From ff2b1359229927563addbf2f5ad480660c350903 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 20 Oct 2015 11:10:38 +0200 Subject: gpio: make the gpiochip a real device GPIO chips have been around for years, but were never real devices, instead they were piggy-backing on a parent device (such as a platform_device or amba_device) but this was always optional. GPIO chips could also exist without any device at all, with its struct device *parent (ex *dev) pointer being set to null. When sysfs was in use, a mock device would be created, with the optional parent assigned, or just floating orphaned with NULL as parent. If sysfs is active, it will use this device as parent. We now create a gpio_device struct containing a real struct device and move the subsystem over to using that. The list of struct gpio_chip:s is augmented to hold struct gpio_device:s and we find gpio_chips:s by first looking up the struct gpio_device. The struct gpio_device is designed to stay around even if the gpio_chip is removed, so as to satisfy users in userspace that need a backing data structure to hold the state of the session initiated with e.g. a character device even if there is no physical chip anymore. From this point on, gpiochips are devices. Cc: Johan Hovold Cc: Michael Welling Cc: Markus Pargmann Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-sysfs.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/gpio/gpiolib-sysfs.c') diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 405dfcaadc4c..28d3bf2328aa 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -547,6 +547,7 @@ static struct class gpio_class = { int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { struct gpio_chip *chip; + struct gpio_device *gdev; struct gpiod_data *data; unsigned long flags; int status; @@ -566,6 +567,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) } chip = desc->chip; + gdev = chip->gpiodev; mutex_lock(&sysfs_lock); @@ -605,7 +607,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) if (chip->names && chip->names[offset]) ioname = chip->names[offset]; - dev = device_create_with_groups(&gpio_class, chip->parent, + dev = device_create_with_groups(&gpio_class, &gdev->dev, MKDEV(0, 0), data, gpio_groups, ioname ? ioname : "gpio%u", desc_to_gpio(desc)); @@ -771,7 +773,7 @@ static int __init gpiolib_sysfs_init(void) { int status; unsigned long flags; - struct gpio_chip *chip; + struct gpio_device *gdev; status = class_register(&gpio_class); if (status < 0) @@ -784,8 +786,8 @@ static int __init gpiolib_sysfs_init(void) * registered, and so arch_initcall() can always gpio_export(). */ spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) { - if (chip->cdev) + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->chip->cdev) continue; /* @@ -798,7 +800,7 @@ static int __init gpiolib_sysfs_init(void) * gpio_lock prevents us from doing this. */ spin_unlock_irqrestore(&gpio_lock, flags); - status = gpiochip_sysfs_register(chip); + status = gpiochip_sysfs_register(gdev->chip); spin_lock_irqsave(&gpio_lock, flags); } spin_unlock_irqrestore(&gpio_lock, flags); -- cgit v1.2.3