[2/4] i.MX DMA: Add support for 2D transfers.

DMAC present in i.MX2 and i.MX1 chips have two
2D configuration slots that any DMA channel can
use to make 2D DMA transfers.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
---
 arch/arm/mach-imx/dma-v1.c              |   86 +++++++++++++++++++++++++++++++
 arch/arm/mach-imx/include/mach/dma-v1.h |    7 +++
 2 files changed, 93 insertions(+), 0 deletions(-)

On Fri, 2012-02-10 at 15:31 +0100, Javier Martin wrote:
> DMAC present in i.MX2 and i.MX1 chips have two
> 2D configuration slots that any DMA channel can
> use to make 2D DMA transfers.
> 
> Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
> ---
>  arch/arm/mach-imx/dma-v1.c              |   86 +++++++++++++++++++++++++++++++
>  arch/arm/mach-imx/include/mach/dma-v1.h |    7 +++
>  2 files changed, 93 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/dma-v1.c b/arch/arm/mach-imx/dma-v1.c
> index 42afc29..7401138 100644
> --- a/arch/arm/mach-imx/dma-v1.c
> +++ b/arch/arm/mach-imx/dma-v1.c
> @@ -121,6 +121,9 @@ struct imx_dma_channel {
>  
>  	int in_use;
>  
> +	bool enabled_2d;
> +	int slot_2d;
> +
>  	u32 ccr_from_device;
>  	u32 ccr_to_device;
>  
> @@ -129,6 +132,13 @@ struct imx_dma_channel {
>  	int hw_chaining;
>  };
>  
> +struct imx_dma_2d_config {
> +	u16		xsr;
> +	u16		ysr;
> +	u16		wsr;
> +	int		count;
> +};
> +
>  static void __iomem *imx_dmav1_baseaddr;
>  
>  static void imx_dmav1_writel(unsigned val, unsigned offset)
> @@ -143,6 +153,9 @@ static unsigned imx_dmav1_readl(unsigned offset)
>  
>  static struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];
>  
> +static struct imx_dma_2d_config imx_dma_2d_slots[IMX_DMA_2D_SLOTS];
> +static spinlock_t lock_2d;
> +
>  static struct clk *dma_clk;
>  
>  static int imx_dma_hw_chain(struct imx_dma_channel *imxdma)
> @@ -369,6 +382,11 @@ imx_dma_config_channel(int channel, unsigned int config_port,
>  	imxdma->ccr_from_device = config_port | (config_mem << 2) | dreq;
>  	imxdma->ccr_to_device = config_mem | (config_port << 2) | dreq;
>  
> +	if (imxdma->enabled_2d && (imxdma->slot_2d == IMX_DMA_2D_SLOT_B)) {
> +		imxdma->ccr_from_device |= CCR_MSEL_B;
> +		imxdma->ccr_to_device |= CCR_MSEL_B;
> +	}
> +
>  	imx_dmav1_writel(dmareq, DMA_RSSR(channel));
>  
>  	return 0;
> @@ -382,6 +400,63 @@ void imx_dma_config_burstlen(int channel, unsigned int burstlen)
>  EXPORT_SYMBOL(imx_dma_config_burstlen);
>  
>  /**
> + * imx_dma_config_2d - prepare i.MX DMA channel for a 2D transfer.
> + * @channel: i.MX DMA channel number
> + * @x: x-size of the 2D window.
> + * @y: number of rows that make up the 2D window.
> + * @w: display size of the 2D window
> + */
> +int imx_dma_config_2d(int channel, unsigned int x, unsigned int y,
> +		      unsigned int w)
> +{
> +	struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
> +	int slot = -1;
> +	int i;
> +
> +	spin_lock(&lock_2d);
> +	/* If the channel already owns a slot, free it first */
> +	if (imxdma->enabled_2d) {
> +		imx_dma_2d_slots[imxdma->slot_2d].count--;
> +		imxdma->enabled_2d = false;
> +	}
> +	/* Try to get free 2D slot */
> +	for (i = 0; i < IMX_DMA_2D_SLOTS; i++) {
> +		if ((imx_dma_2d_slots[i].count > 0) &&
> +		    ((imx_dma_2d_slots[i].xsr != x) ||
> +		     (imx_dma_2d_slots[i].ysr != y) ||
> +		     (imx_dma_2d_slots[i].wsr != w)))
> +			continue;
> +		slot = i;
> +		break;
> +	}
> +	if (slot < 0)
> +		return -EBUSY;
> +
> +	imx_dma_2d_slots[slot].xsr = x;
> +	imx_dma_2d_slots[slot].ysr = y;
> +	imx_dma_2d_slots[slot].wsr = w;
> +	imx_dma_2d_slots[slot].count++;
> +
> +	spin_unlock(&lock_2d);
> +
> +	imxdma->slot_2d = slot;
> +	imxdma->enabled_2d = true;
> +
> +	if (slot == IMX_DMA_2D_SLOT_A) {
> +		imx_dmav1_writel(x, DMA_XSRA);
> +		imx_dmav1_writel(y, DMA_YSRA);
> +		imx_dmav1_writel(w, DMA_WSRA);
> +	} else {
> +		imx_dmav1_writel(x, DMA_XSRB);
> +		imx_dmav1_writel(y, DMA_YSRB);
> +		imx_dmav1_writel(w, DMA_WSRB);
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(imx_dma_config_2d);
why EXPORT?? This should be done using the interleaved API
> +
> +/**
>   * imx_dma_setup_handlers - setup i.MX DMA channel end and error notification
>   * handlers
>   * @channel: i.MX DMA channel number
> @@ -732,6 +807,13 @@ void imx_dma_free(int channel)
>  		return;
>  	}
>  
> +	spin_lock(&lock_2d);
> +	if (imxdma->enabled_2d) {
> +		imx_dma_2d_slots[imxdma->slot_2d].count--;
> +		imxdma->enabled_2d = false;
> +	}
> +	spin_unlock(&lock_2d);
> +
>  	local_irq_save(flags);
>  	/* Disable interrupts */
>  	imx_dma_disable(channel);
> @@ -840,6 +922,10 @@ static int __init imx_dma_init(void)
>  		imx_dma_channels[i].dma_num = i;
>  	}
>  
> +	for (i = 0; i < IMX_DMA_2D_SLOTS; i++)
> +		imx_dma_2d_slots[i].count = 0;
> +	spin_lock_init(&lock_2d);
> +
>  	return ret;
>  }
>  
> diff --git a/arch/arm/mach-imx/include/mach/dma-v1.h b/arch/arm/mach-imx/include/mach/dma-v1.h
> index ac6fd71..bab9183 100644
> --- a/arch/arm/mach-imx/include/mach/dma-v1.h
> +++ b/arch/arm/mach-imx/include/mach/dma-v1.h
> @@ -30,6 +30,10 @@
>  #include <mach/dma.h>
>  
>  #define IMX_DMA_CHANNELS  16
> +#define IMX_DMA_2D_SLOTS   2
> +
> +#define IMX_DMA_2D_SLOT_A  0
> +#define IMX_DMA_2D_SLOT_B  1
>  
>  #define DMA_MODE_READ		0
>  #define DMA_MODE_WRITE		1
> @@ -64,6 +68,9 @@ void
>  imx_dma_config_burstlen(int channel, unsigned int burstlen);
>  
>  int
> +imx_dma_config_2d(int channel, unsigned int x, unsigned int y, unsigned int w);
> +
> +int
>  imx_dma_setup_single(int channel, dma_addr_t dma_address,
>  		unsigned int dma_length, unsigned int dev_addr,
>  		unsigned int dmamode);