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linux-next/sound/soc/fsl/mpc5200_dma.h
Grant Likely d56b6eb6df ASoC/mpc5200: get rid of the appl_ptr tracking nonsense
Sound drivers PCM DMA is supposed to free-run until told to stop
by the trigger callback.  The current code tries to track appl_ptr,
to avoid stale buffer data getting played out at the end of the
data stream.  Unfortunately it also results in race conditions
which can cause the audio to stall.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-11-07 12:40:08 +00:00

76 lines
1.9 KiB
C

/*
* Freescale MPC5200 Audio DMA driver
*/
#ifndef __SOUND_SOC_FSL_MPC5200_DMA_H__
#define __SOUND_SOC_FSL_MPC5200_DMA_H__
#define PSC_STREAM_NAME_LEN 32
/**
* psc_ac97_stream - Data specific to a single stream (playback or capture)
* @active: flag indicating if the stream is active
* @psc_dma: pointer back to parent psc_dma data structure
* @bcom_task: bestcomm task structure
* @irq: irq number for bestcomm task
* @period_end: physical address of end of DMA region
* @period_next_pt: physical address of next DMA buffer to enqueue
* @period_bytes: size of DMA period in bytes
*/
struct psc_dma_stream {
struct snd_pcm_runtime *runtime;
int active;
struct psc_dma *psc_dma;
struct bcom_task *bcom_task;
int irq;
struct snd_pcm_substream *stream;
int period_next;
int period_current;
int period_bytes;
};
/**
* psc_dma - Private driver data
* @name: short name for this device ("PSC0", "PSC1", etc)
* @psc_regs: pointer to the PSC's registers
* @fifo_regs: pointer to the PSC's FIFO registers
* @irq: IRQ of this PSC
* @dev: struct device pointer
* @dai: the CPU DAI for this device
* @sicr: Base value used in serial interface control register; mode is ORed
* with this value.
* @playback: Playback stream context data
* @capture: Capture stream context data
*/
struct psc_dma {
char name[32];
struct mpc52xx_psc __iomem *psc_regs;
struct mpc52xx_psc_fifo __iomem *fifo_regs;
unsigned int irq;
struct device *dev;
spinlock_t lock;
struct mutex mutex;
u32 sicr;
uint sysclk;
int imr;
int id;
unsigned int slots;
/* per-stream data */
struct psc_dma_stream playback;
struct psc_dma_stream capture;
/* Statistics */
struct {
unsigned long overrun_count;
unsigned long underrun_count;
} stats;
};
int mpc5200_audio_dma_create(struct of_device *op);
int mpc5200_audio_dma_destroy(struct of_device *op);
extern struct snd_soc_platform mpc5200_audio_dma_platform;
#endif /* __SOUND_SOC_FSL_MPC5200_DMA_H__ */