linux/sound/soc/davinci/davinci-mcasp.h
Daniel Mack 1b3bc060fb ASoC: McASP: implement a way to force BCLK/LRCLK ratios
Depending on the Codec, the the BCLK/LRCLK ratio might not be freely
chosen by the CPU DAI.

For example, some Codec might want to be supplied with 32-bit samples
for both its channels regardless of the actual audio word size the CPU
sends. In such cases, the rest of the bits on the data lines must be
padded with zeros:

          _______________________________
LRCLK    /                               \
      --'                                 `---------- .....

BCLK  ||||||||||||||||||||||||||||||||||||||||||||||| .....

DATA  ____||||||||||||||||_________________|||||||||| .....

          |<--  data  -->|<--   pads  --> |

This patch adds a new clock divider to configure the BCLK/LRCLK ratio.
If the machine code uses that divider, the driver uses the specified
value, instead of deriving that information from the audio word size.

Otherwise, the original behaviour is retained.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-12-07 14:47:10 +09:00

48 lines
1.1 KiB
C

/*
* ALSA SoC McASP Audio Layer for TI DAVINCI processor
*
* MCASP related definitions
*
* Author: Nirmal Pandey <n-pandey@ti.com>,
* Suresh Rajashekara <suresh.r@ti.com>
* Steve Chen <schen@.mvista.com>
*
* Copyright: (C) 2009 MontaVista Software, Inc., <source@mvista.com>
* Copyright: (C) 2009 Texas Instruments, India
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef DAVINCI_MCASP_H
#define DAVINCI_MCASP_H
#include <linux/io.h>
#include <linux/platform_data/davinci_asp.h>
#include "davinci-pcm.h"
#define DAVINCI_MCASP_RATES SNDRV_PCM_RATE_8000_192000
#define DAVINCI_MCASP_I2S_DAI 0
#define DAVINCI_MCASP_DIT_DAI 1
struct davinci_audio_dev {
struct davinci_pcm_dma_params dma_params[2];
void __iomem *base;
struct device *dev;
/* McASP specific data */
int tdm_slots;
u8 op_mode;
u8 num_serializer;
u8 *serial_dir;
u8 version;
u8 bclk_lrclk_ratio;
/* McASP FIFO related */
u8 txnumevt;
u8 rxnumevt;
};
#endif /* DAVINCI_MCASP_H */