From 6a4b6b0a3b55f23f4cc9ad85a1539c581bcb0874 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 4 May 2015 17:10:31 +0200 Subject: [PATCH] gpio: sysfs: clean up chip class-device handling Clean gpio-chip class device registration and deregistration. The class device is registered when a gpio-chip is added (or from gpiolib_sysfs_init post-core init call), and deregistered when the chip is removed. Store the class device in struct gpio_chip directly rather than do a class-device lookup on deregistration. This also removes the need for the exported flag. Signed-off-by: Johan Hovold Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-sysfs.c | 39 ++++++++++++------------------------ include/linux/gpio/driver.h | 4 ++-- 2 files changed, 15 insertions(+), 28 deletions(-) diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index d19bf234e878..767b79adb9a4 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -582,7 +582,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) mutex_lock(&sysfs_lock); /* check if chip is being removed */ - if (!chip || !chip->exported) { + if (!chip || !chip->cdev) { status = -ENODEV; goto fail_unlock; } @@ -767,7 +767,6 @@ EXPORT_SYMBOL_GPL(gpiod_unexport); int gpiochip_export(struct gpio_chip *chip) { - int status; struct device *dev; /* Many systems register gpio chips for SOC support very early, @@ -783,41 +782,29 @@ int gpiochip_export(struct gpio_chip *chip) chip, gpiochip_groups, "gpiochip%d", chip->base); if (IS_ERR(dev)) - status = PTR_ERR(dev); - else - status = 0; + return PTR_ERR(dev); mutex_lock(&sysfs_lock); - chip->exported = (status == 0); + chip->cdev = dev; mutex_unlock(&sysfs_lock); - if (status) - chip_dbg(chip, "%s: status %d\n", __func__, status); - - return status; + return 0; } void gpiochip_unexport(struct gpio_chip *chip) { - int status; - struct device *dev; struct gpio_desc *desc; unsigned int i; - dev = class_find_device(&gpio_class, NULL, chip, match_export); - if (dev) { - put_device(dev); - device_unregister(dev); - /* prevent further gpiod exports */ - mutex_lock(&sysfs_lock); - chip->exported = false; - mutex_unlock(&sysfs_lock); - status = 0; - } else - status = -ENODEV; + if (!chip->cdev) + return; - if (status) - chip_dbg(chip, "%s: status %d\n", __func__, status); + device_unregister(chip->cdev); + + /* prevent further gpiod exports */ + mutex_lock(&sysfs_lock); + chip->cdev = NULL; + mutex_unlock(&sysfs_lock); /* unregister gpiod class devices owned by sysfs */ for (i = 0; i < chip->ngpio; i++) { @@ -845,7 +832,7 @@ static int __init gpiolib_sysfs_init(void) */ spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(chip, &gpio_chips, list) { - if (chip->exported) + if (chip->cdev) continue; /* diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index f1b36593ec9f..2c1e639f66bd 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -20,6 +20,7 @@ struct seq_file; * struct gpio_chip - abstract a GPIO controller * @label: for diagnostics * @dev: optional device providing the GPIOs + * @cdev: class device used by sysfs interface (may be NULL) * @owner: helps prevent removal of modules exporting active GPIOs * @list: links gpio_chips together for traversal * @request: optional hook for chip-specific activation, such as @@ -57,7 +58,6 @@ struct seq_file; * implies that if the chip supports IRQs, these IRQs need to be threaded * as the chip access may sleep when e.g. reading out the IRQ status * registers. - * @exported: flags if the gpiochip is exported for use from sysfs. Private. * @irq_not_threaded: flag must be set if @can_sleep is set but the * IRQs don't need to be threaded * @@ -74,6 +74,7 @@ struct seq_file; struct gpio_chip { const char *label; struct device *dev; + struct device *cdev; struct module *owner; struct list_head list; @@ -109,7 +110,6 @@ struct gpio_chip { const char *const *names; bool can_sleep; bool irq_not_threaded; - bool exported; #ifdef CONFIG_GPIOLIB_IRQCHIP /* -- 2.30.2