tty: serial8250: allow platforms to override irq handler
Some ports (e.g. Synopsys DesignWare 8250) have special requirements for
handling the interrupts. Allow these platforms to specify their own
interrupt handler that will override the default.
serial8250_handle_irq() is provided so that platforms can extend the IRQ
handler rather than completely replacing it.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index f2dfec8..833e011 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -509,6 +509,8 @@
outb(value, p->iobase + offset);
}
+static int serial8250_default_handle_irq(struct uart_port *port);
+
static void set_io_from_upio(struct uart_port *p)
{
struct uart_8250_port *up =
@@ -557,6 +559,7 @@
}
/* Remember loaded iotype */
up->cur_iotype = p->iotype;
+ p->handle_irq = serial8250_default_handle_irq;
}
static void
@@ -1621,6 +1624,28 @@
spin_unlock_irqrestore(&up->port.lock, flags);
}
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
+{
+ struct uart_8250_port *up =
+ container_of(port, struct uart_8250_port, port);
+
+ if (!(iir & UART_IIR_NO_INT)) {
+ serial8250_handle_port(up);
+ return 1;
+ }
+
+ return 0;
+}
+
+static int serial8250_default_handle_irq(struct uart_port *port)
+{
+ struct uart_8250_port *up =
+ container_of(port, struct uart_8250_port, port);
+ unsigned int iir = serial_in(up, UART_IIR);
+
+ return serial8250_handle_irq(port, iir);
+}
+
/*
* This is the serial driver's interrupt routine.
*
@@ -1648,13 +1673,12 @@
l = i->head;
do {
struct uart_8250_port *up;
- unsigned int iir;
+ struct uart_port *port;
up = list_entry(l, struct uart_8250_port, list);
+ port = &up->port;
- iir = serial_in(up, UART_IIR);
- if (!(iir & UART_IIR_NO_INT)) {
- serial8250_handle_port(up);
+ if (port->handle_irq(port)) {
handled = 1;
@@ -3048,6 +3072,10 @@
p->serial_in = port->serial_in;
if (port->serial_out)
p->serial_out = port->serial_out;
+ if (port->handle_irq)
+ p->handle_irq = port->handle_irq;
+ else
+ p->handle_irq = serial8250_default_handle_irq;
return 0;
}
@@ -3116,6 +3144,7 @@
port.type = p->type;
port.serial_in = p->serial_in;
port.serial_out = p->serial_out;
+ port.handle_irq = p->handle_irq;
port.set_termios = p->set_termios;
port.pm = p->pm;
port.dev = &dev->dev;
@@ -3281,6 +3310,8 @@
uart->port.serial_in = port->serial_in;
if (port->serial_out)
uart->port.serial_out = port->serial_out;
+ if (port->handle_irq)
+ uart->port.handle_irq = port->handle_irq;
/* Possibly override set_termios call */
if (port->set_termios)
uart->port.set_termios = port->set_termios;
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 97f5b45..1f05bbe 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -35,6 +35,7 @@
void (*set_termios)(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
+ int (*handle_irq)(struct uart_port *);
void (*pm)(struct uart_port *, unsigned int state,
unsigned old);
};
@@ -80,6 +81,7 @@
struct ktermios *termios, struct ktermios *old);
extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate);
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
extern void serial8250_set_isa_configurator(void (*v)
(int port, struct uart_port *up,