From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Tue, 13 Oct 2015 14:25:12 +0200 Subject: [PATCH v7 1/7] ARM: dts: imx: imx7d-sbd remove fixed can2-3v3 regulator In-Reply-To: References: <1443477401-17238-1-git-send-email-aalonso@freescale.com> Message-ID: <561CF828.7050609@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/13/2015 02:04 PM, Dong Aisheng wrote: > On Tue, Sep 29, 2015 at 5:56 AM, Adrian Alonso wrote: >> Remove incorrect can2-3v3 fixed regulator, imx7d-sdb doesn't >> have a dedicated can2 fixed regulator instead it shares PERI_3V3 >> fixed regulator (RT8070ZS) which is enabled by default (hardwired) >> from pmic pfuze3000 NVCC_3V3 power rail. >> >> Signed-off-by: Adrian Alonso >> --- >> Changes for V7: New patch in series >> > > It is a correct regulator here, but i have to admit that it's a bit confusing. > Here the regulator is an abstract regulator which is actually used to > control CAN > transceiver STBY signals, it is introduced by below patch: > commit b7c4114b07bbacfe0aee1d04ad1ade9e42309620 > Author: Fabio Estevam > Date: Mon Jun 10 23:12:57 2013 -0300 > > can: flexcan: Use a regulator to control the CAN transceiver > > Instead of using a GPIO to turn on/off the CAN transceiver, it is better to > use a regulator as some systems may use a PMIC to power the CAN transceiver. > > Acked-by: Shawn Guo > Signed-off-by: Fabio Estevam > Signed-off-by: Marc Kleine-Budde > > From the commit messages, it should be likely to control the > transceiver external suppy, > not control signals, but it does do that unproper work currently. > > Besides the unproperly handling control signals, this solution also can't handle > multiple CAN transceiver control signals ways. You can chain several transceivers together if you need to control more than one GPIO line. > I was trying to write a common transceiver driver to handling this issue. > But get interrupted by a few other FSL official works, will resume soon. Have a look at drivers/phy. > I would suggest keep the regulator first until the new solution got in. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 455 bytes Desc: OpenPGP digital signature URL: