[PATCH 7/8 resend] dw_dmac.c: Pass Channel Allocation Order from platform_data

Koul, Vinod vinod.koul at intel.com
Wed Mar 2 13:37:54 EST 2011


On Mon, 2011-02-28 at 16:11 +0530, Viresh Kumar wrote:
> In SPEAr Platform channels 4-7 have more Fifo depth. So we must get better
> channel first. This patch introduces concept of channel allocation order in
> dw_dmac. If user doesn't paas anything or 0, than normal (ascending) channel
pass?
> allocation will follow, else channels will be allocated in descending order.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar at st.com>
> ---
>  drivers/dma/dw_dmac.c   |    6 +++++-
>  include/linux/dw_dmac.h |    3 +++
>  2 files changed, 8 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index 01f783d..37ffd2c 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -1314,7 +1314,11 @@ static int __init dw_probe(struct platform_device *pdev)
>  		dwc->chan.device = &dw->dma;
>  		dwc->chan.cookie = dwc->completed = 1;
>  		dwc->chan.chan_id = i;
> -		list_add_tail(&dwc->chan.device_node, &dw->dma.channels);
> +		if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
> +			list_add_tail(&dwc->chan.device_node,
> +					&dw->dma.channels);
> +		else
> +			list_add(&dwc->chan.device_node, &dw->dma.channels);
>  
>  		dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
>  		spin_lock_init(&dwc->lock);
> diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h
> index c8aad71..057e883 100644
> --- a/include/linux/dw_dmac.h
> +++ b/include/linux/dw_dmac.h
> @@ -19,6 +19,9 @@
>   */
>  struct dw_dma_platform_data {
>  	unsigned int	nr_channels;
> +#define CHAN_ALLOCATION_ASCENDING	0	/* zero to seven */
> +#define CHAN_ALLOCATION_DESCENDING	1	/* seven to zero */
Can you add these defines outside of this struct?
> +	unsigned int	chan_allocation_order;
>  };
>  
>  /**


-- 
~Vinod




More information about the linux-arm-kernel mailing list