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");