1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004 Marcel Moolenaar
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
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 ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35
36 #include <machine/bus.h>
37 #include <machine/vmparam.h>
38
39 #include <dev/uart/uart.h>
40 #include <dev/uart/uart_cpu.h>
41
42 #define UART_TAG_BR 0
43 #define UART_TAG_CH 1
44 #define UART_TAG_DB 2
45 #define UART_TAG_DT 3
46 #define UART_TAG_IO 4
47 #define UART_TAG_MM 5
48 #define UART_TAG_PA 6
49 #define UART_TAG_RS 7
50 #define UART_TAG_SB 8
51 #define UART_TAG_XO 9
52 #define UART_TAG_BD 10
53
54 static struct uart_class *uart_classes[] = {
55 &uart_ns8250_class,
56 &uart_z8530_class,
57 #if defined(__arm__)
58 &uart_s3c2410_class,
59 #endif
60 };
61
62 static bus_addr_t
63 uart_parse_addr(const char **p)
64 {
65 return (strtoul(*p, (char**)(uintptr_t)p, 0));
66 }
67
68 static struct uart_class *
69 uart_parse_class(struct uart_class *class, const char **p)
70 {
71 struct uart_class *uc;
72 const char *nm;
73 size_t len;
74 u_int i;
75
76 for (i = 0; i < nitems(uart_classes); i++) {
77 uc = uart_classes[i];
78 nm = uart_getname(uc);
79 if (nm == NULL || *nm == '\0')
80 continue;
81 len = strlen(nm);
82 if (strncmp(nm, *p, len) == 0) {
83 *p += len;
84 return (uc);
85 }
86 }
87 return (class);
88 }
89
90 static long
91 uart_parse_long(const char **p)
92 {
93 return (strtol(*p, (char**)(uintptr_t)p, 0));
94 }
95
96 static int
97 uart_parse_parity(const char **p)
98 {
99 if (!strncmp(*p, "even", 4)) {
100 *p += 4;
101 return UART_PARITY_EVEN;
102 }
103 if (!strncmp(*p, "mark", 4)) {
104 *p += 4;
105 return UART_PARITY_MARK;
106 }
107 if (!strncmp(*p, "none", 4)) {
108 *p += 4;
109 return UART_PARITY_NONE;
110 }
111 if (!strncmp(*p, "odd", 3)) {
112 *p += 3;
113 return UART_PARITY_ODD;
114 }
115 if (!strncmp(*p, "space", 5)) {
116 *p += 5;
117 return UART_PARITY_SPACE;
118 }
119 return (-1);
120 }
121
122 static int
123 uart_parse_tag(const char **p)
124 {
125 int tag;
126
127 if ((*p)[0] == 'b' && (*p)[1] == 'd') {
128 tag = UART_TAG_BD;
129 goto out;
130 }
131 if ((*p)[0] == 'b' && (*p)[1] == 'r') {
132 tag = UART_TAG_BR;
133 goto out;
134 }
135 if ((*p)[0] == 'c' && (*p)[1] == 'h') {
136 tag = UART_TAG_CH;
137 goto out;
138 }
139 if ((*p)[0] == 'd' && (*p)[1] == 'b') {
140 tag = UART_TAG_DB;
141 goto out;
142 }
143 if ((*p)[0] == 'd' && (*p)[1] == 't') {
144 tag = UART_TAG_DT;
145 goto out;
146 }
147 if ((*p)[0] == 'i' && (*p)[1] == 'o') {
148 tag = UART_TAG_IO;
149 goto out;
150 }
151 if ((*p)[0] == 'm' && (*p)[1] == 'm') {
152 tag = UART_TAG_MM;
153 goto out;
154 }
155 if ((*p)[0] == 'p' && (*p)[1] == 'a') {
156 tag = UART_TAG_PA;
157 goto out;
158 }
159 if ((*p)[0] == 'r' && (*p)[1] == 's') {
160 tag = UART_TAG_RS;
161 goto out;
162 }
163 if ((*p)[0] == 's' && (*p)[1] == 'b') {
164 tag = UART_TAG_SB;
165 goto out;
166 }
167 if ((*p)[0] == 'x' && (*p)[1] == 'o') {
168 tag = UART_TAG_XO;
169 goto out;
170 }
171 return (-1);
172
173 out:
174 *p += 2;
175 if ((*p)[0] != ':' && (*p)[0] != '=')
176 return (-1);
177 (*p)++;
178 return (tag);
179 }
180
181 /*
182 * Parse a device specification. The specification is a list of attributes
183 * separated by commas. Each attribute is a tag-value pair with the tag and
184 * value separated by a colon. Supported tags are:
185 *
186 * bd = Busy Detect
187 * br = Baudrate
188 * ch = Channel
189 * db = Data bits
190 * dt = Device type
191 * io = I/O port address
192 * mm = Memory mapped I/O address
193 * pa = Parity
194 * rs = Register shift
195 * sb = Stopbits
196 * xo = Device clock (xtal oscillator)
197 *
198 * The io and mm tags are mutually exclusive.
