2 * Serial Port driver for Open Firmware platform devices
4 * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
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.
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>
21 struct of_serial_info {
27 * Fill a struct uart_port for a given device node
29 static int __devinit of_platform_serial_setup(struct of_device *ofdev,
30 int type, struct uart_port *port)
32 struct resource resource;
33 struct device_node *np = ofdev->node;
34 const unsigned int *clk, *spd;
38 memset(port, 0, sizeof *port);
39 spd = of_get_property(np, "current-speed", NULL);
40 clk = of_get_property(np, "clock-frequency", NULL);
42 dev_warn(&ofdev->dev, "no clock-frequency property set\n");
46 ret = of_address_to_resource(np, 0, &resource);
48 dev_warn(&ofdev->dev, "invalid address\n");
52 spin_lock_init(&port->lock);
53 port->mapbase = resource.start;
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;
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;
65 port->irq = irq_of_parse_and_map(np, 0);
66 port->iotype = UPIO_MEM;
69 port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
71 port->dev = &ofdev->dev;
72 /* If current-speed was set, then try not to change it. */
74 port->custom_divisor = *clk / (16 * (*spd));
80 * Try to register a serial port
82 static int __devinit of_platform_serial_probe(struct of_device *ofdev,
83 const struct of_device_id *id)
85 struct of_serial_info *info;
86 struct uart_port port;
90 if (of_find_property(ofdev->node, "used-by-rtas", NULL))
93 info = kmalloc(sizeof(*info), GFP_KERNEL);
97 port_type = (unsigned long)id->data;
98 ret = of_platform_serial_setup(ofdev, port_type, &port);
103 #ifdef CONFIG_SERIAL_8250
104 case PORT_8250 ... PORT_MAX_8250:
105 ret = serial8250_register_port(&port);
108 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
110 ret = nwpserial_register_port(&port);
114 /* need to add code for these */
116 dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
123 info->type = port_type;
125 ofdev->dev.driver_data = info;
129 irq_dispose_mapping(port.irq);
136 static int of_platform_serial_remove(struct of_device *ofdev)
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);
145 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
147 nwpserial_unregister_port(info->line);
151 /* need to add code for these */
159 * A few common types, add more as needed.
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, },
170 { .type = "serial", .data = (void *)PORT_UNKNOWN, },
171 { /* end of list */ },
174 static struct of_platform_driver of_platform_serial_driver = {
175 .owner = THIS_MODULE,
177 .probe = of_platform_serial_probe,
178 .remove = of_platform_serial_remove,
179 .match_table = of_platform_serial_table,
182 static int __init of_platform_serial_init(void)
184 return of_register_platform_driver(&of_platform_serial_driver);
186 module_init(of_platform_serial_init);
188 static void __exit of_platform_serial_exit(void)
190 return of_unregister_platform_driver(&of_platform_serial_driver);
192 module_exit(of_platform_serial_exit);
194 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
195 MODULE_LICENSE("GPL");
196 MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");