From patchwork Tue Dec 4 20:39:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roland Stigge X-Patchwork-Id: 1839491 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 394553FC64 for ; Tue, 4 Dec 2012 20:44:09 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TfzIO-00038k-LB; Tue, 04 Dec 2012 20:40:48 +0000 Received: from mail.work-microwave.de ([62.245.205.51] helo=work-microwave.de) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TfzI1-00033m-40 for linux-arm-kernel@lists.infradead.org; Tue, 04 Dec 2012 20:40:30 +0000 Received: from rst-pc1.lan.work-microwave.de ([192.168.11.78]) (authenticated bits=0) by mail.work-microwave.de with ESMTP id qB4KeHei027103 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 4 Dec 2012 21:40:18 +0100 Received: by rst-pc1.lan.work-microwave.de (Postfix, from userid 1000) id 1ADEDAE0F4; Tue, 4 Dec 2012 21:40:17 +0100 (CET) From: Roland Stigge To: gregkh@linuxfoundation.org, grant.likely@secretlab.ca, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, w.sang@pengutronix.de, jbe@pengutronix.de, plagnioj@jcrosoft.com, highguy@gmail.com, broonie@opensource.wolfsonmicro.com, daniel-gl@gmx.net, rmallon@gmail.com, tru@work-microwave.de, sr@denx.de, wg@grandegger.com Subject: [PATCH 2/6 v9] gpio: Add sysfs support to block GPIO API Date: Tue, 4 Dec 2012 21:39:44 +0100 Message-Id: <1354653588-4018-3-git-send-email-stigge@antcom.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1354653588-4018-1-git-send-email-stigge@antcom.de> References: <1354653588-4018-1-git-send-email-stigge@antcom.de> X-FEAS-SYSTEM-WL: rst@work-microwave.de, 192.168.11.78 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121204_154026_419278_A43DD494 X-CRM114-Status: GOOD ( 19.96 ) 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 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Roland Stigge 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: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This patch adds sysfs support to the block GPIO API. Signed-off-by: Roland Stigge --- Documentation/ABI/testing/sysfs-gpio | 20 ++ drivers/gpio/gpiolib.c | 250 ++++++++++++++++++++++++++++++++++- include/asm-generic/gpio.h | 11 + include/linux/gpio.h | 15 ++ 4 files changed, 295 insertions(+), 1 deletion(-) --- linux-2.6.orig/Documentation/ABI/testing/sysfs-gpio +++ linux-2.6/Documentation/ABI/testing/sysfs-gpio @@ -25,3 +25,23 @@ Description: /label ... (r/o) descriptive, not necessarily unique /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1) +What: /sys/class/gpioblock/ +Date: October 2012 +KernelVersion: 3.7 +Contact: Roland Stigge +Description: + + Block GPIO devices are visible in sysfs as soon as they are registered + (e.g. via devicetree definition). For actual I/O use, their "exported" + boolean attribute must be set to "1". Then, the attribute "values" is + created and at the same time, the GPIOs in the block are requested for + exclusive use by sysfs. + + /sys/class/gpioblock + /BLOCKNAME ... for each GPIO block name + /ngpio ... (r/o) number of GPIOs in this group + /exported ... sysfs export state of this group (0, 1) + /value ... current value as 32 or 64 bit integer in hex + (only available if /exported is 1) + /mask ... current mask as 32 or 64 bit integer in hex + (only available if /exported is 1) --- linux-2.6.orig/drivers/gpio/gpiolib.c +++ linux-2.6/drivers/gpio/gpiolib.c @@ -198,7 +198,8 @@ static bool gpio_block_is_output(struct int i; for (i = 0; i < block->ngpio; i++) - if (!test_bit(FLAG_IS_OUT, &gpio_desc[block->gpio[i]].flags)) + if ((block->cur_mask & BIT(i)) && + !test_bit(FLAG_IS_OUT, &gpio_desc[block->gpio[i]].flags)) return false; return true; } @@ -984,6 +985,238 @@ static void gpiochip_unexport(struct gpi chip->label, status); } +static ssize_t gpio_block_ngpio_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_block *block = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", block->ngpio); +} + +static