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Diffstat (limited to 'drivers/serial/of_serial.c')
-rw-r--r--drivers/serial/of_serial.c143
1 files changed, 143 insertions, 0 deletions
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");