From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id A5B47B7067 for ; Tue, 11 Aug 2009 23:58:05 +1000 (EST) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 108DDDDD04 for ; Tue, 11 Aug 2009 23:58:04 +1000 (EST) Message-Id: From: Kumar Gala To: avorontsov@ru.mvista.com In-Reply-To: <20090811134450.GA9820@oksana.dev.rtsoft.ru> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v936) Subject: Re: [PATCH] powerpc/85xx: Workaround MPC8536 GPIO 1 errata. Date: Tue, 11 Aug 2009 08:57:55 -0500 References: <> <1249981458-16102-1-git-send-email-felix@embedded-sol.com> <20090811134450.GA9820@oksana.dev.rtsoft.ru> Cc: linuxppc-dev@ozlabs.org, Felix Radensky List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Aug 11, 2009, at 8:44 AM, Anton Vorontsov wrote: > On Tue, Aug 11, 2009 at 12:04:18PM +0300, Felix Radensky wrote: >> On MPC8536 Rev 1.0 the status of GPIO pins configured >> as output cannot be determined by reading GPDAT register. >> Workaround by reading the status of input pins from GPDAT >> and the status of output pins from a shadow register. >> >> Signed-off-by: Felix Radensky >> --- >> arch/powerpc/sysdev/mpc8xxx_gpio.c | 6 +++++- >> 1 files changed, 5 insertions(+), 1 deletions(-) >> >> diff --git a/arch/powerpc/sysdev/mpc8xxx_gpio.c b/arch/powerpc/ >> sysdev/mpc8xxx_gpio.c >> index 103eace..0b996f3 100644 >> --- a/arch/powerpc/sysdev/mpc8xxx_gpio.c >> +++ b/arch/powerpc/sysdev/mpc8xxx_gpio.c >> @@ -56,9 +56,13 @@ static void mpc8xxx_gpio_save_regs(struct >> of_mm_gpio_chip *mm) >> >> static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio) >> { >> + u32 val; >> struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc); >> + struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm); >> + >> + val = in_be32(mm->regs + GPIO_DAT) && ~in_be32(mm->regs + >> GPIO_DIR); > > Are you sure about &&? > > Plus, this are two reads instead of just one. I think it'll be better > to implement mpc8536_gpio_get(), and then do > > if (of_device_is_compatible(np, ... 8536-gpio-bank ...)) > gc->get = mpc8536_gpio_get; > else > gc->get = mpc8xxx_gpio_get; I think 8572 has the same errata. > >> - return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio); >> + return (val | mpc8xxx_gc->data) & mpc8xxx_gpio2mask(gpio); >> } >> >> static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int >> gpio, int val) > > Thanks, > > -- > Anton Vorontsov > email: cbouatmailru@gmail.com > irc://irc.freenode.net/bd2 > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev