[U-Boot] [PATCH v2] mmc: sdhci: Add the programmable clock mode support

[Jaehoon Chung]

Hi Kever,

On 09/30/2016 07:05 PM, Kever Yang wrote:
> Hi Wenyou,
> 
>     I can not enable my emmc device  on my evb-rk3399 with this patch, could you help to fix it?
> 
> Here is the debug info may help:
> 
> mmc->cfg->f_max is 200000000;
> 
> [with this patch]
> I get host->clk_mul 16 ;
> When driver want to set clock to 400000, always get div 1024, and then write 0x21 to SDHCI_CLOCK_CONTROL register,
> mmc controller can not work because of the wrong clock rate;
> 
> [without this patch]
> we don't use host->clk_mul;
> When driver want to set clock to 400000, get div 250, and then write 0xfa01 to SDHCI_CLOCK_CONTROL register,
> mmc controller works OK.

If you don't use host->clk_mul, then your host controller is the lower version than V3.0..?

host->clk_mul is assigned to dummy value? Could you check this?

When i have checked Whenyou's patch, there is only difference about "host->clk_mul".

Best Regards,
Jaehoon Chung

> 
> Thanks,
> - Kever
> On 09/18/2016 09:01 AM, Wenyou Yang wrote:
>> Add the programmable clock mode for the clock generator.
>>
>> Signed-off-by: Wenyou Yang <wenyou.yang at atmel.com>
>> ---
>>
>> Changes in v2:
>>   - Rebase on the latest u-boot-mmc.
>>   - Fix the typo Muliplier->Multiplier.
>>
>>   drivers/mmc/sdhci.c | 50 ++++++++++++++++++++++++++++++++++++++++----------
>>   include/sdhci.h     |  2 ++
>>   2 files changed, 42 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
>> index 504f2d2..b2bf5a0 100644
>> --- a/drivers/mmc/sdhci.c
>> +++ b/drivers/mmc/sdhci.c
>> @@ -294,7 +294,7 @@ static int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
>>   static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
>>   {
>>       struct sdhci_host *host = mmc->priv;
>> -    unsigned int div, clk, timeout, reg;
>> +    unsigned int div, clk = 0, timeout, reg;
>>         /* Wait max 20 ms */
>>       timeout = 200;
>> @@ -318,14 +318,36 @@ static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
>>           return 0;
>>         if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300) {
>> -        /* Version 3.00 divisors must be a multiple of 2. */
>> -        if (mmc->cfg->f_max <= clock)
>> -            div = 1;
>> -        else {
>> -            for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) {
>> -                if ((mmc->cfg->f_max / div) <= clock)
>> +        /*
>> +         * Check if the Host Controller supports Programmable Clock
>> +         * Mode.
>> +         */
>> +        if (host->clk_mul) {
>> +            for (div = 1; div <= 1024; div++) {
>> +                if ((mmc->cfg->f_max * host->clk_mul / div)
>> +                    <= clock)
>>                       break;
>>               }
>> +
>> +            /*
>> +             * Set Programmable Clock Mode in the Clock
>> +             * Control register.
>> +             */
>> +            clk = SDHCI_PROG_CLOCK_MODE;
>> +            div--;
>> +        } else {
>> +            /* Version 3.00 divisors must be a multiple of 2. */
>> +            if (mmc->cfg->f_max <= clock) {
>> +                div = 1;
>> +            } else {
>> +                for (div = 2;
>> +                     div < SDHCI_MAX_DIV_SPEC_300;
>> +                     div += 2) {
>> +                    if ((mmc->cfg->f_max / div) <= clock)
>> +                        break;
>> +                }
>> +            }
>> +            div >>= 1;
>>           }
>>       } else {
>>           /* Version 2.00 divisors must be a power of 2. */
>> @@ -333,13 +355,13 @@ static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
>>               if ((mmc->cfg->f_max / div) <= clock)
>>                   break;
>>           }
>> +        div >>= 1;
>>       }
>> -    div >>= 1;
>>         if (host->set_clock)
>>           host->set_clock(host->index, div);
>>   -    clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
>> +    clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
>>       clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
>>           << SDHCI_DIVIDER_HI_SHIFT;
>>       clk |= SDHCI_CLOCK_INT_EN;
>> @@ -513,7 +535,7 @@ static const struct mmc_ops sdhci_ops = {
>>   int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
>>           u32 max_clk, u32 min_clk)
>>   {
>> -    u32 caps;
>> +    u32 caps, caps_1;
>>         caps = sdhci_readl(host, SDHCI_CAPABILITIES);
>>   @@ -577,6 +599,14 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
>>         cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;
>>   +    /*
>> +     * In case of Host Controller v3.00, find out whether clock
>> +     * multiplier is supported.
>> +     */
>> +    caps_1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
>> +    host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >>
>> +            SDHCI_CLOCK_MUL_SHIFT;
>> +
>>       return 0;
>>   }
>>   diff --git a/include/sdhci.h b/include/sdhci.h
>> index 6844c73..144570f 100644
>> --- a/include/sdhci.h
>> +++ b/include/sdhci.h
>> @@ -97,6 +97,7 @@
>>   #define  SDHCI_DIV_MASK    0xFF
>>   #define  SDHCI_DIV_MASK_LEN    8
>>   #define  SDHCI_DIV_HI_MASK    0x300
>> +#define  SDHCI_PROG_CLOCK_MODE  0x0020
>>   #define  SDHCI_CLOCK_CARD_EN    0x0004
>>   #define  SDHCI_CLOCK_INT_STABLE    0x0002
>>   #define  SDHCI_CLOCK_INT_EN    0x0001
>> @@ -242,6 +243,7 @@ struct sdhci_host {
>>       unsigned int quirks;
>>       unsigned int host_caps;
>>       unsigned int version;
>> +    unsigned int clk_mul;   /* Clock Multiplier value */
>>       unsigned int clock;
>>       struct mmc *mmc;
>>       const struct sdhci_ops *ops;
> 
> 
> 
> 
>