* [PATCH 2/3] ASoC: DaVinci: Added selection of clk input pin for McBSP
[not found] <1278405544-3852-1-git-send-email-lamiaposta71@gmail.com>
@ 2010-07-06 8:39 ` Raffaele Recalcati
2010-07-06 8:39 ` [PATCH 3/3] ASoC: DaVinci: More accurate continuous serial clock for McBSP (I2S) Raffaele Recalcati
1 sibling, 0 replies; 4+ messages in thread
From: Raffaele Recalcati @ 2010-07-06 8:39 UTC (permalink / raw)
To: linux-arm-kernel
From: Raffaele Recalcati <raffaele.recalcati@bticino.it>
When McBSP peripheral gets the clock from an external pin,
there are three possible chooses, MCBSP_CLKX, MCBSP_CLKR
and MCBSP_CLKS.
evm-dm365 uses MCBSP_CLKR, instead in bmx board I have a different
hardware connection and I use MCBSP_CLKS, so I have added
this possibility.
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)
Signed-off-by: Raffaele Recalcati <raffaele.recalcati@bticino.it>
Signed-off-by: Davide Bonfanti <davide.bonfanti@bticino.it>
---
arch/arm/mach-davinci/include/mach/asp.h | 15 +++++++++++++++
sound/soc/davinci/davinci-i2s.c | 29 ++++++++++++++++++++++++-----
2 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mach-davinci/include/mach/asp.h b/arch/arm/mach-davinci/include/mach/asp.h
index 834725f..0847d21 100644
--- a/arch/arm/mach-davinci/include/mach/asp.h
+++ b/arch/arm/mach-davinci/include/mach/asp.h
@@ -63,6 +63,16 @@ struct snd_platform_data {
unsigned sram_size_playback;
unsigned sram_size_capture;
+ /*
+ * If McBSP peripheral gets the clock from an external pin,
+ * there are three chooses, that are MCBSP_CLKX, MCBSP_CLKR
+ * and MCBSP_CLKS.
+ * Depending on different hardware connections it is possible
+ * to use this setting to change the behaviour of McBSP
+ * driver. The dm365_clk_input_pin enum is available for dm365
+ */
+ int clk_input_pin;
+
/* McASP specific fields */
int tdm_slots;
u8 op_mode;
@@ -78,6 +88,11 @@ enum {
MCASP_VERSION_2, /* DA8xx/OMAPL1x */
};
+enum dm365_clk_input_pin {
+ MCBSP_CLKR = 0, /* DM365 */
+ MCBSP_CLKS,
+};
+
#define INACTIVE_MODE 0
#define TX_MODE 1
#define RX_MODE 2
diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c
index c8f038c..ba5644b 100644
--- a/sound/soc/davinci/davinci-i2s.c
+++ b/sound/soc/davinci/davinci-i2s.c
@@ -122,6 +122,7 @@ static const unsigned char double_fmt[SNDRV_PCM_FORMAT_S32_LE + 1] = {
};
struct davinci_mcbsp_dev {
+ struct device *dev;
struct davinci_pcm_dma_params dma_params[2];
void __iomem *base;
#define MOD_DSP_A 0
@@ -153,6 +154,7 @@ struct davinci_mcbsp_dev {
unsigned int fmt;
int clk_div;
+ int clk_input_pin;
};
static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
@@ -279,11 +281,26 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
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;
+ pcr = DAVINCI_MCBSP_PCR_FSRM | DAVINCI_MCBSP_PCR_FSXM;
+ /*
+ * Selection of the clock input pin that is the
+ * input for the Sample Rate Generator.
+ * McBSP FSR and FSX are driven by the Sample Rate
+ * Generator.
