Hi,
I am testing out the platform driver and would like to know the
template for platform device register/unregister.
The following code causes a crash whenever the device gets unregistered.
---
#include linux/init.h
#include linux/kernel.h
#include linux/module.h
#include linux/module.h
#include linux/platform_device.h
#include linux/device.h
struct test_platform_data {
int x;
int y;
};
static struct test_platform_data test_pd = {
.x = 2,
.y = 3,
};
static struct platform_device test_platform_device = {
.name = test-plat,
.id = -1,
.resource = NULL,
.num_resources = 0,
.dev = {
.platform_data = test_pd,
}
};
static int __init platform_driver_test_init(void) {
int retval = 0;
printk(KERN_ALERT Platform driver init\n);
retval = platform_device_register(test_platform_device);
if(retval != 0) {
printk(KERN_ALERT Could not register platform device\n);
return retval;
} else {
printk(KERN_ALERT Registered platform device\n);
printk(KERN_ALERT Unregistering\n);
platform_device_unregister(test_platform_device);
}
return 0;
}
static void __exit platform_driver_test_exit(void) {
printk(KERN_ALERT Platform driver exit\n);
}
module_init(platform_driver_test_init);
module_exit(platform_driver_test_exit);
MODULE_LICENSE(GPL);
MODULE_AUTHOR(TEST);
MODULE_DESCRIPTION(Platform driver test);
---
Should the platform device be created using platform_device_alloc(..)
and added using platform_device_add(..) like the below code?
#include linux/init.h
#include linux/kernel.h
#include linux/module.h
#include linux/module.h
#include linux/platform_device.h
#include linux/device.h
struct test_platform_data {
int x;
int y;
};
static struct test_platform_data test_pd = {
.x = 2,
.y = 3,
};
static struct platform_device *test_platform_device;
static int __init platform_driver_test_init(void) {
int retval = 0;
printk(KERN_ALERT Platform driver init\n);
test_platform_device = platform_device_alloc(test-plat,-1);
if(test_platform_device == NULL) {
printk(KERN_ALERT Could not allocate platform device\n);
return 0;
}
platform_device_add_data(test_platform_device,test_pd,sizeof(test_pd));
retval = platform_device_add(test_platform_device);
if(retval != 0) {
printk(KERN_ALERT Could not register platform device\n);
return retval;
} else {
printk(KERN_ALERT Registered platform device\n);
printk(KERN_ALERT Unregistering\n);
platform_device_unregister(test_platform_device);
}
return 0;
}
static void __exit platform_driver_test_exit(void) {
printk(KERN_ALERT Platform driver exit\n);
}
module_init(platform_driver_test_init);
module_exit(platform_driver_test_exit);
MODULE_LICENSE(GPL);
MODULE_AUTHOR(TEST);
MODULE_DESCRIPTION(Platform driver test);
Thanks,
Gautam.
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