[U-Boot] [PATCH] MMC: DWMMC: Correct the CLKDIV register value

[Rajeshwari Birje]

Hi Simon,

On Thu, Aug 29, 2013 at 8:31 PM, Simon Glass <sjg at chromium.org> wrote:
> On Thu, Aug 29, 2013 at 5:04 AM, Rajeshwari Birje
> <rajeshwari.birje at gmail.com> wrote:
>> CCing the MMC Maintainer.
>>
>> On Thu, Aug 29, 2013 at 4:22 PM, Rajeshwari S Shinde
>> <rajeshwari.s at samsung.com> wrote:
>>> This patch corrects the divider value written to CLKDIV register.
>>> Since SDCLKIN is divided inside controller by the DIVRATIO value set
>>> in the CLKSEL register, we need to use the same output clock value to
>>> calculate the CLKDIV value.
>>> as per user manual: cclk_in = SDCLKIN / (DIVRATIO + 1)
>>>
>>> Input parameter to mmc_clk is changed to dwmci_host, since
>>> we need the same to read DWMCI_CLKSEL register.
>>>
>>> This improves the read timing values for channel 0 on SMDK5250
>>> from 0.288sec to 0.144sec
>>>
>>> Signed-off-by: Rajeshwari S Shinde <rajeshwari.s at samsung.com>
>>> ---
>>>  arch/arm/include/asm/arch-exynos/dwmmc.h |  4 ++++
>>>  drivers/mmc/dw_mmc.c                     |  2 +-
>>>  drivers/mmc/exynos_dw_mmc.c              | 17 +++++++++++++++--
>>>  include/dwmmc.h                          |  2 +-
>>>  4 files changed, 21 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/arm/include/asm/arch-exynos/dwmmc.h b/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> index b9eca76..f1c8d8a 100644
>>> --- a/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> +++ b/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> @@ -14,6 +14,10 @@
>>>  #define DWMCI_SET_DRV_CLK(x)   ((x) << 16)
>>>  #define DWMCI_SET_DIV_RATIO(x) ((x) << 24)
>>>
>>> +/* CLKSEL Register */
>>> +#define DWMCI_DIVRATIO_BIT             24
>>> +#define DWMCI_DIVRATIO_MASK            0x7
>>> +
>>>  #ifdef CONFIG_OF_CONTROL
>>>  int exynos_dwmmc_init(const void *blob);
>>>  #endif
>>> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
>>> index a82ee17..3406bdd 100644
>>> --- a/drivers/mmc/dw_mmc.c
>>> +++ b/drivers/mmc/dw_mmc.c
>>> @@ -224,7 +224,7 @@ static int dwmci_setup_bus(struct dwmci_host *host, u32 freq)
>>>          * host->bus_hz should be set from user.
>>>          */
>>>         if (host->mmc_clk)
>>> -               sclk = host->mmc_clk(host->dev_index);
>>> +               sclk = host->mmc_clk(host);
>
> Do you need to change dw_mmc_simple.c as well?
Not able to find any file dw_mmc_simple.c.
Please do let me know if I need to check any file getting effected.
>
> Regards,
> Simon
-- 
Regards,
Rajeshwari Shinde