Hi All-
I have cellular modem (PCM audio line) connected to OMAP4470 McBSP2 line. I made many changes to McBSP2 registry settings and finally got to a point where my speaker is working (RX is working). However, I don't hear anything on the other end (TX is broken).
Modem requirements for PCM line:
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Master mode
2048 kHz clock
Short frame
External clock will be provided only during digital audio activity (non-permanent)
PCM data is always formatted as 16-bit uncompressed two's complement.
PCM data and frame synchronization signals are written to the CM bus on the rising clock edge and read on the falling edge.
Here is a dump of McBSP2 registry from OMAP4470-Android:
[ 87.105041] omap-mcbsp omap-mcbsp.2: **** McBSP2 regs ****
[ 87.110961] omap-mcbsp omap-mcbsp.2: DRR2: 0x0000
[ 87.116210] omap-mcbsp omap-mcbsp.2: DRR1: 0x0000
[ 87.121398] omap-mcbsp omap-mcbsp.2: DXR2: 0x0000
[ 87.126586] omap-mcbsp omap-mcbsp.2: DXR1: 0x0000
[ 87.131805] omap-mcbsp omap-mcbsp.2: SPCR2: 0x0235
[ 87.136993] omap-mcbsp omap-mcbsp.2: SPCR1: 0x0031
[ 87.142242] omap-mcbsp omap-mcbsp.2: RCR2: 0x0042
[ 87.147430] omap-mcbsp omap-mcbsp.2: RCR1: 0x0040
[ 87.152679] omap-mcbsp omap-mcbsp.2: XCR2: 0x0040
[ 87.157836] omap-mcbsp omap-mcbsp.2: XCR1: 0x0040
[ 87.163055] omap-mcbsp omap-mcbsp.2: SRGR2: 0x000f
[ 87.168273] omap-mcbsp omap-mcbsp.2: SRGR1: 0x0180
[ 87.173461] omap-mcbsp omap-mcbsp.2: PCR0: 0x0003
I do have the correct McBSP2 pad configuration and is as below:
OMAP4_MUX(ABE_MCBSP2_CLKX, OMAP_PIN_INPUT | OMAP_MUX_MODE0),
OMAP4_MUX(ABE_MCBSP2_DR, OMAP_PIN_INPUT_PULLDOWN | OMAP_PIN_OFF_OUTPUT_LOW | OMAP_MUX_MODE0),
OMAP4_MUX(ABE_MCBSP2_DX, OMAP_PIN_OUTPUT | OMAP_MUX_MODE0),
OMAP4_MUX(ABE_MCBSP2_FSX, OMAP_PIN_INPUT_PULLDOWN | OMAP_PIN_OFF_INPUT_PULLDOWN | OMAP_MUX_MODE0),
Any help is highly appreciated to enable TX data.
Srinath