[U-Boot] [PATCH v4 04/12] board:samsung: check the boot device and init the right mmc driver.

[Przemyslaw Marczak <p.marczak@samsung.com>]

Hello Jaehoon,

On 07/04/2014 07:45 AM, Jaehoon Chung wrote:
> Hi, Przemyslaw.
>
> On 07/02/2014 08:50 PM, Przemyslaw Marczak wrote:
>> It is possible to boot device using a micro SD or eMMC slots.
>> In this situation, boot device should be registered as a block
>> device 0 in the MMC framework, because CONFIG_SYS_MMC_ENV_DEV
>> is usually set to "0" in the most config cases.
>>
>> Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
>> ---
>> Changes V3:
>> - separate two changes into two commits
>>
>> Changes V4:
>> - board.c: add functions: init_mmc() and init_dwmmc()
>> - board_mmc_init(): call get_boot_mode()
>> ---
>>   board/samsung/common/board.c | 37 +++++++++++++++++++++++++++----------
>>   1 file changed, 27 insertions(+), 10 deletions(-)
>>
>> diff --git a/board/samsung/common/board.c b/board/samsung/common/board.c
>> index 9dc7c83..4d3f216 100644
>> --- a/board/samsung/common/board.c
>> +++ b/board/samsung/common/board.c
>> @@ -240,22 +240,39 @@ int board_eth_init(bd_t *bis)
>>   }
>>
>>   #ifdef CONFIG_GENERIC_MMC
>> -int board_mmc_init(bd_t *bis)
>> +static int init_mmc(void)
>> +{
>> +#ifdef CONFIG_SDHCI
>> +	return exynos_mmc_init(gd->fdt_blob);
>> +#else
>> +	return 0;
>> +#endif
>> +}
>> +
>> +static int init_dwmmc(void)
>>   {
>> -	int ret;
>>   #ifdef CONFIG_DWMMC
>> -	/* dwmmc initializattion for available channels */
>> -	ret = exynos_dwmmc_init(gd->fdt_blob);
>> -	if (ret)
>> -		debug("dwmmc init failed\n");
>> +	return exynos_dwmmc_init(gd->fdt_blob);
>> +#else
>> +	return 0;
>>   #endif
>> +}
>> +
>> +int board_mmc_init(bd_t *bis)
>> +{
>> +	int ret;
>> +
>> +	if (get_boot_mode() == BOOT_MODE_MMC) {
>> +		ret = init_mmc();
>> +		ret |= init_dwmmc();
>> +	} else {
>> +		ret = init_dwmmc();
>> +		ret |= init_mmc();
>> +	}
> Well, i have some confusion for this.
> Did you consider the case like init_dwmmc() is succeed and init_mmc() is failed?
> it's hard to control the error for both.
>
> Best Regards,
> Jaehoon Chung

In our vendor init code, the value returned by this function has no 
significant meaning since there is no implementation of function 
"cpu_mmc_init()".

So checking this error is just for a debug purposes:
# if (ret)
#	debug("mmc init failed\n");

and the returned value:
mmc | dwmmc -> ret
0 | 1 -> 1
1 | 0 -> 1
1 | 1 -> 1
0 | 0 -> 0

So we have an error message on any error.

>>
>> -#ifdef CONFIG_SDHCI
>> -	/* mmc initializattion for available channels */
>> -	ret = exynos_mmc_init(gd->fdt_blob);
>>   	if (ret)
>>   		debug("mmc init failed\n");
>> -#endif
>> +
>>   	return ret;
>>   }
>>   #endif
>>
>
>

Thank you,
-- 
Przemyslaw Marczak
Samsung R&D Institute Poland
Samsung Electronics
p.marczak at samsung.com