xref: /freebsd/sys/dev/uart/uart_bus_fdt.c (revision 0f2bd1e89db1a2f09268edea21e0ead329e092df)
1 /*-
2  * Copyright (c) 2009-2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Semihalf under sponsorship from
6  * the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 
38 #include <machine/bus.h>
39 #include <machine/fdt.h>
40 
41 #include <dev/fdt/fdt_common.h>
42 #include <dev/ofw/ofw_bus.h>
43 #include <dev/ofw/ofw_bus_subr.h>
44 #include <dev/uart/uart.h>
45 #include <dev/uart/uart_bus.h>
46 #include <dev/uart/uart_cpu.h>
47 
48 static int uart_fdt_probe(device_t);
49 
50 static device_method_t uart_fdt_methods[] = {
51 	/* Device interface */
52 	DEVMETHOD(device_probe,		uart_fdt_probe),
53 	DEVMETHOD(device_attach,	uart_bus_attach),
54 	DEVMETHOD(device_detach,	uart_bus_detach),
55 	{ 0, 0 }
56 };
57 
58 static driver_t uart_fdt_driver = {
59 	uart_driver_name,
60 	uart_fdt_methods,
61 	sizeof(struct uart_softc),
62 };
63 
64 static int
65 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
66 {
67 	pcell_t clock;
68 
69 	if ((OF_getprop(node, "clock-frequency", &clock,
70 	    sizeof(clock))) <= 0)
71 		return (ENXIO);
72 
73 	if (clock == 0)
74 		/* Try to retrieve parent 'bus-frequency' */
75 		/* XXX this should go to simple-bus fixup or so */
76 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
77 		    sizeof(clock))) <= 0)
78 			clock = 0;
79 
80 	*cell = fdt32_to_cpu(clock);
81 	return (0);
82 }
83 
84 static int
85 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
86 {
87 	pcell_t shift;
88 
89 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
90 		shift = 0;
91 	*cell = fdt32_to_cpu(shift);
92 	return (0);
93 }
94 
95 static int
96 uart_fdt_probe(device_t dev)
97 {
98 	struct uart_softc *sc;
99 	phandle_t node;
100 	pcell_t clock, shift;
101 	int err;
102 
103 	if (!ofw_bus_is_compatible(dev, "ns16550"))
104 		return (ENXIO);
105 
106 	sc = device_get_softc(dev);
107 	sc->sc_class = &uart_ns8250_class;
108 
109 	node = ofw_bus_get_node(dev);
110 
111 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
112 		return (err);
113 	uart_fdt_get_shift(node, &shift);
114 
115 	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
116 }
117 
118 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
119 
120 /*
121  * UART console routines.
122  */
123 bus_space_tag_t uart_bus_space_io;
124 bus_space_tag_t uart_bus_space_mem;
125 
126 int
127 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
128 {
129 
130 	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
131 }
132 
133 int
134 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
135 {
136 	char buf[64];
137 	struct uart_class *class;
138 	phandle_t node, chosen;
139 	pcell_t shift, br, rclk;
140 	u_long start, size;
141 	int err;
142 
143 	if (devtype != UART_DEV_CONSOLE)
144 		return (ENXIO);
145 
146 	/*
147 	 * Retrieve /chosen/std{in,out}.
148 	 */
149 	if ((chosen = OF_finddevice("/chosen")) == 0)
150 		return (ENXIO);
151 	if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
152 		return (ENXIO);
153 	if ((node = OF_finddevice(buf)) == 0)
154 		return (ENXIO);
155 	if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
156 		return (ENXIO);
157 	if (OF_finddevice(buf) != node)
158 		/* Only stdin == stdout is supported. */
159 		return (ENXIO);
160 	/*
161 	 * Retrieve serial attributes.
162 	 */
163 	uart_fdt_get_shift(node, &shift);
164 
165 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
166 		br = 0;
167 	br = fdt32_to_cpu(br);
168 
169 	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
170 		return (err);
171 	/*
172 	 * Finalize configuration.
173 	 */
174 	class = &uart_quicc_class;
175 	if (fdt_is_compatible(node, "ns16550"))
176 		class = &uart_ns8250_class;
177 
178 	di->bas.chan = 0;
179 	di->bas.regshft = (u_int)shift;
180 	di->baudrate = 0;
181 	di->bas.rclk = (u_int)rclk;
182 	di->ops = uart_getops(class);
183 	di->databits = 8;
184 	di->stopbits = 1;
185 	di->parity = UART_PARITY_NONE;
186 	di->bas.bst = fdtbus_bs_tag;
187 
188 	err = fdt_regsize(node, &start, &size);
189 	if (err)
190 		return (ENXIO);
191 	start += fdt_immr_va;
192 
193 	uart_bus_space_mem = fdtbus_bs_tag;
194 	uart_bus_space_io = NULL;
195 
196 	if (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh) != 0)
197 		return (ENXIO);
198 
199 	return (0);
200 }
201