199 */
200
201 int
202 uart_getenv(int devtype, struct uart_devinfo *di, struct uart_class *class)
203 {
204 const char *spec;
205 char *cp;
206 bus_addr_t addr = ~0U;
207 int error;
208
209 /*
210 * All uart_class references are weak. Make sure the default
211 * device class has been compiled-in.
212 */
213 if (class == NULL)
214 return (ENXIO);
215
216 /*
217 * Check the environment variables "hw.uart.console" and
218 * "hw.uart.dbgport". These variables, when present, specify
219 * which UART port is to be used as serial console or debug
220 * port (resp).
221 */
222 switch (devtype) {
223 case UART_DEV_CONSOLE:
224 cp = kern_getenv("hw.uart.console");
225 break;
226 case UART_DEV_DBGPORT:
227 cp = kern_getenv("hw.uart.dbgport");
228 break;
229 default:
230 cp = NULL;
231 break;
232 }
233
234 if (cp == NULL)
235 return (ENXIO);
236
237 /* Set defaults. */
238 di->bas.chan = 0;
239 di->bas.regshft = 0;
240 di->bas.rclk = 0;
241 di->baudrate = 0;
242 di->databits = 8;
243 di->stopbits = 1;
244 di->parity = UART_PARITY_NONE;
245
246 /* Parse the attributes. */
247 spec = cp;
248 for (;;) {
249 switch (uart_parse_tag(&spec)) {
250 case UART_TAG_BD:
251 di->bas.busy_detect = uart_parse_long(&spec);
252 break;
253 case UART_TAG_BR:
254 di->baudrate = uart_parse_long(&spec);
255 break;
256 case UART_TAG_CH:
257 di->bas.chan = uart_parse_long(&spec);
258 break;
259 case UART_TAG_DB:
260 di->databits = uart_parse_long(&spec);
261 break;
262 case UART_TAG_DT:
263 class = uart_parse_class(class, &spec);
264 break;
265 case UART_TAG_IO:
266 di->bas.bst = uart_bus_space_io;
267 addr = uart_parse_addr(&spec);
268 break;
269 case UART_TAG_MM:
270 di->bas.bst = uart_bus_space_mem;
271 addr = uart_parse_addr(&spec);
272 break;
273 case UART_TAG_PA:
274 di->parity = uart_parse_parity(&spec);
275 break;
276 case UART_TAG_RS:
277 di->bas.regshft = uart_parse_long(&spec);
278 break;
279 case UART_TAG_SB:
280 di->stopbits = uart_parse_long(&spec);
281 break;
282 case UART_TAG_XO:
283 di->bas.rclk = uart_parse_long(&spec);
284 break;
285 default:
286 goto inval;
287 }
288 if (*spec == '\0')
289 break;
290 if (*spec != ',')
291 goto inval;
292 spec++;
293 }
294
295 /*
296 * If we still have an invalid address, the specification must be
297 * missing an I/O port or memory address. We don't like that.
298 */
299 if (addr == ~0U)
300 goto inval;
301 freeenv(cp);
302
303 /*
304 * Accept only the well-known baudrates. Any invalid baudrate
305 * is silently replaced with a 0-valued baudrate. The 0 baudrate
306 * has special meaning. It means that we're not supposed to
307 * program the baudrate and simply communicate with whatever
308 * speed the hardware is currently programmed for.
309 */
310 if (di->baudrate >= 19200) {
311 if (di->baudrate % 19200)
312 di->baudrate = 0;
313 } else if (di->baudrate >= 1200) {
314 if (di->baudrate % 1200)
315 di->baudrate = 0;
316 } else if (di->baudrate > 0) {
317 if (di->baudrate % 75)
318 di->baudrate = 0;
319 } else
320 di->baudrate = 0;
321
322 /* Set the ops and create a bus space handle. */
323 di->ops = uart_getops(class);
324 error = bus_space_map(di->bas.bst, addr, uart_getrange(class), 0,
325 &di->bas.bsh);
326 return (error);
327 inval:
328 printf("warning: bad uart specification: %s\n", cp);
329 freeenv(cp);
330 return (EINVAL);
331 }
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