3 files changed, 154 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 5cc6b91f8408..d0edbaacb1f7 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -999,4 +999,14 @@ config SERIAL_NETX_CONSOLE
           If you have enabled the serial port on the Motorola IMX
           CPU you can make it the console by answering Y to this option.
 
+config SERIAL_OF_PLATFORM
+        tristate "Serial port on Open Firmware platform bus"
+        depends on PPC_OF
+        depends on SERIAL_8250
+        help
+          If you have a PowerPC based system that has serial ports
+          on a platform specific bus, you should enable this option.
+          Currently, only 8250 compatible ports are supported, but
+          others can easily be added.
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index df3632cd7df9..f3f82587b5fa 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o
 obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
 obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
new file mode 100644
index 000000000000..09b0b736a751
--- /dev/null
+++ b/drivers/serial/of_serial.c
@@ -0,0 +1,143 @@
+/*
+ *  Serial Port driver for Open Firmware platform devices
+ *
+ *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/serial_8250.h>
+
+#include <asm/of_platform.h>
+#include <asm/prom.h>
+
+/*
+ * Fill a struct uart_port for a given device node
+ */
+static int __devinit of_platform_serial_setup(struct of_device *ofdev,
+                                        int type, struct uart_port *port)
+{
+        struct resource resource;
+        struct device_node *np = ofdev->node;
+        const unsigned int *clk, *spd;
+        int ret;
+
+        memset(port, 0, sizeof *port);
+        spd = get_property(np, "current-speed", NULL);
+        clk = get_property(np, "clock-frequency", NULL);
+        if (!clk) {
+                dev_warn(&ofdev->dev, "no clock-frequency property set\n");
+                return -ENODEV;
+        }
+
+        ret = of_address_to_resource(np, 0, &resource);
+        if (ret) {
+                dev_warn(&ofdev->dev, "invalid address\n");
+                return ret;
+        }
+
+        spin_lock_init(&port->lock);
+        port->mapbase = resource.start;
+        port->irq = irq_of_parse_and_map(np, 0);
+        port->iotype = UPIO_MEM;
+        port->type = type;
+        port->uartclk = *clk;
+        port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+        port->dev = &ofdev->dev;
+        port->custom_divisor = *clk / (16 * (*spd));
+
+        return 0;
+}
+
+/*
+ * Try to register a serial port
+ */
+static int __devinit of_platform_serial_probe(struct of_device *ofdev,
+                                                const struct of_device_id *id)
+{
+        struct uart_port port;
+        int port_type;
+        int ret;
+
+        if (of_find_property(ofdev->node, "used-by-rtas", NULL))
+                return -EBUSY;
+
+        port_type = (unsigned long)id->data;
+        ret = of_platform_serial_setup(ofdev, port_type, &port);
+        if (ret)
+                goto out;
+
+        switch (port_type) {
+        case PORT_UNKNOWN:
+                dev_info(&ofdev->dev, "Unknown serial port found, "
+                        "attempting to use 8250 driver\n");
+                /* fallthrough */
+        case PORT_8250 ... PORT_MAX_8250:
+                ret = serial8250_register_port(&port);
+                break;
+        default:
+                /* need to add code for these */
+                ret = -ENODEV;
+                break;
+        }
+        if (ret < 0)
+                goto out;
+
+        ofdev->dev.driver_data = (void *)(unsigned long)ret;
+        return 0;
+out:
+        irq_dispose_mapping(port.irq);
+        return ret;
+}
+
+/*
+ * Release a line
+ */
+static int of_platform_serial_remove(struct of_device *ofdev)
+{
+        int line = (unsigned long)ofdev->dev.driver_data;
+        serial8250_unregister_port(line);
+        return 0;
+}
+
+/*
+ * A few common types, add more as needed.
+ */
+static struct of_device_id __devinitdata of_platform_serial_table[] = {
+        { .type = "serial", .compatible = "ns8250",   .data = (void *)PORT_8250, },
+        { .type = "serial", .compatible = "ns16450",  .data = (void *)PORT_16450, },
+        { .type = "serial", .compatible = "ns16550",  .data = (void *)PORT_16550, },
+        { .type = "serial", .compatible = "ns16750",  .data = (void *)PORT_16750, },
+        { .type = "serial",                           .data = (void *)PORT_UNKNOWN, },
+        { /* end of list */ },
+};
+
+static struct of_platform_driver __devinitdata of_platform_serial_driver = {
+        .owner = THIS_MODULE,
+        .name = "of_serial",
+        .probe = of_platform_serial_probe,
+        .remove = of_platform_serial_remove,
+        .match_table = of_platform_serial_table,
+};
+
+static int __init of_platform_serial_init(void)
+{
+        return of_register_platform_driver(&of_platform_serial_driver);
+}
+module_init(of_platform_serial_init);
+
+static void __exit of_platform_serial_exit(void)
+{
+        return of_unregister_platform_driver(&of_platform_serial_driver);
+};
+module_exit(of_platform_serial_exit);
+
+MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");