[PATCH v3 1/4] mmc: dw_mmc: exynos: incorporate ciu_div into timing property

Alim Akhtar alim.akhtar at gmail.com
Mon Jan 12 05:55:58 PST 2015


Hi Jaehoon,

On Thu, Jan 8, 2015 at 7:06 AM, Jaehoon Chung <jh80.chung at samsung.com> wrote:
> Hi,
>
> On 12/31/2014 03:43 PM, Alim Akhtar wrote:
>> From: Seungwon Jeon <tgih.jun at samsung.com>
>>
>> ciu_div may not be common value for all speed mode.
>> So, it needs to be attached to CLKSEL timing.
>> This also introduce a new compatibale 'dw-mshc-hs200-timing'
>> for selecting hs200 timing value
>>
>> Signed-off-by: Seungwon Jeon <tgih.jun at samsung.com>
>> Signed-off-by: Alim Akhtar <alim.akhtar at samsung.com>
>> ---
>>  .../devicetree/bindings/mmc/exynos-dw-mshc.txt     |   15 ++--
>>  drivers/mmc/host/dw_mmc-exynos.c                   |   81 ++++++++++++++------
>>  drivers/mmc/host/dw_mmc-exynos.h                   |    1 +
>>  3 files changed, 67 insertions(+), 30 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> index ee4fc05..06455de 100644
>> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> @@ -23,10 +23,6 @@ Required Properties:
>>       - "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
>>         specific extensions having an SMU.
>>
>> -* samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
>> -  unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
>> -  ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7.
>> -
>>  * samsung,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
>>    in transmit mode and CIU clock phase shift value in receive mode for single
>>    data rate mode operation. Refer notes below for the order of the cells and the
>> @@ -37,11 +33,16 @@ Required Properties:
>>    data rate mode operation. Refer notes below for the order of the cells and the
>>    valid values.
>>
>> +* samsung,dw-mshc-hs200-timing: Similar with dw-mshc-sdr-timing.
>
> What does this comment mean? "Similar with dw-mshc-sdr-timing"
> how about adding the comment "optional"?
>
> And i think this timing doesn't need, we can reuse the sdr-timing or ddr-timing.
> Because it's re-configurated at tuning time, isn't?
>
Ok, I will rework/drop this patch, I will try to use existing binding
as much as mush possible.
>> +
>>    Notes for the sdr-timing and ddr-timing values:
>>
>>      The order of the cells should be
>>        - First Cell: CIU clock phase shift value for tx mode.
>>        - Second Cell: CIU clock phase shift value for rx mode.
>> +      - Thrid Cell: Specifies the divider value for the card interface
>> +        unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
>> +        ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7.
>>
>>      Valid values for SDR and DDR CIU clock timing for Exynos5250:
>>        - valid value for tx phase shift and rx phase shift is 0 to 7.
>> @@ -79,8 +80,8 @@ Example:
>>               broken-cd;
>>               fifo-depth = <0x80>;
>>               card-detect-delay = <200>;
>> -             samsung,dw-mshc-ciu-div = <3>;
>> -             samsung,dw-mshc-sdr-timing = <2 3>;
>> -             samsung,dw-mshc-ddr-timing = <1 2>;
>> +             samsung,dw-mshc-sdr-timing = <2 3 3>;
>> +             samsung,dw-mshc-ddr-timing = <1 2 3>;
>> +             samsung,dw-mshc-hs200-timing = <0 2 3>;
>>               bus-width = <8>;
>>       };
>> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
>> index 12a5eaa..be6530e 100644
>> --- a/drivers/mmc/host/dw_mmc-exynos.c
>> +++ b/drivers/mmc/host/dw_mmc-exynos.c
>> @@ -40,6 +40,7 @@ struct dw_mci_exynos_priv_data {
>>       u8                              ciu_div;
>>       u32                             sdr_timing;
>>       u32                             ddr_timing;
>> +     u32                             hs200_timing;
>>       u32                             cur_speed;
>>  };
>>
>> @@ -71,6 +72,21 @@ static struct dw_mci_exynos_compatible {
>>       },
>>  };
>>
>> +static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
>> +{
>> +     struct dw_mci_exynos_priv_data *priv = host->priv;
>> +
>> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
>> +             return EXYNOS4412_FIXED_CIU_CLK_DIV;
>> +     else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
>> +             return EXYNOS4210_FIXED_CIU_CLK_DIV;
>> +     else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
>> +                     priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
>> +             return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
>> +     else
>> +             return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
>
> If need this, I think more readable that use the switch-case statement. how about?
>
>        switch (priv->ctrl_type) {
>        case DW_MCI_TYPE_EXYNOS4412:
>                 return EXYNOS4412_FIXED_CIU_CLK_DIV;
>        case DW_MCI_TYPE_EXYNOS4210:
>                 return EXYNOS4210_FIXED_CIU_CLK_DIV;
>        case DW_MCI_TYPE_EXYNOS7:
>        case DW_MCI_TYPE_EXYNOS7_SMU:
>                 return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
>        default:
>                 return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
>        }
>
>
>> +}
>> +
>>  static int dw_mci_exynos_priv_init(struct dw_mci *host)
>>  {
>>       struct dw_mci_exynos_priv_data *priv = host->priv;
>> @@ -85,6 +101,8 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
>>                          SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
