From: Bartosz Golaszewski <[email protected]> Add a new debugfs attribute 'delete_device' to which the chip label can be written to dynamically remove the associated dummy device.
Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/gpio/gpio-mockup.c | 70 +++++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 1353239dc315..9d2de78a45c2 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -19,6 +19,7 @@ #include <linux/platform_device.h> #include <linux/property.h> #include <linux/slab.h> +#include <linux/string.h> #include <linux/string_helpers.h> #include <linux/uaccess.h> @@ -668,14 +669,81 @@ static int __init gpio_mockup_register_chips_from_params(void) return 0; } -static int __init gpio_mockup_init(void) +static ssize_t gpio_mockup_debugfs_delete_device_write(struct file *file, + const char __user *usr_buf, + size_t size, loff_t *ppos) { + struct gpio_mockup_device *mockup_dev; + char label[GPIO_MOCKUP_LABEL_SIZE]; + struct list_head *curr; + struct device *dev; + const char *prop; int ret; + if (*ppos != 0) + return -EINVAL; + + ret = getline_from_user(label, sizeof(label), usr_buf, size); + if (ret < 0) + return ret; + + mutex_lock(&gpio_mockup_devices_lock); + + list_for_each(curr, &gpio_mockup_devices) { + mockup_dev = list_entry(curr, struct gpio_mockup_device, list); + dev = &mockup_dev->pdev->dev; + + ret = device_property_read_string(dev, "chip-label", &prop); + if (ret) { + mutex_unlock(&gpio_mockup_devices_lock); + return ret; + } + + if (sysfs_streq(label, prop)) { + gpio_mockup_unregister_one_device(mockup_dev); + mutex_unlock(&gpio_mockup_devices_lock); + return size; + } + } + + mutex_unlock(&gpio_mockup_devices_lock); + return -ENODEV; +} + +static const struct file_operations gpio_mockup_debugfs_delete_device_ops = { + .owner = THIS_MODULE, + .open = gpio_mockup_debugfs_open, + .write = gpio_mockup_debugfs_delete_device_write, + .llseek = no_llseek, + .release = single_release, +}; + +static int __init gpio_mockup_debugfs_init(void) +{ + struct dentry *entry; + gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL); if (IS_ERR(gpio_mockup_dbg_dir)) return PTR_ERR(gpio_mockup_dbg_dir); + entry = debugfs_create_file("delete_device", 0200, gpio_mockup_dbg_dir, + NULL, &gpio_mockup_debugfs_delete_device_ops); + if (IS_ERR(entry)) { + debugfs_remove_recursive(gpio_mockup_dbg_dir); + return PTR_ERR(entry); + } + + return 0; +} + +static int __init gpio_mockup_init(void) +{ + int ret; + + ret = gpio_mockup_debugfs_init(); + if (ret) + return ret; + ret = platform_driver_register(&gpio_mockup_driver); if (ret) { pr_err("error registering platform driver\n"); -- 2.26.1
