[U-Boot] [PATCH v2 00/26] mmc: Add support for HS200 and UHS modes

[Marek Vasut]

On 11/23/2017 10:46 AM, Siva Durga Prasad Paladugu wrote:
> Hi Jaehoon,
> 
>> -----Original Message-----
>> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Jaehoon
>> Chung
>> Sent: Friday, October 20, 2017 5:02 PM
>> To: Jean-Jacques Hiblot <jjhiblot at ti.com>; trini at konsulko.com;
>> kishon at ti.com; sjg at chromium.org
>> Cc: u-boot at lists.denx.de
>> Subject: Re: [U-Boot] [PATCH v2 00/26] mmc: Add support for HS200 and
>> UHS modes
>>
>> Dear JJ
>>
>> On 09/21/2017 11:29 PM, Jean-Jacques Hiblot wrote:
>>> This series brings support for HS200 and UHS modes to the mmc core.
>>> It has been tested with the hsmmc driver on several platforms (DRA7,
>>> AM57x, AM437x, beaglebone black, Atmel SAMA5D3 xplained). Some
>>> modifications are required in the host driver to take advantage of
>>> this (voltage switching, tuning). The changes to the host driver will
>>> be posted a another series as this one is already long enough.
>>>
>>> The series starts with a small refactoring of th sd/mmc startup. The
>>> first 5 commits are mostly moving code around with little or no
>> functionnal change.
>>>
>>> Then the notion of "mode" is introduced. Until now, this information
>>> wasn't kept in struct mmc. Only the clock and a flag for ddr was kept.
>>> Later the mode information will be used to select the clock frequency,
>>> the ddr flag and the tuning procedure. It will be also be check against the
>> host capabilities.
>>>
>>> Then comes the big refactoring job in:
>>> "mmc: refactor MMC startup to make it easier to support new modes"
>> and
>>> "mmc: refactor SD startup to make it easier to support new modes"
>>> Since the number of modes is increasing, it makes sense to try them in
>>> a more organized way. those commits use a list of supported modes and
>>> iterate through them to find the best working one. It also allows to
>>> switch more easilly from one mode to another (switching from HS200 to
>>> DDR52 to access boot partitions for example)
>>>
>>> Then there are a couple of new callback added to:
>>> - send the initialization stream (74 clock cycles)
>>> - wait while the card is busy (used during UHS voltage switching). checking
>> is
>>>   done on dat0.
>>> - select the IO voltage
>>>
>>> Then Power cycle is added. Without power cycle, if a UHS card fails to
>>> enumerate in UHS mode, it can't fall back to high speed mode and card
>> enumeration will fail.
>>> Also in case of a reset (as opposed to a power on), it ensures that
>>> the SDCard is in clean state before re-doing the initialization.
>>>
>>> And finally the last commits add the support for HS200 and UHS.
>>>
>>> With this in place and the required changes in the HSMMC host driver
>>> (including DMA), we observe significant improvements in the
>> performances on a DRA72 evm:
>>> eMMC HS200: 124 MB/s
>>> eMMC DDR52: 78 MB/s
>>> sd   SDR104: 71 MB/s
>>> sd   SDR50: 44 MB/s
>>
>> Applied to u-boot-mmc! Thanks!
>> I will apply the patches relevant to this patchset. Sorry for late applying this.
> 
> I would like to test UHS and HS200 series on ZynqMP platform. 
> Is it the branch " testing-uhs-supporting" that I should be using for testing it?
> Please confirm.

That should do, plus look at the uniphier/renesas SDHI patches posted to
the ML adding UHS200 support, that should get you started with the
arasan IP too.

-- 
Best regards,
Marek Vasut