add character driver fops struct + implementation

1 files changed, 28 insertions, 0 deletions

diff --git a/1/fopdrv.c b/1/fopdrv.c
new file mode 100644
index 0000000..31c76cd
--- /dev/null
+++ b/1/fopdrv.c
@@ -0,0 +1,28 @@
+#include "fopdrv.h"
+
+// driver/char/mem.c read_null (/dev/null)
+ssize_t fop_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) {
+	return 0;
+}
+
+// driver/char/mem.c write_null
+ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) {
+	return count;
+}
+
+int fop_open(struct inode * inode, struct file * file) {
+	printk("%s\n", __PRETTY_FUNCTION__);
+	return 0;
+	// 0 seems to be a safe return value as it's used in driver/char/mem.c. The
+	// manual page for open(2) says that the system call returns a nonnegative
+	// integer representing the file descriptor on success, but it does not
+	// appears to be required.
+}
+
+int fop_release(struct inode * inode, struct file * file) {
+	printk("%s\n", __PRETTY_FUNCTION__);
+	return 0;
+	// same as above, but found in driver/char/lp.c
+}
+
+