xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision 6574b8ed19b093f0af09501d2c9676c28993cb97)
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 "opt_platform.h"
34 
35 #include <sys/param.h>
36 #include <sys/bus.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/systm.h>
40 
41 #include <vm/vm.h>
42 #include <vm/pmap.h>
43 
44 #include <machine/bus.h>
45 #include <machine/fdt.h>
46 
47 #include <dev/fdt/fdt_common.h>
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50 #include <dev/uart/uart.h>
51 #include <dev/uart/uart_bus.h>
52 #include <dev/uart/uart_cpu.h>
53 
54 /*
55  * UART console routines.
56  */
57 bus_space_tag_t uart_bus_space_io;
58 bus_space_tag_t uart_bus_space_mem;
59 
60 static int
61 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
62 {
63 	pcell_t clock;
64 
65 	/* clock-frequency is a FreeBSD-only extention. */
66 	if ((OF_getprop(node, "clock-frequency", &clock,
67 	    sizeof(clock))) <= 0)
68 		clock = 0;
69 
70 	if (clock == 0)
71 		/* Try to retrieve parent 'bus-frequency' */
72 		/* XXX this should go to simple-bus fixup or so */
73 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
74 		    sizeof(clock))) <= 0)
75 			clock = 0;
76 
77 	*cell = fdt32_to_cpu(clock);
78 	return (0);
79 }
80 
81 static int
82 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
83 {
84 	pcell_t shift;
85 
86 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
87 		shift = 0;
88 	*cell = fdt32_to_cpu(shift);
89 	return (0);
90 }
91 
92 int
93 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
94 {
95 
96 	if (b1->bst != b2->bst)
97 		return (0);
98 	if (pmap_kextract(b1->bsh) == 0)
99 		return (0);
100 	if (pmap_kextract(b2->bsh) == 0)
101 		return (0);
102 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
103 }
104 
105 static int
106 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
107 {
108 	char buf[64];
109 
110 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
111 		return (ENXIO);
112 	if ((*node = OF_finddevice(buf)) == -1)
113 		return (ENXIO);
114 
115 	return (0);
116 }
117 
118 int
119 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
120 {
121 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
122 	    "stdin-path", "stdin", NULL};
123 	const char **name;
124 	const struct ofw_compat_data *cd;
125 	struct uart_class *class;
126 	phandle_t node, chosen;
127 	pcell_t shift, br, rclk;
128 	u_long start, size, pbase, psize;
129 	int err;
130 
131 	uart_bus_space_mem = fdtbus_bs_tag;
132 	uart_bus_space_io = NULL;
133 
134 	/* Allow overriding the FDT using the environment. */
135 	class = &uart_ns8250_class;
136 	err = uart_getenv(devtype, di, class);
137 	if (!err)
138 		return (0);
139 
140 	if (devtype != UART_DEV_CONSOLE)
141 		return (ENXIO);
142 
143 	/*
144 	 * Retrieve /chosen/std{in,out}.
145 	 */
146 	node = -1;
147 	if ((chosen = OF_finddevice("/chosen")) != -1) {
148 		for (name = propnames; *name != NULL; name++) {
149 			if (phandle_chosen_propdev(chosen, *name, &node) == 0)
150 				break;
151 		}
152 	}
153 	if (chosen == -1 || *name == NULL)
154 		node = OF_finddevice("serial0"); /* Last ditch */
155 
156 	if (node == -1) /* Can't find anything */
157 		return (ENXIO);
158 
159 	/*
160 	 * Retrieve serial attributes.
161 	 */
162 	uart_fdt_get_shift(node, &shift);
163 
164 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
165 		br = 0;
166 	br = fdt32_to_cpu(br);
167 
168 	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
169 		return (err);
170 	/*
171 	 * Finalize configuration.
172 	 */
173 	for (cd = uart_fdt_compat_data; cd->ocd_str != NULL; ++cd) {
174 		if (fdt_is_compatible(node, cd->ocd_str))
175 			break;
176 	}
177 	if (cd->ocd_str == NULL)
178 		return (ENXIO);
179 	class = (struct uart_class *)cd->ocd_data;
180 
181 	di->bas.chan = 0;
182 	di->bas.regshft = (u_int)shift;
183 	di->baudrate = br;
184 	di->bas.rclk = (u_int)rclk;
185 	di->ops = uart_getops(class);
186 	di->databits = 8;
187 	di->stopbits = 1;
188 	di->parity = UART_PARITY_NONE;
189 	di->bas.bst = uart_bus_space_mem;
190 
191 	err = fdt_regsize(node, &start, &size);
192 	if (err)
193 		return (ENXIO);
194 	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
195 	if (err)
196 		pbase = 0;
197 
198 	start += pbase;
199 
200 	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
201 }
202