xref: /freebsd/sys/dev/uart/uart_bus_fdt.c (revision 12f110aa1ad3c9d0ead55bf80f2f994b4b845ffb)
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 	sc = device_get_softc(dev);
104 	if (ofw_bus_is_compatible(dev, "ns16550"))
105 		sc->sc_class = &uart_ns8250_class;
106 	else if (ofw_bus_is_compatible(dev, "lpc,uart"))
107 		sc->sc_class = &uart_lpc_class;
108 	else if (ofw_bus_is_compatible(dev, "arm,pl011"))
109 		sc->sc_class = &uart_pl011_class;
110 	else
111 		return (ENXIO);
112 
113 	node = ofw_bus_get_node(dev);
114 
115 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
116 		return (err);
117 	uart_fdt_get_shift(node, &shift);
118 
119 	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
120 }
121 
122 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
123 
124 /*
125  * UART console routines.
126  */
127 bus_space_tag_t uart_bus_space_io;
128 bus_space_tag_t uart_bus_space_mem;
129 
130 int
131 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
132 {
133 
134 	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
135 }
136 
137 int
138 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
139 {
140 	char buf[64];
141 	struct uart_class *class;
142 	phandle_t node, chosen;
143 	pcell_t shift, br, rclk;
144 	u_long start, size, pbase, psize;
145 	int err;
146 
147 	uart_bus_space_mem = fdtbus_bs_tag;
148 	uart_bus_space_io = NULL;
149 
150 	/* Allow overriding the FDT uning the environment. */
151 	class = &uart_ns8250_class;
152 	err = uart_getenv(devtype, di, class);
153 	if (!err)
154 		return (0);
155 
156 	if (devtype != UART_DEV_CONSOLE)
157 		return (ENXIO);
158 
159 	/*
160 	 * Retrieve /chosen/std{in,out}.
161 	 */
162 	if ((chosen = OF_finddevice("/chosen")) == -1)
163 		return (ENXIO);
164 	if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
165 		return (ENXIO);
166 	if ((node = OF_finddevice(buf)) == -1)
167 		return (ENXIO);
168 	if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
169 		return (ENXIO);
170 	if (OF_finddevice(buf) != node)
171 		/* Only stdin == stdout is supported. */
172 		return (ENXIO);
173 	/*
174 	 * Retrieve serial attributes.
175 	 */
176 	uart_fdt_get_shift(node, &shift);
177 
178 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
179 		br = 0;
180 	br = fdt32_to_cpu(br);
181 
182 	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
183 		return (err);
184 	/*
185 	 * Finalize configuration.
186 	 */
187 	if (fdt_is_compatible(node, "quicc"))
188 		class = &uart_quicc_class;
189 	if (fdt_is_compatible(node, "lpc"))
190 		class = &uart_lpc_class;
191 	if (fdt_is_compatible(node, "ns16550"))
192 		class = &uart_ns8250_class;
193 	if (fdt_is_compatible(node, "arm,pl011"))
194 		class = &uart_pl011_class;
195 
196 	di->bas.chan = 0;
197 	di->bas.regshft = (u_int)shift;
198 	di->baudrate = br;
199 	di->bas.rclk = (u_int)rclk;
200 	di->ops = uart_getops(class);
201 	di->databits = 8;
202 	di->stopbits = 1;
203 	di->parity = UART_PARITY_NONE;
204 	di->bas.bst = uart_bus_space_mem;
205 
206 	err = fdt_regsize(node, &start, &size);
207 	if (err)
208 		return (ENXIO);
209 	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
210 	if (err)
211 		pbase = 0;
212 
213 	start += pbase;
214 
215 	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
216 }
217