From mboxrd@z Thu Jan 1 00:00:00 1970 From: sergei.shtylyov@cogentembedded.com (Sergei Shtylyov) Date: Wed, 23 Sep 2015 02:22:10 +0300 Subject: [PATCH v2] ARM: shmobile: silk: add SDHI1 DT support In-Reply-To: <20150918002122.GC12858@verge.net.au> References: <10037494.4LD4T2QGPX@wasted.cogentembedded.com> <2757472.iuyUyRzJ3z@wasted.cogentembedded.com> <20150812012652.GH15957@verge.net.au> <55D790A5.1050008@cogentembedded.com> <55D7A3A1.9020009@cogentembedded.com> <20150902022936.GA18115@verge.net.au> <55EA2D8D.90004@cogentembedded.com> <20150918002122.GC12858@verge.net.au> Message-ID: <5601E2A2.9000904@cogentembedded.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello. On 09/18/2015 03:21 AM, Simon Horman 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 >>>>>>> . >>>>>>> >>>>>>> Signed-off-by: Sergei Shtylyov >>>>>>> >>>>>>> --- >>>>>>> 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 OK, I'll try going this way... > 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? Yes. MBR, Sergei