From: Jamie Iles <jamie@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Acked-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/tty/serial/8250.c | 39 +++++++++++++++++++++++++++++++++++----
include/linux/serial_8250.h | 2 ++
2 files changed, 37 insertions(+), 4 deletions(-)
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 @@ static void io_serial_out(struct uart_port *p, int offset, int value)
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 @@ static void set_io_from_upio(struct uart_port *p)
}
/* Remember loaded iotype */
up->cur_iotype = p->iotype;
+ p->handle_irq = serial8250_default_handle_irq;
}
static void
@@ -1621,6 +1624,28 @@ static void serial8250_handle_port(struct uart_8250_port *up)
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 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
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 @@ int __init early_serial_setup(struct uart_port *port)
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 @@ static int __devinit serial8250_probe(struct platform_device *dev)
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 @@ int serial8250_register_port(struct uart_port *port)
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 @@ struct plat_serial8250_port {
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 @@ extern void serial8250_do_set_termios(struct uart_port *port,
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,
--
1.7.7
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