serial: 8250: add IRQ trigger support

There is currently no provision for passing IRQ trigger flags for
serial IRQs with triggering requirements (such as GPIO IRQs)

This patch adds irqflags to plat_serial8250_port that can be passed
from board file to reqest_irq() of 8250 driver

Changes are backward compatible with boards passing UPF_SHARE_IRQ flag

Tested on Zoom2 board that has IRQF_TRIGGER_RISING requirement for 8250 irq

[Moved new flag to end to fix bugs in the original with the old_serial array
	-- Alan]

Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 12 insertions, 5 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index fb867a9f55e9..83168a6c3c05 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1677,7 +1677,7 @@ static int serial_link_irq_chain(struct uart_8250_port *up)
                 INIT_LIST_HEAD(&up->list);
                 i->head = &up->list;
                 spin_unlock_irq(&i->lock);
-
+                irq_flags |= up->port.irqflags;
                 ret = request_irq(up->port.irq, serial8250_interrupt,
                                   irq_flags, "serial", i);
                 if (ret < 0)
@@ -2026,7 +2026,7 @@ static int serial8250_startup(struct uart_port *port)
                  * allow register changes to become visible.
                  */
                 spin_lock_irqsave(&up->port.lock, flags);
-                if (up->port.flags & UPF_SHARE_IRQ)
+                if (up->port.irqflags & IRQF_SHARED)
                         disable_irq_nosync(up->port.irq);
 
                 wait_for_xmitr(up, UART_LSR_THRE);
@@ -2039,7 +2039,7 @@ static int serial8250_startup(struct uart_port *port)
                 iir = serial_in(up, UART_IIR);
                 serial_out(up, UART_IER, 0);
 
-                if (up->port.flags & UPF_SHARE_IRQ)
+                if (up->port.irqflags & IRQF_SHARED)
                         enable_irq(up->port.irq);
                 spin_unlock_irqrestore(&up->port.lock, flags);
 
@@ -2671,6 +2671,7 @@ static void __init serial8250_isa_init_ports(void)
              i++, up++) {
                 up->port.iobase   = old_serial_port[i].port;
                 up->port.irq      = irq_canonicalize(old_serial_port[i].irq);
+                up->port.irqflags = old_serial_port[i].irqflags;
                 up->port.uartclk  = old_serial_port[i].baud_base * 16;
                 up->port.flags    = old_serial_port[i].flags;
                 up->port.hub6     = old_serial_port[i].hub6;
@@ -2679,7 +2680,7 @@ static void __init serial8250_isa_init_ports(void)
                 up->port.regshift = old_serial_port[i].iomem_reg_shift;
                 set_io_from_upio(&up->port);
                 if (share_irqs)
-                        up->port.flags |= UPF_SHARE_IRQ;
+                        up->port.irqflags |= IRQF_SHARED;
         }
 }
 
@@ -2869,6 +2870,7 @@ int __init early_serial_setup(struct uart_port *port)
         p->iobase       = port->iobase;
         p->membase      = port->membase;
         p->irq          = port->irq;
+        p->irqflags     = port->irqflags;
         p->uartclk      = port->uartclk;
         p->fifosize     = port->fifosize;
         p->regshift     = port->regshift;
@@ -2942,6 +2944,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
                 port.iobase             = p->iobase;
                 port.membase            = p->membase;
                 port.irq                = p->irq;
+                port.irqflags           = p->irqflags;
                 port.uartclk            = p->uartclk;
                 port.regshift           = p->regshift;
                 port.iotype             = p->iotype;
@@ -2954,7 +2957,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
                 port.serial_out         = p->serial_out;
                 port.dev                = &dev->dev;
                 if (share_irqs)
-                        port.flags |= UPF_SHARE_IRQ;
+                        port.irqflags |= IRQF_SHARED;
                 ret = serial8250_register_port(&port);
                 if (ret < 0) {
                         dev_err(&dev->dev, "unable to register port at index %d "
@@ -3096,6 +3099,7 @@ int serial8250_register_port(struct uart_port *port)
                 uart->port.iobase       = port->iobase;
                 uart->port.membase      = port->membase;
                 uart->port.irq          = port->irq;
+                uart->port.irqflags     = port->irqflags;
                 uart->port.uartclk      = port->uartclk;
                 uart->port.fifosize     = port->fifosize;
                 uart->port.regshift     = port->regshift;
diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
index 520260326f3d..6e19ea3e48d5 100644
--- a/drivers/serial/8250.h
+++ b/drivers/serial/8250.h
@@ -25,6 +25,7 @@ struct old_serial_port {
         unsigned char io_type;
         unsigned char *iomem_base;
         unsigned short iomem_reg_shift;
+        unsigned long irqflags;
 };
 
 /*
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index d4d2a78ad43e..fb46aba11fb5 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -22,6 +22,7 @@ struct plat_serial8250_port {
         void __iomem    *membase;       /* ioremap cookie or NULL */
         resource_size_t mapbase;        /* resource base */
         unsigned int    irq;            /* interrupt number */
+        unsigned long   irqflags;       /* request_irq flags */
         unsigned int    uartclk;        /* UART clock rate */
         void            *private_data;
         unsigned char   regshift;       /* register shift */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 23d2fb051f97..3cd255f0b211 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -265,6 +265,7 @@ struct uart_port {
         unsigned int            (*serial_in)(struct uart_port *, int);
         void                    (*serial_out)(struct uart_port *, int, int);
         unsigned int            irq;                    /* irq number */
+        unsigned long           irqflags;               /* irq flags  */
         unsigned int            uartclk;                /* base uart clock */
         unsigned int            fifosize;               /* tx fifo size */
         unsigned char           x_char;                 /* xon/xoff char */