From: nicolas.ferre@atmel•com (Nicolas Ferre)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 1/2] ARM: at91: dt: add header to define at_hdmac configuration
Date: Sat, 15 Jun 2013 00:11:56 +0200 [thread overview]
Message-ID: <51BB952C.2070209@atmel.com> (raw)
In-Reply-To: <1371112779-22738-2-git-send-email-ludovic.desroches@atmel.com>
On 13/06/2013 10:39, ludovic.desroches at atmel.com :
> From: Ludovic Desroches <ludovic.desroches@atmel•com>
>
> DMA-cell content is a concatenation of several values. In order to keep this
> stuff human readable, macros are introduced.
>
> The values for the FIFO configuration are not the same as the ones used in the
> configuration register in order to keep backward compatibility. Most devices
> use the half FIFO configuration but USART ones have to use the ASAP
> configuration. This parameter was not initially planed to be into the at91 dma
> dt binding. The third cell will be used to store this parameter, it will
> become a concatenation of the FIFO configuration and of the peripheral ID. In
> order to keep backward compatibility i.e. FIFO configuration is equal to 0, we
> have to perform a translation since the value to put in the register to set
> half FIFO is 1.
>
> Acked-by: Arnd Bergmann <arnd@arndb•de>
> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft•com>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel•com>
Of course:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel•com>
In addition to going through slave-dma Vinod's git tree, I also stack it
on the AT91 DT branch so that it can go in arm-soc and prevent a
dependency between the two trees that could lead to a build error...
Best regards,
> ---
> include/dt-bindings/dma/at91.h | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
> create mode 100644 include/dt-bindings/dma/at91.h
>
> diff --git a/include/dt-bindings/dma/at91.h b/include/dt-bindings/dma/at91.h
> new file mode 100644
> index 0000000..e835037
> --- /dev/null
> +++ b/include/dt-bindings/dma/at91.h
> @@ -0,0 +1,27 @@
> +/*
> + * This header provides macros for at91 dma bindings.
> + *
> + * Copyright (C) 2013 Ludovic Desroches <ludovic.desroches@atmel•com>
> + *
> + * GPLv2 only
> + */
> +
> +#ifndef __DT_BINDINGS_AT91_DMA_H__
> +#define __DT_BINDINGS_AT91_DMA_H__
> +
> +/*
> + * Source and/or destination peripheral ID
> + */
> +#define AT91_DMA_CFG_PER_ID_MASK (0xff)
> +#define AT91_DMA_CFG_PER_ID(id) (id & AT91_DMA_CFG_PER_ID_MASK)
> +
> +/*
> + * FIFO configuration: it defines when a request is serviced.
> + */
> +#define AT91_DMA_CFG_FIFOCFG_OFFSET (8)
> +#define AT91_DMA_CFG_FIFOCFG_MASK (0xf << AT91_DMA_CFG_FIFOCFG_OFFSET)
> +#define AT91_DMA_CFG_FIFOCFG_HALF (0x0 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* half FIFO (default behavior) */
> +#define AT91_DMA_CFG_FIFOCFG_ALAP (0x1 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* largest defined AHB burst */
> +#define AT91_DMA_CFG_FIFOCFG_ASAP (0x2 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* single AHB access */
> +
> +#endif /* __DT_BINDINGS_AT91_DMA_H__ */
>
--
Nicolas Ferre
next prev parent reply other threads:[~2013-06-14 22:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-13 8:39 [PATCH v3 0/2] dmaengine: at_hdmac: dt dma bindings update ludovic.desroches at atmel.com
2013-06-13 8:39 ` [PATCH v3 1/2] ARM: at91: dt: add header to define at_hdmac configuration ludovic.desroches at atmel.com
2013-06-14 22:11 ` Nicolas Ferre [this message]
2013-06-13 8:39 ` [PATCH v3 2/2] at_hdmac: add FIFO configuration parameter to DMA DT binding ludovic.desroches at atmel.com
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