On 11/06/2013 07:24 PM, Mark Brown wrote:
On Tue, Nov 05, 2013 at 04:30:08PM +0800, Qiao Zhou wrote:
add TISSP mode support. with this mode enabled, ssp controller works in TI-ssp protocol automatically and doesn't need to configure sspsp register to set the timing for tx/rx.
What is TISSP mode in an audio context?
It's normal SSP mode, and it has a pulse of one bit clock width, which is the frame start signal. previously it's mainly used for voice call which is mono stream. current I2S or DSP_x format use PSP, which configures the details of transmit/receive timing. we can also use PSP to suit this SSP format. But since the SSP controller provides such HW convenience, so we want to add it. I'm not sure it's proper, and want to ask for suggestions.
/*
* add TISSP protocol support. setting to this mode, ssp controller* works in TI-ssp mode, and need not set psp register to conf* detailed timing.*/case SND_SOC_DAIFMT_SSP:
sscr0 |= SSCR0_TISSP;sscr1 |= SSCR1_RWOT;default: return -EINVAL;
I don't think this code has been tested...
sorry for missing the "break", will update it. I want to ask suggestions about the logic of this piece of code from mainline and we do test the code logic on our platform.