xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision ec0e626bafb335b30c499d06066997f54b10c092)
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 #include <dev/uart/uart_cpu_fdt.h>
54 
55 /*
56  * UART console routines.
57  */
58 bus_space_tag_t uart_bus_space_io;
59 bus_space_tag_t uart_bus_space_mem;
60 
61 static int
62 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
63 {
64 	pcell_t clock;
65 
66 	/* clock-frequency is a FreeBSD-only extention. */
67 	if ((OF_getprop(node, "clock-frequency", &clock,
68 	    sizeof(clock))) <= 0)
69 		clock = 0;
70 
71 	if (clock == 0)
72 		/* Try to retrieve parent 'bus-frequency' */
73 		/* XXX this should go to simple-bus fixup or so */
74 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
75 		    sizeof(clock))) <= 0)
76 			clock = 0;
77 
78 	*cell = fdt32_to_cpu(clock);
79 	return (0);
80 }
81 
82 static int
83 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
84 {
85 	pcell_t shift;
86 
87 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
88 		shift = 0;
89 	*cell = fdt32_to_cpu(shift);
90 	return (0);
91 }
92 
93 int
94 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
95 {
96 
97 	if (b1->bst != b2->bst)
98 		return (0);
99 	if (pmap_kextract(b1->bsh) == 0)
100 		return (0);
101 	if (pmap_kextract(b2->bsh) == 0)
102 		return (0);
103 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
104 }
105 
106 static int
107 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
108 {
109 	char buf[64];
110 
111 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
112 		return (ENXIO);
113 	if ((*node = OF_finddevice(buf)) == -1)
114 		return (ENXIO);
115 
116 	return (0);
117 }
118 
119 static const struct ofw_compat_data *
120 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
121 {
122 	const struct ofw_compat_data *ocd;
123 
124 	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
125 		if (fdt_is_compatible(node, ocd->ocd_str))
126 			return (ocd);
127 	}
128 	return (NULL);
129 }
130 
131 static uintptr_t
132 uart_fdt_find_by_node(phandle_t node, int class_list)
133 {
134 	struct ofw_compat_data **cd;
135 	const struct ofw_compat_data *ocd;
136 
137 	if (class_list) {
138 		SET_FOREACH(cd, uart_fdt_class_set) {
139 			ocd = uart_fdt_find_compatible(node, *cd);
140 			if ((ocd != NULL) && (ocd->ocd_data != 0))
141 				return (ocd->ocd_data);
142 		}
143 	} else {
144 		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
145 			ocd = uart_fdt_find_compatible(node, *cd);
146 			if ((ocd != NULL) && (ocd->ocd_data != 0))
147 				return (ocd->ocd_data);
148 		}
149 	}
150 	return (0);
151 }
152 
153 int
154 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
155 {
156 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
157 	    "stdin-path", "stdin", NULL};
158 	const char **name;
159 	struct uart_class *class;
160 	phandle_t node, chosen;
161 	pcell_t shift, br, rclk;
162 	u_long start, size, pbase, psize;
163 	int err;
164 
165 	uart_bus_space_mem = fdtbus_bs_tag;
166 	uart_bus_space_io = NULL;
167 
168 	/* Allow overriding the FDT using the environment. */
169 	class = &uart_ns8250_class;
170 	err = uart_getenv(devtype, di, class);
171 	if (!err)
172 		return (0);
173 
174 	if (devtype != UART_DEV_CONSOLE)
175 		return (ENXIO);
176 
177 	/*
178 	 * Retrieve /chosen/std{in,out}.
179 	 */
180 	node = -1;
181 	if ((chosen = OF_finddevice("/chosen")) != -1) {
182 		for (name = propnames; *name != NULL; name++) {
183 			if (phandle_chosen_propdev(chosen, *name, &node) == 0)
184 				break;
185 		}
186 	}
187 	if (chosen == -1 || *name == NULL)
188 		node = OF_finddevice("serial0"); /* Last ditch */
189 
190 	if (node == -1) /* Can't find anything */
191 		return (ENXIO);
192 
193 	/*
194 	 * Retrieve serial attributes.
195 	 */
196 	uart_fdt_get_shift(node, &shift);
197 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
198 		br = 0;
199 	else
200 		br = fdt32_to_cpu(br);
201 
202 	/*
203 	 * Check old style of UART definition first. Unfortunately, the common
204 	 * FDT processing is not possible if we have clock, power domains and
205 	 * pinmux stuff.
206 	 */
207 	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
208 	if (class != NULL) {
209 		if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
210 			return (err);
211 	} else {
212 		/* Check class only linker set */
213 		class =
214 		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
215 		if (class == NULL)
216 			return (ENXIO);
217 		rclk = 0;
218 	}
219 
220 	/*
221 	 * Finalize configuration.
222 	 */
223 	di->bas.chan = 0;
224 	di->bas.regshft = (u_int)shift;
225 	di->baudrate = br;
226 	di->bas.rclk = (u_int)rclk;
227 	di->ops = uart_getops(class);
228 	di->databits = 8;
229 	di->stopbits = 1;
230 	di->parity = UART_PARITY_NONE;
231 	di->bas.bst = uart_bus_space_mem;
232 
233 	err = fdt_regsize(node, &start, &size);
234 	if (err)
235 		return (ENXIO);
236 	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
237 	if (err)
238 		pbase = 0;
239 
240 	start += pbase;
241 
242 	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
243 }
244