[alsa-devel] [PATCH] ASoC: davinci-mcasp: set up user bits for S/PDIF mode

[Daniel Mack]

On 03/27/2014 10:10 AM, Peter Ujfalusi wrote:
> On 03/27/2014 10:39 AM, Daniel Mack wrote:

>> No, these defines are mapped on to 32-bit values, as seen in
>> include/sound/asounddef.h. Over all 6 registers, 192 bits can be stored,
>> which is the full length of channel status bits. Hence, they really need
>> an individual mcasp_set_reg() each.
> 
> I don't think they are mapped for the 32bit:
> #define IEC958_AES0_CON_NOT_COPYRIGHT   (1<<2)
> 
> #define IEC958_AES1_CON_DIGDIGCONV_ID   0x02
> #define IEC958_AES1_CON_PCM_CODER       (IEC958_AES1_CON_DIGDIGCONV_ID|0x00)
> 
> #define IEC958_AES3_CON_FS_48000        (2<<0)  /* 48kHz */
> #define IEC958_AES3_CON_FS_32000        (3<<0)  /* 32kHz */
> #define IEC958_AES3_CON_FS_22050        (4<<0)  /* 22.05kHz */
> #define IEC958_AES3_CON_FS_24000        (6<<0)  /* 24kHz */

Hmm, that's odd. What about this one then, which definitely needs a
larger type than uint16?

#define IEC958_AES4_CON_ORIGFS_44100	(15<<4)	/* 44.1kHz */

I considered DITCSRA0 to DITCSRA5 to carry 6 32 bit values, which map to
the values defined as IEC958_AESX*.

> From the AES3 spec (byte numbers are 1 based while bit numbers are 0 based for
> some reason in the specs):
> Copyright bit is on Byte1's bit 2

"Byte 1" is the at index 0, right?

#define IEC958_AES0_CON_NOT_COPYRIGHT	(1<<2)

> Byte2 has the category code
> and Byte4's 0-3 bits for the sampling frequency.

#define IEC958_AES3_CON_FS_44100	(0<<0)
...

You're right that my register address calculation has to go in 32bit
(DAVINCI_MCASP_DITCSRA_REG + 4, DAVINCI_MCASP_DITCSRA_REG + 8, ...), but
I still don't think the u8-mapping is correct.

I'm confused. :)


Daniel