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/slab.h>
15 #include <linux/delay.h>
16 #include <linux/serial_core.h>
17 #include <linux/serial_8250.h>
18 #include <linux/serial_reg.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_platform.h>
22 #include <linux/nwpserial.h>
23 #include <linux/clk.h>
25 struct of_serial_info {
31 #ifdef CONFIG_ARCH_TEGRA
32 void tegra_serial_handle_break(struct uart_port *p)
34 unsigned int status, tmout = 10000;
37 status = p->serial_in(p, UART_LSR);
38 if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
39 status = p->serial_in(p, UART_RX);
48 static inline void tegra_serial_handle_break(struct uart_port *port)
54 * Fill a struct uart_port for a given device node
56 static int of_platform_serial_setup(struct platform_device *ofdev,
57 int type, struct uart_port *port,
58 struct of_serial_info *info)
60 struct resource resource;
61 struct device_node *np = ofdev->dev.of_node;
65 memset(port, 0, sizeof *port);
66 if (of_property_read_u32(np, "clock-frequency", &clk)) {
68 /* Get clk rate through clk driver if present */
69 info->clk = clk_get(&ofdev->dev, NULL);
70 if (IS_ERR(info->clk)) {
72 "clk or clock-frequency not defined\n");
73 return PTR_ERR(info->clk);
76 clk_prepare_enable(info->clk);
77 clk = clk_get_rate(info->clk);
79 /* If current-speed was set, then try not to change it. */
80 if (of_property_read_u32(np, "current-speed", &spd) == 0)
81 port->custom_divisor = clk / (16 * spd);
83 ret = of_address_to_resource(np, 0, &resource);
85 dev_warn(&ofdev->dev, "invalid address\n");
89 spin_lock_init(&port->lock);
90 port->mapbase = resource.start;
92 /* Check for shifted address mapping */
93 if (of_property_read_u32(np, "reg-offset", &prop) == 0)
94 port->mapbase += prop;
96 /* Check for registers offset within the devices address range */
97 if (of_property_read_u32(np, "reg-shift", &prop) == 0)
98 port->regshift = prop;
100 port->irq = irq_of_parse_and_map(np, 0);
101 port->iotype = UPIO_MEM;
102 if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
105 port->iotype = UPIO_MEM;
108 port->iotype = UPIO_MEM32;
111 dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
120 port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
121 | UPF_FIXED_PORT | UPF_FIXED_TYPE;
123 if (of_find_property(np, "no-loopback-test", NULL))
124 port->flags |= UPF_SKIP_TEST;
126 port->dev = &ofdev->dev;
128 if (type == PORT_TEGRA)
129 port->handle_break = tegra_serial_handle_break;
134 clk_disable_unprepare(info->clk);
139 * Try to register a serial port
141 static struct of_device_id of_platform_serial_table[];
142 static int of_platform_serial_probe(struct platform_device *ofdev)
144 const struct of_device_id *match;
145 struct of_serial_info *info;
146 struct uart_port port;
150 match = of_match_device(of_platform_serial_table, &ofdev->dev);
154 if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
157 info = kmalloc(sizeof(*info), GFP_KERNEL);
161 port_type = (unsigned long)match->data;
162 ret = of_platform_serial_setup(ofdev, port_type, &port, info);
167 #ifdef CONFIG_SERIAL_8250
168 case PORT_8250 ... PORT_MAX_8250:
170 /* For now the of bindings don't support the extra
171 8250 specific bits */
172 struct uart_8250_port port8250;
173 memset(&port8250, 0, sizeof(port8250));
174 port8250.port = port;
175 ret = serial8250_register_8250_port(&port8250);
179 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
181 ret = nwpserial_register_port(&port);
185 /* need to add code for these */
187 dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
194 info->type = port_type;
196 dev_set_drvdata(&ofdev->dev, info);
200 irq_dispose_mapping(port.irq);
207 static int of_platform_serial_remove(struct platform_device *ofdev)
209 struct of_serial_info *info = dev_get_drvdata(&ofdev->dev);
210 switch (info->type) {
211 #ifdef CONFIG_SERIAL_8250
212 case PORT_8250 ... PORT_MAX_8250:
213 serial8250_unregister_port(info->line);
216 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
218 nwpserial_unregister_port(info->line);
222 /* need to add code for these */
227 clk_disable_unprepare(info->clk);
233 * A few common types, add more as needed.
235 static struct of_device_id of_platform_serial_table[] = {
236 { .compatible = "ns8250", .data = (void *)PORT_8250, },
237 { .compatible = "ns16450", .data = (void *)PORT_16450, },
238 { .compatible = "ns16550a", .data = (void *)PORT_16550A, },
239 { .compatible = "ns16550", .data = (void *)PORT_16550, },
240 { .compatible = "ns16750", .data = (void *)PORT_16750, },
241 { .compatible = "ns16850", .data = (void *)PORT_16850, },
242 { .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
243 { .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
244 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
245 { .compatible = "ibm,qpace-nwp-serial",
246 .data = (void *)PORT_NWPSERIAL, },
248 { .type = "serial", .data = (void *)PORT_UNKNOWN, },
249 { /* end of list */ },
252 static struct platform_driver of_platform_serial_driver = {
255 .owner = THIS_MODULE,
256 .of_match_table = of_platform_serial_table,
258 .probe = of_platform_serial_probe,
259 .remove = of_platform_serial_remove,
262 module_platform_driver(of_platform_serial_driver);
264 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
265 MODULE_LICENSE("GPL");
266 MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");