From patchwork Mon Dec 17 19:47:31 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfgang Grandegger X-Patchwork-Id: 1888691 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 206CC3FCD5 for ; Mon, 17 Dec 2012 19:50:44 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TkgfL-00021t-IL; Mon, 17 Dec 2012 19:47:55 +0000 Received: from ngcobalt02.manitu.net ([217.11.48.102]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TkgfH-00021A-4F for linux-arm-kernel@lists.infradead.org; Mon, 17 Dec 2012 19:47:52 +0000 Received: from [10.0.30.2] (p4FE63A6B.dip.t-dialin.net [79.230.58.107]) (authenticated as wg with PLAIN) by ngcobalt02.manitu.net (8.10.2/8.10.2) with ESMTP id qBHJlX401226; Mon, 17 Dec 2012 20:47:33 +0100 X-manitu-Original-Sender-IP: 79.230.58.107 X-manitu-Original-Receiver-Name: ngcobalt02.manitu.net Message-ID: <50CF76D3.9030708@grandegger.com> Date: Mon, 17 Dec 2012 20:47:31 +0100 From: Wolfgang Grandegger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Roland Stigge 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> In-Reply-To: <50CF5E45.5030104@antcom.de> X-Enigmail-Version: 1.4.6 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121217_144752_150287_F99C00A3 X-CRM114-Status: GOOD ( 17.98 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [217.11.48.102 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: rmallon@gmail.com, gregkh@linuxfoundation.org, linus.walleij@linaro.org, broonie@opensource.wolfsonmicro.com, linux-kernel@vger.kernel.org, w.sang@pengutronix.de, grant.likely@secretlab.ca, daniel-gl@gmx.net, sr@denx.de, plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org, highguy@gmail.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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: 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;