serial: 8250: Separate legacy irq handling from core port operations

Prepare for 8250 split; decouple irq setup/teardown and handler from
core port operations.

Introduce setup_irq() and release_irq() 8250 driver methods; the 8250
core will use these methods to install and remove irq handling for
the given 8250 port.

Refactor irq chain linking/unlinking from 8250 core into
univ8250_setup_irq()/univ8250_release_irq() for the universal 8250 driver.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ca9f87beac63..50735a9ad598 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -60,6 +60,20 @@ enum {
 };
 
 struct uart_8250_dma;
+struct uart_8250_port;
+
+/**
+ * 8250 core driver operations
+ *
+ * @setup_irq()		Setup irq handling. The universal 8250 driver links this
+ *			port to the irq chain. Other drivers may @request_irq().
+ * @release_irq()	Undo irq handling. The universal 8250 driver unlinks
+ *			the port from the irq chain.
+ */
+struct uart_8250_ops {
+	int		(*setup_irq)(struct uart_8250_port *);
+	void		(*release_irq)(struct uart_8250_port *);
+};
 
 /*
  * This should be used by drivers which want to register
@@ -100,6 +114,7 @@ struct uart_8250_port {
 	unsigned char		msr_saved_flags;
 
 	struct uart_8250_dma	*dma;
+	const struct uart_8250_ops *ops;
 
 	/* 8250 specific callbacks */
 	int			(*dl_read)(struct uart_8250_port *);