[PATCH] ASoC: DaVinci: Added support for stereo I2S

From: Raffaele Recalcati
Date: Wed Jun 23 2010 - 10:41:34 EST


From: Raffaele Recalcati <raffaele.recalcati@xxxxxxxxxx>

Added audio playback support with [frame sync master - clock master] mode
and with [frame sync master - clock slave].
Clock slave can be important when the external codec need system clock
and bit clock synchronized.
In the clock master case there is a FIXME message in the source code, because we
(Davide and myself) have guessed a frequency of 122000000 that seems the base
to be divided.
This patch has been developed against the
http://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci.git
git tree and has been tested on bmx board (similar to dm365 evm, but using
uda1345 as external audio codec).

Signed-off-by: Raffaele Recalcati <raffaele.recalcati@xxxxxxxxxx>
Signed-off-by: Davide Bonfanti <davide.bonfanti@xxxxxxxxxx>
---
arch/arm/mach-davinci/include/mach/asp.h | 7 ++
sound/soc/davinci/davinci-i2s.c | 141 ++++++++++++++++++++++++++----
2 files changed, 129 insertions(+), 19 deletions(-)

diff --git a/arch/arm/mach-davinci/include/mach/asp.h b/arch/arm/mach-davinci/include/mach/asp.h
index 834725f..b1faeb9 100644
--- a/arch/arm/mach-davinci/include/mach/asp.h
+++ b/arch/arm/mach-davinci/include/mach/asp.h
@@ -63,6 +63,13 @@ struct snd_platform_data {
unsigned sram_size_playback;
unsigned sram_size_capture;

+ /*
+ * This define works when both clock and FS are output for the cpu
+ * and makes clock very fast (FS is not simmetrical, but sampling
+ * frequency is better approximated
+ */
+ int i2s_fast_clock;
+
/* McASP specific fields */
int tdm_slots;
u8 op_mode;
diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c
index adadcd3..8811d25 100644
--- a/sound/soc/davinci/davinci-i2s.c
+++ b/sound/soc/davinci/davinci-i2s.c
@@ -68,16 +68,23 @@
#define DAVINCI_MCBSP_RCR_RDATDLY(v) ((v) << 16)
#define DAVINCI_MCBSP_RCR_RFIG (1 << 18)
#define DAVINCI_MCBSP_RCR_RWDLEN2(v) ((v) << 21)
+#define DAVINCI_MCBSP_RCR_RFRLEN2(v) ((v) << 24)
+#define DAVINCI_MCBSP_RCR_RPHASE (1 << 31)

#define DAVINCI_MCBSP_XCR_XWDLEN1(v) ((v) << 5)
#define DAVINCI_MCBSP_XCR_XFRLEN1(v) ((v) << 8)
#define DAVINCI_MCBSP_XCR_XDATDLY(v) ((v) << 16)
#define DAVINCI_MCBSP_XCR_XFIG (1 << 18)
#define DAVINCI_MCBSP_XCR_XWDLEN2(v) ((v) << 21)
+#define DAVINCI_MCBSP_XCR_XFRLEN2(v) ((v) << 24)
+#define DAVINCI_MCBSP_XCR_XPHASE (1 << 31)

+
+#define CLKGDV(v) (v) /* Bits 0:7 */
#define DAVINCI_MCBSP_SRGR_FWID(v) ((v) << 8)
#define DAVINCI_MCBSP_SRGR_FPER(v) ((v) << 16)
#define DAVINCI_MCBSP_SRGR_FSGM (1 << 28)
+#define DAVINCI_MCBSP_SRGR_CLKSM (1 << 29)

#define DAVINCI_MCBSP_PCR_CLKRP (1 << 0)
#define DAVINCI_MCBSP_PCR_CLKXP (1 << 1)
@@ -144,8 +151,17 @@ struct davinci_mcbsp_dev {
* won't end up being swapped because of the underrun.
*/
unsigned enable_channel_combine:1;
+
+ int i2s_fast_clock;
+};
+
+struct davinci_mcbsp_data {
+ unsigned int fmt;
+ int clk_div;
};

