From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 1/2] mfd: palmas: support IRQ inversion at the board level Date: Mon, 17 Feb 2014 09:26:58 +0000 Message-ID: <20140217092658.GC17875@lee--X1> References: <1392415108-4365-1-git-send-email-swarren@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1392415108-4365-1-git-send-email-swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Samuel Ortiz , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, J Keerthy , Ian Lartey , Stefan Agner , josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, Stephen Warren List-Id: devicetree@vger.kernel.org > From: Stephen Warren >=20 > Some boards or SoCs have an inverter between the PMIC IRQ output pin = and > the IRQ controller input signal. >=20 > The IRQ specifier in DT is meant to represent the IRQ flags at the in= put > to the IRQ controller. >=20 > The Palmas HW's IRQ output has configurable polarity. The driver > currently selects the output polarity by querying the input polarity = at > the IRQ controller. This works fine if the IRQ signal is routed direc= tly > from the PMIC to the IRQ controller with no intervening logic. Howeve= r, > if the signal is inverted between the two, this automatic polarity > selection gets the wrong answer. >=20 > Add an additional optional DT and platform data parameter which indic= ates > that such an inversion occurs. If this option is enabled, the Palmas > driver will configure its IRQ output to the opposite polarity of the = IRQ > controller's input. >=20 > An alternative would have been to add a new non-optional DT parameter= to > indicate the exact desired output polarity. However, this would have = been > an incompatible change to the DT binding. >=20 > Signed-off-by: Stephen Warren > --- > If this patch could be applied to its own branch (w/ signed tag) in t= he > MFD tree, that would great; then I can pull patch 1/2 into the Tegra = tree > so that I can apply patch 2/2 to the Tegra tree. Thanks. > --- > Documentation/devicetree/bindings/mfd/palmas.txt | 6 ++++++ > drivers/mfd/palmas.c | 4 ++++ > include/linux/mfd/palmas.h | 1 + > 3 files changed, 11 insertions(+) =46or the core changes: Acked-by: Lee Jones NB: The DT guys prefer documentation to be submitted in a separate patch these days. --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog