1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32
33 #include <machine/bus.h>
34 #include <machine/vmparam.h>
35
36 #include <dev/uart/uart.h>
37 #include <dev/uart/uart_cpu.h>
38
39 #define UART_TAG_BR 0
40 #define UART_TAG_CH 1
41 #define UART_TAG_DB 2
42 #define UART_TAG_DT 3
43 #define UART_TAG_IO 4
44 #define UART_TAG_MM 5
45 #define UART_TAG_PA 6
46 #define UART_TAG_RS 7
47 #define UART_TAG_SB 8
48 #define UART_TAG_XO 9
49 #define UART_TAG_BD 10
50 #define UART_TAG_RW 11
51
52 static bus_addr_t
uart_parse_addr(const char ** p)53 uart_parse_addr(const char **p)
54 {
55 return (strtoul(*p, (char**)(uintptr_t)p, 0));
56 }
57
58 static struct uart_class *
uart_parse_class(struct uart_class * class,const char ** p)59 uart_parse_class(struct uart_class *class, const char **p)
60 {
61 struct uart_class **puc, *uc;
62 const char *nm;
63 size_t len;
64
65 SET_FOREACH(puc, uart_class_set) {
66 uc = *puc;
67 nm = uart_getname(uc);
68 if (nm == NULL || *nm == '\0')
69 continue;
70 len = strlen(nm);
71 if (strncmp(nm, *p, len) == 0) {
72 *p += len;
73 return (uc);
74 }
75 }
76 return (class);
77 }
78
79 static long
uart_parse_long(const char ** p)80 uart_parse_long(const char **p)
81 {
82 return (strtol(*p, (char**)(uintptr_t)p, 0));
83 }
84
85 static int
uart_parse_parity(const char ** p)86 uart_parse_parity(const char **p)
87 {
88 if (!strncmp(*p, "even", 4)) {
89 *p += 4;
90 return UART_PARITY_EVEN;
91 }
92 if (!strncmp(*p, "mark", 4)) {
93 *p += 4;
94 return UART_PARITY_MARK;
95 }
96 if (!strncmp(*p, "none", 4)) {
97 *p += 4;
98 return UART_PARITY_NONE;
99 }
100 if (!strncmp(*p, "odd", 3)) {
101 *p += 3;
102 return UART_PARITY_ODD;
103 }
104 if (!strncmp(*p, "space", 5)) {
105 *p += 5;
106 return UART_PARITY_SPACE;
107 }
108 return (-1);
109 }
110
111 static int
uart_parse_tag(const char ** p)112 uart_parse_tag(const char **p)
113 {
114 int tag;
115
116 if ((*p)[0] == 'b' && (*p)[1] == 'd') {
117 tag = UART_TAG_BD;
118 goto out;
119 }
120 if ((*p)[0] == 'b' && (*p)[1] == 'r') {
121 tag = UART_TAG_BR;
122 goto out;
123 }
124 if ((*p)[0] == 'c' && (*p)[1] == 'h') {
125 tag = UART_TAG_CH;
126 goto out;
127 }
128 if ((*p)[0] == 'd' && (*p)[1] == 'b') {
129 tag = UART_TAG_DB;
130 goto out;
131 }
132 if ((*p)[0] == 'd' && (*p)[1] == 't') {
133 tag = UART_TAG_DT;
134 goto out;
135 }
136 if ((*p)[0] == 'i' && (*p)[1] == 'o') {
137 tag = UART_TAG_IO;
138 goto out;
139 }
140 if ((*p)[0] == 'm' && (*p)[1] == 'm') {
141 tag = UART_TAG_MM;
142 goto out;
143 }
144 if ((*p)[0] == 'p' && (*p)[1] == 'a') {
145 tag = UART_TAG_PA;
146 goto out;
147 }
148 if ((*p)[0] == 'r' && (*p)[1] == 's') {
149 tag = UART_TAG_RS;
150 goto out;
151 }
152 if ((*p)[0] == 'r' && (*p)[1] == 'w') {
153 tag = UART_TAG_RW;
154 goto out;
155 }
156 if ((*p)[0] == 's' && (*p)[1] == 'b') {
157 tag = UART_TAG_SB;
158 goto out;
159 }
160 if ((*p)[0] == 'x' && (*p)[1] == 'o') {
161 tag = UART_TAG_XO;
162 goto out;
163 }
164 return (-1);
165
166 out:
167 *p += 2;
168 if ((*p)[0] != ':' && (*p)[0] != '=')
169 return (-1);
170 (*p)++;
171 return (tag);
172 }
173
174 /*
175 * Parse a device specification. The specification is a list of attributes
176 * separated by commas. Each attribute is a tag-value pair with the tag and
177 * value separated by a colon. Supported tags are:
178 *
179 * bd = Busy Detect
180 * br = Baudrate
181 * ch = Channel
182 * db = Data bits
183 * dt = Device type
184 * io = I/O port address
185 * mm = Memory mapped I/O address
186 * pa = Parity
187 * rs = Register shift
188 * rw = Register width
189 * sb = Stopbits
190 * xo = Device clock (xtal oscillator)
191 *
192 * The io and mm tags are mutually exclusive.
193 */
194
195 int
uart_getenv(int devtype,struct uart_devinfo * di,struct uart_class * class)196 uart_getenv(int devtype, struct uart_devinfo *di, struct uart_class *class)
197 {
198 const char *spec;
199 char *cp;
200 bus_addr_t addr = ~0U;
201 int error;
202
203 /*
204 * Check the environment variables "hw.uart.console" and
205 * "hw.uart.dbgport". These variables, when present, specify
206 * which UART port is to be used as serial console or debug
207 * port (resp).
208 */
209 switch (devtype) {
210 case UART_DEV_CONSOLE:
211 cp = kern_getenv("hw.uart.console");
212 break;
213 case UART_DEV_DBGPORT:
214 cp = kern_getenv("hw.uart.dbgport");
215 break;
216 default:
217 cp = NULL;
218 break;
219 }
220
221 if (cp == NULL)
222 return (ENXIO);
223
224 /* Set defaults. */
225 di->bas.chan = 0;
226 di->bas.regshft = 0;
227 di->bas.regiowidth = 1;
228 di->bas.rclk = 0;
229 di->baudrate = 0;
230 di->databits = 8;
231 di->stopbits = 1;
232 di->parity = UART_PARITY_NONE;
233
234 /* Parse the attributes. */
235 spec = cp;
236 for (;;) {
237 switch (uart_parse_tag(&spec)) {
238 case UART_TAG_BD:
239 di->bas.busy_detect = uart_parse_long(&spec);
240 break;
241 case UART_TAG_BR:
242 di->baudrate = uart_parse_long(&spec);
243 break;
244 case UART_TAG_CH:
245 di->bas.chan = uart_parse_long(&spec);
246 break;
247 case UART_TAG_DB:
248 di->databits = uart_parse_long(&spec);
249 break;
250 case UART_TAG_DT:
251 class = uart_parse_class(class, &spec);
252 break;
253 case UART_TAG_IO:
254 di->bas.bst = uart_bus_space_io;
255 addr = uart_parse_addr(&spec);
256 break;
257 case UART_TAG_MM:
258 di->bas.bst = uart_bus_space_mem;
259 addr = uart_parse_addr(&spec);
260 break;
261 case UART_TAG_PA:
262 di->parity = uart_parse_parity(&spec);
263 break;
264 case UART_TAG_RS:
265 di->bas.regshft = uart_parse_long(&spec);
266 break;
267 case UART_TAG_RW:
268 di->bas.regiowidth = uart_parse_long(&spec);
269 break;
270 case UART_TAG_SB:
271 di->stopbits = uart_parse_long(&spec);
272 break;
273 case UART_TAG_XO:
274 di->bas.rclk = uart_parse_long(&spec);
275 if (di->bas.rclk == 0)
276 di->bas.rclk_guess = 1;
277 break;
278 default:
279 goto inval;
280 }
281 if (*spec == '\0')
282 break;
283 if (*spec != ',')
284 goto inval;
285 spec++;
286 }
287
288 /*
289 * If we still have an invalid address, the specification must be
290 * missing an I/O port or memory address. We don't like that.
291 */
292 if (addr == ~0U)
293 goto inval;
294 freeenv(cp);
295
296 /*
297 * The default uart_class reference is weak. Make sure the default
298 * device class has been compiled-in or we've set one with dt=.
299 */
300 if (class == NULL)
301 return (ENXIO);
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 }
332