On Wednesday, July 6, 2016 10:23:29 PM CEST Simon Horman wrote:
> @@ -117,6 +124,23 @@ void sdhi_sys_dmac_init_dma(void);
> static void sdhi_sys_dmac_init_dma(void) { }
> #endif
>
> +#if IS_ENABLED(CONFIG_MMC_SDHI_INTERNAL_DMA)
> +void sdhi_internal_dmac_init_dma(void);
> +#else
> +static void sdhi_internal_dmac_init_dma(void) { }
> +#endif
> +
> +static void sh_mobile_sdhi_init_dma(enum tmio_mmc_dmac_type dmac_type)
> +{
> + switch (dmac_type) {
> + case TMIO_MMC_INTERNAL_DMAC:
> + return sdhi_internal_dmac_init_dma();
> +
> + case TMIO_MMC_SYSC_DMAC:
> + return sdhi_sys_dmac_init_dma();
> + }
> +}
> +
> static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
> {
> u32 val;
>
I've commented on this part for v2 already but got no reply. This
time I took a little more care to understand the structure of the
driver and how it gets modified.
The way I see it, we have the MMC_TMIO_CORE driver that consists of
tmio_mmc_pio.c and tmio_mmc_dma.c, which are tightly connected though the
second one is optional, and two front-ends named tmio_mmc.c and
sh_mobile_sdhi.c.
The first front-end never uses DMA, while the second one may or may
not use DMA but is always built with the DMA support linked into the
core driver.
I think abstracting the two DMA modes through a structure of
function pointers as you do is the right strategy, but to build on
top of that, we can change the link order:
- rename tmio_mmc_pio.c to tmio_mmc_core.c and make that the actual
driver core (without DMA)
- tmio_mmc_dma.c becomes the main driver module for sh_mobile_sdhi
and gets the sh_mobile_sdhi_driver structure, sh_mobile_sdhi_of_match
table and module_platform_driver() statement
- the existing sh_mobile_sdhi.c is a library module that exports
sh_mobile_sdhi_probe() and sh_mobile_sdhi_remove(), which now
gain a 'struct tmio_mmc_dma_ops *' and a 'struct sh_mobile_sdhi_of_data *'
argument and get called by the new probe function in what used to
be tmio_mmc_dma.c.
- The new renesas_sdhi_internal_dmac.c becomes a third top-level
module that also calls sh_mobile_sdhi_probe() but passes its
own struct tmio_mmc_dma_ops and registers a different
platform_driver that only matches the of_rcar_gen3_compatible.
Arnd
