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Shorten sample code

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This commit is contained in:
Jim Huang 2021-07-22 10:55:14 +08:00
parent 52dfb6744d
commit 1c93f2f5ef
1 changed files with 3 additions and 13 deletions
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16
examples/chardev2.c
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@ -43,9 +43,7 @@ static struct class *cls;
*/
static int device_open(struct inode *inode, struct file *file)
{
#ifdef DEBUG
pr_info("device_open(%p)\n", file);
#endif
/*
* We don't want to talk to two processes at the same time
@ -64,9 +62,7 @@ static int device_open(struct inode *inode, struct file *file)
static int device_release(struct inode *inode, struct file *file)
{
#ifdef DEBUG
pr_info("device_release(%p,%p)\n", inode, file);
#endif
/*
* We're now ready for our next caller
@ -92,9 +88,7 @@ static ssize_t device_read(struct file *file, /* see include/linux/fs.h */
*/
int bytes_read = 0;
#ifdef DEBUG
pr_info("device_read(%p,%p,%d)\n", file, buffer, length);
#endif
pr_info("device_read(%p,%p,%ld)\n", file, buffer, length);
/*
* If we're at the end of the message, return 0
@ -119,9 +113,7 @@ static ssize_t device_read(struct file *file, /* see include/linux/fs.h */
bytes_read++;
}
#ifdef DEBUG
pr_info("Read %d bytes, %d left\n", bytes_read, length);
#endif
pr_info("Read %d bytes, %ld left\n", bytes_read, length);
/*
* Read functions are supposed to return the number
@ -141,9 +133,7 @@ static ssize_t device_write(struct file *file,
{
int i;
#ifdef DEBUG
pr_info("device_write(%p,%s,%d)", file, buffer, length);
#endif
pr_info("device_write(%p,%s,%ld)", file, buffer, length);
for (i = 0; i < length && i < BUF_LEN; i++)
get_user(Message[i], buffer + i);