On Thu, Aug 16, 2018 at 04:16:36PM +0900, Masahiro Yamada wrote:
> Here is another TMIO MMC variant found in Socionext UniPhier SoCs.
>
> As commit b6147490e6aa ("mmc: tmio: split core functionality, DMA and
> MFD glue") said, these MMC controllers use the IP from Panasonic.
>
> However, the MMC controller in the TMIO (Toshiba Mobile IO) MFD chip
> was the first upstreamed user of this IP. The common driver code
> for this IP is now called 'tmio-mmc-core' in Linux although it is a
> historical misnomer.
>
> Anyway, this driver select's MMC_TMIO_CORE to borrow the common code
> from tmio-mmc-core.c
>
> Older UniPhier SoCs (LD4, Pro4, sLD8) support the external DMA engine
> like renesas_sdhi_sys_dmac.c. The difference is UniPhier SoCs use a
> single DMA channel whereas Renesas chips request separate channels for
> RX and TX.
>
> Newer UniPhier SoCs (Pro5 and later) support the internal DMA engine
> like renesas_sdhi_internal_dmac.c The register map is almost the same,
> so I guess Renesas and Socionext use the same internal DMA hardware.
> The main difference is, the register offsets are doubled for Renesas.
>
> Renesas Socionext
> SDHI UniPhier
> DM_CM_DTRAN_MODE 0x820 0x410
> DM_CM_DTRAN_CTRL 0x828 0x414
> DM_CM_RST 0x830 0x418
> DM_CM_INFO1 0x840 0x420
> DM_CM_INFO1_MASK 0x848 0x424
> DM_CM_INFO2 0x850 0x428
> DM_CM_INFO2_MASK 0x858 0x42c
> DM_DTRAN_ADDR 0x880 0x440
> DM_DTRAN_ADDREX --- 0x444
>
> This comes from the difference of host->bus_shift; 2 for Renesas SoCs,
> and 1 for UniPhier SoCs. Also, the datasheet for UniPhier SoCs defines
> DM_DTRAN_ADDR and DM_DTRAN_ADDREX as two separate registers.
>
> It could be possible to factor out the DMA common code by introducing
> some hooks to cope with platform quirks, but this patch does not touch
> that for now.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Without docs and HW I cannot really review the driver, but it looks good
and it makes sense to me to keep it seperate and not factor out more
SDHI stuff. Thus:
Acked-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
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