ssize_t gpio_block_value_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_block *block = dev_get_drvdata(dev); + + return sprintf(buf, sizeof(unsigned long) == 4 ? "0x%08lx\n" : + "0x%016lx\n", gpio_block_get(block, block->cur_mask)); +} + +static ssize_t gpio_block_value_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + ssize_t status; + struct gpio_block *block = dev_get_drvdata(dev); + unsigned long value; + + status = kstrtoul(buf, 0, &value); + if (status == 0) { + mutex_lock(&sysfs_lock); + if (gpio_block_is_output(block)) { + gpio_block_set(block, block->cur_mask, value); + status = size; + } else { + status = -EPERM; + } + mutex_unlock(&sysfs_lock); + } + return status; +} + +static struct device_attribute +dev_attr_block_value = __ATTR(value, S_IWUSR | S_IRUGO, gpio_block_value_show, + gpio_block_value_store); + +static ssize_t gpio_block_mask_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_block *block = dev_get_drvdata(dev); + + return sprintf(buf, sizeof(unsigned long) == 4 ? "0x%08lx\n" : + "0x%016lx\n", block->cur_mask); +} + +static ssize_t gpio_block_mask_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + ssize_t status; + struct gpio_block *block = dev_get_drvdata(dev); + unsigned long mask; + + status = kstrtoul(buf, 0, &mask); + if (status == 0) + block->cur_mask = mask; + return status; +} + +static struct device_attribute +dev_attr_block_mask = __ATTR(mask, S_IWUSR | S_IRUGO, gpio_block_mask_show, + gpio_block_mask_store); + +static struct class gpio_block_class; + +static int gpio_block_value_is_exported(struct gpio_block *block) +{ + struct device *dev; + struct sysfs_dirent *sd = NULL; + + mutex_lock(&sysfs_lock); + dev = class_find_device(&gpio_block_class, NULL, block, match_export); + if (!dev) + goto out; + + sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); + +out: + mutex_unlock(&sysfs_lock); + return !!sd; +} + +static ssize_t gpio_block_exported_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct gpio_block *block = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", gpio_block_value_is_exported(block)); +} + +static int gpio_block_value_export(struct gpio_block *block) +{ + struct device *dev; + int status; + int i; + + mutex_lock(&sysfs_lock); + + for (i = 0; i < block->ngpio; i++) { + status = gpio_request(block->gpio[i], "sysfs"); + if (status) + goto out1; + } + + dev = class_find_device(&gpio_block_class, NULL, block, match_export); + if (!dev) { + status = -ENODEV; + goto out1; + } + + status = device_create_file(dev, &dev_attr_block_value); + if (status) + goto out1; + + status = device_create_file(dev, &dev_attr_block_mask); + if (status) + goto out2; + + mutex_unlock(&sysfs_lock); + return 0; + +out2: + device_remove_file(dev, &dev_attr_block_value); +out1: + while (--i >= 0) + gpio_free(block->gpio[i]); + + mutex_unlock(&sysfs_lock); + return status; +} + +static int gpio_block_value_unexport(struct gpio_block *block) +{ + struct device *dev; + int i; + + dev = class_find_device(&gpio_block_class, NULL, block, match_export); + if (!dev) + return -ENODEV; + + for (i = 0; i < block->ngpio; i++) + gpio_free(block->gpio[i]); + + device_remove_file(dev, &dev_attr_block_value); + device_remove_file(dev, &dev_attr_block_mask); + + return 0; +} + +static ssize_t gpio_block_exported_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + long value; + int status; + struct gpio_block *block = dev_get_drvdata(dev); + int exported = gpio_block_value_is_exported(block); + + status = kstrtoul(buf, 0, &value); + if (status < 0) + goto err; + + if (value != exported) { + if (value) + status = gpio_block_value_export(block); + else + status = gpio_block_value_unexport(block); + if (!status) + status = size; + } else { + status = size; + } +err: + return status; +} + +static struct device_attribute gpio_block_attrs[] = { + __ATTR(exported, S_IWUSR | S_IRUGO, gpio_block_exported_show, + gpio_block_exported_store), + __ATTR(ngpio, S_IRUGO, gpio_block_ngpio_show, NULL), + __ATTR_NULL, +}; + +static struct class gpio_block_class = { + .name = "gpioblock", + .owner = THIS_MODULE, + + .dev_attrs = gpio_block_attrs, +}; + +int gpio_block_export(struct gpio_block *block) +{ + int status = 0; + struct device *dev; + + /* can't export until sysfs is available ... */ + if (!gpio_block_class.p) { + pr_debug("%s: called too early!