Re: [RFC PATCH 04/10] dma-engine: sun4i: Add support for Allwinner suniv F1C100s

[Maxime Ripard <maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org>]

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On Mon, Dec 03, 2018 at 12:23:11AM +0300, Mesih Kilinc wrote:
> DMA of Allwinner suniv F1C100s is similar to sun4i. It has 4 NDMA, 4
> DDMA channels and endpoints are different. Also F1C100s has reset bit
> for DMA in CCU. Add support for it.
> 
> Signed-off-by: Mesih Kilinc <mesihkilinc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/dma/Kconfig     |  4 ++--
>  drivers/dma/sun4i-dma.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 62 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index de511db..f8a65d2 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -163,8 +163,8 @@ config DMA_SA11X0
>  
>  config DMA_SUN4I
>  	tristate "Allwinner A10 DMA SoCs support"
> -	depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I
> -	default (MACH_SUN4I || MACH_SUN5I || MACH_SUN7I)
> +	depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUNIV
> +	default (MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUNIV)
>  	select DMA_ENGINE
>  	select DMA_VIRTUAL_CHANNELS
>  	help
> diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
> index d267ff9..c0452c9 100644
> --- a/drivers/dma/sun4i-dma.c
> +++ b/drivers/dma/sun4i-dma.c
> @@ -36,7 +36,11 @@
>  #define SUN4I_DMA_CFG_SRC_ADDR_MODE(mode)	((mode) << 5)
>  #define SUN4I_DMA_CFG_SRC_DRQ_TYPE(type)	(type)
>  
> +#define SUNIV_DMA_CFG_DST_DATA_WIDTH(width)	((width) << 24)
> +#define SUNIV_DMA_CFG_SRC_DATA_WIDTH(width)	((width) << 8)
> +
>  #define SUN4I_MAX_BURST	8
> +#define SUNIV_MAX_BURST	4
>  
>  /** Normal DMA register values **/
>  
> @@ -44,6 +48,9 @@
>  #define SUN4I_NDMA_DRQ_TYPE_SDRAM		0x16
>  #define SUN4I_NDMA_DRQ_TYPE_LIMIT		(0x1F + 1)
>  
> +#define SUNIV_NDMA_DRQ_TYPE_SDRAM		0x11
> +#define SUNIV_NDMA_DRQ_TYPE_LIMIT		(0x17 + 1)
> +
>  /** Normal DMA register layout **/
>  
>  /* Dedicated DMA source/destination address mode values */
> @@ -57,6 +64,9 @@
>  #define SUN4I_NDMA_CFG_BYTE_COUNT_MODE_REMAIN	BIT(15)
>  #define SUN4I_NDMA_CFG_SRC_NON_SECURE		BIT(6)
>  
> +#define SUNIV_NDMA_CFG_CONT_MODE		BIT(29)
> +#define SUNIV_NDMA_CFG_WAIT_STATE(n)		((n) << 26)
> +
>  /** Dedicated DMA register values **/
>  
>  /* Dedicated DMA source/destination address mode values */
> @@ -69,6 +79,9 @@
>  #define SUN4I_DDMA_DRQ_TYPE_SDRAM		0x1
>  #define SUN4I_DDMA_DRQ_TYPE_LIMIT		(0x1F + 1)
>  
> +#define SUNIV_DDMA_DRQ_TYPE_SDRAM		0x1
> +#define SUNIV_DDMA_DRQ_TYPE_LIMIT		(0x9 + 1)
> +
>  /** Dedicated DMA register layout **/
>  
>  /* Dedicated DMA configuration register layout */
> @@ -122,6 +135,11 @@
>  #define SUN4I_DMA_NR_MAX_VCHANS						\
>  	(SUN4I_NDMA_NR_MAX_VCHANS + SUN4I_DDMA_NR_MAX_VCHANS)
>  
> +#define SUNIV_NDMA_NR_MAX_CHANNELS	4
> +#define SUNIV_DDMA_NR_MAX_CHANNELS	4
> +#define SUNIV_NDMA_NR_MAX_VCHANS	(24 * 2 - 1)
> +#define SUNIV_DDMA_NR_MAX_VCHANS	10
> +
>  /* This set of SUN4I_DDMA timing parameters were found experimentally while
>   * working with the SPI driver and seem to make it behave correctly */
>  #define SUN4I_DDMA_MAGIC_SPI_PARAMETERS \
> @@ -236,6 +254,16 @@ static void set_src_data_width_a10(u32 *p_cfg, s8 data_width)
>  	*p_cfg |= SUN4I_DMA_CFG_SRC_DATA_WIDTH(data_width);
>  }
>  
> +static void set_dst_data_width_f1c100s(u32 *p_cfg, s8 data_width)
> +{
> +	*p_cfg |= SUNIV_DMA_CFG_DST_DATA_WIDTH(data_width);
> +}
> +
> +static void set_src_data_width_f1c100s(u32 *p_cfg, s8 data_width)
> +{
> +	*p_cfg |= SUNIV_DMA_CFG_SRC_DATA_WIDTH(data_width);
> +}
> +
>  static int convert_burst_a10(u32 maxburst)
>  {
>  	if (maxburst > 8)
> @@ -245,6 +273,15 @@ static int convert_burst_a10(u32 maxburst)
>  	return (maxburst >> 2);
>  }
>  
> +static int convert_burst_f1c100s(u32 maxburst)
> +{
> +	if (maxburst > 4)
> +		return -EINVAL;
> +
> +	/* 1 -> 0, 4 -> 1 */
> +	return (maxburst >> 2);
> +}
> +

This is essentially the same function than for the A10, with a
different limit. Like a was saying, use a bitmask for the supported
bursts length, and test whether the burst is supported against that
mask. You won't have to duplicate those functions anymore.

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com