xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
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 
46 #include <dev/fdt/fdt_common.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
49 #include <dev/uart/uart.h>
50 #include <dev/uart/uart_bus.h>
51 #include <dev/uart/uart_cpu.h>
52 #include <dev/uart/uart_cpu_fdt.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 int
61 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
62 {
63 
64 	if (b1->bst != b2->bst)
65 		return (0);
66 	if (pmap_kextract(b1->bsh) == 0)
67 		return (0);
68 	if (pmap_kextract(b2->bsh) == 0)
69 		return (0);
70 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
71 }
72 
73 static int
74 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
75 {
76 	char buf[64];
77 
78 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
79 		return (ENXIO);
80 	if ((*node = OF_finddevice(buf)) == -1)
81 		return (ENXIO);
82 
83 	return (0);
84 }
85 
86 static const struct ofw_compat_data *
87 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
88 {
89 	const struct ofw_compat_data *ocd;
90 
91 	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
92 		if (fdt_is_compatible(node, ocd->ocd_str))
93 			return (ocd);
94 	}
95 	return (NULL);
96 }
97 
98 static uintptr_t
99 uart_fdt_find_by_node(phandle_t node, int class_list)
100 {
101 	struct ofw_compat_data **cd;
102 	const struct ofw_compat_data *ocd;
103 
104 	if (class_list) {
105 		SET_FOREACH(cd, uart_fdt_class_set) {
106 			ocd = uart_fdt_find_compatible(node, *cd);
107 			if ((ocd != NULL) && (ocd->ocd_data != 0))
108 				return (ocd->ocd_data);
109 		}
110 	} else {
111 		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
112 			ocd = uart_fdt_find_compatible(node, *cd);
113 			if ((ocd != NULL) && (ocd->ocd_data != 0))
114 				return (ocd->ocd_data);
115 		}
116 	}
117 	return (0);
118 }
119 
120 int
121 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
122 {
123 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
124 	    "stdin-path", "stdin", NULL};
125 	const char **name;
126 	struct uart_class *class;
127 	phandle_t node, chosen;
128 	pcell_t shift, br, rclk;
129 	char *cp;
130 	int err;
131 
132 	/* Allow overriding the FDT using the environment. */
133 	class = &uart_ns8250_class;
134 	err = uart_getenv(devtype, di, class);
135 	if (!err)
136 		return (0);
137 
138 	if (devtype != UART_DEV_CONSOLE)
139 		return (ENXIO);
140 
141 	/* Has the user forced a specific device node? */
142 	cp = kern_getenv("hw.fdt.console");
143 	if (cp == NULL) {
144 		/*
145 		 * Retrieve /chosen/std{in,out}.
146 		 */
147 		node = -1;
148 		if ((chosen = OF_finddevice("/chosen")) != -1) {
149 			for (name = propnames; *name != NULL; name++) {
150 				if (phandle_chosen_propdev(chosen, *name,
151 				    &node) == 0)
152 					break;
153 			}
154 		}
155 		if (chosen == -1 || *name == NULL)
156 			node = OF_finddevice("serial0"); /* Last ditch */
157 	} else {
158 		node = OF_finddevice(cp);
159 	}
160 
161 	if (node == -1) /* Can't find anything */
162 		return (ENXIO);
163 
164 	/*
165 	 * Check old style of UART definition first. Unfortunately, the common
166 	 * FDT processing is not possible if we have clock, power domains and
167 	 * pinmux stuff.
168 	 */
169 	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
170 	if (class != NULL) {
171 		if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
172 			return (err);
173 	} else {
174 		/* Check class only linker set */
175 		class =
176 		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
177 		if (class == NULL)
178 			return (ENXIO);
179 		rclk = 0;
180 	}
181 
182 	/*
183 	 * Retrieve serial attributes.
184 	 */
185 	if (uart_fdt_get_shift(node, &shift) != 0)
186 		shift = uart_getregshift(class);
187 
188 	if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
189 		br = 0;
190 
191 	/*
192 	 * Finalize configuration.
193 	 */
194 	di->bas.chan = 0;
195 	di->bas.regshft = (u_int)shift;
196 	di->baudrate = br;
197 	di->bas.rclk = (u_int)rclk;
198 	di->ops = uart_getops(class);
199 	di->databits = 8;
200 	di->stopbits = 1;
201 	di->parity = UART_PARITY_NONE;
202 
203 	err = OF_decode_addr(node, 0, &di->bas.bst, &di->bas.bsh, NULL);
204 	uart_bus_space_mem = di->bas.bst;
205 	uart_bus_space_io = NULL;
206 
207 	return (err);
208 }
209