From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: rtc-linux@googlegroups.com Received: from mail.free-electrons.com (down.free-electrons.com. [37.187.137.238]) by gmr-mx.google.com with ESMTP id e78si123333wmc.3.2016.04.22.13.12.04 for ; Fri, 22 Apr 2016 13:12:04 -0700 (PDT) Date: Fri, 22 Apr 2016 22:11:53 +0200 From: Alexandre Belloni To: Rob Herring Cc: Jeppe Ledet-Pedersen , lee.jones@linaro.org, arnd@arndb.de, gregkh@linuxfoundation.org, a.zummo@towertech.it, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, rtc-linux@googlegroups.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [rtc-linux] Re: [PATCH 1/3] mfd: add Cypress FM33256B Processor Companion driver Message-ID: <20160422201153.GB17051@piout.net> References: <1461150471-23163-1-git-send-email-jlp@gomspace.com> <1461150471-23163-2-git-send-email-jlp@gomspace.com> <20160422193232.GA9737@rob-hp-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 In-Reply-To: <20160422193232.GA9737@rob-hp-laptop> Reply-To: rtc-linux@googlegroups.com List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , On 22/04/2016 at 14:32:32 -0500, Rob Herring wrote : > On Wed, Apr 20, 2016 at 01:07:49PM +0200, Jeppe Ledet-Pedersen wrote: > > This patch adds support for the Cypress Semiconductor FM33256B processor > > companion. The device contains a 256 kbit FRAM, an RTC, a supply voltage > > monitor, and a watchdog timer. > > > > Signed-off-by: Jeppe Ledet-Pedersen > > --- > > Documentation/devicetree/bindings/mfd/fm33256b.txt | 30 ++ > > MAINTAINERS | 6 + > > drivers/mfd/Kconfig | 16 + > > drivers/mfd/Makefile | 1 + > > drivers/mfd/fm33256b.c | 488 +++++++++++++++++++++ > > include/linux/mfd/fm33256b.h | 76 ++++ > > 6 files changed, 617 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/mfd/fm33256b.txt > > create mode 100644 drivers/mfd/fm33256b.c > > create mode 100644 include/linux/mfd/fm33256b.h > > > > diff --git a/Documentation/devicetree/bindings/mfd/fm33256b.txt b/Documentation/devicetree/bindings/mfd/fm33256b.txt > > new file mode 100644 > > index 0000000..6591c94 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/mfd/fm33256b.txt > > @@ -0,0 +1,30 @@ > > +Device-tree bindings for Cypress Semiconductor FM33256B Processor Companion > > +--------------------------------------------------------------------------- > > + > > +Required properties: > > +- compatible: must be "cypress,fm33256b". > > +- reg: SPI chip select > > +- spi-max-frequency: Max SPI frequency to use (< 16000000) > > + > > +Optional properties: > > +- cypress,charge-enabled: enable trickle charger > > What does the driver do if charging is disabled? Would using 'status = > "disabled"' be any different? > Good catch, I didn't look at this patch but it includes a lot of code that should be going to the RTC driver. If trickle charging is not enabled, I guess the RTC will not charge its backup battery. > > +- cypress,charge-fast: enable fast (1 mA) charging > > What does fast mean? > > I think it is time for a common binding here. There's all sorts of > variations on setting the charge current in bindings. Add something like > "charge-current-microamp" in power_supply.txt and use it here. Then > 1000uA implies "fast charge". Well, this is not a power supply, it is an RTC. I think both properties should got to the RTC subdevice and be parsed in the RTC driver. Note that for trickle charging, we currently have the following properties: - trickle-resistor-ohms - trickle-diode-disable - abracon,tc-diode - abracon,tc-resistor abracon,tc-resistor can be replaced by trickle-resistor-ohms, I'll make a patch but abracon,tc-diode allows to select a diode type (and in particular a voltage drop). I think we could add a trickle-current-microamp like you suggested and trickle-diode-disable can be reused. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.