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Diffstat (limited to 'sound/soc/codecs/wm8960.c')
-rw-r--r--sound/soc/codecs/wm8960.c195
1 files changed, 146 insertions, 49 deletions
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 3bf081a7e450..9ed455700954 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -604,12 +604,150 @@ static const int bclk_divs[] = {
120, 160, 220, 240, 320, 320, 320
};
+/**
+ * wm8960_configure_sysclk - checks if there is a sysclk frequency available
+ * The sysclk must be chosen such that:
+ * - sysclk = MCLK / sysclk_divs
+ * - lrclk = sysclk / dac_divs
+ * - 10 * bclk = sysclk / 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.
+ *
+ * @wm8960_priv: wm8960 codec private data
+ * @mclk: MCLK used to derive sysclk
+ * @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 sysclk frequency available found
+ * >=0, in case we could derive bclk and lrclk from sysclk using
+ * (@sysclk_idx, @dac_idx, @bclk_idx) dividers
+ */
+static
+int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
+ int *sysclk_idx, int *dac_idx, int *bclk_idx)
+{
+ int sysclk, bclk, lrclk;
+ int i, j, k;
+ int diff, closest = mclk;
+
+ /* marker for no match */
+ *bclk_idx = -1;
+
+ bclk = wm8960->bclk;
+ lrclk = wm8960->lrclk;
+
+ /* check if the sysclk frequency is available. */
+ for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+ if (sysclk_divs[i] == -1)
+ continue;
+ sysclk = mclk / sysclk_divs[i];
+ for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+ if (sysclk != dac_divs[j] * lrclk)
+ continue;
+ for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+ diff = sysclk - bclk * bclk_divs[k] / 10;
+ if (diff == 0) {
+ *sysclk_idx = i;
+ *dac_idx = j;
+ *bclk_idx = k;
+ break;
+ }
+ if (diff > 0 && closest > diff) {
+ *sysclk_idx = i;
+ *dac_idx = j;
+ *bclk_idx = k;
+ closest = diff;
+ }
+ }
+ if (k != ARRAY_SIZE(bclk_divs))
+ break;
+ }
+ if (j != ARRAY_SIZE(dac_divs))
+ break;
+ }
+ 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
+ *
+ * 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
+ * @dac_idx: dac_divs index for found lrclk
+ * @bclk_idx: bclk_divs index for found bclk
+ *
+ * Returns:
+ * < 0, 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, closest, best_freq_out;
+ int i, j, k;
+
+ bclk = wm8960->bclk;
+ lrclk = wm8960->lrclk;
+ closest = freq_in;
+
+ best_freq_out = -EINVAL;
+ *sysclk_idx = *dac_idx = *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;
+ return freq_out;
+ }
+ if (diff > 0 && closest > diff) {
+ *sysclk_idx = i;
+ *dac_idx = j;
+ *bclk_idx = k;
+ closest = diff;
+ best_freq_out = freq_out;
+ }
+ }
+ }
+ }
+
+ return best_freq_out;
+}
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;
if (!(iface1 & (1<<6))) {
dev_dbg(codec->dev,
@@ -623,8 +761,6 @@ 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
@@ -643,60 +779,21 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
}
if (wm8960->clk_id != WM8960_SYSCLK_PLL) {
- /* check if the sysclk frequency is available. */
- for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
- if (sysclk_divs[i] == -1)
- continue;
- sysclk = freq_out / sysclk_divs[i];
- for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
- if (sysclk != dac_divs[j] * lrclk)
- continue;
- for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k)
- if (sysclk == bclk * bclk_divs[k] / 10)
- break;
- if (k != ARRAY_SIZE(bclk_divs))
- break;
- }
- if (j != ARRAY_SIZE(dac_divs))
- break;
- }
-
- if (i != ARRAY_SIZE(sysclk_divs)) {
+ ret = wm8960_configure_sysclk(wm8960, freq_out, &i, &j, &k);
+ if (ret >= 0) {
goto configure_clock;
} else if (wm8960->clk_id != WM8960_SYSCLK_AUTO) {
dev_err(codec->dev, "failed to configure clock\n");
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");
- return -EINVAL;
+ freq_out = wm8960_configure_pll(codec, freq_in, &i, &j, &k);
+ if (freq_out < 0) {
+ dev_err(codec->dev, "failed to configure clock via PLL\n");
+ return freq_out;
}
+ wm8960_set_pll(codec, freq_in, freq_out);
configure_clock:
/* configure sysclk clock */
generated by cgit (git 2.34.1) at 2024-05-29 11:42:18 +0000