Arnd Bergmann | 8d38a5b | 2007-02-13 21:35:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Serial Port driver for Open Firmware platform devices |
| 3 | * |
| 4 | * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | */ |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/serial_core.h> |
| 15 | #include <linux/serial_8250.h> |
| 16 | |
| 17 | #include <asm/of_platform.h> |
| 18 | #include <asm/prom.h> |
| 19 | |
| 20 | /* |
| 21 | * Fill a struct uart_port for a given device node |
| 22 | */ |
| 23 | static int __devinit of_platform_serial_setup(struct of_device *ofdev, |
| 24 | int type, struct uart_port *port) |
| 25 | { |
| 26 | struct resource resource; |
| 27 | struct device_node *np = ofdev->node; |
| 28 | const unsigned int *clk, *spd; |
| 29 | int ret; |
| 30 | |
| 31 | memset(port, 0, sizeof *port); |
Stephen Rothwell | 40cd3a4 | 2007-05-01 13:54:02 +1000 | [diff] [blame] | 32 | spd = of_get_property(np, "current-speed", NULL); |
| 33 | clk = of_get_property(np, "clock-frequency", NULL); |
Arnd Bergmann | 8d38a5b | 2007-02-13 21:35:38 +0100 | [diff] [blame] | 34 | if (!clk) { |
| 35 | dev_warn(&ofdev->dev, "no clock-frequency property set\n"); |
| 36 | return -ENODEV; |
| 37 | } |
| 38 | |
| 39 | ret = of_address_to_resource(np, 0, &resource); |
| 40 | if (ret) { |
| 41 | dev_warn(&ofdev->dev, "invalid address\n"); |
| 42 | return ret; |
| 43 | } |
| 44 | |
| 45 | spin_lock_init(&port->lock); |
| 46 | port->mapbase = resource.start; |
| 47 | port->irq = irq_of_parse_and_map(np, 0); |
| 48 | port->iotype = UPIO_MEM; |
| 49 | port->type = type; |
| 50 | port->uartclk = *clk; |
David Gibson | abb4a23 | 2007-05-06 14:48:49 -0700 | [diff] [blame] | 51 | port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP |
| 52 | | UPF_FIXED_PORT; |
Arnd Bergmann | 8d38a5b | 2007-02-13 21:35:38 +0100 | [diff] [blame] | 53 | port->dev = &ofdev->dev; |
| 54 | port->custom_divisor = *clk / (16 * (*spd)); |
| 55 | |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Try to register a serial port |
| 61 | */ |
| 62 | static int __devinit of_platform_serial_probe(struct of_device *ofdev, |
| 63 | const struct of_device_id *id) |
| 64 | { |
| 65 | struct uart_port port; |
| 66 | int port_type; |
| 67 | int ret; |
| 68 | |
| 69 | if (of_find_property(ofdev->node, "used-by-rtas", NULL)) |
| 70 | return -EBUSY; |
| 71 | |
| 72 | port_type = (unsigned long)id->data; |
| 73 | ret = of_platform_serial_setup(ofdev, port_type, &port); |
| 74 | if (ret) |
| 75 | goto out; |
| 76 | |
| 77 | switch (port_type) { |
Arnd Bergmann | 8d38a5b | 2007-02-13 21:35:38 +0100 | [diff] [blame] | 78 | case PORT_8250 ... PORT_MAX_8250: |
| 79 | ret = serial8250_register_port(&port); |
| 80 | break; |
| 81 | default: |
| 82 | /* need to add code for these */ |
Ishizaki Kou | 1558f9b | 2007-05-31 19:30:33 +1000 | [diff] [blame^] | 83 | case PORT_UNKNOWN: |
| 84 | dev_info(&ofdev->dev, "Unknown serial port found, ignored\n"); |
Arnd Bergmann | 8d38a5b | 2007-02-13 21:35:38 +0100 | [diff] [blame] | 85 | ret = -ENODEV; |
| 86 | break; |
| 87 | } |
| 88 | if (ret < 0) |
| 89 | goto out; |
| 90 | |
| 91 | ofdev->dev.driver_data = (void *)(unsigned long)ret; |
| 92 | return 0; |
| 93 | out: |
| 94 | irq_dispose_mapping(port.irq); |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Release a line |
| 100 | */ |
| 101 | static int of_platform_serial_remove(struct of_device *ofdev) |
| 102 | { |
| 103 | int line = (unsigned long)ofdev->dev.driver_data; |
| 104 | serial8250_unregister_port(line); |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * A few common types, add more as needed. |
| 110 | */ |
| 111 | static struct of_device_id __devinitdata of_platform_serial_table[] = { |
| 112 | { .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, }, |
| 113 | { .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, }, |
| 114 | { .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, }, |
| 115 | { .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, }, |
| 116 | { .type = "serial", .data = (void *)PORT_UNKNOWN, }, |
| 117 | { /* end of list */ }, |
| 118 | }; |
| 119 | |
| 120 | static struct of_platform_driver __devinitdata of_platform_serial_driver = { |
| 121 | .owner = THIS_MODULE, |
| 122 | .name = "of_serial", |
| 123 | .probe = of_platform_serial_probe, |
| 124 | .remove = of_platform_serial_remove, |
| 125 | .match_table = of_platform_serial_table, |
| 126 | }; |
| 127 | |
| 128 | static int __init of_platform_serial_init(void) |
| 129 | { |
| 130 | return of_register_platform_driver(&of_platform_serial_driver); |
| 131 | } |
| 132 | module_init(of_platform_serial_init); |
| 133 | |
| 134 | static void __exit of_platform_serial_exit(void) |
| 135 | { |
| 136 | return of_unregister_platform_driver(&of_platform_serial_driver); |
| 137 | }; |
| 138 | module_exit(of_platform_serial_exit); |
| 139 | |
| 140 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); |
| 141 | MODULE_LICENSE("GPL"); |
| 142 | MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices"); |