xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision c0e5e7f3d2e1bac7ada43b35843e3a018777854e)
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 #ifndef __aarch64__
46 #include <machine/fdt.h>
47 #endif
48 
49 #include <dev/fdt/fdt_common.h>
50 #include <dev/ofw/ofw_bus.h>
51 #include <dev/ofw/ofw_bus_subr.h>
52 #include <dev/uart/uart.h>
53 #include <dev/uart/uart_bus.h>
54 #include <dev/uart/uart_cpu.h>
55 #include <dev/uart/uart_cpu_fdt.h>
56 
57 /*
58  * UART console routines.
59  */
60 bus_space_tag_t uart_bus_space_io;
61 bus_space_tag_t uart_bus_space_mem;
62 
63 int
64 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
65 {
66 
67 	if (b1->bst != b2->bst)
68 		return (0);
69 	if (pmap_kextract(b1->bsh) == 0)
70 		return (0);
71 	if (pmap_kextract(b2->bsh) == 0)
72 		return (0);
73 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
74 }
75 
76 static int
77 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
78 {
79 	char buf[64];
80 
81 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
82 		return (ENXIO);
83 	if ((*node = OF_finddevice(buf)) == -1)
84 		return (ENXIO);
85 
86 	return (0);
87 }
88 
89 static const struct ofw_compat_data *
90 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
91 {
92 	const struct ofw_compat_data *ocd;
93 
94 	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
95 		if (fdt_is_compatible(node, ocd->ocd_str))
96 			return (ocd);
97 	}
98 	return (NULL);
99 }
100 
101 static uintptr_t
102 uart_fdt_find_by_node(phandle_t node, int class_list)
103 {
104 	struct ofw_compat_data **cd;
105 	const struct ofw_compat_data *ocd;
106 
107 	if (class_list) {
108 		SET_FOREACH(cd, uart_fdt_class_set) {
109 			ocd = uart_fdt_find_compatible(node, *cd);
110 			if ((ocd != NULL) && (ocd->ocd_data != 0))
111 				return (ocd->ocd_data);
112 		}
113 	} else {
114 		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
115 			ocd = uart_fdt_find_compatible(node, *cd);
116 			if ((ocd != NULL) && (ocd->ocd_data != 0))
117 				return (ocd->ocd_data);
118 		}
119 	}
120 	return (0);
121 }
122 
123 int
124 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
125 {
126 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
127 	    "stdin-path", "stdin", NULL};
128 	const char **name;
129 	struct uart_class *class;
130 	phandle_t node, chosen;
131 	pcell_t shift, br, rclk;
132 	char *cp;
133 	int err;
134 
135 	/* Allow overriding the FDT using the environment. */
136 	class = &uart_ns8250_class;
137 	err = uart_getenv(devtype, di, class);
138 	if (!err)
139 		return (0);
140 
141 	if (devtype != UART_DEV_CONSOLE)
142 		return (ENXIO);
143 
144 	/* Has the user forced a specific device node? */
145 	cp = kern_getenv("hw.fdt.console");
146 	if (cp == NULL) {
147 		/*
148 		 * Retrieve /chosen/std{in,out}.
149 		 */
150 		node = -1;
151 		if ((chosen = OF_finddevice("/chosen")) != -1) {
152 			for (name = propnames; *name != NULL; name++) {
153 				if (phandle_chosen_propdev(chosen, *name,
154 				    &node) == 0)
155 					break;
156 			}
157 		}
158 		if (chosen == -1 || *name == NULL)
159 			node = OF_finddevice("serial0"); /* Last ditch */
160 	} else {
161 		node = OF_finddevice(cp);
162 	}
163 
164 	if (node == -1) /* Can't find anything */
165 		return (ENXIO);
166 
167 	/*
168 	 * Check old style of UART definition first. Unfortunately, the common
169 	 * FDT processing is not possible if we have clock, power domains and
170 	 * pinmux stuff.
171 	 */
172 	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
173 	if (class != NULL) {
174 		if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
175 			return (err);
176 	} else {
177 		/* Check class only linker set */
178 		class =
179 		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
180 		if (class == NULL)
181 			return (ENXIO);
182 		rclk = 0;
183 	}
184 
185 	/*
186 	 * Retrieve serial attributes.
187 	 */
188 	if (uart_fdt_get_shift(node, &shift) != 0)
189 		shift = uart_getregshift(class);
190 
191 	if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
192 		br = 0;
193 
194 	/*
195 	 * Finalize configuration.
196 	 */
197 	di->bas.chan = 0;
198 	di->bas.regshft = (u_int)shift;
199 	di->baudrate = br;
200 	di->bas.rclk = (u_int)rclk;
201 	di->ops = uart_getops(class);
202 	di->databits = 8;
203 	di->stopbits = 1;
204 	di->parity = UART_PARITY_NONE;
205 
206 	err = OF_decode_addr(node, 0, &di->bas.bst, &di->bas.bsh, NULL);
207 	uart_bus_space_mem = di->bas.bst;
208 	uart_bus_space_io = NULL;
209 
210 	return (err);
211 }
212