[alsa-devel] How to structure CPU DAI
The LPC3130 has two independent I2S channels but it is not two copies of the same hardware block. Instead it is a single hardware block implementing the two channels. Some setup registers contain setup bits for both channels.
So I have one CPU DAI with two independent CODECs hung off from it.
So in a function like hw_params() for the CPU DAI, how do I know which I2S channel I'm supposed to be using? At the point where I created the soc_card I know the right channel. But I can't use the card pointer in the CPU DAI, since there are two cards and only on CPU DAI. The card pointer points to the last one registered. Can I put the info into the substream?
Or should I register two CPU DAIs from a single I2S device driver and give then two different names?
A device tree like this describes the hardware..
i2s@16000000 { #address-cells = <2>; #size-cells = <0>; compatible = "nxp,lpc31xx-i2s"; reg = <0x16000000 0x1000>; i2s0:i2s@0 { interrupts = <13 15>; reg = <0x80 0x180>; /*receive-slave;*/ /* default is master */ }; i2s1:i2s@1 { interrupts = <14 16>; reg = <0x100 0x200>; /*receive-slave;*/ /* default is master */ }; };
sound@1 { compatible = "ea,ea3131-uda1380"; audio-codec = <&uda1380-0>; i2s-controller = <&i2s0>; };
sound@2 { compatible = "ea,ea3131-uda1380"; audio-codec = <&uda1380-1>; i2s-controller = <&i2s1>; };
-- Jon Smirl jonsmirl@gmail.com
Getting runtime from the substream gives me a pointer chain which lets me identify the channel.
rtd->card->dev->of_node
On Sun, Nov 18, 2012 at 5:04 PM, jonsmirl@gmail.com jonsmirl@gmail.com wrote:
The LPC3130 has two independent I2S channels but it is not two copies of the same hardware block. Instead it is a single hardware block implementing the two channels. Some setup registers contain setup bits for both channels.
So I have one CPU DAI with two independent CODECs hung off from it.
So in a function like hw_params() for the CPU DAI, how do I know which I2S channel I'm supposed to be using? At the point where I created the soc_card I know the right channel. But I can't use the card pointer in the CPU DAI, since there are two cards and only on CPU DAI. The card pointer points to the last one registered. Can I put the info into the substream?
Or should I register two CPU DAIs from a single I2S device driver and give then two different names?
A device tree like this describes the hardware..
i2s@16000000 { #address-cells = <2>; #size-cells = <0>; compatible = "nxp,lpc31xx-i2s"; reg = <0x16000000 0x1000>; i2s0:i2s@0 { interrupts = <13 15>; reg = <0x80 0x180>; /*receive-slave;*/ /* default is master */ }; i2s1:i2s@1 { interrupts = <14 16>; reg = <0x100 0x200>; /*receive-slave;*/ /* default is master */ }; };
sound@1 { compatible = "ea,ea3131-uda1380"; audio-codec = <&uda1380-0>; i2s-controller = <&i2s0>; };
sound@2 { compatible = "ea,ea3131-uda1380"; audio-codec = <&uda1380-1>; i2s-controller = <&i2s1>; };
-- Jon Smirl jonsmirl@gmail.com
participants (1)
-
jonsmirl＠gmail.com