sparc64: vcc: Add chars_in_buffer TTY operation

Add handler to support TTY chars_in_buffer operation

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
index 0c0fe22..070c541 100644 (file)
--- a/drivers/tty/vcc.c
+++ b/drivers/tty/vcc.c
@@ -937,12 +937,36 @@ static int vcc_write_room(struct tty_struct *tty)
        return num;
 }
 
+static int vcc_chars_in_buffer(struct tty_struct *tty)
+{
+       struct vcc_port *port;
+       u64 num;
+
+       if (unlikely(!tty)) {
+               pr_err("VCC: chars_in_buffer: Invalid TTY handle\n");
+               return -ENXIO;
+       }
+
+       port = vcc_get_ne(tty->index);
+       if (unlikely(!port)) {
+               pr_err("VCC: chars_in_buffer: Failed to find VCC port\n");
+               return -ENODEV;
+       }
+
+       num = port->chars_in_buffer;
+
+       vcc_put(port, false);
+
+       return num;
+}
+
 static const struct tty_operations vcc_ops = {
-       .open           = vcc_open,
-       .close          = vcc_close,
-       .hangup         = vcc_hangup,
-       .write          = vcc_write,
-       .write_room     = vcc_write_room,
+       .open                   = vcc_open,
+       .close                  = vcc_close,
+       .hangup                 = vcc_hangup,
+       .write                  = vcc_write,
+       .write_room             = vcc_write_room,
+       .chars_in_buffer        = vcc_chars_in_buffer,
 };
 
 #define VCC_TTY_FLAGS   (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)