xref: /rk3399_rockchip-uboot/drivers/serial/serial-uclass.c (revision fbf99d9116409fd59686dfd3f891547b111d65cb) 
1 /*
2  * Copyright (c) 2014 The Chromium OS Authors.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <environment.h>
10 #include <errno.h>
11 #include <os.h>
12 #include <serial.h>
13 #include <stdio_dev.h>
14 #include <watchdog.h>
15 #include <dm/lists.h>
16 #include <dm/device-internal.h>
17 #include <dm/of_access.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 /*
22  * Table with supported baudrates (defined in config_xyz.h)
23  */
24 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
25 
26 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
27 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
28 #endif
29 
30 static int serial_check_stdout(const void *blob, struct udevice **devp)
31 {
32 	int node;
33 
34 	/* Check for a chosen console */
35 	node = fdtdec_get_chosen_node(blob, "stdout-path");
36 	if (node < 0) {
37 		const char *str, *p, *name;
38 
39 		/*
40 		 * Deal with things like
41 		 *	stdout-path = "serial0:115200n8";
42 		 *
43 		 * We need to look up the alias and then follow it to the
44 		 * correct node.
45 		 */
46 		str = fdtdec_get_chosen_prop(blob, "stdout-path");
47 		if (str) {
48 			p = strchr(str, ':');
49 			name = fdt_get_alias_namelen(blob, str,
50 					p ? p - str : strlen(str));
51 			if (name)
52 				node = fdt_path_offset(blob, name);
53 		}
54 	}
55 	if (node < 0)
56 		node = fdt_path_offset(blob, "console");
57 
58 	if (gd && gd->serial.using_pre_serial) {
59 		const char *serial_path;
60 		char serial[12];
61 
62 		snprintf(serial, 12, "serial%d", gd->serial.id);
63 		serial_path = fdt_get_alias(blob, serial);
64 		if (serial_path) {
65 			debug("Find alias %s, path: %s\n", serial, serial_path);
66 			node = fdt_path_offset(blob, serial_path);
67 			if (node < 0)
68 				printf("Can't find %s by path\n", serial);
69 		} else {
70 			printf("Can't find alias %s\n", serial);
71 		}
72 	}
73 
74 	if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
75 		return 0;
76 
77 	/*
78 	 * If the console is not marked to be bound before relocation, bind it
79 	 * anyway.
80 	 */
81 	if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
82 					devp)) {
83 		if (!device_probe(*devp))
84 			return 0;
85 	}
86 
87 	return -ENODEV;
88 }
89 
90 static void serial_find_console_or_panic(void)
91 {
92 	const void *blob = gd->fdt_blob;
93 	struct udevice *dev;
94 
95 	if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
96 		uclass_first_device(UCLASS_SERIAL, &dev);
97 		if (dev) {
98 			gd->cur_serial_dev = dev;
99 			return;
100 		}
101 	} else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
102 		/* Live tree has support for stdout */
103 		if (of_live_active()) {
104 			struct device_node *np = of_get_stdout();
105 
106 			if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
107 					np_to_ofnode(np), &dev)) {
108 				gd->cur_serial_dev = dev;
109 				return;
110 			}
111 		} else {
112 			if (!serial_check_stdout(blob, &dev)) {
113 				gd->cur_serial_dev = dev;
114 				return;
115 			}
116 		}
117 	}
118 	if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
119 		/*
120 		 * Try to use CONFIG_CONS_INDEX if available (it is numbered
121 		 * from 1!).
122 		 *
123 		 * Failing that, get the device with sequence number 0, or in
124 		 * extremis just the first serial device we can find. But we
125 		 * insist on having a console (even if it is silent).
126 		 */
127 #ifdef CONFIG_CONS_INDEX
128 #define INDEX (CONFIG_CONS_INDEX - 1)
129 #else
130 #define INDEX 0
131 #endif
132 		if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
133 		    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
134 		    (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
135 			gd->cur_serial_dev = dev;
136 			return;
137 		}
138 #undef INDEX
139 	}
140 
141 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
142 	panic_str("No serial driver found");
143 #endif
144 }
145 
146 /* Called prior to relocation */
147 int serial_init(void)
148 {
149 	serial_find_console_or_panic();
150 	gd->flags |= GD_FLG_SERIAL_READY;
151 
152 	return 0;
153 }
154 
155 /* Called after relocation */
156 void serial_initialize(void)
157 {
158 	serial_init();
159 }
160 
161 static void _serial_putc(struct udevice *dev, char ch)
162 {
163 	struct dm_serial_ops *ops = serial_get_ops(dev);
164 	int err;
165 
166 	if (ch == '\n')
167 		_serial_putc(dev, '\r');
168 
169 	do {
170 		err = ops->putc(dev, ch);
171 	} while (err == -EAGAIN);
172 }
173 
174 static void _serial_puts(struct udevice *dev, const char *str)
175 {
176 	while (*str)
177 		_serial_putc(dev, *str++);
178 }
179 
180 static int __serial_getc(struct udevice *dev)
181 {
182 	struct dm_serial_ops *ops = serial_get_ops(dev);
183 	int err;
184 
185 	do {
186 		err = ops->getc(dev);
187 		if (err == -EAGAIN)
188 			WATCHDOG_RESET();
189 	} while (err == -EAGAIN);
190 
191 	return err >= 0 ? err : 0;
192 }
193 
194 static int __serial_tstc(struct udevice *dev)
195 {
196 	struct dm_serial_ops *ops = serial_get_ops(dev);
197 
198 	if (ops->pending)
199 		return ops->pending(dev, true);
200 
201 	return 1;
