[U-Boot] [UBOOT PATCH v2 2/2] arm64: zynqmp: mmc: Added Kconfig support for CONFIG_ZYNQ_SDHCI1

[Michal Simek]

On 5.3.2018 10:38, Jaehoon Chung wrote:
> On 03/02/2018 06:18 PM, Michal Simek wrote:
>> On 2.3.2018 10:01, Jaehoon Chung wrote:
>>> On 03/02/2018 04:44 PM, Michal Simek wrote:
>>>> On 2.3.2018 07:27, Jaehoon Chung wrote:
>>>>> On 03/02/2018 12:13 AM, Michal Simek wrote:
>>>>>> On 28.2.2018 08:42, Jaehoon Chung wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> On 02/28/2018 03:28 PM, Vipul Kumar wrote:
>>>>>>>> This patch added Kconfig support for CONFIG_ZYNQ_SDHCI1 and
>>>>>>>> enabled it in defconfig.
>>>>>>>
>>>>>>> I think that CONFIG_ZYNQ_SDHCI1 is meaningful when CONFIG_ZYNQ_SDHCI0 is enabled.
>>>>>>> It's used in zynqmp.c and spl.c ..like below..
>>>>>>>
>>>>>>> #if defined(CONFIG_ZYNQ_SDHCI0) && defined(CONFIG_ZYNQ_SDHCI1)
>>>>>>> ....
>>>>>>> #endif
>>>>>>>
>>>>>>> If CONFIG_ZYNQ_SDHCI0 isn't enabled, doesn't it need to set CONFIG_ZYNQ_SDHCI1 in defconfigs.
>>>>>>>
>>>>>>> If i missed something, let me know, plz.
>>>>>>
>>>>>> you are right. Dependency should be
>>>>>>
>>>>>> config ZYNQ_SDHCI1
>>>>>> 	...
>>>>>> 	depends on ZYNQ_SDHCI0
>>>>>
>>>>> Hmm. I didn't check fully, but it seems that it's possible to use only one config.
>>>>> I will check in more detail. After that, resend the email. :)
>>>>
>>>> I can't also see any issue with using just one symbol with proper name.
>>>
>>> Maybe you know more than me about zynq boards.
>>> In SPL, it seems that it needs to add some config in spl.c for distinguishing boot device.
>>> But in not SPL, if zynq boards are supported the device-tree, then can you use the below concept?
>>>
>>> commit 02ad33aa3a84821c8d9a6c4f167f143f6248b084
>>> Author: Jaehoon Chung <jh80.chung at samsung.com>
>>> Date:   Thu Feb 2 13:41:14 2017 +0900
>>>
>>>     mmc: mmc-uclass: use the fixed devnum with alias node
>>>     
>>>     If there are alias nodes as "mmc", use the devnum as alias index
>>>     number.
>>>     This patch is for fixing a problem of Exynos4 series.
>>>     Problem is the below thing.
>>>     
>>>     Current legacy mode:
>>>     EXYNOS DWMMC: 0, SAMSUNG SDHCI: 1
>>>     
>>>     After using DM:
>>>     SAMSUNG SDHCI: 0, EXYNOS DWMMC: 1
>>>     
>>>     Dev index is swapped.
>>>     Then u-boot can't find the kernel image..because it is already set to 0 as mmcdev.
>>>     If change from legacy to DM, also needs to touch all exynos4 config file.
>>>     For using simply, just supporting the fixed devnum with alias node is better than it.
>>>     
>>>     Usage:
>>>     alaise {
>>>             ....
>>>             mmc0 = &sdhci2; /* eMMC */
>>>             mmc1 = &sdhci1; /* SD */
>>>             ...
>>>     }
>>>     
>>
>> Chips are supporting booting from SD0 or SD1 controller.
>>
>> #define SD_MODE         0x00000003 /* sd 0 */
>> #define SD_MODE1        0x00000005 /* sd 1 */
>> #define EMMC_MODE       0x00000006
>> #define SD1_LSHFT_MODE  0x0000000E /* SD1 Level shifter */
>>
>> It means on systems which has only sd0 or sd1 we are setting up alias as
>> mmc0 = &sdhci0; (sd0)
>> or
>> mmc0 = &sdhci1; (sd1)
>>
>> It means dev 0 is used all the time.
>>
>> In case of system with both controllers on the same board you need to
>> have two aliases. Normally like this.
>> mmc0 = &sdhci0; (sd0)
>> mmc1 = &sdhci1; (sd1)
>>
>> In case you choose to boot from sd1 default behavior should be that all
>> images are on sd1 that's why boot device needs to be setup.
>> When you load the same u-boot to sd0 it should boot from sd0.
>>
>> Changing aliases for certain boot mode configuration should just work
>> but that's not intention. Normally the same boot files can be loaded to
>> sd, qspi, nand, jtag, you setup boot mode and they should primary boot
>> from that boot device and that's what that logic is about.
> 
> Thanks for explaining this. I understood what purpose those configs are used.

Good.
Vipul: Please send v2 with proper dependency or new symbol which
describe that configuration better.

Thanks,
Michal