From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [PATCH v4 04/14] mfd: Add Samsung PWM/timer master driver Date: Fri, 05 Apr 2013 18:53:31 +0200 Message-ID: <5507947.WEhmSUi7vd@amdc1227> References: <1365093431-30621-1-git-send-email-t.figa@samsung.com> <1365093431-30621-5-git-send-email-t.figa@samsung.com> <20130405163958.GP17363@zurbaran> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <20130405163958.GP17363@zurbaran> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Samuel Ortiz Cc: mark.rutland@arm.com, heiko@sntech.de, tomasz.figa@gmail.com, buserror@gmail.com, jacmet@sunsite.dk, augulis.darius@gmail.com, christer@weinigel.se, sylvester.nawrocki@gmail.com, m.szyprowski@samsung.com, kgene.kim@samsung.com, linux@arm.linux.org.uk, kwangwoo.lee@gmail.com, mcuelenaere@gmail.com, arnd@arndb.de, devicetree-discuss@lists.ozlabs.org, linux-samsung-soc@vger.kernel.org, john.stultz@linaro.org, ghcstop@gmail.com, linux@simtec.co.uk, linux-arm-kernel@lists.infradead.org, broonie@opensource.wolfsonmicro.com, jekhor@gmail.com, kyungmin.park@samsung.com, tglx@linutronix.de List-Id: devicetree@vger.kernel.org Hi Samuel, On Friday 05 of April 2013 18:39:58 Samuel Ortiz wrote: > Hi Tomasz, > > On Thu, Apr 04, 2013 at 06:37:01PM +0200, Tomasz Figa wrote: > > This patch adds master driver for PWM/timer block available on many > > Samsung SoCs providing clocksource and PWM output capabilities. > > > > Signed-off-by: Tomasz Figa > > Signed-off-by: Kyungmin Park > > --- > > > > .../devicetree/bindings/pwm/pwm-samsung.txt | 37 ++ > > drivers/clocksource/Kconfig | 1 + > > drivers/mfd/Kconfig | 3 + > > drivers/mfd/Makefile | 1 + > > drivers/mfd/samsung-pwm.c | 439 > > +++++++++++++++++++++ drivers/pwm/Kconfig > > | 1 + > > include/linux/mfd/samsung-pwm.h | 49 +++ > > include/linux/platform_data/samsung-pwm.h | 28 ++ > > 8 files changed, 559 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/pwm/pwm-samsung.txt > > create mode 100644 drivers/mfd/samsung-pwm.c > > create mode 100644 include/linux/mfd/samsung-pwm.h > > create mode 100644 include/linux/platform_data/samsung-pwm.h > > Why is that an MFD driver, and why aren't you using the PWM APIs for it ? > Also, you probably want to look at using the regmap APIs for your IO. The case of Samsung PWM timers is rather complicated. It is a hardware block that can be used at the same time to generate PWM signal and as a system clocksource. There was a discussion on how to solve the problem of sharing the hardware: http://thread.gmane.org/gmane.linux.kernel.samsung-soc/16480/focus=16500 (see the linked post and replies to it). Best regards, -- Tomasz Figa Samsung Poland R&D Center SW Solution Development, Kernel and System Framework