From patchwork Fri Mar 29 02:41:15 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 2361771 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by patchwork2.kernel.org (Postfix) with ESMTP id 4629FDF2A1 for ; Fri, 29 Mar 2013 02:51:10 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [IPv6:::1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 8C3CEBD0; Fri, 29 Mar 2013 02:46:23 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 15E3BCAA for ; Fri, 29 Mar 2013 02:46:11 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 0FB461FCA3 for ; Fri, 29 Mar 2013 02:46:03 +0000 (UTC) Received: from ayumi.akashicho.tokyo.vergenet.net (p8120-ipbfp1001kobeminato.hyogo.ocn.ne.jp [118.10.137.120]) by kirsty.vergenet.net (Postfix) with ESMTP id C464E2C6A1B; Fri, 29 Mar 2013 13:45:41 +1100 (EST) Received: by ayumi.akashicho.tokyo.vergenet.net (Postfix, from userid 7100) id 60DC5EDE139; Fri, 29 Mar 2013 11:45:40 +0900 (JST) From: Simon Horman To: ltsi-dev@lists.linuxfoundation.org Date: Fri, 29 Mar 2013 11:41:15 +0900 Message-Id: <1364525119-31791-147-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1364525119-31791-1-git-send-email-horms+renesas@verge.net.au> References: <1364525119-31791-1-git-send-email-horms+renesas@verge.net.au> X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Magnus Damm Subject: [LTSI-dev] [PATCH/RFC 146/390] gpiolib: add gpio get direction callback support X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org From: Mathias Nyman Add .get_direction callback to gpio_chip. This allows gpiolib to check the current direction of a gpio. Used to show the correct gpio direction in sysfs and debug entries. If callback is not set then gpiolib will work as previously; e.g. guessing everything is input until a direction is set. Signed-off-by: Mathias Nyman Signed-off-by: Linus Walleij (cherry picked from commit 80b0a6029272247f19146bf8f88e5d4bba94cba5) Signed-off-by: Simon Horman --- drivers/gpio/gpiolib.c | 38 +++++++++++++++++++++++++++++++++++++- include/asm-generic/gpio.h | 5 ++++- 2 files changed, 41 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6fa60df..4f17768 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -191,6 +191,32 @@ err: return ret; } +/* caller ensures gpio is valid and requested, chip->get_direction may sleep */ +static int gpio_get_direction(unsigned gpio) +{ + struct gpio_chip *chip; + struct gpio_desc *desc = &gpio_desc[gpio]; + int status = -EINVAL; + + chip = gpio_to_chip(gpio); + gpio -= chip->base; + + if (!chip->get_direction) + return status; + + status = chip->get_direction(chip, gpio); + if (status > 0) { + /* GPIOF_DIR_IN, or other positive */ + status = 1; + clear_bit(FLAG_IS_OUT, &desc->flags); + } + if (status == 0) { + /* GPIOF_DIR_OUT */ + set_bit(FLAG_IS_OUT, &desc->flags); + } + return status; +} + #ifdef CONFIG_GPIO_SYSFS /* lock protects against unexport_gpio() being called while @@ -223,6 +249,7 @@ static ssize_t gpio_direction_show(struct device *dev, struct device_attribute *attr, char *buf) { const struct gpio_desc *desc = dev_get_drvdata(dev); + unsigned gpio = desc - gpio_desc; ssize_t status; mutex_lock(&sysfs_lock); @@ -230,6 +257,7 @@ static ssize_t gpio_direction_show(struct device *dev, if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; else + gpio_get_direction(gpio); status = sprintf(buf, "%s\n", test_bit(FLAG_IS_OUT, &desc->flags) ? "out" : "in"); @@ -1082,6 +1110,7 @@ int gpiochip_add(struct gpio_chip *chip) * inputs (often with pullups enabled) so power * usage is minimized. Linux code should set the * gpio direction first thing; but until it does, + * and in case chip->get_direction is not set, * we may expose the wrong direction in sysfs. */ gpio_desc[id].flags = !chip->direction_input @@ -1235,9 +1264,15 @@ int gpio_request(unsigned gpio, const char *label) desc_set_label(desc, NULL); module_put(chip->owner); clear_bit(FLAG_REQUESTED, &desc->flags); + goto done; } } - + if (chip->get_direction) { + /* chip->get_direction may sleep */ + spin_unlock_irqrestore(&gpio_lock, flags); + gpio_get_direction(gpio); + spin_lock_irqsave(&gpio_lock, flags); + } done: if (status) pr_debug("gpio_request: gpio-%d (%s) status %d\n", @@ -1773,6 +1808,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) continue; + gpio_get_direction(gpio); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", gpio, gdesc->label, diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index a9432fc..eb70ca2 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -56,6 +56,8 @@ struct device_node; * enabling module power and clock; may sleep * @free: optional hook for chip-specific deactivation, such as * disabling module power and clock; may sleep + * @get_direction: returns direction for signal "offset", 0=out, 1=in, + * (same as GPIOF_DIR_XXX), or negative error * @direction_input: configures signal "offset" as input, or returns error * @get: returns value for signal "offset"; for output signals this * returns either the value actually sensed, or zero @@ -100,7 +102,8 @@ struct gpio_chip { unsigned offset); void (*free)(struct gpio_chip *chip, unsigned offset); - + int (*get_direction)(struct gpio_chip *chip, + unsigned offset); int (*direction_input)(struct gpio_chip *chip, unsigned offset); int (*get)(struct gpio_chip *chip,