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_reg.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/nwpserial.h>
22 #include <linux/clk.h>
24 #include "8250/8250.h"
26 struct of_serial_info
{
32 #ifdef CONFIG_ARCH_TEGRA
33 void tegra_serial_handle_break(struct uart_port
*p
)
35 unsigned int status
, tmout
= 10000;
38 status
= p
->serial_in(p
, UART_LSR
);
39 if (status
& (UART_LSR_FIFOE
| UART_LSR_BRK_ERROR_BITS
))
40 status
= p
->serial_in(p
, UART_RX
);
49 static inline void tegra_serial_handle_break(struct uart_port
*port
)
55 * Fill a struct uart_port for a given device node
57 static int of_platform_serial_setup(struct platform_device
*ofdev
,
58 int type
, struct uart_port
*port
,
59 struct of_serial_info
*info
)
61 struct resource resource
;
62 struct device_node
*np
= ofdev
->dev
.of_node
;
66 memset(port
, 0, sizeof *port
);
67 if (of_property_read_u32(np
, "clock-frequency", &clk
)) {
69 /* Get clk rate through clk driver if present */
70 info
->clk
= clk_get(&ofdev
->dev
, NULL
);
71 if (IS_ERR(info
->clk
)) {
73 "clk or clock-frequency not defined\n");
74 return PTR_ERR(info
->clk
);
77 clk_prepare_enable(info
->clk
);
78 clk
= clk_get_rate(info
->clk
);
80 /* If current-speed was set, then try not to change it. */
81 if (of_property_read_u32(np
, "current-speed", &spd
) == 0)
82 port
->custom_divisor
= clk
/ (16 * spd
);
84 ret
= of_address_to_resource(np
, 0, &resource
);
86 dev_warn(&ofdev
->dev
, "invalid address\n");
90 spin_lock_init(&port
->lock
);
91 port
->mapbase
= resource
.start
;
93 /* Check for shifted address mapping */
94 if (of_property_read_u32(np
, "reg-offset", &prop
) == 0)
95 port
->mapbase
+= prop
;
97 /* Check for registers offset within the devices address range */
98 if (of_property_read_u32(np
, "reg-shift", &prop
) == 0)
99 port
->regshift
= prop
;
101 /* Check for fifo size */
102 if (of_property_read_u32(np
, "fifo-size", &prop
) == 0)
103 port
->fifosize
= prop
;
105 port
->irq
= irq_of_parse_and_map(np
, 0);
106 port
->iotype
= UPIO_MEM
;
107 if (of_property_read_u32(np
, "reg-io-width", &prop
) == 0) {
110 port
->iotype
= UPIO_MEM
;
113 port
->iotype
= UPIO_MEM32
;
116 dev_warn(&ofdev
->dev
, "unsupported reg-io-width (%d)\n",
125 port
->flags
= UPF_SHARE_IRQ
| UPF_BOOT_AUTOCONF
| UPF_IOREMAP
126 | UPF_FIXED_PORT
| UPF_FIXED_TYPE
;
128 if (of_find_property(np
, "no-loopback-test", NULL
))
129 port
->flags
|= UPF_SKIP_TEST
;
131 port
->dev
= &ofdev
->dev
;
133 if (type
== PORT_TEGRA
)
134 port
->handle_break
= tegra_serial_handle_break
;
139 clk_disable_unprepare(info
->clk
);
144 * Try to register a serial port
146 static struct of_device_id of_platform_serial_table
[];
147 static int of_platform_serial_probe(struct platform_device
*ofdev
)
149 const struct of_device_id
*match
;
150 struct of_serial_info
*info
;
151 struct uart_port port
;
155 match
= of_match_device(of_platform_serial_table
, &ofdev
->dev
);
159 if (of_find_property(ofdev
->dev
.of_node
, "used-by-rtas", NULL
))
162 info
= kmalloc(sizeof(*info
), GFP_KERNEL
);
166 port_type
= (unsigned long)match
->data
;
167 ret
= of_platform_serial_setup(ofdev
, port_type
, &port
, info
);
172 #ifdef CONFIG_SERIAL_8250
173 case PORT_8250
... PORT_MAX_8250
:
175 struct uart_8250_port port8250
;
176 memset(&port8250
, 0, sizeof(port8250
));
177 port8250
.port
= port
;
180 port8250
.capabilities
= UART_CAP_FIFO
;
182 if (of_property_read_bool(ofdev
->dev
.of_node
,
183 "auto-flow-control"))
184 port8250
.capabilities
|= UART_CAP_AFE
;
186 ret
= serial8250_register_8250_port(&port8250
);
190 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
192 ret
= nwpserial_register_port(&port
);
196 /* need to add code for these */
198 dev_info(&ofdev
->dev
, "Unknown serial port found, ignored\n");
205 info
->type
= port_type
;
207 dev_set_drvdata(&ofdev
->dev
, info
);
211 irq_dispose_mapping(port
.irq
);
218 static int of_platform_serial_remove(struct platform_device
*ofdev
)
220 struct of_serial_info
*info
= dev_get_drvdata(&ofdev
->dev
);
221 switch (info
->type
) {
222 #ifdef CONFIG_SERIAL_8250
223 case PORT_8250
... PORT_MAX_8250
:
224 serial8250_unregister_port(info
->line
);
227 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
229 nwpserial_unregister_port(info
->line
);
233 /* need to add code for these */
238 clk_disable_unprepare(info
->clk
);
244 * A few common types, add more as needed.
246 static struct of_device_id of_platform_serial_table
[] = {
247 { .compatible
= "ns8250", .data
= (void *)PORT_8250
, },
248 { .compatible
= "ns16450", .data
= (void *)PORT_16450
, },
249 { .compatible
= "ns16550a", .data
= (void *)PORT_16550A
, },
250 { .compatible
= "ns16550", .data
= (void *)PORT_16550
, },
251 { .compatible
= "ns16750", .data
= (void *)PORT_16750
, },
252 { .compatible
= "ns16850", .data
= (void *)PORT_16850
, },
253 { .compatible
= "nvidia,tegra20-uart", .data
= (void *)PORT_TEGRA
, },
254 { .compatible
= "nxp,lpc3220-uart", .data
= (void *)PORT_LPC3220
, },
255 { .compatible
= "altr,16550-FIFO32",
256 .data
= (void *)PORT_ALTR_16550_F32
, },
257 { .compatible
= "altr,16550-FIFO64",
258 .data
= (void *)PORT_ALTR_16550_F64
, },
259 { .compatible
= "altr,16550-FIFO128",
260 .data
= (void *)PORT_ALTR_16550_F128
, },
261 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
262 { .compatible
= "ibm,qpace-nwp-serial",
263 .data
= (void *)PORT_NWPSERIAL
, },
265 { .type
= "serial", .data
= (void *)PORT_UNKNOWN
, },
266 { /* end of list */ },
269 static struct platform_driver of_platform_serial_driver
= {
272 .owner
= THIS_MODULE
,
273 .of_match_table
= of_platform_serial_table
,
275 .probe
= of_platform_serial_probe
,
276 .remove
= of_platform_serial_remove
,
279 module_platform_driver(of_platform_serial_driver
);
281 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
282 MODULE_LICENSE("GPL");
283 MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");