[PATCH 2/3] mmc: Add APM X-Gene SoC SDHC controller support to Arasan SDHCI driver

Arnd Bergmann
2014-05-19T09:07:51Z

On Sunday 18 May 2014 01:41:57 Loc Ho wrote:
> @@ -34,6 +36,19 @@
> */
> struct sdhci_arasan_data {
> struct clk *clk_ahb;
> + struct platform_device *pdev;
> + void __iomem *ahb_aim_csr;
> + const struct sdhci_arasan_ahb_ops *ahb_ops;
> +};
> +
> +/**
> + * struct sdhci_arasan_ahb_ops
> + * @init_ahb Initialize translation bus
> + * @xlat_addr Set up an 64-bit addressing translation
> + */
> +struct sdhci_arasan_ahb_ops {
> + int (*init_ahb)(struct sdhci_arasan_data *data);
> + void (*xlat_addr)(struct sdhci_arasan_data *data, u64 dma_addr);
> };
>
> static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> @@ -51,7 +66,21 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> return freq;
> }
>
> +static void sdhci_arasan_writel(struct sdhci_host *host, u32 val, int reg)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
> +
> + if (reg == SDHCI_DMA_ADDRESS) {
> + if (sdhci_arasan->ahb_ops && sdhci_arasan->ahb_ops->xlat_addr)
> + sdhci_arasan->ahb_ops->xlat_addr(sdhci_arasan,
> + sg_dma_address(host->data->sg));
> + }
> + writel(val, host->ioaddr + reg);
> +}
> +
> static struct sdhci_ops sdhci_arasan_ops = {
> + .write_l = sdhci_arasan_writel,
> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> .get_timeout_clock = sdhci_arasan_get_timeout_clock,
> };

This looks like you are doing it at the wrong place. From what I understand,
you are using the AHB inbound window as a minimal IOMMU. Why don't you make
this a proper IOMMU driver instead and leave the SDHCI driver unchanged?

Arnd