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[linux-2.6-omap-h63xx.git] / 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 #include <linux/of_platform.h>
17 #include <linux/nwpserial.h>
18
19 #include <asm/prom.h>
20
21 struct of_serial_info {
22         int type;
23         int line;
24 };
25
26 /*
27  * Fill a struct uart_port for a given device node
28  */
29 static int __devinit of_platform_serial_setup(struct of_device *ofdev,
30                                         int type, struct uart_port *port)
31 {
32         struct resource resource;
33         struct device_node *np = ofdev->node;
34         const unsigned int *clk, *spd;
35         const u32 *prop;
36         int ret, prop_size;
37
38         memset(port, 0, sizeof *port);
39         spd = of_get_property(np, "current-speed", NULL);
40         clk = of_get_property(np, "clock-frequency", NULL);
41         if (!clk) {
42                 dev_warn(&ofdev->dev, "no clock-frequency property set\n");
43                 return -ENODEV;
44         }
45
46         ret = of_address_to_resource(np, 0, &resource);
47         if (ret) {
48                 dev_warn(&ofdev->dev, "invalid address\n");
49                 return ret;
50         }
51
52         spin_lock_init(&port->lock);
53         port->mapbase = resource.start;
54
55         /* Check for shifted address mapping */
56         prop = of_get_property(np, "reg-offset", &prop_size);
57         if (prop && (prop_size == sizeof(u32)))
58                 port->mapbase += *prop;
59
60         /* Check for registers offset within the devices address range */
61         prop = of_get_property(np, "reg-shift", &prop_size);
62         if (prop && (prop_size == sizeof(u32)))
63                 port->regshift = *prop;
64
65         port->irq = irq_of_parse_and_map(np, 0);
66         port->iotype = UPIO_MEM;
67         port->type = type;
68         port->uartclk = *clk;
69         port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
70                 | UPF_FIXED_PORT;
71         port->dev = &ofdev->dev;
72         /* If current-speed was set, then try not to change it. */
73         if (spd)
74                 port->custom_divisor = *clk / (16 * (*spd));
75
76         return 0;
77 }
78
79 /*
80  * Try to register a serial port
81  */
82 static int __devinit of_platform_serial_probe(struct of_device *ofdev,
83                                                 const struct of_device_id *id)
84 {
85         struct of_serial_info *info;
86         struct uart_port port;
87         int port_type;
88         int ret;
89
90         if (of_find_property(ofdev->node, "used-by-rtas", NULL))
91                 return -EBUSY;
92
93         info = kmalloc(sizeof(*info), GFP_KERNEL);
94         if (info == NULL)
95                 return -ENOMEM;
96
97         port_type = (unsigned long)id->data;
98         ret = of_platform_serial_setup(ofdev, port_type, &port);
99         if (ret)
100                 goto out;
101
102         switch (port_type) {
103 #ifdef CONFIG_SERIAL_8250
104         case PORT_8250 ... PORT_MAX_8250:
105                 ret = serial8250_register_port(&port);
106                 break;
107 #endif
108 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
109         case PORT_NWPSERIAL:
110                 ret = nwpserial_register_port(&port);
111                 break;
112 #endif
113         default:
114                 /* need to add code for these */
115         case PORT_UNKNOWN:
116                 dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
117                 ret = -ENODEV;
118                 break;
119         }
120         if (ret < 0)
121                 goto out;
122
123         info->type = port_type;
124         info->line = ret;
125         ofdev->dev.driver_data = info;
126         return 0;
127 out:
128         kfree(info);
129         irq_dispose_mapping(port.irq);
130         return ret;
131 }
132
133 /*
134  * Release a line
135  */
136 static int of_platform_serial_remove(struct of_device *ofdev)
137 {
138         struct of_serial_info *info = ofdev->dev.driver_data;
139         switch (info->type) {
140 #ifdef CONFIG_SERIAL_8250
141         case PORT_8250 ... PORT_MAX_8250:
142                 serial8250_unregister_port(info->line);
143                 break;
144 #endif
145 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
146         case PORT_NWPSERIAL:
147                 nwpserial_unregister_port(info->line);
148                 break;
149 #endif
150         default:
151                 /* need to add code for these */
152                 break;
153         }
154         kfree(info);
155         return 0;
156 }
157
158 /*
159  * A few common types, add more as needed.
160  */
161 static struct of_device_id __devinitdata of_platform_serial_table[] = {
162         { .type = "serial", .compatible = "ns8250",   .data = (void *)PORT_8250, },
163         { .type = "serial", .compatible = "ns16450",  .data = (void *)PORT_16450, },
164         { .type = "serial", .compatible = "ns16550",  .data = (void *)PORT_16550, },
165         { .type = "serial", .compatible = "ns16750",  .data = (void *)PORT_16750, },
166 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
167         { .type = "serial", .compatible = "ibm,qpace-nwp-serial",
168                                         .data = (void *)PORT_NWPSERIAL, },
169 #endif
170         { .type = "serial",                           .data = (void *)PORT_UNKNOWN, },
171         { /* end of list */ },
172 };
173
174 static struct of_platform_driver of_platform_serial_driver = {
175         .owner = THIS_MODULE,
176         .name = "of_serial",
177         .probe = of_platform_serial_probe,
178         .remove = of_platform_serial_remove,
179         .match_table = of_platform_serial_table,
180 };
181
182 static int __init of_platform_serial_init(void)
183 {
184         return of_register_platform_driver(&of_platform_serial_driver);
185 }
186 module_init(of_platform_serial_init);
187
188 static void __exit of_platform_serial_exit(void)
189 {
190         return of_unregister_platform_driver(&of_platform_serial_driver);
191 };
192 module_exit(of_platform_serial_exit);
193
194 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
195 MODULE_LICENSE("GPL");
196 MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");