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

[Peter Ujfalusi <peter.ujfalusi@nokia.com>]

On Monday 31 May 2010 20:41:12 ext Nishanth Menon wrote:
> 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..

I can add comments in the mach-omap2/mcbsp.c like this:

> 
> > 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,

 +		.buffer_size	= 0x80, /* The FIFO has 128 locations */

> > 
> >   	},
> >   	{
> >   	
> >   		.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,

 +		.buffer_size	= 0x500, /* The FIFO has 1024 + 256 locations */

> > 
> >   	},
> >   	{
> >   	
> >   		.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,

 +		.buffer_size	= 0x80, /* The FIFO has 128 locations */

> > 
> >   	},
> >   	{
> >   	
> >   		.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.

Is this sufficient?

-- 
Péter