xref: /freebsd/sys/dev/uart/uart_bus_fdt.c (revision af6a5351a1fdb1130f18be6c782c4d48916eb971)
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/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 
41 #include <machine/bus.h>
42 
43 #include <dev/fdt/fdt_common.h>
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 #include <dev/uart/uart.h>
47 #include <dev/uart/uart_bus.h>
48 #include <dev/uart/uart_cpu.h>
49 #include <dev/uart/uart_cpu_fdt.h>
50 
51 static int uart_fdt_probe(device_t);
52 
53 static device_method_t uart_fdt_methods[] = {
54 	/* Device interface */
55 	DEVMETHOD(device_probe,		uart_fdt_probe),
56 	DEVMETHOD(device_attach,	uart_bus_attach),
57 	DEVMETHOD(device_detach,	uart_bus_detach),
58 	{ 0, 0 }
59 };
60 
61 static driver_t uart_fdt_driver = {
62 	uart_driver_name,
63 	uart_fdt_methods,
64 	sizeof(struct uart_softc),
65 };
66 
67 int
68 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
69 {
70 
71 	/* clock-frequency is a FreeBSD-only extension. */
72 	if ((OF_getencprop(node, "clock-frequency", cell,
73 	    sizeof(*cell))) <= 0) {
74 		/* Try to retrieve parent 'bus-frequency' */
75 		/* XXX this should go to simple-bus fixup or so */
76 		if ((OF_getencprop(OF_parent(node), "bus-frequency", cell,
77 		    sizeof(*cell))) <= 0)
78 			*cell = 0;
79 	}
80 
81 	return (0);
82 }
83 
84 int
85 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
86 {
87 
88 	if ((OF_getencprop(node, "reg-shift", cell, sizeof(*cell))) <= 0)
89 		return (-1);
90 	return (0);
91 }
92 
93 int
94 uart_fdt_get_io_width(phandle_t node, pcell_t *cell)
95 {
96 
97 	if ((OF_getencprop(node, "reg-io-width", cell, sizeof(*cell))) <= 0)
98 		return (-1);
99 	return (0);
100 }
101 
102 static uintptr_t
103 uart_fdt_find_device(device_t dev)
104 {
105 	struct ofw_compat_data **cd;
106 	const struct ofw_compat_data *ocd;
107 
108 	SET_FOREACH(cd, uart_fdt_class_and_device_set) {
109 		ocd = ofw_bus_search_compatible(dev, *cd);
110 		if (ocd->ocd_data != 0)
111 			return (ocd->ocd_data);
112 	}
113 	return (0);
114 }
115 
116 static int
117 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
118 {
119 	char buf[64];
120 
121 	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
122 		return (ENXIO);
123 	if ((*node = OF_finddevice(buf)) == -1)
124 		return (ENXIO);
125 
126 	return (0);
127 }
128 
129 static const struct ofw_compat_data *
130 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
131 {
132 	const struct ofw_compat_data *ocd;
133 
134 	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
135 		if (ofw_bus_node_is_compatible(node, ocd->ocd_str))
136 			return (ocd);
137 	}
138 	return (NULL);
139 }
140 
141 static uintptr_t
142 uart_fdt_find_by_node(phandle_t node, int class_list)
143 {
144 	struct ofw_compat_data **cd;
145 	const struct ofw_compat_data *ocd;
146 
147 	if (class_list) {
148 		SET_FOREACH(cd, uart_fdt_class_set) {
149 			ocd = uart_fdt_find_compatible(node, *cd);
150 			if ((ocd != NULL) && (ocd->ocd_data != 0))
151 				return (ocd->ocd_data);
152 		}
153 	} else {
154 		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
155 			ocd = uart_fdt_find_compatible(node, *cd);
156 			if ((ocd != NULL) && (ocd->ocd_data != 0))
157 				return (ocd->ocd_data);
158 		}
159 	}
160 
161 	return (0);
162 }
163 
164 int
165 uart_cpu_fdt_probe(struct uart_class **classp, bus_space_tag_t *bst,
166     bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp,
167     u_int *iowidthp)
168 {
169 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
170 	    "stdin-path", "stdin", NULL};
171 	const char **name;
172 	struct uart_class *class;
173 	phandle_t node, chosen;
174 	pcell_t br, clk, shift, iowidth;
175 	char *cp;
176 	int err;
177 
178 	/* Has the user forced a specific device node? */
179 	cp = kern_getenv("hw.fdt.console");
180 	if (cp == NULL) {
181 		/*
182 		 * Retrieve /chosen/std{in,out}.
183 		 */
184 		node = -1;
185 		if ((chosen = OF_finddevice("/chosen")) != -1) {
186 			for (name = propnames; *name != NULL; name++) {
187 				if (phandle_chosen_propdev(chosen, *name,
188 				    &node) == 0)
189 					break;
190 			}
191 		}
192 		if (chosen == -1 || *name == NULL)
193 			node = OF_finddevice("serial0"); /* Last ditch */
194 	} else {
195 		node = OF_finddevice(cp);
196 	}
197 
198 	if (node == -1)
199 		return (ENXIO);
200 
201 	/*
202 	 * Check old style of UART definition first. Unfortunately, the common
203 	 * FDT processing is not possible if we have clock, power domains and
204 	 * pinmux stuff.
205 	 */
206 	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
207 	if (class != NULL) {
208 		if ((err = uart_fdt_get_clock(node, &clk)) != 0)
209 			return (err);
210 	} else {
211 		/* Check class only linker set */
212 		class =
213 		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
214 		if (class == NULL)
215 			return (ENXIO);
216 		clk = 0;
217 	}
218 
219 	/*
220 	 * Retrieve serial attributes.
221 	 */
222 	if (uart_fdt_get_shift(node, &shift) != 0)
223 		shift = uart_getregshift(class);
224 
225 	if (uart_fdt_get_io_width(node, &iowidth) != 0)
226 		iowidth = uart_getregiowidth(class);
227 
228 	if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
229 		br = 0;
230 
231 	err = OF_decode_addr(node, 0, bst, bsh, NULL);
232 	if (err != 0)
233 		return (err);
234 
235 	*classp = class;
236 	*baud = br;
237 	*rclk = clk;
238 	*shiftp = shift;
239 	*iowidthp = iowidth;
240 
241 	return (0);
242 }
243 
244 static int
245 uart_fdt_probe(device_t dev)
246 {
247 	struct uart_softc *sc;
248 	phandle_t node;
249 	pcell_t clock, shift, iowidth;
250 	int err;
251 
252 	sc = device_get_softc(dev);
253 
254 	if (!ofw_bus_status_okay(dev))
255 		return (ENXIO);
256 
257 	sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
258 	if (sc->sc_class == NULL)
259 		return (ENXIO);
260 
261 	node = ofw_bus_get_node(dev);
262 
263 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
264 		return (err);
265 	if (uart_fdt_get_shift(node, &shift) != 0)
266 		shift = uart_getregshift(sc->sc_class);
267 	if (uart_fdt_get_io_width(node, &iowidth) != 0)
268 		iowidth = uart_getregiowidth(sc->sc_class);
269 
270 	return (uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0));
271 }
272 
273 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
274 DRIVER_MODULE(uart, ofwbus, uart_fdt_driver, uart_devclass, 0, 0);
275