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_sab82532_class,
57 &uart_z8530_class,
58 #if defined(__arm__)
59 &uart_s3c2410_class,
60 #endif
61 };
62
63 static bus_addr_t
uart_parse_addr(const char ** p)64 uart_parse_addr(const char **p)
65 {
66 return (strtoul(*p, (char**)(uintptr_t)p, 0));
67 }
68
69 static struct uart_class *
uart_parse_class(struct uart_class * class,const char ** p)70 uart_parse_class(struct uart_class *class, const char **p)
71 {
72 struct uart_class *uc;
73 const char *nm;
74 size_t len;
75 u_int i;
76
77 for (i = 0; i < nitems(uart_classes); i++) {
78 uc = uart_classes[i];
79 nm = uart_getname(uc);
80 if (nm == NULL || *nm == '\0')
81 continue;
82 len = strlen(nm);
83 if (strncmp(nm, *p, len) == 0) {
84 *p += len;
85 return (uc);
86 }
87 }
88 return (class);
89 }
90
91 static long
uart_parse_long(const char ** p)92 uart_parse_long(const char **p)
93 {
94 return (strtol(*p, (char**)(uintptr_t)p, 0));
95 }
96
97 static int
uart_parse_parity(const char ** p)98 uart_parse_parity(const char **p)
99 {
100 if (!strncmp(*p, "even", 4)) {
101 *p += 4;
102 return UART_PARITY_EVEN;
103 }
104 if (!strncmp(*p, "mark", 4)) {
105 *p += 4;
106 return UART_PARITY_MARK;
107 }
108 if (!strncmp(*p, "none", 4)) {
109 *p += 4;
110 return UART_PARITY_NONE;
111 }
112 if (!strncmp(*p, "odd", 3)) {
113 *p += 3;
114 return UART_PARITY_ODD;
115 }
116 if (!strncmp(*p, "space", 5)) {
117 *p += 5;
118 return UART_PARITY_SPACE;
119 }
120 return (-1);
121 }
122
123 static int
uart_parse_tag(const char ** p)124 uart_parse_tag(const char **p)
125 {
126 int tag;
127
128 if ((*p)[0] == 'b' && (*p)[1] == 'd') {
129 tag = UART_TAG_BD;
130 goto out;
131 }
132 if ((*p)[0] == 'b' && (*p)[1] == 'r') {
133 tag = UART_TAG_BR;
134 goto out;
135 }
136 if ((*p)[0] == 'c' && (*p)[1] == 'h') {
137 tag = UART_TAG_CH;
138 goto out;
139 }
140 if ((*p)[0] == 'd' && (*p)[1] == 'b') {
141 tag = UART_TAG_DB;
142 goto out;
143 }
144 if ((*p)[0] == 'd' && (*p)[1] == 't') {
145 tag = UART_TAG_DT;
146 goto out;
147 }
148 if ((*p)[0] == 'i' && (*p)[1] == 'o') {
149 tag = UART_TAG_IO;
150 goto out;
151 }
152 if ((*p)[0] == 'm' && (*p)[1] == 'm') {
153 tag = UART_TAG_MM;
154 goto out;
155 }
156 if ((*p)[0] == 'p' && (*p)[1] == 'a') {
157 tag = UART_TAG_PA;
158 goto out;
159 }
160 if ((*p)[0] == 'r' && (*p)[1] == 's') {
161 tag = UART_TAG_RS;
162 goto out;
163 }
164 if ((*p)[0] == 's' && (*p)[1] == 'b') {
165 tag = UART_TAG_SB;
166 goto out;
167 }
168 if ((*p)[0] == 'x' && (*p)[1] == 'o') {
169 tag = UART_TAG_XO;
170 goto out;
171 }
172 return (-1);
173
174 out:
175 *p += 2;
176 if ((*p)[0] != ':')
177 return (-1);
178 (*p)++;
179 return (tag);
180 }
181
182 /*
183 * Parse a device specification. The specification is a list of attributes
184 * separated by commas. Each attribute is a tag-value pair with the tag and
185 * value separated by a colon. Supported tags are:
186 *
187 * bd = Busy Detect
188 * br = Baudrate
189 * ch = Channel
190 * db = Data bits
191 * dt = Device type
192 * io = I/O port address
193 * mm = Memory mapped I/O address
194 * pa = Parity
195 * rs = Register shift
196 * sb = Stopbits
197 * xo = Device clock (xtal oscillator)
198 *
199 * The io and mm tags are mutually exclusive.
200 */
201
202 int
uart_getenv(int devtype,struct uart_devinfo * di,struct uart_class * class)203 uart_getenv(int devtype, struct uart_devinfo *di, struct uart_class *class)
204 {
205 const char *spec;
206 char *cp;
207 bus_addr_t addr = ~0U;
208 int error;
209
210 /*
211 * All uart_class references are weak. Make sure the default
212 * device class has been compiled-in.
213 */
214 if (class == NULL)
215 return (ENXIO);
216
217 /*
218 * Check the environment variables "hw.uart.console" and
219 * "hw.uart.dbgport". These variables, when present, specify
220 * which UART port is to be used as serial console or debug
221 * port (resp).
222 */
223 switch (devtype) {
224 case UART_DEV_CONSOLE:
225 cp = kern_getenv("hw.uart.console");
226 break;
227 case UART_DEV_DBGPORT:
228 cp = kern_getenv("hw.uart.dbgport");
229 break;
230 default:
231 cp = NULL;
232 break;
233 }
234
235 if (cp == NULL)
236 return (ENXIO);
237
238 /* Set defaults. */
239 di->bas.chan = 0;
240 di->bas.regshft = 0;
241 di->bas.rclk = 0;
242 di->baudrate = 0;
243 di->databits = 8;
244 di->stopbits = 1;
245 di->parity = UART_PARITY_NONE;
246
247 /* Parse the attributes. */
248 spec = cp;
249 for (;;) {
250 switch (uart_parse_tag(&spec)) {
251 case UART_TAG_BD:
252 di->bas.busy_detect = uart_parse_long(&spec);
253 break;
254 case UART_TAG_BR:
255 di->baudrate = uart_parse_long(&spec);
256 break;
257 case UART_TAG_CH:
258 di->bas.chan = uart_parse_long(&spec);
259 break;
260 case UART_TAG_DB:
261 di->databits = uart_parse_long(&spec);
262 break;
263 case UART_TAG_DT:
264 class = uart_parse_class(class, &spec);
265 break;
266 case UART_TAG_IO:
267 di->bas.bst = uart_bus_space_io;
268 addr = uart_parse_addr(&spec);
269 break;
270 case UART_TAG_MM:
271 di->bas.bst = uart_bus_space_mem;
272 addr = uart_parse_addr(&spec);
273 break;
274 case UART_TAG_PA:
275 di->parity = uart_parse_parity(&spec);
276 break;
277 case UART_TAG_RS:
278 di->bas.regshft = uart_parse_long(&spec);
279 break;
280 case UART_TAG_SB:
281 di->stopbits = uart_parse_long(&spec);
282 break;
283 case UART_TAG_XO:
284 di->bas.rclk = uart_parse_long(&spec);
285 break;
286 default:
287 freeenv(cp);
288 return (EINVAL);
289 }
290 if (*spec == '\0')
291 break;
292 if (*spec != ',') {
293 freeenv(cp);
294 return (EINVAL);
295 }
296 spec++;
297 }
298 freeenv(cp);
299
300 /*
301 * If we still have an invalid address, the specification must be
302 * missing an I/O port or memory address. We don't like that.
303 */
304 if (addr == ~0U)
305 return (EINVAL);
306
307 /*
308 * Accept only the well-known baudrates. Any invalid baudrate
309 * is silently replaced with a 0-valued baudrate. The 0 baudrate
310 * has special meaning. It means that we're not supposed to
311 * program the baudrate and simply communicate with whatever
312 * speed the hardware is currently programmed for.
313 */
314 if (di->baudrate >= 19200) {
315 if (di->baudrate % 19200)
316 di->baudrate = 0;
317 } else if (di->baudrate >= 1200) {
318 if (di->baudrate % 1200)
319 di->baudrate = 0;
320 } else if (di->baudrate > 0) {
321 if (di->baudrate % 75)
322 di->baudrate = 0;
323 } else
324 di->baudrate = 0;
325
326 /* Set the ops and create a bus space handle. */
327 di->ops = uart_getops(class);
328 error = bus_space_map(di->bas.bst, addr, uart_getrange(class), 0,
329 &di->bas.bsh);
330 return (error);
331 }
332