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.
Changes since v1:
* fixed "may be used uninitialized" warnings [i strongly believe
they were compiler false positive - see full warning log here (1)]
* fixed break for inner loop
[1] http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/119513.html
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 | 109 ++++++++++++++++++++++++++++++++++------------
1 file changed, 80 insertions(+), 29 deletions(-)
--
2.7.4
Add a separate function for deriving (sysclk, lrclk, bclk)
when the clock is auto or pll.
Signed-off-by: Daniel Baluta <[email protected]>
Acked-by: Charles Keepax <[email protected]>
---
sound/soc/codecs/wm8960.c | 97 +++++++++++++++++++++++++++++++++--------------
1 file changed, 68 insertions(+), 29 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index ce159f1..1c973f0 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -672,10 +672,74 @@ 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 = 0;
+ int i, j, k;
+
+ bclk = wm8960->bclk;
+ lrclk = wm8960->lrclk;
+
+ *bclk_idx = *dac_idx = *sysclk_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 (k != ARRAY_SIZE(bclk_divs))
+ break;
+ }
+ if (j != ARRAY_SIZE(dac_divs))
+ 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 +756,6 @@ 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 +782,10 @@ 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
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 <[email protected]>
Acked-by: Charles Keepax <[email protected]>
---
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 1c973f0..8ab9fa2 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 = 0;
+ int diff, closest, best_freq_out = 0;
int i, j, k;
bclk = wm8960->bclk;
lrclk = wm8960->lrclk;
+ closest = freq_in;
*bclk_idx = *dac_idx = *sysclk_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;
+ }
}
if (k != ARRAY_SIZE(bclk_divs))
break;
--
2.7.4