allow lower jitter and better signal quality. The behavior has to be controlled by the sound card driver, because some sample frequency share the same setting. e.g. 192kHz and 96kHz use 24.576MHz master clock. The only difference is the MCLK divider.
Signed-off-by: Daniel Matuschek daniel@matuschek.net
sound/soc/codecs/wm8804.c | 17 ++++++++++++++--- sound/soc/codecs/wm8804.h | 4 ++++ 2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/sound/soc/codecs/wm8804.c b/sound/soc/codecs/wm8804.c index 1704b1e..4619bf8 100644 --- a/sound/soc/codecs/wm8804.c +++ b/sound/soc/codecs/wm8804.c @@ -63,6 +63,7 @@ struct wm8804_priv { struct regmap *regmap; struct regulator_bulk_data supplies[WM8804_NUM_SUPPLIES]; struct notifier_block disable_nb[WM8804_NUM_SUPPLIES];
- int mclk_div;
};
static int txsrc_get(struct snd_kcontrol *kcontrol, @@ -318,7 +319,7 @@ static struct {
#define FIXED_PLL_SIZE ((1ULL << 22) * 10) static int pll_factors(struct pll_div *pll_div, unsigned int target,
unsigned int source)
unsigned int source, unsigned int mclk_div)
{ u64 Kpart; unsigned long int K, Ndiv, Nmod, tmp; @@ -330,7 +331,8 @@ static int pll_factors(struct pll_div *pll_div, unsigned int target, */ for (i = 0; i < ARRAY_SIZE(post_table); i++) { tmp = target * post_table[i].div;
if (tmp >= 90000000 && tmp <= 100000000) {
if ((tmp >= 90000000 && tmp <= 100000000) &&
(mclk_div == post_table[i].mclkdiv)) { pll_div->freqmode = post_table[i].freqmode; pll_div->mclkdiv = post_table[i].mclkdiv; target *= post_table[i].div;
@@ -387,8 +389,12 @@ static int wm8804_set_pll(struct snd_soc_dai *dai, int pll_id, } else { int ret; struct pll_div pll_div;
struct wm8804_priv *wm8804;
ret = pll_factors(&pll_div, freq_out, freq_in);
wm8804 = snd_soc_codec_get_drvdata(codec);
ret = pll_factors(&pll_div, freq_out, freq_in,
wm8804->mclk_div); if (ret) return ret;
@@ -452,6 +458,7 @@ static int wm8804_set_clkdiv(struct snd_soc_dai *dai, int div_id, int div) { struct snd_soc_codec *codec;
struct wm8804_priv *wm8804;
codec = dai->codec; switch (div_id) {
@@ -459,6 +466,10 @@ static int wm8804_set_clkdiv(struct snd_soc_dai *dai, snd_soc_update_bits(codec, WM8804_PLL5, 0x30, (div & 0x3) << 4); break;
- case WM8804_MCLK_DIV:
wm8804 = snd_soc_codec_get_drvdata(codec);
wm8804->mclk_div = div;
default: dev_err(dai->dev, "Unknown clock divider: %d\n", div_id); return -EINVAL;break;
diff --git a/sound/soc/codecs/wm8804.h b/sound/soc/codecs/wm8804.h index 8ec14f5..e72d4f4 100644 --- a/sound/soc/codecs/wm8804.h +++ b/sound/soc/codecs/wm8804.h @@ -57,5 +57,9 @@ #define WM8804_CLKOUT_SRC_OSCCLK 4
#define WM8804_CLKOUT_DIV 1 +#define WM8804_MCLK_DIV 2
+#define WM8804_MCLKDIV_256FS 0 +#define WM8804_MCLKDIV_128FS 1
#endif /* _WM8804_H */
On Fri, Jan 17, 2014 at 05:43:14PM +0100, Florian Meier wrote:
I have tested your patch. There is a (non blocking) error message regarding .idle_bias_off, but I assume that should not have something to do with your patch. Can we just set idle_bias_off to false here?
What is the error message? I remember that the first version of this had an undocumented change to idle_bias_off in it, I expect that needed to split out into a separate patch rather than dropped.
The idle_bias_off should not be part of this patch. I will check this again.
Am 17.01.2014 um 18:59 schrieb Mark Brown broonie@kernel.org:
On Fri, Jan 17, 2014 at 05:43:14PM +0100, Florian Meier wrote:
I have tested your patch. There is a (non blocking) error message regarding .idle_bias_off, but I assume that should not have something to do with your patch. Can we just set idle_bias_off to false here?
What is the error message? I remember that the first version of this had an undocumented change to idle_bias_off in it, I expect that needed to split out into a separate patch rather than dropped.
participants (6)
-
Ben Dooks
-
Charles Keepax
-
Daniel Matuschek
-
Dimitris Papastamos
-
Florian Meier
-
Mark Brown