1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009-2010 The FreeBSD Foundation
5 *
6 * This software was developed by Semihalf under sponsorship from
7 * the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 #include "opt_platform.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39
40 #include <machine/bus.h>
41
42 #include <dev/fdt/fdt_common.h>
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 #include <dev/uart/uart.h>
46 #include <dev/uart/uart_bus.h>
47 #include <dev/uart/uart_cpu.h>
48 #include <dev/uart/uart_cpu_fdt.h>
49
50 static int uart_fdt_probe(device_t);
51
52 static device_method_t uart_fdt_methods[] = {
53 /* Device interface */
54 DEVMETHOD(device_probe, uart_fdt_probe),
55 DEVMETHOD(device_attach, uart_bus_attach),
56 DEVMETHOD(device_detach, uart_bus_detach),
57 { 0, 0 }
58 };
59
60 static driver_t uart_fdt_driver = {
61 uart_driver_name,
62 uart_fdt_methods,
63 sizeof(struct uart_softc),
64 };
65
66 int
uart_fdt_get_clock(phandle_t node,pcell_t * cell)67 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
68 {
69
70 /* clock-frequency is a FreeBSD-only extension. */
71 if ((OF_getencprop(node, "clock-frequency", cell,
72 sizeof(*cell))) <= 0) {
73 /* Try to retrieve parent 'bus-frequency' */
74 /* XXX this should go to simple-bus fixup or so */
75 if ((OF_getencprop(OF_parent(node), "bus-frequency", cell,
76 sizeof(*cell))) <= 0)
77 *cell = 0;
78 }
79
80 return (0);
81 }
82
83 int
uart_fdt_get_shift(phandle_t node,pcell_t * cell)84 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
85 {
86
87 if ((OF_getencprop(node, "reg-shift", cell, sizeof(*cell))) <= 0)
88 return (-1);
89 return (0);
90 }
91
92 int
uart_fdt_get_io_width(phandle_t node,pcell_t * cell)93 uart_fdt_get_io_width(phandle_t node, pcell_t *cell)
94 {
95
96 if ((OF_getencprop(node, "reg-io-width", cell, sizeof(*cell))) <= 0)
97 return (-1);
98 return (0);
99 }
100
101 static uintptr_t
uart_fdt_find_device(device_t dev)102 uart_fdt_find_device(device_t dev)
103 {
104 struct ofw_compat_data **cd;
105 const struct ofw_compat_data *ocd;
106
107 SET_FOREACH(cd, uart_fdt_class_and_device_set) {
108 ocd = ofw_bus_search_compatible(dev, *cd);
109 if (ocd->ocd_data != 0)
110 return (ocd->ocd_data);
111 }
112 return (0);
113 }
114
115 static int
phandle_chosen_propdev(phandle_t chosen,const char * name,phandle_t * node)116 phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
117 {
118 char buf[64];
119 char *sep;
120
121 if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
122 return (ENXIO);
123 /*
124 * stdout-path may have a ':' to separate the device from the
125 * connection settings. Split the string so we just pass the former
126 * to OF_finddevice.
