On 04/04/2017 19:12, Fabio Estevam wrote:
On Tue, Apr 4, 2017 at 8:38 AM, Fabio Estevam <festevam@xxxxxxxxx> wrote:
I have the following SSI1 values (with the original 4.1-rc5 + pictrl patch):
# cat /sys/kernel/debug/regmap/2028000.ssi/registers
00: 00000200
04: 00000000
10: 0000105b
Bits 6-5 (I2S_MODE) of register SCR are 10 of register SCR, which
means I2S slave mode.
The MX6 Reference Manual states:
"In I2S slave mode(SSI_SCR[6:5]=10), the following settings are
internally overridden by
the hardware:
Normal mode is selected (SSI_SCR[3]=0)
Tx frame sync length set to one-bit-long-frame (SSI_STCR[1]=1)
Rx frame sync length set to one-bit-long-frame (SSI_SRCR[1]=1)"
so I tried not to use the the one-bit-long-frame (since ENGcm06222 is
about bit length frame sync) override and changed it to I2S normal
mode instead:
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -973,7 +973,7 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_MASTER;
break;
case SND_SOC_DAIFMT_CBM_CFM:
- ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_SLAVE;
+ ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_NORMAL;
break;
default:
return -EINVAL;
and I do not get the channel swap anymore.
In what cases could we safely switch to I2S normal mode?
SCR bit 3 (NET) is also set, so you should be in network mode with a
long frame sync.
In fact, you can entirely simulate a I2S behavior using Network mode.
you should just be careful about the way everything is configured (eg.
place of samples in the stream)
Also, I just read the ENGcm06222 chip errata.
http://www.nxp.com/assets/documents/data/en/errata/IMX35CE.pdf
and I don't understand why it affects us in this case.
- you are slave in your case and you don't send the Fsync
- it talk about writing EN and TE in the same frame (so with less than
1/44100s).
=> Writing the register at once is simply a good way to be sure it is
effective... except if it takes more than a frame to configure the whole
stuff.
And I also don't understand how all of this could have work so long
before in "Capture, then later, playback scenario", were TE is set very
long after EN...
Arnaud
Thanks
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