[PATCH 0/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

[PATCH 0/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

[Daniel Baluta]

This is a follow up of commit 3c01b9ee2ab ("ASoC: codec: wm8960: Relax bit clock computation")
where we relaxed bitclk when sysclk was derived from MCLK.

Now, we do the same thing for sysclk derived using PLL.

Daniel Baluta (2):
  ASoC: codec: wm9860: Refactor PLL out freq search
  ASoC: codec: wm8960: Relax bit clock computation when using PLL

 sound/soc/codecs/wm8960.c | 105 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 76 insertions(+), 29 deletions(-)

-- 
2.7.4

[PATCH 1/2] ASoC: codec: wm9860: Refactor PLL out freq search

[Daniel Baluta]

Add a separate function for deriving (sysclk, lrclk, bclk)
when the clock is auto or pll.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/codecs/wm8960.c | 93 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 64 insertions(+), 29 deletions(-)

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index ce159f1..36c8454 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -672,10 +672,70 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
 	return *bclk_idx;
 }
 
+/**
+ * wm8960_configure_pll - checks if there is a PLL out frequency available
+ *	The PLL out frequency must be chosen such that:
+ *		- sysclk      = lrclk * dac_divs
+ *		- freq_out    = sysclk * sysclk_divs
+ *		- 10 * sysclk = bclk * bclk_divs
+ *
+ * @codec: codec structure
+ * @freq_in: input frequency used to derive freq out via PLL
+ * @sysclk_idx: sysclk_divs index for found sysclk
+ * @dac_idx: dac_divs index for found lrclk
+ * @bclk_idx: bclk_divs index for found bclk
+ *
+ * Returns:
+ *  -1, in case no PLL frequency out available was found
+ * >=0, in case we could derive bclk, lrclk, sysclk from PLL out using
+ *      (@sysclk_idx, @dac_idx, @bclk_idx) dividers
+ */
+static
+int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
+			 int *sysclk_idx, int *dac_idx, int *bclk_idx)
+{
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+	int sysclk, bclk, lrclk, freq_out;
+	int diff, best_freq_out;
+	int i, j, k;
+
+	bclk = wm8960->bclk;
+	lrclk = wm8960->lrclk;
+
+	*bclk_idx = -1;
+
+	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+		if (sysclk_divs[i] == -1)
+			continue;
+		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+			sysclk = lrclk * dac_divs[j];
+			freq_out = sysclk * sysclk_divs[i];
+
+			for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+				if (!is_pll_freq_available(freq_in, freq_out))
+					continue;
+
+				diff = sysclk - bclk * bclk_divs[k] / 10;
+				if (diff == 0) {
+					*sysclk_idx = i;
+					*dac_idx = j;
+					*bclk_idx = k;
+					best_freq_out = freq_out;
+					break;
+				}
+			}
+		}
+	}
+
+	if (*bclk_idx != -1)
+		wm8960_set_pll(codec, freq_in, best_freq_out);
+
+	return *bclk_idx;
+}
 static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 {
 	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
-	int sysclk, bclk, lrclk, freq_out, freq_in;
+	int freq_out, freq_in;
 	u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);
 	int i, j, k;
 	int ret;
@@ -692,8 +752,6 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 	}
 
 	freq_in = wm8960->freq_in;
-	bclk = wm8960->bclk;
-	lrclk = wm8960->lrclk;
 	/*
 	 * If it's sysclk auto mode, check if the MCLK can provide sysclk or
 	 * not. If MCLK can provide sysclk, using MCLK to provide sysclk
@@ -720,33 +778,10 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 			return -EINVAL;
 		}
 	}
-	/* get a available pll out frequency and set pll */
-	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
-		if (sysclk_divs[i] == -1)
-			continue;
-		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
-			sysclk = lrclk * dac_divs[j];
-			freq_out = sysclk * sysclk_divs[i];
-
-			for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
-				if (sysclk == bclk * bclk_divs[k] / 10 &&
-				    is_pll_freq_available(freq_in, freq_out)) {
-					wm8960_set_pll(codec,
-						       freq_in, freq_out);
-					break;
-				} else {
-					continue;
-				}
-			}
-			if (k != ARRAY_SIZE(bclk_divs))
-				break;
-		}
-		if (j != ARRAY_SIZE(dac_divs))
-			break;
-	}
 
-	if (i == ARRAY_SIZE(sysclk_divs)) {
-		dev_err(codec->dev, "failed to configure clock\n");
+	ret = wm8960_configure_pll(codec, freq_in, &i, &j, &k);
+	if (ret < 0) {
+		dev_err(codec->dev, "failed to configure clock via PLL\n");
 		return -EINVAL;
 	}
 
-- 
2.7.4

Re: [PATCH 1/2] ASoC: codec: wm9860: Refactor PLL out freq search

[Charles Keepax]

On Tue, Apr 04, 2017 at 07:45:13PM +0300, Daniel Baluta wrote:
> Add a separate function for deriving (sysclk, lrclk, bclk)
> when the clock is auto or pll.
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>

Thanks,
Charles

Re: [PATCH 1/2] ASoC: codec: wm9860: Refactor PLL out freq search

[Daniel Baluta]

On Tue, Apr 4, 2017 at 7:45 PM, Daniel Baluta <daniel.baluta@nxp.com> wrote:
> Add a separate function for deriving (sysclk, lrclk, bclk)
> when the clock is auto or pll.
>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Just noticed this warnings:

sound/soc/codecs/wm8960.c:743:3: warning: 'best_freq_out' may be used
uninitialized in this function [-Wmaybe-uninitialized]
   wm8960_set_pll(codec, freq_in, best_freq_out);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/soc/codecs/wm8960.c:703:21: note: 'best_freq_out' was declared here
  int diff, closest, best_freq_out;
                     ^~~~~~~~~~~~~
sound/soc/codecs/wm8960.c:806:46: warning: 'j' may be used
uninitialized in this function [-Wmaybe-uninitialized]
  snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6);
                                            ~~^~~~
sound/soc/codecs/wm8960.c:802:44: warning: 'i' may be used
uninitialized in this function [-Wmaybe-uninitialized]
  snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1);


There is no way I can end up with these variable uninitialized. Will
look more close and resend.

Thanks Charles for review.

Applied "ASoC: codec: wm9860: Refactor PLL out freq search" to the asoc tree

[Mark Brown]

The patch

   ASoC: codec: wm9860: Refactor PLL out freq search

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 84fdc00d519ffdf8ae6e34d7841bcc6f38928953 Mon Sep 17 00:00:00 2001
From: Daniel Baluta <daniel.baluta@nxp.com>
Date: Tue, 4 Apr 2017 19:45:13 +0300
Subject: [PATCH] ASoC: codec: wm9860: Refactor PLL out freq search

Add a separate function for deriving (sysclk, lrclk, bclk)
when the clock is auto or pll.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/codecs/wm8960.c | 93 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 64 insertions(+), 29 deletions(-)

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index ce159f13e7a4..36c84549da23 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -672,10 +672,70 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
 	return *bclk_idx;
 }
 
+/**
+ * wm8960_configure_pll - checks if there is a PLL out frequency available
+ *	The PLL out frequency must be chosen such that:
+ *		- sysclk      = lrclk * dac_divs
+ *		- freq_out    = sysclk * sysclk_divs
+ *		- 10 * sysclk = bclk * bclk_divs
+ *
+ * @codec: codec structure
+ * @freq_in: input frequency used to derive freq out via PLL
+ * @sysclk_idx: sysclk_divs index for found sysclk
+ * @dac_idx: dac_divs index for found lrclk
+ * @bclk_idx: bclk_divs index for found bclk
+ *
+ * Returns:
+ *  -1, in case no PLL frequency out available was found
+ * >=0, in case we could derive bclk, lrclk, sysclk from PLL out using
+ *      (@sysclk_idx, @dac_idx, @bclk_idx) dividers
+ */
+static
+int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
+			 int *sysclk_idx, int *dac_idx, int *bclk_idx)
+{
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+	int sysclk, bclk, lrclk, freq_out;
+	int diff, best_freq_out;
+	int i, j, k;
+
+	bclk = wm8960->bclk;
+	lrclk = wm8960->lrclk;
+
+	*bclk_idx = -1;
+
+	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+		if (sysclk_divs[i] == -1)
+			continue;
+		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+			sysclk = lrclk * dac_divs[j];
+			freq_out = sysclk * sysclk_divs[i];
+
+			for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+				if (!is_pll_freq_available(freq_in, freq_out))
+					continue;
+
+				diff = sysclk - bclk * bclk_divs[k] / 10;
+				if (diff == 0) {
+					*sysclk_idx = i;
+					*dac_idx = j;
+					*bclk_idx = k;
+					best_freq_out = freq_out;
+					break;
+				}
+			}
+		}
+	}
+
+	if (*bclk_idx != -1)
+		wm8960_set_pll(codec, freq_in, best_freq_out);
+
+	return *bclk_idx;
+}
 static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 {
 	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
-	int sysclk, bclk, lrclk, freq_out, freq_in;
+	int freq_out, freq_in;
 	u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);
 	int i, j, k;
 	int ret;
@@ -692,8 +752,6 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 	}
 
 	freq_in = wm8960->freq_in;
-	bclk = wm8960->bclk;
-	lrclk = wm8960->lrclk;
 	/*
 	 * If it's sysclk auto mode, check if the MCLK can provide sysclk or
 	 * not. If MCLK can provide sysclk, using MCLK to provide sysclk
@@ -720,33 +778,10 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 			return -EINVAL;
 		}
 	}
-	/* get a available pll out frequency and set pll */
-	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
-		if (sysclk_divs[i] == -1)
-			continue;
-		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
-			sysclk = lrclk * dac_divs[j];
-			freq_out = sysclk * sysclk_divs[i];
-
-			for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
-				if (sysclk == bclk * bclk_divs[k] / 10 &&
-				    is_pll_freq_available(freq_in, freq_out)) {
-					wm8960_set_pll(codec,
-						       freq_in, freq_out);
-					break;
-				} else {
-					continue;
-				}
-			}
-			if (k != ARRAY_SIZE(bclk_divs))
-				break;
-		}
-		if (j != ARRAY_SIZE(dac_divs))
-			break;
-	}
 
-	if (i == ARRAY_SIZE(sysclk_divs)) {
-		dev_err(codec->dev, "failed to configure clock\n");
+	ret = wm8960_configure_pll(codec, freq_in, &i, &j, &k);
+	if (ret < 0) {
+		dev_err(codec->dev, "failed to configure clock via PLL\n");
 		return -EINVAL;
 	}
 
-- 
2.11.0

[PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

[Daniel Baluta]

Bitclk is derived from sysclk using bclk_divs.
Sysclk can be derived in two ways:
	(1) directly from MLCK
	(2) MCLK via PLL

Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation")
relaxed bitclk computation when sysclk is directly derived from MCLK.

Lets do the same thing when sysclk is derived via PLL.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/codecs/wm8960.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 36c8454..e8cb764 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
  *		- freq_out    = sysclk * sysclk_divs
  *		- 10 * sysclk = bclk * bclk_divs
  *
+ *	If we cannot find an exact match for (sysclk, lrclk, bclk)
+ *	triplet, we relax the bclk such that bclk is chosen as the
+ *	closest available frequency greater than expected bclk.
+ *
  * @codec: codec structure
  * @freq_in: input frequency used to derive freq out via PLL
  * @sysclk_idx: sysclk_divs index for found sysclk
@@ -696,11 +700,12 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
 {
 	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
 	int sysclk, bclk, lrclk, freq_out;
-	int diff, best_freq_out;
+	int diff, closest, best_freq_out;
 	int i, j, k;
 
 	bclk = wm8960->bclk;
 	lrclk = wm8960->lrclk;
+	closest = freq_in;
 
 	*bclk_idx = -1;
 
@@ -723,6 +728,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
 					best_freq_out = freq_out;
 					break;
 				}
+				if (diff > 0 && closest > diff) {
+					*sysclk_idx = i;
+					*dac_idx = j;
+					*bclk_idx = k;
+					closest = diff;
+					best_freq_out = freq_out;
+				}
 			}
 		}
 	}
-- 
2.7.4

