From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753570Ab2LQVfF (ORCPT ); Mon, 17 Dec 2012 16:35:05 -0500 Received: from antcom.de ([188.40.178.216]:57160 "EHLO chuck.antcom.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753107Ab2LQVfD (ORCPT ); Mon, 17 Dec 2012 16:35:03 -0500 Message-ID: <50CF8FA9.8050609@antcom.de> Date: Mon, 17 Dec 2012 22:33:29 +0100 From: Roland Stigge Organization: ANTCOM Open Source Research and Development User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.10) Gecko/20121027 Icedove/10.0.10 MIME-Version: 1.0 To: Wolfgang Grandegger CC: rmallon@gmail.com, gregkh@linuxfoundation.org, linus.walleij@linaro.org, broonie@opensource.wolfsonmicro.com, w.sang@pengutronix.de, linux-kernel@vger.kernel.org, grant.likely@secretlab.ca, daniel-gl@gmx.net, sr@denx.de, plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org, highguy@gmail.com Subject: Re: [PATCH RESEND 0/6 v10] gpio: Add block GPIO References: <1355495185-24220-1-git-send-email-stigge@antcom.de> <50CB68AB.5070806@grandegger.com> <50CBBB25.20002@antcom.de> <50CF03FB.2030100@grandegger.com> <50CF0744.7040404@grandegger.com> <50CF1EF1.2070601@antcom.de> <50CF237E.5020409@antcom.de> <50CF4838.9000401@grandegger.com> <50CF5327.6070205@antcom.de> <50CF584E.1040601@grandegger.com> <50CF5E45.5030104@antcom.de> <50CF76D3.9030708@grandegger.com> In-Reply-To: <50CF76D3.9030708@grandegger.com> X-Enigmail-Version: 1.4.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/12/12 20:47, Wolfgang Grandegger wrote: > On 12/17/2012 07:02 PM, Roland Stigge wrote: >> On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote: >>> /* Do synchronous data output with a single write access */ >>> __raw_writel(~mask, pio + PIO_OWDR); >>> __raw_writel(mask, pio + PIO_OWER); >>> __raw_writel(val, pio + PIO_ODSR); >>> >>> For caching we would need a storage. Not sure if it's worth compared to >>> a context switch into the kernel. >> >> Block GPIO is not only for you in userspace. ;-) You can also implement >> efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not >> always context switches involved. > > OK, what do you think about the following untested patch: Looks good! Why "untested"? ;-) Thanks, Roland >>>From b44cad16cbbca84715dffd4cb5268497216add25 Mon Sep 17 00:00:00 2001 > From: Wolfgang Grandegger > Date: Mon, 3 Dec 2012 08:31:55 +0100 > Subject: [PATCH 1/2] gpio: add GPIO block callback functions for AT91 > > Signed-off-by: Wolfgang Grandegger > --- > arch/arm/mach-at91/gpio.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c > index be42cf0..cf6bd45 100644 > --- a/arch/arm/mach-at91/gpio.c > +++ b/arch/arm/mach-at91/gpio.c > @@ -42,13 +42,16 @@ struct at91_gpio_chip { > void __iomem *regbase; /* PIO bank virtual address */ > struct clk *clock; /* associated clock */ > struct irq_domain *domain; /* associated irq domain */ > + unsigned long mask_shadow; /* synchronous data output */ > }; > > #define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip) > > static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip); > static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val); > +static void at91_gpiolib_set_block(struct gpio_chip *chip, unsigned long mask, unsigned long val); > static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset); > +static unsigned long at91_gpiolib_get_block(struct gpio_chip *chip, unsigned long mask); > static int at91_gpiolib_direction_output(struct gpio_chip *chip, > unsigned offset, int val); > static int at91_gpiolib_direction_input(struct gpio_chip *chip, > @@ -62,7 +65,9 @@ static int at91_gpiolib_to_irq(struct gpio_chip *chip, unsigned offset); > .direction_input = at91_gpiolib_direction_input, \ > .direction_output = at91_gpiolib_direction_output, \ > .get = at91_gpiolib_get, \ > + .get_block = at91_gpiolib_get_block, \ > .set = at91_gpiolib_set, \ > + .set_block = at91_gpiolib_set_block, \ > .dbg_show = at91_gpiolib_dbg_show, \ > .to_irq = at91_gpiolib_to_irq, \ > .ngpio = nr_gpio, \ > @@ -896,6 +901,16 @@ static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset) > return (pdsr & mask) != 0; > } > > +static unsigned long at91_gpiolib_get_block(struct gpio_chip *chip, unsigned long mask) > +{ > + struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip); > + void __iomem *pio = at91_gpio->regbase; > + u32 pdsr; > + > + pdsr = __raw_readl(pio + PIO_PDSR); > + return pdsr & mask; > +} > + > static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val) > { > struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip); > @@ -905,6 +920,20 @@ static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val) > __raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR)); > } > > +static void at91_gpiolib_set_block(struct gpio_chip *chip, unsigned long mask, unsigned long val) > +{ > + struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip); > + void __iomem *pio = at91_gpio->regbase; > + > + /* Do synchronous data output with a single write access */ > + if (mask != at91_gpio->mask_shadow) { > + at91_gpio->mask_shadow = mask; > + __raw_writel(~mask, pio + PIO_OWDR); > + __raw_writel(mask, pio + PIO_OWER); > + } > + __raw_writel(val, pio + PIO_ODSR); > +} > + > static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) > { > int i;