From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@stericsson.com (Ulf Hansson) Date: Mon, 24 Oct 2011 13:48:06 +0200 Subject: [PATCH] mmc: mmci: Improve runtime PM support In-Reply-To: <20111024101416.GK9893@n2100.arm.linux.org.uk> References: <1319210754-22775-1-git-send-email-ulf.hansson@stericsson.com> <20111021173637.GG21648@n2100.arm.linux.org.uk> <4EA51C4A.7040802@stericsson.com> <20111024090432.GA9893@n2100.arm.linux.org.uk> <4EA53181.2050700@stericsson.com> <20111024094203.GI9893@n2100.arm.linux.org.uk> <4EA538A3.9070501@stericsson.com> <20111024101416.GK9893@n2100.arm.linux.org.uk> Message-ID: <4EA55076.2010701@stericsson.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org >> Could you maybe elaborate a bit of how the power is controlled in the >> ARM dev boards? Would it be possible to control such a switch in "GPIO" >> manner instead? For example via the vdd_handler or similar? >> >> I will also think if and see if is feasible to re-design and see if this >> hole feature can be controlled by the variant struct instead. My feeling >> is although it can be kind of messy. But let's see... > > The MCIPWR register contains two bits to control _the_ _power_ _state_. > See Table A-4: the MCIPWR signal. See section 2.2.2. See section 3.3.1. > > The MCIPWR signal controls the external power switch. This is the only > signal for it. This is the only connection for it. There is no other > control form for this power switch. > Then we are only left to use the variant struct I believe. In principle, a flag in the variant struct, could indicate whether it is OK to disable the vcore regulator and thus clear the MCIPWR when doing runtime_suspend. How do you feel about this kind of approach to find a solution? BR Ulf Hansson