+static struct davinci_mcbsp_data mcbsp_data;
+
static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
int reg, u32 val)
{
@@ -255,24 +271,27 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
unsigned int pcr;
unsigned int srgr;
srgr = DAVINCI_MCBSP_SRGR_FSGM |
- DAVINCI_MCBSP_SRGR_FPER(DEFAULT_BITPERSAMPLE * 2 - 1) |
- DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);
+ DAVINCI_MCBSP_SRGR_FPER(DEFAULT_BITPERSAMPLE * 2 - 1) |
+ DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);
+ /* Attention srgr is updated by hw_params! */

+ mcbsp_data.fmt = fmt;
/* set master/slave audio interface */
switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBS_CFM:
case SND_SOC_DAIFMT_CBS_CFS:
/* cpu is master */
pcr = DAVINCI_MCBSP_PCR_FSXM |
- DAVINCI_MCBSP_PCR_FSRM |
- DAVINCI_MCBSP_PCR_CLKXM |
- DAVINCI_MCBSP_PCR_CLKRM;
+ DAVINCI_MCBSP_PCR_FSRM |
+ DAVINCI_MCBSP_PCR_CLKXM |
+ DAVINCI_MCBSP_PCR_CLKRM;
break;
case SND_SOC_DAIFMT_CBM_CFS:
/* McBSP CLKR pin is the input for the Sample Rate Generator.
* McBSP FSR and FSX are driven by the Sample Rate Generator. */
pcr = DAVINCI_MCBSP_PCR_SCLKME |
- DAVINCI_MCBSP_PCR_FSXM |
- DAVINCI_MCBSP_PCR_FSRM;
+ DAVINCI_MCBSP_PCR_FSXM |
+ DAVINCI_MCBSP_PCR_FSRM;
break;
case SND_SOC_DAIFMT_CBM_CFM:
/* codec is master */
@@ -372,6 +391,17 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
return 0;
}

+static int davinci_i2s_dai_set_clkdiv(struct snd_soc_dai *cpu_dai,
+ int div_id, int div)
+{
+ struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
+ int srgr;
+
+ mcbsp_data.clk_div = div;
+ return 0;
+}
+
+
static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *dai)
@@ -380,11 +410,12 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
struct davinci_pcm_dma_params *dma_params =
&dev->dma_params[substream->stream];
struct snd_interval *i = NULL;
- int mcbsp_word_length;
- unsigned int rcr, xcr, srgr;
+ int mcbsp_word_length, master;
+ unsigned int rcr, xcr, srgr, clk_div, freq, framesize;
u32 spcr;
snd_pcm_format_t fmt;
unsigned element_cnt = 1;
+ struct clk *clk;

/* general line settings */
spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
@@ -396,12 +427,60 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
}

- i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
- srgr = DAVINCI_MCBSP_SRGR_FSGM;
- srgr |= DAVINCI_MCBSP_SRGR_FWID(snd_interval_value(i) - 1);
+ master = mcbsp_data.fmt & SND_SOC_DAIFMT_MASTER_MASK;
+ fmt = params_format(params);
+ mcbsp_word_length = asp_word_length[fmt];

- i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_FRAME_BITS);
- srgr |= DAVINCI_MCBSP_SRGR_FPER(snd_interval_value(i) - 1);
+ if (master == SND_SOC_DAIFMT_CBS_CFS) {
+ clk = clk_get(NULL, "pll1_sysclk6");
+ if (clk)
+ freq = clk_get_rate(clk);
+ freq = 122000000; /* FIXME ask to Texas */
+ if (dev->i2s_fast_clock) {
+ clk_div = 256;
+ do {
+ framesize = (freq / (--clk_div)) /
+ params->rate_num *
+ params->rate_den;
+ } while (((framesize < 33) || (framesize > 4095)) &&
+ (clk_div));
+ clk_div--;
+ srgr = DAVINCI_MCBSP_SRGR_FSGM |
+ DAVINCI_MCBSP_SRGR_CLKSM;
+ srgr |= DAVINCI_MCBSP_SRGR_FWID(mcbsp_word_length *
+ 8 - 1);
+ srgr |= DAVINCI_MCBSP_SRGR_FPER(framesize - 1);
+ } else {
+ /* simmetric waveforms */
+ srgr = DAVINCI_MCBSP_SRGR_FSGM |
+ DAVINCI_MCBSP_SRGR_CLKSM;
+ srgr |= DAVINCI_MCBSP_SRGR_FWID(mcbsp_word_length *
+ 8 - 1);
+ srgr |= DAVINCI_MCBSP_SRGR_FPER(mcbsp_word_length *
+ 16 - 1);
+ clk_div = freq / (mcbsp_word_length * 16) /
+ params->rate_num * params->rate_den;
+ }
+ clk_div &= 0xFF;
+ srgr |= clk_div;
+ } else if (master == SND_SOC_DAIFMT_CBS_CFM) {
+ /* Clock given on CLKS */
+ srgr = DAVINCI_MCBSP_SRGR_FSGM;
+ clk_div = mcbsp_data.clk_div - 1;
+ srgr |= DAVINCI_MCBSP_SRGR_FWID(mcbsp_word_length * 8 - 1);
+ srgr |= DAVINCI_MCBSP_SRGR_FPER(mcbsp_word_length * 16 - 1);
+ clk_div &= 0xFF;
+ srgr |= clk_div;
+ } else {
+ i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+ srgr = DAVINCI_MCBSP_SRGR_FSGM;
+ srgr |= DAVINCI_MCBSP_SRGR_FWID(snd_interval_value(i) - 1);
+ pr_debug("%s - %d FWID set: re-read srgr = %X\n",
+ __func__, __LINE__, snd_interval_value(i) - 1);
+
+ i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_FRAME_BITS);
+ srgr |= DAVINCI_MCBSP_SRGR_FPER(snd_interval_value(i) - 1);
+ }
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);

