8250.c: support specifying DW APB UARTs in device platform_data

Allow the private_data field to be specified in platform_data for the
standard 8250/16550 UART.  This field is used by DW APB type UARTs and
without this patch it's only possible to set this field when registering
the port by hand.  If private_data is not set then the driver will
potentially oops with a NULL pointer dereference.

Signed-off-by: Will Newton <will.newton@gmail.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 22 insertions, 19 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index f94109cbb46e..c93ef205aa2f 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2662,16 +2662,17 @@ static int __devinit serial8250_probe(struct platform_device *dev)
         memset(&port, 0, sizeof(struct uart_port));
 
         for (i = 0; p && p->flags != 0; p++, i++) {
-                port.iobase     = p->iobase;
-                port.membase    = p->membase;
-                port.irq        = p->irq;
-                port.uartclk    = p->uartclk;
-                port.regshift   = p->regshift;
-                port.iotype     = p->iotype;
-                port.flags      = p->flags;
-                port.mapbase    = p->mapbase;
-                port.hub6       = p->hub6;
-                port.dev        = &dev->dev;
+                port.iobase             = p->iobase;
+                port.membase            = p->membase;
+                port.irq                = p->irq;
+                port.uartclk            = p->uartclk;
+                port.regshift           = p->regshift;
+                port.iotype             = p->iotype;
+                port.flags              = p->flags;
+                port.mapbase            = p->mapbase;
+                port.hub6               = p->hub6;
+                port.private_data       = p->private_data;
+                port.dev                = &dev->dev;
                 if (share_irqs)
                         port.flags |= UPF_SHARE_IRQ;
                 ret = serial8250_register_port(&port);
@@ -2812,15 +2813,16 @@ int serial8250_register_port(struct uart_port *port)
         if (uart) {
                 uart_remove_one_port(&serial8250_reg, &uart->port);
 
-                uart->port.iobase   = port->iobase;
-                uart->port.membase  = port->membase;
-                uart->port.irq      = port->irq;
-                uart->port.uartclk  = port->uartclk;
-                uart->port.fifosize = port->fifosize;
-                uart->port.regshift = port->regshift;
-                uart->port.iotype   = port->iotype;
-                uart->port.flags    = port->flags | UPF_BOOT_AUTOCONF;
-                uart->port.mapbase  = port->mapbase;
+                uart->port.iobase       = port->iobase;
+                uart->port.membase      = port->membase;
+                uart->port.irq          = port->irq;
+                uart->port.uartclk      = port->uartclk;
+                uart->port.fifosize     = port->fifosize;
+                uart->port.regshift     = port->regshift;
+                uart->port.iotype       = port->iotype;
+                uart->port.flags        = port->flags | UPF_BOOT_AUTOCONF;
+                uart->port.mapbase      = port->mapbase;
+                uart->port.private_data = port->private_data;
                 if (port->dev)
                         uart->port.dev = port->dev;
 
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index afe0f6d9b9bc..00b65c0a82ca 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -23,6 +23,7 @@ struct plat_serial8250_port {
         resource_size_t mapbase;        /* resource base */
         unsigned int    irq;            /* interrupt number */
         unsigned int    uartclk;        /* UART clock rate */
+        void            *private_data;
         unsigned char   regshift;       /* register shift */
         unsigned char   iotype;         /* UPIO_* */
         unsigned char   hub6;