>>       }
>>
>> +     priv->ciu_div = dw_mci_exynos_get_ciu_div(host);
>> +
>>       return 0;
>>  }
>>
>> @@ -92,7 +110,7 @@ static int dw_mci_exynos_setup_clock(struct dw_mci *host)
>>  {
>>       struct dw_mci_exynos_priv_data *priv = host->priv;
>>
>> -     host->bus_hz /= (priv->ciu_div + 1);
>> +     host->bus_hz /= priv->ciu_div;
>>
>>       return 0;
>>  }
>> @@ -177,9 +195,14 @@ static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>>       struct dw_mci_exynos_priv_data *priv = host->priv;
>>       unsigned int wanted = ios->clock;
>>       unsigned long actual;
>> -     u8 div = priv->ciu_div + 1;
>>
>> -     if (ios->timing == MMC_TIMING_MMC_DDR52) {
>> +     if (ios->timing == MMC_TIMING_MMC_HS200) {
>> +             if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
>> +                     priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
>> +                     mci_writel(host, CLKSEL64, priv->hs200_timing);
>> +             else
>> +                     mci_writel(host, CLKSEL, priv->hs200_timing);
>> +     } else if (ios->timing == MMC_TIMING_MMC_DDR52) {
>>               if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
>>                       priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
>>                       mci_writel(host, CLKSEL64, priv->ddr_timing);
>> @@ -208,6 +231,7 @@ static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>>               wanted = EXYNOS_CCLKIN_MIN;
>>
>>       if (wanted != priv->cur_speed) {
>> +             u8 div = dw_mci_exynos_get_ciu_div(host);
>>               int ret = clk_set_rate(host->ciu_clk, wanted * div);
>>               if (ret)
>>                       dev_warn(host->dev,
>> @@ -220,14 +244,34 @@ static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>>       }
>>  }
>>
>> +static int dw_mci_exynos_dt_populate_timing(struct dw_mci *host,
>> +                                         unsigned int ctrl_type,
>> +                                         const char *propname,
>> +                                         u32 *out_values)
>> +{
>> +     struct device_node *np = host->dev->of_node;
>> +     u32 timing[3];
>> +     int ret;
>> +
>> +     ret = of_property_read_u32_array(np, propname, timing, 3);
>> +     if (ret)
>> +             return ret;
>> +
>> +     if (ctrl_type == DW_MCI_TYPE_EXYNOS4412 ||
>> +         ctrl_type == DW_MCI_TYPE_EXYNOS4210)
>> +             timing[2] = 0;
>
> Is it set to 0 into dt-file?
>
>> +
>> +     *out_values = SDMMC_CLKSEL_TIMING(timing[0], timing[1], timing[2]);
>> +
>> +     return 0;
>> +}
>> +
>> +
>>  static int dw_mci_exynos_parse_dt(struct dw_mci *host)
>>  {
>>       struct dw_mci_exynos_priv_data *priv;
>>       struct device_node *np = host->dev->of_node;
>> -     u32 timing[2];
>> -     u32 div = 0;
>> -     int idx;
>> -     int ret;
>> +     int idx, ret;
>>
>>       priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
>>       if (!priv)
>> @@ -238,29 +282,20 @@ static int dw_mci_exynos_parse_dt(struct dw_mci *host)
>>                       priv->ctrl_type = exynos_compat[idx].ctrl_type;
>>       }
>>
>> -     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
>> -             priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
>> -     else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
>> -             priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
>> -     else {
>> -             of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
>> -             priv->ciu_div = div;
>> -     }
>> -
>> -     ret = of_property_read_u32_array(np,
>> -                     "samsung,dw-mshc-sdr-timing", timing, 2);
>> +     ret = dw_mci_exynos_dt_populate_timing(host, priv->ctrl_type,
>> +                     "samsung,dw-mshc-sdr-timing", &priv->sdr_timing);
>>       if (ret)
>>               return ret;
>>
>> -     priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
>> -
>> -     ret = of_property_read_u32_array(np,
>> -                     "samsung,dw-mshc-ddr-timing", timing, 2);
>> +     ret = dw_mci_exynos_dt_populate_timing(host, priv->ctrl_type,
>> +                     "samsung,dw-mshc-ddr-timing", &priv->ddr_timing);
>>       if (ret)
>>               return ret;
>>
>> -     priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
>> +     dw_mci_exynos_dt_populate_timing(host, priv->ctrl_type,
>> +             "samsung,dw-mshc-hs200-timing", &priv->hs200_timing);
>
> hs200-timing is optional, so it needs not to check return value, right?
>
> Best Regards,
> Jaehoon Chung
>
>>       host->priv = priv;
>> +
>>       return 0;
>>  }
>>
>> diff --git a/drivers/mmc/host/dw_mmc-exynos.h b/drivers/mmc/host/dw_mmc-exynos.h
>> index 7872ce5..c04ecef 100644
>> --- a/drivers/mmc/host/dw_mmc-exynos.h
>> +++ b/drivers/mmc/host/dw_mmc-exynos.h
>> @@ -21,6 +21,7 @@
>>  #define SDMMC_CLKSEL_CCLK_DRIVE(x)   (((x) & 7) << 16)
>>  #define SDMMC_CLKSEL_CCLK_DIVIDER(x) (((x) & 7) << 24)
>>  #define SDMMC_CLKSEL_GET_DRV_WD3(x)  (((x) >> 16) & 0x7)
>> +#define SDMMC_CLKSEL_GET_DIV(x)              (((x) >> 24) & 0x7)
>>  #define SDMMC_CLKSEL_TIMING(x, y, z) (SDMMC_CLKSEL_CCLK_SAMPLE(x) |  \
>>                                        SDMMC_CLKSEL_CCLK_DRIVE(y) |   \
>>                                        SDMMC_CLKSEL_CCLK_DIVIDER(z))
>>
>



-- 
Regards,
Alim



More information about the linux-arm-kernel mailing list