On 16 July 2012 14:15, Girish K S <girish.shivananjappa@xxxxxxxxxx> wrote:
> In some Soc'S that integrate Designware mmc host controllers, the
> HCON register is broken. The hardware configuration is not
> updated. One specific usecase is the IDMAC. In Exysons5 SoC
> there exist a internal DMA, but the HCON register's DMA_INTERFACE
> field is not set to indicate its existance.
>
> This quirk can be used in such case to force the existance broken
> HCON field.
>
> Signed-off-by: Girish K S <girish.shivananjappa@xxxxxxxxxx>
> ---
This patch is based on Thomas Abraham's patch series for device tree support
> drivers/mmc/host/dw_mmc-pltfm.c | 5 +++++
> drivers/mmc/host/dw_mmc.c | 11 ++++++++++-
> drivers/mmc/host/dw_mmc.h | 1 +
> include/linux/mmc/host.h | 1 +
> 4 files changed, 17 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
> index 900f412..24ea485 100644
> --- a/drivers/mmc/host/dw_mmc-pltfm.c
> +++ b/drivers/mmc/host/dw_mmc-pltfm.c
> @@ -35,9 +35,14 @@ static unsigned long exynos5250_dwmmc_caps[4] = {
> MMC_CAP_CMD23,
> };
>
> +static unsigned long exynos5250_dwmmc_caps2[1] = {
> + MMC_CAP2_CONFIG_BROKEN,
> +};
> +
> static struct dw_mci_drv_data exynos5250_drv_data = {
> .ctrl_type = DW_MCI_TYPE_EXYNOS5250,
> .caps = exynos5250_dwmmc_caps,
> + .caps2 = exynos5250_dwmmc_caps2,
> };
>
> static const struct of_device_id dw_mci_pltfm_match[] = {
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 1a59a92..030224c 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -431,7 +431,13 @@ static int dw_mci_idmac_init(struct dw_mci *host)
> /* Check if Hardware Configuration Register has support for DMA */
> dma_support = (mci_readl(host, HCON) >> 16) & 0x3;
>
> - if (!dma_support || dma_support > 2) {
> + /*
> + * In Some of the Soc's the HCON Register is broken. Even though the
> + * Soc's has a internal DMA the HCON register's DMA field doesnt
> + * show it. So additional quirk is added for such Soc's
> + */
> + if ((!dma_support || dma_support > 2) &&
> + !((u32)host->drv_data->caps2 & MMC_CAP2_CONFIG_BROKEN)) {
> dev_err(&host->dev,
> "Host Controller does not support IDMA Tx.\n");
> host->dma_ops = NULL;
> @@ -1957,6 +1963,9 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
> if (host->pdata->caps2)
> mmc->caps2 = host->pdata->caps2;
>
> + if (host->drv_data->caps2)
> + mmc->caps2 |= host->drv_data->caps2[ctrl_id];
> +
> if (host->pdata->get_bus_wd) {
> if (host->pdata->get_bus_wd(slot->id) >= 4)
> mmc->caps |= MMC_CAP_4_BIT_DATA;
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 6c17282..8c4810a 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -203,6 +203,7 @@ extern int dw_mci_resume(struct dw_mci *host);
> struct dw_mci_drv_data {
> unsigned long ctrl_type;
> unsigned long *caps;
> + unsigned long *caps2;
> };
>
> #endif /* _DW_MMC_H_ */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 65c64ee..ab5c7f9 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -261,6 +261,7 @@ struct mmc_host {
> #define MMC_CAP2_HC_ERASE_SZ (1 << 9) /* High-capacity erase size */
> #define MMC_CAP2_CD_ACTIVE_HIGH (1 << 10) /* Card-detect signal active high */
> #define MMC_CAP2_RO_ACTIVE_HIGH (1 << 11) /* Write-protect signal active high */
> +#define MMC_CAP2_CONFIG_BROKEN (1 << 12) /* Broken Config Register */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
> unsigned int power_notify_type;
> --
> 1.7.4.1
>
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