Re: [PATCH 21/23] gpio: mockup: provide a way to delete dummy chips
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2020-09-04 16:56:59
Also in:
linux-acpi, linux-gpio, lkml
On Fri, Sep 04, 2020 at 05:45:45PM +0200, Bartosz Golaszewski wrote:
quoted hunk ↗ jump to hunk
From: Bartosz Golaszewski <redacted> 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 <redacted> --- 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);
Why not list_for_each_entry()?
+ 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-- With Best Regards, Andy Shevchenko