fsi: Fix panic on scom file read

Reading the scom file without the custom open method (i2cr_scom_open)
causes a kernel panic. This change replaces simple_open with i2cr_scom_open
to properly initialize the private_data field in the file structure,
preventing the panic during scom file operations.

Fixes: c0b34bed ("fsi: Add I2C Responder SCOM driver")
Signed-off-by: Lakshmi Yadlapati <lakshmiy@us.ibm.com>
Reviewed-by: Ninad Palsule <ninad@linux.ibm.com>
Link: https://lore.kernel.org/r/20231214000744.1281464-1-lakshmiy@us.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>

drivers/fsi/i2cr-scom.c

@@ -73,9 +73,18 @@ static ssize_t i2cr_scom_write(struct file *filep, const char __user *buf, size_
 	return len;
 }
 
+static int i2cr_scom_open(struct inode *inode, struct file *file)
+{
+	struct i2cr_scom *scom = container_of(inode->i_cdev, struct i2cr_scom, cdev);
+
+	file->private_data = scom;
+
+	return 0;
+}
+
 static const struct file_operations i2cr_scom_fops = {
 	.owner		= THIS_MODULE,
-	.open		= simple_open,
+	.open		= i2cr_scom_open,
 	.llseek		= i2cr_scom_llseek,
 	.read		= i2cr_scom_read,
 	.write		= i2cr_scom_write,