On Fri, Apr 18, 2008 at 01:47:33PM +0300, Jarkko Nikula wrote:
> > Well, the constraint for that condition is that MCLK = 256*WCLK, and the
> > reason why that works for the chip without PLL is that Q=2. I stated
> > that a little better in the attached patch.
> >
>
> I would rather refer there just "Fsref = CLKDIV_IN / (128*Q)" as the
> condition where PLL can be disabled (or is mandatory where it must be
> disabled?).
>
> Referring to data sheet page 27 is not good as it's correct only for certain
> version of AIC33 spec and driver supports other AIC3x chips as well :-)
Ok, I agree. I changed that to find an appropriate value for Q
programmatically. Have a look at the attached patch, please. I hope i
finally got it now ;)
Daniel
Subject: [PATCH] asoc tlv320aic33: skip usage of PLL in some cases
Try to find an appropriate value for Q during clock setup in order to
bypass the usage of the PLL in some cases. This saves some entries in
the dividers table.
Signed-off-by: Daniel Mack <daniel@xxxxxxxx>
diff --git a/sound/soc/codecs/tlv320aic3x.c b/sound/soc/codecs/tlv320aic3x.c
index 630684f..4ddfe91 100644
--- a/sound/soc/codecs/tlv320aic3x.c
+++ b/sound/soc/codecs/tlv320aic3x.c
@@ -720,7 +720,7 @@ static inline int aic3x_get_divs(int mclk, int rate)
return i;
}
- return 0;
+ return -1;
}
static int aic3x_hw_params(struct snd_pcm_substream *substream,
@@ -730,11 +730,52 @@ static int aic3x_hw_params(struct snd_pcm_substream *substream,
struct snd_soc_device *socdev = rtd->socdev;
struct snd_soc_codec *codec = socdev->codec;
struct aic3x_priv *aic3x = codec->private_data;
- int i;
- u8 data, pll_p, pll_r, pll_j;
+ int i, bypass_pll = 0;
+ u8 data, pll_p, pll_r, pll_j, pll_q;
u16 pll_d;
- i = aic3x_get_divs(aic3x->sysclk, params_rate(params));
+ /* select data word length */
+ data =
+ aic3x_read_reg_cache(codec, AIC3X_ASD_INTF_CTRLB) & (~(0x3 << 4));
+ switch (params_format(params)) {
+ case SNDRV_PCM_FORMAT_S16_LE:
+ break;
+ case SNDRV_PCM_FORMAT_S20_3LE:
+ data |= (0x01 << 4);
+ break;
+ case SNDRV_PCM_FORMAT_S24_LE:
+ data |= (0x02 << 4);
+ break;
+ case SNDRV_PCM_FORMAT_S32_LE:
+ data |= (0x03 << 4);
+ break;
+ }
+ aic3x_write(codec, AIC3X_ASD_INTF_CTRLB, data);
+
+ /* Try to find a value for Q which allows us to bypass the PLL and
+ * generate CODEC_CLK directly. This saves some entries in
+ * aic3x_divs[]. */
+ for (pll_q = 2; pll_q < 18; pll_q++)
+ if (params_rate(params) == aic3x->sysclk / (128 * pll_q)) {
+ bypass_pll = 1;
+ break;
+ }
+
+ /* If the PLL is bypassed, use first entry in the dividers table
+ * to lookup fsref. */
+ if (bypass_pll) {
+ pll_q &= 0xf;
+ i = aic3x_get_divs(aic3x_divs[0].mclk, params_rate(params));
+ aic3x_write(codec, AIC3X_SAMPLE_RATE_SEL_REG, 0);
+ aic3x_write(codec, AIC3X_PLL_PROGA_REG, pll_q << PLLQ_SHIFT);
+ aic3x_write(codec, AIC3X_GPIOB_REG, CODEC_CLKIN_CLKDIV);
+ } else {
+ i = aic3x_get_divs(aic3x->sysclk, params_rate(params));
+ aic3x_write(codec, AIC3X_GPIOB_REG, CODEC_CLKIN_PLLDIV);
+ }
+
+ if (i < 0)
+ return -EINVAL;
/* Route Left DAC to left channel input and
* right DAC to right channel input */
@@ -755,6 +796,9 @@ static int aic3x_hw_params(struct snd_pcm_substream *substream,
}
aic3x_write(codec, AIC3X_CODEC_DATAPATH_REG, data);
+ if (bypass_pll)
+ return 0;
+
/* codec sample rate select */
data = aic3x_divs[i].sr_reg;
data |= (data << 4);
@@ -782,24 +826,6 @@ static int aic3x_hw_params(struct snd_pcm_substream *substream,
aic3x_write(codec, AIC3X_PLL_PROGD_REG,
(pll_d & 0x3F) << PLLD_LSB_SHIFT);
- /* select data word length */
- data =
- aic3x_read_reg_cache(codec, AIC3X_ASD_INTF_CTRLB) & (~(0x3 << 4));
- switch (params_format(params)) {
- case SNDRV_PCM_FORMAT_S16_LE:
- break;
- case SNDRV_PCM_FORMAT_S20_3LE:
- data |= (0x01 << 4);
- break;
- case SNDRV_PCM_FORMAT_S24_LE:
- data |= (0x02 << 4);
- break;
- case SNDRV_PCM_FORMAT_S32_LE:
- data |= (0x03 << 4);
- break;
- }
- aic3x_write(codec, AIC3X_ASD_INTF_CTRLB, data);
-
return 0;
}
@@ -826,16 +852,8 @@ static int aic3x_set_dai_sysclk(struct snd_soc_codec_dai *codec_dai,
struct snd_soc_codec *codec = codec_dai->codec;
struct aic3x_priv *aic3x = codec->private_data;
- switch (freq) {
- case 12000000:
- case 19200000:
- case 22579200:
- case 33868800:
- aic3x->sysclk = freq;
- return 0;
- }
-
- return -EINVAL;
+ aic3x->sysclk = freq;
+ return 0;
}
static int aic3x_set_dai_fmt(struct snd_soc_codec_dai *codec_dai,
diff --git a/sound/soc/codecs/tlv320aic3x.h b/sound/soc/codecs/tlv320aic3x.h
index d0cdeeb..d49d001 100644
--- a/sound/soc/codecs/tlv320aic3x.h
+++ b/sound/soc/codecs/tlv320aic3x.h
@@ -109,6 +109,7 @@
#define LLOPM_CTRL 86
#define RLOPM_CTRL 93
/* Clock generation control register */
+#define AIC3X_GPIOB_REG 101
#define AIC3X_CLKGEN_CTRL_REG 102
/* Page select register bits */
@@ -128,12 +129,15 @@
/* PLL registers bitfields */
#define PLLP_SHIFT 0
+#define PLLQ_SHIFT 3
#define PLLR_SHIFT 0
#define PLLJ_SHIFT 2
#define PLLD_MSB_SHIFT 0
#define PLLD_LSB_SHIFT 2
/* Clock generation register bits */
+#define CODEC_CLKIN_PLLDIV 0
+#define CODEC_CLKIN_CLKDIV 1
#define PLL_CLKIN_SHIFT 4
#define MCLK_SOURCE 0x0
#define PLL_CLKDIV_SHIFT 0
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