145 lines
3.7 KiB
C
145 lines
3.7 KiB
C
/*
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* Serial Port driver for Open Firmware platform devices
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*
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* Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/serial_core.h>
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#include <linux/serial_8250.h>
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#include <asm/of_platform.h>
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#include <asm/prom.h>
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/*
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* Fill a struct uart_port for a given device node
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*/
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static int __devinit of_platform_serial_setup(struct of_device *ofdev,
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int type, struct uart_port *port)
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{
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struct resource resource;
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struct device_node *np = ofdev->node;
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const unsigned int *clk, *spd;
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int ret;
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memset(port, 0, sizeof *port);
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spd = of_get_property(np, "current-speed", NULL);
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clk = of_get_property(np, "clock-frequency", NULL);
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if (!clk) {
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dev_warn(&ofdev->dev, "no clock-frequency property set\n");
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return -ENODEV;
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}
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ret = of_address_to_resource(np, 0, &resource);
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if (ret) {
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dev_warn(&ofdev->dev, "invalid address\n");
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return ret;
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}
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spin_lock_init(&port->lock);
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port->mapbase = resource.start;
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port->irq = irq_of_parse_and_map(np, 0);
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port->iotype = UPIO_MEM;
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port->type = type;
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port->uartclk = *clk;
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port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
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| UPF_FIXED_PORT;
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port->dev = &ofdev->dev;
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port->custom_divisor = *clk / (16 * (*spd));
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return 0;
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}
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/*
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* Try to register a serial port
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*/
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static int __devinit of_platform_serial_probe(struct of_device *ofdev,
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const struct of_device_id *id)
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{
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struct uart_port port;
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int port_type;
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int ret;
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if (of_find_property(ofdev->node, "used-by-rtas", NULL))
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return -EBUSY;
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port_type = (unsigned long)id->data;
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ret = of_platform_serial_setup(ofdev, port_type, &port);
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if (ret)
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goto out;
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switch (port_type) {
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case PORT_UNKNOWN:
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dev_info(&ofdev->dev, "Unknown serial port found, "
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"attempting to use 8250 driver\n");
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/* fallthrough */
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case PORT_8250 ... PORT_MAX_8250:
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ret = serial8250_register_port(&port);
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break;
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default:
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/* need to add code for these */
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ret = -ENODEV;
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break;
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}
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if (ret < 0)
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goto out;
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ofdev->dev.driver_data = (void *)(unsigned long)ret;
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return 0;
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out:
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irq_dispose_mapping(port.irq);
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return ret;
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}
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/*
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* Release a line
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*/
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static int of_platform_serial_remove(struct of_device *ofdev)
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{
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int line = (unsigned long)ofdev->dev.driver_data;
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serial8250_unregister_port(line);
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return 0;
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}
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/*
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* A few common types, add more as needed.
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*/
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static struct of_device_id __devinitdata of_platform_serial_table[] = {
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{ .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, },
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{ .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, },
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{ .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, },
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{ .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, },
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{ .type = "serial", .data = (void *)PORT_UNKNOWN, },
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{ /* end of list */ },
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};
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static struct of_platform_driver __devinitdata of_platform_serial_driver = {
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.owner = THIS_MODULE,
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.name = "of_serial",
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.probe = of_platform_serial_probe,
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.remove = of_platform_serial_remove,
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.match_table = of_platform_serial_table,
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};
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static int __init of_platform_serial_init(void)
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{
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return of_register_platform_driver(&of_platform_serial_driver);
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}
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module_init(of_platform_serial_init);
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static void __exit of_platform_serial_exit(void)
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{
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return of_unregister_platform_driver(&of_platform_serial_driver);
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};
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module_exit(of_platform_serial_exit);
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MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");
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