From: sergei.shtylyov@cogentembedded.com (Sergei Shtylyov)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] ARM: shmobile: silk: add SDHI1 DT support
Date: Wed, 23 Sep 2015 02:19:19 +0300 [thread overview]
Message-ID: <5601E1F7.1060907@cogentembedded.com> (raw)
In-Reply-To: <CANqRtoSRZo_J1kV0EkYdVzg9YRJ5=Ha3eQRVPKeq9M=kAPLwpA@mail.gmail.com>
Hello.
On 09/18/2015 05:56 AM, Magnus Damm wrote:
>>>>>>>> Define the SILK board dependent part of the SDHI1 (connected to micro-SD slot)
>>>>>>>> device nodes along with the necessary voltage regulators.
>>>>>>>>
>>>>>>>> Based on the original patch by Vladimir Barinov
>>>>>>>> <vladimir.barinov@cogentembedded.com>.
>>>>>>>>
>>>>>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>>>>>>
>>>>>>>> ---
>>>>>>>> This patch is against 'renesas-devel-20150810-v4.2-rc6' tag of Simon Horman's
>>>>>>>> 'renesas.git' repo plus the R8A7794/SILK QSPI patches just re-posted. It needs
>>>>>>>> the R8A7794 GPIO patches in order to compile.
>>>>>>>>
>>>>>>>> Changes in version 2:
>>>>>>>> - removed not working SDHI0 stuff, renamed the patch;
>>>>>>>> - replaced SDHI1's "wp-gpios" property with "disable-wp".
>>>>>>>
>>>>>>> I am wondering if you could explain the motivation for the "disable-wp"
>>>>>>> update
>>>>>>
>>>>>> Please see the comment in mmc_sd_get_ro().
>>>>>>
>>>>>>> and weather it is appropriate for other r8a779* dts files.
>>>>>>
>>>>>> In case of micro-SD slots, yes.
>>>>>
>>>>> The MMC binding document says it should only be specified if the
>>>>> controller has WP detection logic. We, so far, seem to have been replying on
>>>>> the GPIOs despite this logic is present (according to the R-Car gen2 SDHI
>>>>> manuals I have). The driver will first call mmc_gpio_get_ro() and when that
>>>>> fails due to "wp-gpios" not being specified, it proceeds to reading the
>>>>> register but that is forbidden by TMIO_MMC_WRPROTECT_DISABLE flag set for
>>>>> the R-Car gen1/2 chips, so 0 is always returned from tmio_mmc_get_ro().
>>>>> There seems to be no point in going that far (and doing the runtime PM
>>>>> dances) --
>>>
>>> Alternatively, the driver could be fixed to check the flag before the RPM
>>> call unlike what it does now.
>>
>> If the driver can be updated to do the right thing then that seems
>> preferable to me. If so would it be the case that the presence of the
>> "disable-wp" property would not have any run-time effect?
>>>
>>>>> and MMC_CAP2_NO_WRITE_PROTECT (set when "disable-wp" is specified) prohibits
>>>>> doing that...
>>>>
>>>> That sounds reasonable to me.
>>>
>>> I'm still wondering why TMIO_MMC_WRPROTECT_DISABLE is set for the R-Car
>>> SoCs. Morimoto-san, any comments? Your change logs are too terse. :-)
>>
>> I will follow up on this.
[...]
> Now what is the issue that you guys are having?
My main issue is that I don't understand why checking the write protect
bit is always prohibited for the R-Car SoCs (by setting
TMIO_MMC_WRPROTECT_DISABLE), i.e. it can only be read via GPIO (though that
GPIO is just an alias of the WP signal).
>>>> Some more questions from my side:
>>>
>>>> * What is the status of this patch
>>>
>>> Tested, working.
>>>
>>>> * Can you prepare patches for r8a779* dts files for micro-SD slots?
>>>
>>> Ugh, I probably can but won't promise anything.
>>
>> Likewise, ugh.
> What needs to be updated for R-Car Gen1 again?
We haven't reached the agreement about the need for update yet.
> Thanks,
> / magnus
MBR, Sergei
next prev parent reply other threads:[~2015-09-22 23:19 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-21 22:25 [PATCH 0/2] Add R8A7794/SILK board SDHI DT support Sergei Shtylyov
2015-02-21 22:26 ` [PATCH 1/2] ARM: shmobile: r8a7794: add " Sergei Shtylyov
2015-02-23 0:28 ` Kuninori Morimoto
2015-02-23 11:18 ` Geert Uytterhoeven
2015-02-23 11:16 ` Geert Uytterhoeven
2015-02-23 22:00 ` Simon Horman
2015-02-21 22:27 ` [PATCH 2/2] ARM: shmobile: silk: add SDHI0/1 " Sergei Shtylyov
2015-02-22 0:45 ` Magnus Damm
2015-02-22 14:54 ` Sergei Shtylyov
2015-02-23 22:01 ` Simon Horman
2015-02-24 4:28 ` Magnus Damm
2015-08-10 22:44 ` [PATCH v2] ARM: shmobile: silk: add SDHI1 " Sergei Shtylyov
2015-08-12 1:26 ` Simon Horman
2015-08-21 20:57 ` Sergei Shtylyov
2015-08-21 22:18 ` Sergei Shtylyov
2015-09-02 2:29 ` Simon Horman
2015-09-04 23:47 ` Sergei Shtylyov
2015-09-18 0:21 ` Simon Horman
2015-09-18 2:56 ` Magnus Damm
2015-09-22 23:19 ` Sergei Shtylyov [this message]
2015-09-29 8:44 ` Magnus Damm
2015-10-06 20:12 ` Sergei Shtylyov
2015-09-22 23:22 ` Sergei Shtylyov
2015-08-13 22:47 ` Sergei Shtylyov
2015-10-16 21:37 ` Sergei Shtylyov
2015-10-18 11:04 ` Sergei Shtylyov
2015-10-19 0:46 ` Simon Horman
2015-10-20 17:58 ` Sergei Shtylyov
2015-10-21 0:31 ` Simon Horman
2015-10-21 18:13 ` Sergei Shtylyov
2015-10-22 0:54 ` Simon Horman
2015-10-21 23:04 ` [PATCH 1/2] ARM: shmobile: r8a7790: fix "gpio-ranges" props Sergei Shtylyov
2015-10-23 0:19 ` Simon Horman
2015-10-21 23:05 ` [PATCH 2/2] ARM: shmobile: r8a7791: " Sergei Shtylyov
2015-10-22 11:06 ` Geert Uytterhoeven
2015-10-23 0:20 ` Simon Horman
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