[PATCH 1/3] ASoC: DaVinci: Added two clocking possibilities to McBSP (I2S)

Raffaele Recalcati
2010-07-06T08:39:08Z

Added two clocking options for dm365 McBSP peripheral when used
with I2S timings, that are SND_SOC_DAIFMT_CBS_CFS (the cpu generates
clock and frame sync) and SND_SOC_DAIFMT_CBS_CFM (the cpu gets clock
from external pin and generates frame sync).
A slave clock management can be important when the external codec needs
the system clock and the bit clock synchronized (tested with uda1345).
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@bticino.it>
Signed-off-by: Davide Bonfanti <davide.bonfanti@bticino.it>
---
sound/soc/davinci/davinci-i2s.c | 110 +++++++++++++++++++++++++++++++++++---
sound/soc/davinci/davinci-i2s.h | 5 ++
2 files changed, 106 insertions(+), 9 deletions(-)

diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c
index adadcd3..c8f038c 100644
--- a/sound/soc/davinci/davinci-i2s.c
+++ b/sound/soc/davinci/davinci-i2s.c
@@ -26,6 +26,7 @@
#include <mach/asp.h>

#include "davinci-pcm.h"
+#include "davinci-i2s.h"

/*
@@ -68,16 +69,21 @@
#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 BIT(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 BIT(31)

#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 BIT(29)

#define DAVINCI_MCBSP_PCR_CLKRP (1 << 0)
#define DAVINCI_MCBSP_PCR_CLKXP (1 << 1)
@@ -144,6 +150,9 @@ struct davinci_mcbsp_dev {
* won't end up being swapped because of the underrun.
*/
unsigned enable_channel_combine:1;
+
+ unsigned int fmt;
+ int clk_div;
};

static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
@@ -254,10 +263,12 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
unsigned int pcr;
unsigned int srgr;
+ /* Attention srgr is updated by hw_params! */
srgr = DAVINCI_MCBSP_SRGR_FSGM |
DAVINCI_MCBSP_SRGR_FPER(DEFAULT_BITPERSAMPLE * 2 - 1) |
DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);

+ dev->fmt = fmt;
/* set master/slave audio interface */
switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBS_CFS:
@@ -372,6 +383,18 @@ 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;
+
+ if (div_id != DAVINCI_MCBSP_CLKGDV)
+ return -ENODEV;
+
+ dev->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)
@@ -380,8 +403,8 @@ 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;
@@ -396,12 +419,47 @@ 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 = dev->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);
+ switch (master) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ freq = clk_get_rate(dev->clk);
+ srgr = DAVINCI_MCBSP_SRGR_FSGM |
+ DAVINCI_MCBSP_SRGR_CLKSM;
+ srgr |= DAVINCI_MCBSP_SRGR_FWID(mcbsp_word_length *
+ 8 - 1);
+ /* symmetric waveforms */
+ clk_div = freq / (mcbsp_word_length * 16) /
+ params->rate_num * params->rate_den;
+ srgr |= DAVINCI_MCBSP_SRGR_FPER(mcbsp_word_length *
+ 16 - 1);
+ clk_div &= 0xFF;
+ srgr |= clk_div;
+ break;
+ case SND_SOC_DAIFMT_CBM_CFS:
+ srgr = DAVINCI_MCBSP_SRGR_FSGM;
+ clk_div = dev->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;
+ break;
+ case SND_SOC_DAIFMT_CBM_CFM:
+ /* Clock and frame sync given from external sources */
+ 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);
+ break;
+ default:
+ return -EINVAL;
+ }
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);

rcr = DAVINCI_MCBSP_RCR_RFIG;
@@ -426,12 +484,41 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
element_cnt = 1;
fmt = double_fmt[fmt];
}
+ switch (master) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case 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;
+ break;
+ case SND_SOC_DAIFMT_CBM_CFM:
+ case SND_SOC_DAIFMT_CBM_CFS:
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN2(element_cnt - 1);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN2(element_cnt - 1);
+ break;
+ default:
+ return -EINVAL;
+ }
}
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);
+
+ switch (master) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case SND_SOC_DAIFMT_CBS_CFM:
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(0);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(0);
+ break;
+ case SND_SOC_DAIFMT_CBM_CFM:
+ case SND_SOC_DAIFMT_CBM_CFS:
+ rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(element_cnt - 1);
+ xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(element_cnt - 1);
+ break;
+ default:
+ return -EINVAL;
+ }

rcr |= DAVINCI_MCBSP_RCR_RWDLEN1(mcbsp_word_length) |
DAVINCI_MCBSP_RCR_RWDLEN2(mcbsp_word_length);
@@ -442,6 +529,10 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
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;
}

@@ -500,6 +591,7 @@ 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,

};

diff --git a/sound/soc/davinci/davinci-i2s.h b/sound/soc/davinci/davinci-i2s.h
index 241648c..0b1e77b 100644
--- a/sound/soc/davinci/davinci-i2s.h
+++ b/sound/soc/davinci/davinci-i2s.h
@@ -12,6 +12,11 @@
#ifndef _DAVINCI_I2S_H
#define _DAVINCI_I2S_H

+/* McBSP dividers */
+enum davinci_mcbsp_div {
+ DAVINCI_MCBSP_CLKGDV, /* Sample rate generator divider */
+};
+
extern struct snd_soc_dai davinci_i2s_dai;

#endif
--
1.7.0.4