rcr = DAVINCI_MCBSP_RCR_RFIG;
@@ -426,22 +505,45 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
element_cnt = 1;
fmt = double_fmt[fmt];
}
+ if (master == SND_SOC_DAIFMT_CBS_CFS ||
+ master == SND_SOC_DAIFMT_CBS_CFM) {
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN2(0);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN2(0);
+ rcr |= DAVINCI_MCBSP_RCR_RPHASE;
+ xcr |= DAVINCI_MCBSP_XCR_XPHASE;
+ } else {
+ /* FIXME ask to Texas */
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN2(element_cnt - 1);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN2(element_cnt - 1);
+ }
}
dma_params->acnt = dma_params->data_type = data_type[fmt];
dma_params->fifo_level = 0;
mcbsp_word_length = asp_word_length[fmt];
- rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(element_cnt - 1);
- xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(element_cnt - 1);
+
+ if (master == SND_SOC_DAIFMT_CBS_CFS ||
+ master == SND_SOC_DAIFMT_CBS_CFM) {
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(0);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(0);
+ } else {
+ /* FIXME ask to Texas */
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(element_cnt - 1);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(element_cnt - 1);
+ }

rcr |= DAVINCI_MCBSP_RCR_RWDLEN1(mcbsp_word_length) |
- DAVINCI_MCBSP_RCR_RWDLEN2(mcbsp_word_length);
+ DAVINCI_MCBSP_RCR_RWDLEN2(mcbsp_word_length);
xcr |= DAVINCI_MCBSP_XCR_XWDLEN1(mcbsp_word_length) |
- DAVINCI_MCBSP_XCR_XWDLEN2(mcbsp_word_length);
+ DAVINCI_MCBSP_XCR_XWDLEN2(mcbsp_word_length);

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_XCR_REG, xcr);
else
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_RCR_REG, rcr);
+
+ pr_debug("%s - %d srgr=%X\n", __func__, __LINE__, srgr);
+ pr_debug("%s - %d xcr=%X\n", __func__, __LINE__, xcr);
+ pr_debug("%s - %d rcr=%X\n", __func__, __LINE__, rcr);
return 0;
}

@@ -500,7 +602,7 @@ static struct snd_soc_dai_ops davinci_i2s_dai_ops = {
.trigger = davinci_i2s_trigger,
.hw_params = davinci_i2s_hw_params,
.set_fmt = davinci_i2s_set_dai_fmt,
-
+ .set_clkdiv = davinci_i2s_dai_set_clkdiv,
};

struct snd_soc_dai davinci_i2s_dai = {
@@ -548,6 +650,7 @@ static int davinci_i2s_probe(struct platform_device *pdev)
}
if (pdata) {
dev->enable_channel_combine = pdata->enable_channel_combine;
+ dev->i2s_fast_clock = pdata->i2s_fast_clock;
dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK].sram_size =
pdata->sram_size_playback;
dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].sram_size =
--
1.7.0.4

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