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8d38a5b2 AB |
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); | |
32 | spd = get_property(np, "current-speed", NULL); | |
33 | clk = get_property(np, "clock-frequency", NULL); | |
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; | |
51 | port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP; | |
52 | port->dev = &ofdev->dev; | |
53 | port->custom_divisor = *clk / (16 * (*spd)); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | /* | |
59 | * Try to register a serial port | |
60 | */ | |
61 | static int __devinit of_platform_serial_probe(struct of_device *ofdev, | |
62 | const struct of_device_id *id) | |
63 | { | |
64 | struct uart_port port; | |
65 | int port_type; | |
66 | int ret; | |
67 | ||
68 | if (of_find_property(ofdev->node, "used-by-rtas", NULL)) | |
69 | return -EBUSY; | |
70 | ||
71 | port_type = (unsigned long)id->data; | |
72 | ret = of_platform_serial_setup(ofdev, port_type, &port); | |
73 | if (ret) | |
74 | goto out; | |
75 | ||
76 | switch (port_type) { | |
77 | case PORT_UNKNOWN: | |
78 | dev_info(&ofdev->dev, "Unknown serial port found, " | |
79 | "attempting to use 8250 driver\n"); | |
80 | /* fallthrough */ | |
81 | case PORT_8250 ... PORT_MAX_8250: | |
82 | ret = serial8250_register_port(&port); | |
83 | break; | |
84 | default: | |
85 | /* need to add code for these */ | |
86 | ret = -ENODEV; | |
87 | break; | |
88 | } | |
89 | if (ret < 0) | |
90 | goto out; | |
91 | ||
92 | ofdev->dev.driver_data = (void *)(unsigned long)ret; | |
93 | return 0; | |
94 | out: | |
95 | irq_dispose_mapping(port.irq); | |
96 | return ret; | |
97 | } | |
98 | ||
99 | /* | |
100 | * Release a line | |
101 | */ | |
102 | static int of_platform_serial_remove(struct of_device *ofdev) | |
103 | { | |
104 | int line = (unsigned long)ofdev->dev.driver_data; | |
105 | serial8250_unregister_port(line); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | /* | |
110 | * A few common types, add more as needed. | |
111 | */ | |
112 | static struct of_device_id __devinitdata of_platform_serial_table[] = { | |
113 | { .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, }, | |
114 | { .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, }, | |
115 | { .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, }, | |
116 | { .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, }, | |
117 | { .type = "serial", .data = (void *)PORT_UNKNOWN, }, | |
118 | { /* end of list */ }, | |
119 | }; | |
120 | ||
121 | static struct of_platform_driver __devinitdata of_platform_serial_driver = { | |
122 | .owner = THIS_MODULE, | |
123 | .name = "of_serial", | |
124 | .probe = of_platform_serial_probe, | |
125 | .remove = of_platform_serial_remove, | |
126 | .match_table = of_platform_serial_table, | |
127 | }; | |
128 | ||
129 | static int __init of_platform_serial_init(void) | |
130 | { | |
131 | return of_register_platform_driver(&of_platform_serial_driver); | |
132 | } | |
133 | module_init(of_platform_serial_init); | |
134 | ||
135 | static void __exit of_platform_serial_exit(void) | |
136 | { | |
137 | return of_unregister_platform_driver(&of_platform_serial_driver); | |
138 | }; | |
139 | module_exit(of_platform_serial_exit); | |
140 | ||
141 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); | |
142 | MODULE_LICENSE("GPL"); | |
143 | MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices"); |