xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision 43faedc1339a9624c7acedb7f3e5624e64da5b99)
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 #ifdef __aarch64__
58 extern bus_space_tag_t fdtbus_bs_tag;
59 #endif
60 
61 /*
62  * UART console routines.
63  */
64 bus_space_tag_t uart_bus_space_io;
65 bus_space_tag_t uart_bus_space_mem;
66 
67 int
68 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
69 {
70 
71 	if (b1->bst != b2->bst)
72 		return (0);
73 	if (pmap_kextract(b1->bsh) == 0)
74 		return (0);
75 	if (pmap_kextract(b2->bsh) == 0)
76 		return (0);
77 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
78 }
79 
80 static int
81 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
82 {
83 	char buf[64];
84 
85 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
86 		return (ENXIO);
87 	if ((*node = OF_finddevice(buf)) == -1)
88 		return (ENXIO);
89 
90 	return (0);
91 }
92 
93 static const struct ofw_compat_data *
94 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
95 {
96 	const struct ofw_compat_data *ocd;
97 
98 	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
99 		if (fdt_is_compatible(node, ocd->ocd_str))
100 			return (ocd);
101 	}
102 	return (NULL);
103 }
104 
105 static uintptr_t
106 uart_fdt_find_by_node(phandle_t node, int class_list)
107 {
108 	struct ofw_compat_data **cd;
109 	const struct ofw_compat_data *ocd;
110 
111 	if (class_list) {
112 		SET_FOREACH(cd, uart_fdt_class_set) {
113 			ocd = uart_fdt_find_compatible(node, *cd);
114 			if ((ocd != NULL) && (ocd->ocd_data != 0))
115 				return (ocd->ocd_data);
116 		}
117 	} else {
118 		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
119 			ocd = uart_fdt_find_compatible(node, *cd);
120 			if ((ocd != NULL) && (ocd->ocd_data != 0))
121 				return (ocd->ocd_data);
122 		}
123 	}
124 	return (0);
125 }
126 
127 int
128 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
129 {
130 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
131 	    "stdin-path", "stdin", NULL};
132 	const char **name;
133 	struct uart_class *class;
134 	phandle_t node, chosen;
135 	pcell_t shift, br, rclk;
136 	char *cp;
137 	int err;
138 
139 	uart_bus_space_mem = fdtbus_bs_tag;
140 	uart_bus_space_io = NULL;
141 
142 	/* Allow overriding the FDT using the environment. */
143 	class = &uart_ns8250_class;
144 	err = uart_getenv(devtype, di, class);
145 	if (!err)
146 		return (0);
147 
148 	if (devtype != UART_DEV_CONSOLE)
149 		return (ENXIO);
150 
151 	/* Has the user forced a specific device node? */
152 	cp = kern_getenv("hw.fdt.console");
153 	if (cp == NULL) {
154 		/*
155 		 * Retrieve /chosen/std{in,out}.
156 		 */
157 		node = -1;
158 		if ((chosen = OF_finddevice("/chosen")) != -1) {
159 			for (name = propnames; *name != NULL; name++) {
160 				if (phandle_chosen_propdev(chosen, *name,
161 				    &node) == 0)
162 					break;
163 			}
164 		}
165 		if (chosen == -1 || *name == NULL)
166 			node = OF_finddevice("serial0"); /* Last ditch */
167 	} else {
168 		node = OF_finddevice(cp);
169 	}
170 
171 	if (node == -1) /* Can't find anything */
172 		return (ENXIO);
173 
174 	/*
175 	 * Check old style of UART definition first. Unfortunately, the common
176 	 * FDT processing is not possible if we have clock, power domains and
177 	 * pinmux stuff.
178 	 */
179 	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
180 	if (class != NULL) {
181 		if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
182 			return (err);
183 	} else {
184 		/* Check class only linker set */
185 		class =
186 		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
187 		if (class == NULL)
188 			return (ENXIO);
189 		rclk = 0;
190 	}
191 
192 	/*
193 	 * Retrieve serial attributes.
194 	 */
195 	if (uart_fdt_get_shift(node, &shift) != 0)
196 		shift = uart_getregshift(class);
197 
198 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
199 		br = 0;
200 	else
201 		br = fdt32_to_cpu(br);
202 
203 	/*
204 	 * Finalize configuration.
205 	 */
206 	di->bas.chan = 0;
207 	di->bas.regshft = (u_int)shift;
208 	di->baudrate = br;
209 	di->bas.rclk = (u_int)rclk;
210 	di->ops = uart_getops(class);
211 	di->databits = 8;
212 	di->stopbits = 1;
213 	di->parity = UART_PARITY_NONE;
214 
215 	return (OF_decode_addr(node, 0, &di->bas.bst, &di->bas.bsh));
216 }
217