\n", __func__); + return -ENOENT; + } + + mutex_lock(&sysfs_lock); + dev = device_create(&gpio_block_class, NULL, MKDEV(0, 0), block, + block->name); + if (IS_ERR(dev)) + status = PTR_ERR(dev); + mutex_unlock(&sysfs_lock); + + return status; +} +EXPORT_SYMBOL_GPL(gpio_block_export); + +void gpio_block_unexport(struct gpio_block *block) +{ + struct device *dev; + + mutex_lock(&sysfs_lock); + dev = class_find_device(&gpio_block_class, NULL, block, match_export); + if (dev) + device_unregister(dev); + mutex_unlock(&sysfs_lock); +} +EXPORT_SYMBOL_GPL(gpio_block_unexport); + static int __init gpiolib_sysfs_init(void) { int status; @@ -994,6 +1227,10 @@ static int __init gpiolib_sysfs_init(voi if (status < 0) return status; + status = class_register(&gpio_block_class); + if (status < 0) + return status; + /* Scan and register the gpio_chips which registered very * early (e.g. before the class_register above was called). * @@ -1724,6 +1961,7 @@ struct gpio_block *gpio_block_create(uns block->name = name; block->ngpio = size; + block->cur_mask = ~0; INIT_LIST_HEAD(&block->gbc_list); block->gpio = kzalloc(sizeof(*block->gpio) * size, GFP_KERNEL); if (!block->gpio) @@ -1886,12 +2124,21 @@ EXPORT_SYMBOL_GPL(gpio_block_find_by_nam int gpio_block_register(struct gpio_block *block) { + int ret; + if (gpio_block_find_by_name(block->name)) return -EBUSY; list_add(&block->list, &gpio_block_list); + ret = gpio_block_export(block); + if (ret) + goto err1; + return 0; +err1: + list_del(&block->list); + return ret; } EXPORT_SYMBOL_GPL(gpio_block_register); @@ -1902,6 +2149,7 @@ void gpio_block_unregister(struct gpio_b list_for_each_entry(i, &gpio_block_list, list) if (i == block) { list_del(&i->list); + gpio_block_unexport(block); break; } } --- linux-2.6.orig/include/asm-generic/gpio.h +++ linux-2.6/include/asm-generic/gpio.h @@ -213,6 +213,8 @@ extern int gpio_export_link(struct devic unsigned gpio); extern int gpio_sysfs_set_active_low(unsigned gpio, int value); extern void gpio_unexport(unsigned gpio); +extern int gpio_block_export(struct gpio_block *block); +extern void gpio_block_unexport(struct gpio_block *block); #endif /* CONFIG_GPIO_SYSFS */ @@ -272,6 +274,15 @@ static inline int gpio_sysfs_set_active_ static inline void gpio_unexport(unsigned gpio) { } + +static inline int gpio_block_export(struct gpio_block *block) +{ + return -ENOSYS; +} + +static inline void gpio_block_unexport(struct gpio_block *block) +{ +} #endif /* CONFIG_GPIO_SYSFS */ #endif /* _ASM_GENERIC_GPIO_H */ --- linux-2.6.orig/include/linux/gpio.h +++ linux-2.6/include/linux/gpio.h @@ -88,6 +88,7 @@ struct gpio_block_chip { * @ngpio: number of gpios in this block * @gpio: list of gpios in this block * @list: global list of blocks, maintained by gpiolib + * @cur_mask: currently used gpio mask used by userspace API */ struct gpio_block { struct list_head gbc_list; @@ -97,6 +98,7 @@ struct gpio_block { unsigned *gpio; struct list_head list; + unsigned long cur_mask; }; #ifdef CONFIG_GENERIC_GPIO @@ -314,6 +316,19 @@ static inline void gpio_unexport(unsigne WARN_ON(1); } +static inline int gpio_block_export(struct gpio_block *block) +{ + /* GPIO block can never have been requested or set as {in,out}put */ + WARN_ON(1); + return -EINVAL; +} + +static inline void gpio_block_unexport(struct gpio_block *block) +{ + /* GPIO block can never have been exported */ + WARN_ON(1); +} + static inline int gpio_to_irq(unsigned gpio) { /* GPIO can never have been requested or set as input */