[alsa-devel] [PATCH] ASoC: Allow WM8915 BCLK calculation outside hw_params()
Mark Brown
broonie at opensource.wolfsonmicro.com
Mon Jun 6 20:21:04 CEST 2011
Allow more dynamic management of the device clocking by allowing BCLK to
be calculated when we set SYSCLK. This means that if the system is idle
when hw_params() runs then we don't try to use the SYSCLK used in that case
to set up the BCLK dividers, we can instead wait until a later point such
as bias level configuration. This makes it easier to manage low power modes.
Signed-off-by: Mark Brown <broonie at opensource.wolfsonmicro.com>
---
sound/soc/codecs/wm8915.c | 82 +++++++++++++++++++++++++++++----------------
1 files changed, 53 insertions(+), 29 deletions(-)
diff --git a/sound/soc/codecs/wm8915.c b/sound/soc/codecs/wm8915.c
index a1d8618..423baa9 100644
--- a/sound/soc/codecs/wm8915.c
+++ b/sound/soc/codecs/wm8915.c
@@ -75,6 +75,7 @@ struct wm8915_priv {
struct wm8915_pdata pdata;
int rx_rate[WM8915_AIFS];
+ int bclk_rate[WM8915_AIFS];
/* Platform dependant ReTune mobile configuration */
int num_retune_mobile_texts;
@@ -1562,6 +1563,50 @@ static int wm8915_reset(struct snd_soc_codec *codec)
return snd_soc_write(codec, WM8915_SOFTWARE_RESET, 0x8915);
}
+static const int bclk_divs[] = {
+ 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96
+};
+
+static void wm8915_update_bclk(struct snd_soc_codec *codec)
+{
+ struct wm8915_priv *wm8915 = snd_soc_codec_get_drvdata(codec);
+ int aif, best, cur_val, bclk_rate, bclk_reg, i;
+
+ /* Don't bother if we're in a low frequency idle mode that
+ * can't support audio.
+ */
+ if (wm8915->sysclk < 64000)
+ return;
+
+ for (aif = 0; aif < WM8915_AIFS; aif++) {
+ switch (aif) {
+ case 0:
+ bclk_reg = WM8915_AIF1_BCLK;
+ break;
+ case 1:
+ bclk_reg = WM8915_AIF2_BCLK;
+ break;
+ }
+
+ bclk_rate = wm8915->bclk_rate[aif];
+
+ /* Pick a divisor for BCLK as close as we can get to ideal */
+ best = 0;
+ for (i = 0; i < ARRAY_SIZE(bclk_divs); i++) {
+ cur_val = (wm8915->sysclk / bclk_divs[i]) - bclk_rate;
+ if (cur_val < 0) /* BCLK table is sorted */
+ break;
+ best = i;
+ }
+ bclk_rate = wm8915->sysclk / bclk_divs[best];
+ dev_dbg(codec->dev, "Using BCLK_DIV %d for actual BCLK %dHz\n",
+ bclk_divs[best], bclk_rate);
+
+ snd_soc_update_bits(codec, bclk_reg,
+ WM8915_AIF1_BCLK_DIV_MASK, best);
+ }
+}
+
static int wm8915_set_bias_level(struct snd_soc_codec *codec,
enum snd_soc_bias_level level)
{
@@ -1714,10 +1759,6 @@ static int wm8915_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
return 0;
}
-static const int bclk_divs[] = {
- 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96
-};
-
static const int dsp_divs[] = {
48000, 32000, 16000, 8000
};
@@ -1728,17 +1769,11 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
{
struct snd_soc_codec *codec = dai->codec;
struct wm8915_priv *wm8915 = snd_soc_codec_get_drvdata(codec);
- int bits, i, bclk_rate, best, cur_val;
+ int bits, i, bclk_rate;
int aifdata = 0;
- int bclk = 0;
int lrclk = 0;
int dsp = 0;
- int aifdata_reg, bclk_reg, lrclk_reg, dsp_shift;
-
- if (!wm8915->sysclk) {
- dev_err(codec->dev, "SYSCLK not configured\n");
- return -EINVAL;
- }
+ int aifdata_reg, lrclk_reg, dsp_shift;
switch (dai->id) {
case 0:
@@ -1750,7 +1785,6 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
aifdata_reg = WM8915_AIF1TX_DATA_CONFIGURATION_1;
lrclk_reg = WM8915_AIF1_TX_LRCLK_1;
}
- bclk_reg = WM8915_AIF1_BCLK;
dsp_shift = 0;
break;
case 1:
@@ -1762,7 +1796,6 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
aifdata_reg = WM8915_AIF2TX_DATA_CONFIGURATION_1;
lrclk_reg = WM8915_AIF2_TX_LRCLK_1;
}
- bclk_reg = WM8915_AIF2_BCLK;
dsp_shift = WM8915_DSP2_DIV_SHIFT;
break;
default:
@@ -1776,6 +1809,9 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
return bclk_rate;
}
+ wm8915->bclk_rate[dai->id] = bclk_rate;
+ wm8915->rx_rate[dai->id] = params_rate(params);
+
/* Needs looking at for TDM */
bits = snd_pcm_format_width(params_format(params));
if (bits < 0)
@@ -1793,18 +1829,7 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
}
dsp |= i << dsp_shift;
- /* Pick a divisor for BCLK as close as we can get to ideal */
- best = 0;
- for (i = 0; i < ARRAY_SIZE(bclk_divs); i++) {
- cur_val = (wm8915->sysclk / bclk_divs[i]) - bclk_rate;
- if (cur_val < 0) /* BCLK table is sorted */
- break;
- best = i;
- }
- bclk_rate = wm8915->sysclk / bclk_divs[best];
- dev_dbg(dai->dev, "Using BCLK_DIV %d for actual BCLK %dHz\n",
- bclk_divs[best], bclk_rate);
- bclk |= best;
+ wm8915_update_bclk(codec);
lrclk = bclk_rate / params_rate(params);
dev_dbg(dai->dev, "Using LRCLK rate %d for actual LRCLK %dHz\n",
@@ -1814,14 +1839,11 @@ static int wm8915_hw_params(struct snd_pcm_substream *substream,
WM8915_AIF1TX_WL_MASK |
WM8915_AIF1TX_SLOT_LEN_MASK,
aifdata);
- snd_soc_update_bits(codec, bclk_reg, WM8915_AIF1_BCLK_DIV_MASK, bclk);
snd_soc_update_bits(codec, lrclk_reg, WM8915_AIF1RX_RATE_MASK,
lrclk);
snd_soc_update_bits(codec, WM8915_AIF_CLOCKING_2,
WM8915_DSP1_DIV_SHIFT << dsp_shift, dsp);
- wm8915->rx_rate[dai->id] = params_rate(params);
-
return 0;
}
@@ -1882,6 +1904,8 @@ static int wm8915_set_sysclk(struct snd_soc_dai *dai,
return -EINVAL;
}
+ wm8915_update_bclk(codec);
+
snd_soc_update_bits(codec, WM8915_AIF_CLOCKING_1,
WM8915_SYSCLK_SRC_MASK | WM8915_SYSCLK_DIV_MASK,
src << WM8915_SYSCLK_SRC_SHIFT | ratediv);
--
1.7.5.3
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