Re: [RFC PATCH 2/5] OMAP3: McBSP: Change the way how the FIFO is handled

[Nishanth Menon <menon.nishanth@gmail.com>]

On 05/31/2010 11:16 AM, Peter Ujfalusi wrote:
> Use the actual FIFO size in words as buffer_size on OMAP2.
> Change the threshold configuration to use 1 based numbering, when
> specifying the allowed threshold maximum or the McBSP threshold value.
> Set the default maximum threshold to (buffer_size - 0x10) intialy.
>> From users of McBSP, now it is expected to use this method.
> Asking for threshold 1 means that the value written to threshold registers
> are going to be 0, which means 1 word threshold.

just a 2cent minor comment: maybe omap_mcbsp_platform_data needs 
structure documentation.. it might be difficult for folks to figure that 
out from commit ID itself..
>
> Signed-off-by: Peter Ujfalusi<peter.ujfalusi@nokia.com>
> ---
>   arch/arm/mach-omap2/mcbsp.c |   10 +++++-----
>   arch/arm/plat-omap/mcbsp.c  |   10 ++++++----
>   2 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/mcbsp.c b/arch/arm/mach-omap2/mcbsp.c
> index 016fe60..9139958 100644
> --- a/arch/arm/mach-omap2/mcbsp.c
> +++ b/arch/arm/mach-omap2/mcbsp.c
> @@ -132,7 +132,7 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
>   		.rx_irq		= INT_24XX_MCBSP1_IRQ_RX,
>   		.tx_irq		= INT_24XX_MCBSP1_IRQ_TX,
>   		.ops		=&omap2_mcbsp_ops,
> -		.buffer_size	= 0x6F,
> +		.buffer_size	= 0x80,
>   	},
>   	{
>   		.phys_base	= OMAP34XX_MCBSP2_BASE,
> @@ -142,7 +142,7 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
>   		.rx_irq		= INT_24XX_MCBSP2_IRQ_RX,
>   		.tx_irq		= INT_24XX_MCBSP2_IRQ_TX,
>   		.ops		=&omap2_mcbsp_ops,
> -		.buffer_size	= 0x3FF,
> +		.buffer_size	= 0x500,
>   	},
>   	{
>   		.phys_base	= OMAP34XX_MCBSP3_BASE,
> @@ -152,7 +152,7 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
>   		.rx_irq		= INT_24XX_MCBSP3_IRQ_RX,
>   		.tx_irq		= INT_24XX_MCBSP3_IRQ_TX,
>   		.ops		=&omap2_mcbsp_ops,
> -		.buffer_size	= 0x6F,
> +		.buffer_size	= 0x80,
>   	},
>   	{
>   		.phys_base	= OMAP34XX_MCBSP4_BASE,
> @@ -161,7 +161,7 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
>   		.rx_irq		= INT_24XX_MCBSP4_IRQ_RX,
>   		.tx_irq		= INT_24XX_MCBSP4_IRQ_TX,
>   		.ops		=&omap2_mcbsp_ops,
> -		.buffer_size	= 0x6F,
> +		.buffer_size	= 0x80,
>   	},
>   	{
>   		.phys_base	= OMAP34XX_MCBSP5_BASE,
> @@ -170,7 +170,7 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
>   		.rx_irq		= INT_24XX_MCBSP5_IRQ_RX,
>   		.tx_irq		= INT_24XX_MCBSP5_IRQ_TX,
>   		.ops		=&omap2_mcbsp_ops,
> -		.buffer_size	= 0x6F,
> +		.buffer_size	= 0x80,
>   	},
>   };
>   #define OMAP34XX_MCBSP_PDATA_SZ		ARRAY_SIZE(omap34xx_mcbsp_pdata)
> diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
> index 51d8abf..6462968 100644
> --- a/arch/arm/plat-omap/mcbsp.c
> +++ b/arch/arm/plat-omap/mcbsp.c
> @@ -497,7 +497,8 @@ void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold)
>   	}
>   	mcbsp = id_to_mcbsp_ptr(id);
>
> -	MCBSP_WRITE(mcbsp, THRSH2, threshold);
> +	if (threshold&&  threshold<= mcbsp->max_tx_thres)
> +		MCBSP_WRITE(mcbsp, THRSH2, threshold - 1);
>   }
>   EXPORT_SYMBOL(omap_mcbsp_set_tx_threshold);
>
> @@ -519,7 +520,8 @@ void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold)
>   	}
>   	mcbsp = id_to_mcbsp_ptr(id);
>
> -	MCBSP_WRITE(mcbsp, THRSH1, threshold);
> +	if (threshold&&  threshold<= mcbsp->max_rx_thres)
> +		MCBSP_WRITE(mcbsp, THRSH1, threshold - 1);
>   }
>   EXPORT_SYMBOL(omap_mcbsp_set_rx_threshold);
>
> @@ -1696,8 +1698,8 @@ static inline void __devinit omap34xx_device_init(struct omap_mcbsp *mcbsp)
>   {
>   	mcbsp->dma_op_mode = MCBSP_DMA_MODE_ELEMENT;
>   	if (cpu_is_omap34xx()) {
> -		mcbsp->max_tx_thres = max_thres(mcbsp);
> -		mcbsp->max_rx_thres = max_thres(mcbsp);
> +		mcbsp->max_tx_thres = max_thres(mcbsp) - 0x10;
> +		mcbsp->max_rx_thres = max_thres(mcbsp) - 0x10;
>   		/*
>   		 * REVISIT: Set dmap_op_mode to THRESHOLD as default
>   		 * for mcbsp2 instances.