From 583d28e92f667eb6cc81ea87daaa7e321c23fe14 Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Mon, 15 Aug 2011 10:17:52 +0100 Subject: [PATCH] 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 Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- 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 f2dfec82faf8..833e011a426f 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 97f5b45bbc07..1f05bbeac01e 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,