127 */
128 sep = strchr(buf, ':');
129 if (sep != NULL)
130 *sep = '\0';
131 if ((*node = OF_finddevice(buf)) == -1)
132 return (ENXIO);
133
134 return (0);
135 }
136
137 static const struct ofw_compat_data *
uart_fdt_find_compatible(phandle_t node,const struct ofw_compat_data * cd)138 uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
139 {
140 const struct ofw_compat_data *ocd;
141
142 for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
143 if (ofw_bus_node_is_compatible(node, ocd->ocd_str))
144 return (ocd);
145 }
146 return (NULL);
147 }
148
149 static uintptr_t
uart_fdt_find_by_node(phandle_t node,int class_list)150 uart_fdt_find_by_node(phandle_t node, int class_list)
151 {
152 struct ofw_compat_data **cd;
153 const struct ofw_compat_data *ocd;
154
155 if (class_list) {
156 SET_FOREACH(cd, uart_fdt_class_set) {
157 ocd = uart_fdt_find_compatible(node, *cd);
158 if ((ocd != NULL) && (ocd->ocd_data != 0))
159 return (ocd->ocd_data);
160 }
161 } else {
162 SET_FOREACH(cd, uart_fdt_class_and_device_set) {
163 ocd = uart_fdt_find_compatible(node, *cd);
164 if ((ocd != NULL) && (ocd->ocd_data != 0))
165 return (ocd->ocd_data);
166 }
167 }
168
169 return (0);
170 }
171
172 int
uart_cpu_fdt_probe(struct uart_class ** classp,bus_space_tag_t * bst,bus_space_handle_t * bsh,int * baud,u_int * rclk,u_int * shiftp,u_int * iowidthp,const int devtype)173 uart_cpu_fdt_probe(struct uart_class **classp, bus_space_tag_t *bst,
174 bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp,
175 u_int *iowidthp, const int devtype)
176 {
177 const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
178 "stdin-path", "stdin", NULL};
179 const char *propnames_dbgport[] = {"freebsd,debug-path", NULL};
180 const char **name;
181 struct uart_class *class;
182 phandle_t node, chosen;
183 pcell_t br, clk, shift, iowidth;
184 char *cp = NULL;
185 int err;
186
187 /* Has the user forced a specific device node? */
188 switch (devtype) {
189 case UART_DEV_DBGPORT:
190 cp = kern_getenv("hw.fdt.dbgport");
191 name = propnames_dbgport;
192 break;
193 case UART_DEV_CONSOLE:
194 cp = kern_getenv("hw.fdt.console");
195 name = propnames;
196 break;
197 default:
198 return (ENXIO);
199 }
200
201 if (cp == NULL) {
202 /*
203 * Retrieve a node from /chosen.
204 */
205 node = -1;
206 if ((chosen = OF_finddevice("/chosen")) != -1) {
207 for (; *name != NULL; name++) {
208 if (phandle_chosen_propdev(chosen, *name,
209 &node) == 0)
210 break;
211 }
212 }
213 if (chosen == -1 || *name == NULL)
214 node = OF_finddevice("serial0"); /* Last ditch */
215 } else {
216 node = OF_finddevice(cp);
217 }
218
219 if (node == -1)
220 return (ENXIO);
221
222 /*
223 * Check old style of UART definition first. Unfortunately, the common
224 * FDT processing is not possible if we have clock, power domains and
225 * pinmux stuff.
226 */
227 class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
228 if (class != NULL) {
229 if ((err = uart_fdt_get_clock(node, &clk)) != 0)
230 return (err);
231 } else {
232 /* Check class only linker set */
233 class =
234 (struct uart_class *)uart_fdt_find_by_node(node, 1);
235 if (class == NULL)
236 return (ENXIO);
237 if (uart_fdt_get_clock(node, &clk) != 0)
238 clk = 0;
239 }
240
241 /*
242 * Retrieve serial attributes.
243 */
244 if (uart_fdt_get_shift(node, &shift) != 0)
245 shift = uart_getregshift(class);
246
247 if (uart_fdt_get_io_width(node, &iowidth) != 0)
248 iowidth = uart_getregiowidth(class);
249
250 if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
251 br = 0;
252
253 err = OF_decode_addr(node, 0, bst, bsh, NULL);
254 if (err != 0)
255 return (err);
256
257 *classp = class;
258 *baud = br;
259 *rclk = clk;
260 *shiftp = shift;
261 *iowidthp = iowidth;
262
263 return (0);
264 }
265
266 static int
uart_fdt_probe(device_t dev)267 uart_fdt_probe(device_t dev)
268 {
269 struct uart_softc *sc;
270 phandle_t node;
271 pcell_t clock, shift, iowidth;
272 int err;
273
274 sc = device_get_softc(dev);
275
276 if (!ofw_bus_status_okay(dev))
277 return (ENXIO);
278
279 sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
280 if (sc->sc_class == NULL)
281 return (ENXIO);
282
283 node = ofw_bus_get_node(dev);
284
285 if ((err = uart_fdt_get_clock(node, &clock)) != 0)
286 return (err);
287 if (uart_fdt_get_shift(node, &shift) != 0)
288 shift = uart_getregshift(sc->sc_class);
289 if (uart_fdt_get_io_width(node, &iowidth) != 0)
290 iowidth = uart_getregiowidth(sc->sc_class);
291
292 return (uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, 0));
293 }
294
295 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, 0, 0);
296 DRIVER_MODULE(uart, ofwbus, uart_fdt_driver, 0, 0);
297