+ */
+ switch (dev->clk_input_pin) {
+ case MCBSP_CLKS:
+ pcr |= DAVINCI_MCBSP_PCR_CLKXM |
+ DAVINCI_MCBSP_PCR_CLKRM;
+ break;
+ case MCBSP_CLKR:
+ pcr |= DAVINCI_MCBSP_PCR_SCLKME;
+ break;
+ default:
+ dev_err(dev->dev, "bad clk_input_pin\n");
+ return -EINVAL;
+ }
+
break;
case SND_SOC_DAIFMT_CBM_CFM:
/* codec is master */
@@ -644,6 +661,7 @@ static int davinci_i2s_probe(struct platform_device *pdev)
pdata->sram_size_playback;
dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].sram_size =
pdata->sram_size_capture;
+ dev->clk_input_pin = pdata->clk_input_pin;
}
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
@@ -676,6 +694,7 @@ static int davinci_i2s_probe(struct platform_device *pdev)
goto err_free_mem;
}
dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].channel = res->start;
+ dev->dev = &pdev->dev;
davinci_i2s_dai.private_data = dev;
davinci_i2s_dai.capture.dma_data = dev->dma_params;
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 3/3] ASoC: DaVinci: More accurate continuous serial clock for McBSP (I2S)
[not found] <1278405544-3852-1-git-send-email-lamiaposta71@gmail.com>
2010-07-06 8:39 ` [PATCH 2/3] ASoC: DaVinci: Added selection of clk input pin for McBSP Raffaele Recalcati
@ 2010-07-06 8:39 ` Raffaele Recalcati
1 sibling, 0 replies; 4+ messages in thread
From: Raffaele Recalcati @ 2010-07-06 8:39 UTC (permalink / raw)
To: linux-arm-kernel
From: Raffaele Recalcati <raffaele.recalcati@bticino.it>
i2s_accurate_sck switch can be used to have a better approximate
sampling frequency.
The clock is an externally visible bit clock and it is named
i2s continuous serial clock (I2S_SCK).
The trade off is between more accurate clock (fast clock)
and less accurate clock (slow clock).
The waveform will be not symmetric.
Probably it is possible to get a better algorithm for calculating
the divider, trying to keep a slower clock as possible.
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>
---
arch/arm/mach-davinci/include/mach/asp.h | 33 ++++++++++++++++++++++++++++++
sound/soc/davinci/davinci-i2s.c | 24 +++++++++++++++++----
2 files changed, 52 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mach-davinci/include/mach/asp.h b/arch/arm/mach-davinci/include/mach/asp.h
index 0847d21..b12c69e 100644
--- a/arch/arm/mach-davinci/include/mach/asp.h
+++ b/arch/arm/mach-davinci/include/mach/asp.h
@@ -73,6 +73,39 @@ struct snd_platform_data {
*/
int clk_input_pin;
+ /*
+ * This flag works when both clock and FS are outputs for the cpu
+ * and makes clock more accurate (FS is not symmetrical and the
+ * clock is very fast.
+ * The clock becoming faster is named
+ * i2s continuous serial clock (I2S_SCK) and it is an externally
+ * visible bit clock.
+ *
+ * first line : WordSelect
+ * second line : ContinuousSerialClock
+ * third line: SerialData
+ *
+ * SYMMETRICAL APPROACH:
+ * _______________________ LEFT
+ * _| RIGHT |______________________|
+ * _ _ _ _ _ _ _ _
+ * _| |_| |_ x16 _| |_| |_| |_| |_ x16 _| |_| |_
+ * _ _ _ _ _ _ _ _
+ * _/ \_/ \_ ... _/ \_/ \_/ \_/ \_ ... _/ \_/ \_
+ * \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
+ *
+ * ACCURATE CLOCK APPROACH:
+ * ______________ LEFT
+ * _| RIGHT |_______________________________|
+ * _ _ _ _ _ _ _ _ _
+ * _| |_ x16 _| |_| |_ x16 _| |_| |_| |_| |_| |_| |
+ * _ _ _ _ dummy cycles
+ * _/ \_ ... _/ \_/ \_ ... _/ \__________________
+ * \_/ \_/ \_/ \_/
+ *
+ */
+ bool i2s_accurate_sck;
+
/* 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 ba5644b..b251bc9 100644
--- a/sound/soc/davinci/davinci-i2s.c
+++ b/sound/soc/davinci/davinci-i2s.c
@@ -155,6 +155,7 @@ struct davinci_mcbsp_dev {
unsigned int fmt;
int clk_div;
int clk_input_pin;
+ bool i2s_accurate_sck;
};
static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
@@ -447,11 +448,23 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
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);
+ if (dev->i2s_accurate_sck) {
+ 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_FPER(framesize - 1);
+ } else {
+ /* 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;
@@ -662,6 +675,7 @@ static int davinci_i2s_probe(struct platform_device *pdev)
dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].sram_size =
pdata->sram_size_capture;
dev->clk_input_pin = pdata->clk_input_pin;
+ dev->i2s_accurate_sck = pdata->i2s_accurate_sck;
}
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread