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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 | ||
e34b9c94 IK |
20 | struct of_serial_info { |
21 | int type; | |
22 | int line; | |
23 | }; | |
24 | ||
8d38a5b2 AB |
25 | /* |
26 | * Fill a struct uart_port for a given device node | |
27 | */ | |
28 | static int __devinit of_platform_serial_setup(struct of_device *ofdev, | |
29 | int type, struct uart_port *port) | |
30 | { | |
31 | struct resource resource; | |
32 | struct device_node *np = ofdev->node; | |
33 | const unsigned int *clk, *spd; | |
34 | int ret; | |
35 | ||
36 | memset(port, 0, sizeof *port); | |
40cd3a45 SR |
37 | spd = of_get_property(np, "current-speed", NULL); |
38 | clk = of_get_property(np, "clock-frequency", NULL); | |
8d38a5b2 AB |
39 | if (!clk) { |
40 | dev_warn(&ofdev->dev, "no clock-frequency property set\n"); | |
41 | return -ENODEV; | |
42 | } | |
43 | ||
44 | ret = of_address_to_resource(np, 0, &resource); | |
45 | if (ret) { | |
46 | dev_warn(&ofdev->dev, "invalid address\n"); | |
47 | return ret; | |
48 | } | |
49 | ||
50 | spin_lock_init(&port->lock); | |
51 | port->mapbase = resource.start; | |
52 | port->irq = irq_of_parse_and_map(np, 0); | |
53 | port->iotype = UPIO_MEM; | |
54 | port->type = type; | |
55 | port->uartclk = *clk; | |
abb4a239 DG |
56 | port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP |
57 | | UPF_FIXED_PORT; | |
8d38a5b2 AB |
58 | port->dev = &ofdev->dev; |
59 | port->custom_divisor = *clk / (16 * (*spd)); | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | /* | |
65 | * Try to register a serial port | |
66 | */ | |
67 | static int __devinit of_platform_serial_probe(struct of_device *ofdev, | |
68 | const struct of_device_id *id) | |
69 | { | |
e34b9c94 | 70 | struct of_serial_info *info; |
8d38a5b2 AB |
71 | struct uart_port port; |
72 | int port_type; | |
73 | int ret; | |
74 | ||
75 | if (of_find_property(ofdev->node, "used-by-rtas", NULL)) | |
76 | return -EBUSY; | |
77 | ||
e34b9c94 IK |
78 | info = kmalloc(sizeof(*info), GFP_KERNEL); |
79 | if (info == NULL) | |
80 | return -ENOMEM; | |
81 | ||
8d38a5b2 AB |
82 | port_type = (unsigned long)id->data; |
83 | ret = of_platform_serial_setup(ofdev, port_type, &port); | |
84 | if (ret) | |
85 | goto out; | |
86 | ||
87 | switch (port_type) { | |
8d38a5b2 AB |
88 | case PORT_8250 ... PORT_MAX_8250: |
89 | ret = serial8250_register_port(&port); | |
90 | break; | |
91 | default: | |
92 | /* need to add code for these */ | |
1558f9b4 IK |
93 | case PORT_UNKNOWN: |
94 | dev_info(&ofdev->dev, "Unknown serial port found, ignored\n"); | |
8d38a5b2 AB |
95 | ret = -ENODEV; |
96 | break; | |
97 | } | |
98 | if (ret < 0) | |
99 | goto out; | |
100 | ||
e34b9c94 IK |
101 | info->type = port_type; |
102 | info->line = ret; | |
103 | ofdev->dev.driver_data = info; | |
8d38a5b2 AB |
104 | return 0; |
105 | out: | |
e34b9c94 | 106 | kfree(info); |
8d38a5b2 AB |
107 | irq_dispose_mapping(port.irq); |
108 | return ret; | |
109 | } | |
110 | ||
111 | /* | |
112 | * Release a line | |
113 | */ | |
114 | static int of_platform_serial_remove(struct of_device *ofdev) | |
115 | { | |
e34b9c94 IK |
116 | struct of_serial_info *info = ofdev->dev.driver_data; |
117 | switch (info->type) { | |
118 | case PORT_8250 ... PORT_MAX_8250: | |
119 | serial8250_unregister_port(info->line); | |
120 | break; | |
121 | default: | |
122 | /* need to add code for these */ | |
123 | break; | |
124 | } | |
125 | kfree(info); | |
8d38a5b2 AB |
126 | return 0; |
127 | } | |
128 | ||
129 | /* | |
130 | * A few common types, add more as needed. | |
131 | */ | |
132 | static struct of_device_id __devinitdata of_platform_serial_table[] = { | |
133 | { .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, }, | |
134 | { .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, }, | |
135 | { .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, }, | |
136 | { .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, }, | |
137 | { .type = "serial", .data = (void *)PORT_UNKNOWN, }, | |
138 | { /* end of list */ }, | |
139 | }; | |
140 | ||
e84290dc | 141 | static struct of_platform_driver of_platform_serial_driver = { |
8d38a5b2 AB |
142 | .owner = THIS_MODULE, |
143 | .name = "of_serial", | |
144 | .probe = of_platform_serial_probe, | |
145 | .remove = of_platform_serial_remove, | |
146 | .match_table = of_platform_serial_table, | |
147 | }; | |
148 | ||
149 | static int __init of_platform_serial_init(void) | |
150 | { | |
151 | return of_register_platform_driver(&of_platform_serial_driver); | |
152 | } | |
153 | module_init(of_platform_serial_init); | |
154 | ||
155 | static void __exit of_platform_serial_exit(void) | |
156 | { | |
157 | return of_unregister_platform_driver(&of_platform_serial_driver); | |
158 | }; | |
159 | module_exit(of_platform_serial_exit); | |
160 | ||
161 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); | |
162 | MODULE_LICENSE("GPL"); | |
163 | MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices"); |