From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH v2 8/8] reset: Add driver for gpio-controlled reset pins Date: Fri, 15 Feb 2013 10:27:57 +0100 Message-ID: <1360920477.4142.18.camel@pizza.hi.pengutronix.de> References: <1360776872-18584-1-git-send-email-p.zabel@pengutronix.de> <1360776872-18584-9-git-send-email-p.zabel@pengutronix.de> <20130214105611.GG17833@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130214105611.GG17833-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Russell King - ARM Linux Cc: Marek Vasut , Fabio Estevam , Mike Turquette , Sascha Hauer , kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Russell, Am Donnerstag, den 14.02.2013, 10:56 +0000 schrieb Russell King - ARM Linux: > On Wed, Feb 13, 2013 at 06:34:32PM +0100, Philipp Zabel wrote: > > Signed-off-by: Philipp Zabel > > Just be aware that PXA has a "gpio reset" facility which is used for SoC > reset - see arch/arm/mach-pxa/reset.c > > The use of gpio-reset would be ambiguous... or maybe PXA's usage could be > combined somehow with this? thank you for pointing this out. The PXA gpio reset code is used for system/board reset and fiddles with the reset line to trigger all possible types of reset without needing configuration. The code I suggest is targeted at resetting peripheral devices, like I2C and SPI ICs with a reset line connected via GPIO, and it has to be configured for either active-high or active-low GPIOs. Should this be combined? I wonder if it would be worth the effort to make the PXA gpio reset go through this reset API, as there isn't even a struct device that would be the reset "consumer". In fact, I don't even think most drivers that currently implement gpio resets themselves would gain much from switching to another level of abstraction, unless the SoC already has an on-chip reset controller anyway - in which case this would mostly increase overall consistency. regards Philipp