uart_cpu_fdt.c revision 279723 
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: head/sys/dev/uart/uart_cpu_fdt.c 279723 2015-03-07 15:18:57Z ian $");
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 */
58bus_space_tag_t uart_bus_space_io;
59bus_space_tag_t uart_bus_space_mem;
60
61static int
62uart_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
82static int
83uart_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
93int
94uart_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
106static int
107phandle_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
119static const struct ofw_compat_data *
120uart_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
131static uintptr_t
132uart_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
153int
154uart_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