/* * 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");