On 17 July 2012 13:16, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
> Hi Girish,
>
> On 07/16/2012 05:45 PM, Girish K S 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>
>> ---
>> 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)) {
> Just caps2? if use the device tree, need to get ctrl_id?
ctrl id is available for exynos5 in the parent structure of caps2.
I think device tree will be used to only get the platform related
information. The platform information that dwmmc expects is only the
compatible string.
The quirk information is part of the driver data. And the caps2 is
embedded inside the driver data.
In the above case. IDMAC init is called in probe for every instance of
the host controller.
> It didn't work..
I tested it for exynos5. There is no issue.
>> 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;
>>
>
>
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