[alsa-devel] [PATCH 1/4] OMAP: mcbsp - add omap_mcbsp_set_dma_op_mode()

[Eduardo Valentin]

On Tue, May 18, 2010 at 10:13:11PM +0200, Liam Girdwood wrote:
> This adds a method to set the MCBSP DMA OP mode.

OK. good. But again, why do you need set dma op mode other than inside mcbsp code?

Right, so, from what I have read briefly, the idea is to remove the user space ability to set the mode and
let mcbsp clients to do it. What is not clear to me is how mcbsp clients (inside kernel) will determine if they want
short delay or pm friendly. That usually is bound to upper use case though.

It would be really nice if you improve your patch descriptions.

> 
> Signed-off-by: Liam Girdwood <lrg at slimlogic.co.uk>
> ---
>  arch/arm/plat-omap/include/plat/mcbsp.h |    2 ++
>  arch/arm/plat-omap/mcbsp.c              |   31 +++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/include/plat/mcbsp.h b/arch/arm/plat-omap/include/plat/mcbsp.h
> index 1bd7021..f8823f4 100644
> --- a/arch/arm/plat-omap/include/plat/mcbsp.h
> +++ b/arch/arm/plat-omap/include/plat/mcbsp.h
> @@ -476,6 +476,7 @@ u16 omap_mcbsp_get_max_rx_threshold(unsigned int id);
>  u16 omap_mcbsp_get_tx_delay(unsigned int id);
>  u16 omap_mcbsp_get_rx_delay(unsigned int id);
>  int omap_mcbsp_get_dma_op_mode(unsigned int id);
> +int omap_mcbsp_set_dma_op_mode(unsigned int id, unsigned int mode);
>  #else
>  static inline void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold)
>  { }
> @@ -486,6 +487,7 @@ static inline u16 omap_mcbsp_get_max_rx_threshold(unsigned int id) { return 0; }
>  static inline u16 omap_mcbsp_get_tx_delay(unsigned int id) { return 0; }
>  static inline u16 omap_mcbsp_get_rx_delay(unsigned int id) { return 0; }
>  static inline int omap_mcbsp_get_dma_op_mode(unsigned int id) { return 0; }
> +static inline int omap_mcbsp_set_dma_op_mode(unsigned int id, unsigned int mode) {return 0;}
>  #endif
>  int omap_mcbsp_request(unsigned int id);
>  void omap_mcbsp_free(unsigned int id);
> diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
> index 4820cab..cc2b73c 100644
> --- a/arch/arm/plat-omap/mcbsp.c
> +++ b/arch/arm/plat-omap/mcbsp.c
> @@ -635,6 +635,37 @@ int omap_mcbsp_get_dma_op_mode(unsigned int id)
>  }
>  EXPORT_SYMBOL(omap_mcbsp_get_dma_op_mode);
>  
> +/*
> + * omap_mcbsp_set_dma_op_mode set the current DMA
> + * operating mode for the mcbsp channel
> + */
> +int omap_mcbsp_set_dma_op_mode(unsigned int id, unsigned int mode)
> +{
> +	struct omap_mcbsp *mcbsp;
> +	int ret = 0;
> +
> +	if (mode > MCBSP_DMA_MODE_FRAME)
> +		return -EINVAL;
> +
> +	if (!omap_mcbsp_check_valid_id(id)) {
> +		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
> +		return -ENODEV;
> +	}
> +	mcbsp = id_to_mcbsp_ptr(id);
> +
> +	spin_lock_irq(&mcbsp->lock);
> +	if (!mcbsp->free) {
> +		ret = -EBUSY;
> +		goto unlock;
> +	}
> +	mcbsp->dma_op_mode = mode;
> +
> +unlock:
> +	spin_unlock_irq(&mcbsp->lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL(omap_mcbsp_set_dma_op_mode);
> +
>  static inline void omap34xx_mcbsp_request(struct omap_mcbsp *mcbsp)
>  {
>  	/*
> -- 
> 1.7.0.4
> 
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