Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jk/spufs
[linux-2.6] / drivers / serial / of_serial.c
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 struct of_serial_info {
21         int type;
22         int line;
23 };
24
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);
37         spd = of_get_property(np, "current-speed", NULL);
38         clk = of_get_property(np, "clock-frequency", NULL);
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;
56         port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
57                 | UPF_FIXED_PORT;
58         port->dev = &ofdev->dev;
59         /* If current-speed was set, then try not to change it. */
60         if (spd)
61                 port->custom_divisor = *clk / (16 * (*spd));
62
63         return 0;
64 }
65
66 /*
67  * Try to register a serial port
68  */
69 static int __devinit of_platform_serial_probe(struct of_device *ofdev,
70                                                 const struct of_device_id *id)
71 {
72         struct of_serial_info *info;
73         struct uart_port port;
74         int port_type;
75         int ret;
76
77         if (of_find_property(ofdev->node, "used-by-rtas", NULL))
78                 return -EBUSY;
79
80         info = kmalloc(sizeof(*info), GFP_KERNEL);
81         if (info == NULL)
82                 return -ENOMEM;
83
84         port_type = (unsigned long)id->data;
85         ret = of_platform_serial_setup(ofdev, port_type, &port);
86         if (ret)
87                 goto out;
88
89         switch (port_type) {
90         case PORT_8250 ... PORT_MAX_8250:
91                 ret = serial8250_register_port(&port);
92                 break;
93         default:
94                 /* need to add code for these */
95         case PORT_UNKNOWN:
96                 dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
97                 ret = -ENODEV;
98                 break;
99         }
100         if (ret < 0)
101                 goto out;
102
103         info->type = port_type;
104         info->line = ret;
105         ofdev->dev.driver_data = info;
106         return 0;
107 out:
108         kfree(info);
109         irq_dispose_mapping(port.irq);
110         return ret;
111 }
112
113 /*
114  * Release a line
115  */
116 static int of_platform_serial_remove(struct of_device *ofdev)
117 {
118         struct of_serial_info *info = ofdev->dev.driver_data;
119         switch (info->type) {
120         case PORT_8250 ... PORT_MAX_8250:
121                 serial8250_unregister_port(info->line);
122                 break;
123         default:
124                 /* need to add code for these */
125                 break;
126         }
127         kfree(info);
128         return 0;
129 }
130
131 /*
132  * A few common types, add more as needed.
133  */
134 static struct of_device_id __devinitdata of_platform_serial_table[] = {
135         { .type = "serial", .compatible = "ns8250",   .data = (void *)PORT_8250, },
136         { .type = "serial", .compatible = "ns16450",  .data = (void *)PORT_16450, },
137         { .type = "serial", .compatible = "ns16550",  .data = (void *)PORT_16550, },
138         { .type = "serial", .compatible = "ns16750",  .data = (void *)PORT_16750, },
139         { .type = "serial",                           .data = (void *)PORT_UNKNOWN, },
140         { /* end of list */ },
141 };
142
143 static struct of_platform_driver of_platform_serial_driver = {
144         .owner = THIS_MODULE,
145         .name = "of_serial",
146         .probe = of_platform_serial_probe,
147         .remove = of_platform_serial_remove,
148         .match_table = of_platform_serial_table,
149 };
150
151 static int __init of_platform_serial_init(void)
152 {
153         return of_register_platform_driver(&of_platform_serial_driver);
154 }
155 module_init(of_platform_serial_init);
156
157 static void __exit of_platform_serial_exit(void)
158 {
159         return of_unregister_platform_driver(&of_platform_serial_driver);
160 };
161 module_exit(of_platform_serial_exit);
162
163 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
164 MODULE_LICENSE("GPL");
165 MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");