Re: [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

[Charles Keepax]

On Tue, Apr 04, 2017 at 07:45:14PM +0300, Daniel Baluta wrote:
> Bitclk is derived from sysclk using bclk_divs.
> Sysclk can be derived in two ways:
> 	(1) directly from MLCK
> 	(2) MCLK via PLL
> 
> Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation")
> relaxed bitclk computation when sysclk is directly derived from MCLK.
> 
> Lets do the same thing when sysclk is derived via PLL.
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>

Thanks,
Charles

Re: [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL

[kbuild test robot]

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Hi Daniel,

[auto build test WARNING on asoc/for-next]
[also build test WARNING on next-20170405]
[cannot apply to v4.11-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Daniel-Baluta/ASoC-codec-wm8960-Relax-bit-clock-computation-when-using-PLL/20170405-144647
base:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
config: i386-randconfig-s0-201714 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking':
>> sound/soc/codecs/wm8960.c:743:3: warning: 'best_freq_out' may be used uninitialized in this function [-Wmaybe-uninitialized]
      wm8960_set_pll(codec, freq_in, best_freq_out);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   sound/soc/codecs/wm8960.c:703:21: note: 'best_freq_out' was declared here
     int diff, closest, best_freq_out;
                        ^~~~~~~~~~~~~
   sound/soc/codecs/wm8960.c:806:56: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
     snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6);
                                                         ~~^~~~
   sound/soc/codecs/wm8960.c:802:54: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
     snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1);
                                                       ~~^~~~

vim +/best_freq_out +743 sound/soc/codecs/wm8960.c

6b662dee Daniel Baluta 2017-04-04  727  					*bclk_idx = k;
6b662dee Daniel Baluta 2017-04-04  728  					best_freq_out = freq_out;
6b662dee Daniel Baluta 2017-04-04  729  					break;
6b662dee Daniel Baluta 2017-04-04  730  				}
16c42f46 Daniel Baluta 2017-04-04  731  				if (diff > 0 && closest > diff) {
16c42f46 Daniel Baluta 2017-04-04  732  					*sysclk_idx = i;
16c42f46 Daniel Baluta 2017-04-04  733  					*dac_idx = j;
16c42f46 Daniel Baluta 2017-04-04  734  					*bclk_idx = k;
16c42f46 Daniel Baluta 2017-04-04  735  					closest = diff;
16c42f46 Daniel Baluta 2017-04-04  736  					best_freq_out = freq_out;
16c42f46 Daniel Baluta 2017-04-04  737  				}
6b662dee Daniel Baluta 2017-04-04  738  			}
6b662dee Daniel Baluta 2017-04-04  739  		}
6b662dee Daniel Baluta 2017-04-04  740  	}
6b662dee Daniel Baluta 2017-04-04  741  
6b662dee Daniel Baluta 2017-04-04  742  	if (*bclk_idx != -1)
6b662dee Daniel Baluta 2017-04-04 @743  		wm8960_set_pll(codec, freq_in, best_freq_out);
6b662dee Daniel Baluta 2017-04-04  744  
6b662dee Daniel Baluta 2017-04-04  745  	return *bclk_idx;
6b662dee Daniel Baluta 2017-04-04  746  }
3176bf2d Zidan Wang    2015-08-11  747  static int wm8960_configure_clocking(struct snd_soc_codec *codec)
0e50b51a Zidan Wang    2015-05-12  748  {
0e50b51a Zidan Wang    2015-05-12  749  	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
6b662dee Daniel Baluta 2017-04-04  750  	int freq_out, freq_in;
0e50b51a Zidan Wang    2015-05-12  751  	u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);

:::::: The code at line 743 was first introduced by commit
:::::: 6b662deec0da0ad4f9dce8112d01828ed72b5a4c ASoC: codec: wm9860: Refactor PLL out freq search

:::::: TO: Daniel Baluta <daniel.baluta@nxp.com>
:::::: CC: 0day robot <fengguang.wu@intel.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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