202 }
203 
204 static void __serial_clear(struct udevice *dev)
205 {
206 	struct dm_serial_ops *ops = serial_get_ops(dev);
207 
208 	if (ops->clear)
209 		ops->clear(dev);
210 }
211 
212 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
213 static int _serial_tstc(struct udevice *dev)
214 {
215 	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
216 
217 	/* Read all available chars into the RX buffer */
218 	while (__serial_tstc(dev)) {
219 		upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
220 		upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
221 	}
222 
223 	return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
224 }
225 
226 static int _serial_getc(struct udevice *dev)
227 {
228 	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
229 	char val;
230 
231 	val = upriv->buf[upriv->rd_ptr++];
232 	upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
233 
234 	return val;
235 }
236 
237 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
238 
239 static int _serial_getc(struct udevice *dev)
240 {
241 	return __serial_getc(dev);
242 }
243 
244 static int _serial_tstc(struct udevice *dev)
245 {
246 	return __serial_tstc(dev);
247 }
248 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
249 
250 void serial_putc(char ch)
251 {
252 	if (gd->cur_serial_dev)
253 		_serial_putc(gd->cur_serial_dev, ch);
254 }
255 
256 void serial_puts(const char *str)
257 {
258 	if (gd->cur_serial_dev)
259 		_serial_puts(gd->cur_serial_dev, str);
260 }
261 
262 int serial_getc(void)
263 {
264 	if (!gd->cur_serial_dev)
265 		return 0;
266 
267 	return _serial_getc(gd->cur_serial_dev);
268 }
269 
270 int serial_tstc(void)
271 {
272 	if (!gd->cur_serial_dev)
273 		return 0;
274 
275 	return _serial_tstc(gd->cur_serial_dev);
276 }
277 
278 void serial_setbrg(void)
279 {
280 	struct dm_serial_ops *ops;
281 
282 	if (!gd->cur_serial_dev)
283 		return;
284 
285 	ops = serial_get_ops(gd->cur_serial_dev);
286 	if (ops->setbrg)
287 		ops->setbrg(gd->cur_serial_dev, gd->baudrate);
288 }
289 
290 void serial_clear(void)
291 {
292 	if (!gd->cur_serial_dev)
293 		return;
294 
295 	__serial_clear(gd->cur_serial_dev);
296 }
297 
298 void serial_stdio_init(void)
299 {
300 }
301 
302 #if defined(CONFIG_DM_STDIO)
303 
304 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
305 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
306 {
307 	_serial_putc(sdev->priv, ch);
308 }
309 #endif
310 
311 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
312 {
313 	_serial_puts(sdev->priv, str);
314 }
315 
316 static int serial_stub_getc(struct stdio_dev *sdev)
317 {
318 	return _serial_getc(sdev->priv);
319 }
320 
321 static int serial_stub_tstc(struct stdio_dev *sdev)
322 {
323 	return _serial_tstc(sdev->priv);
324 }
325 #endif
326 
327 /**
328  * on_baudrate() - Update the actual baudrate when the env var changes
329  *
330  * This will check for a valid baudrate and only apply it if valid.
331  */
332 static int on_baudrate(const char *name, const char *value, enum env_op op,
333 	int flags)
334 {
335 	int i;
336 	int baudrate;
337 
338 	switch (op) {
339 	case env_op_create:
340 	case env_op_overwrite:
341 		/*
342 		 * Switch to new baudrate if new baudrate is supported
343 		 */
344 		baudrate = simple_strtoul(value, NULL, 10);
345 
346 		/* Not actually changing */
347 		if (gd->baudrate == baudrate)
348 			return 0;
349 
350 		for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
351 			if (baudrate == baudrate_table[i])
352 				break;
353 		}
354 		if (i == ARRAY_SIZE(baudrate_table)) {
355 			if ((flags & H_FORCE) == 0)
356 				printf("## Baudrate %d bps not supported\n",
357 				       baudrate);
358 			return 1;
359 		}
360 		if ((flags & H_INTERACTIVE) != 0) {
361 			printf("## Switch baudrate to %d bps and press ENTER ...\n",
362 			       baudrate);
363 			udelay(50000);
364 		}
365 
366 		gd->baudrate = baudrate;
367 
368 		serial_setbrg();
369 
370 		udelay(50000);
371 
372 		if ((flags & H_INTERACTIVE) != 0)
373 			while (1) {
374 				if (getc() == '\r')
375 					break;
376 			}
377 
378 		return 0;
379 	case env_op_delete:
380 		printf("## Baudrate may not be deleted\n");
381 		return 1;
382 	default:
383 		return 0;
384 	}
385 }
386 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
387 
388 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
389 static int serial_post_probe(struct udevice *dev)
390 {
391 	struct dm_serial_ops *ops = serial_get_ops(dev);
392 #ifdef CONFIG_DM_STDIO
393 	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
394 	struct stdio_dev sdev;
395 #endif
396 	int ret;
397 
398 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
399 	if (ops->setbrg)
400 		ops->setbrg += gd->reloc_off;
401 	if (ops->getc)
402 		ops->getc += gd->reloc_off;
403 	if (ops->putc)
404 		ops->putc += gd->reloc_off;
405 	if (ops->pending)
406 		ops->pending += gd->reloc_off;
407 	if (ops->clear)
408 		ops->clear += gd->reloc_off;
409 #if CONFIG_POST & CONFIG_SYS_POST_UART
410 	if (ops->loop)
411 		ops->loop += gd->reloc_off
412 #endif
413 #endif
414 	/* Set the baud rate */
415 	if (ops->setbrg) {
416 		ret = ops->setbrg(dev, gd->baudrate);
417 		if (ret)
418 			return ret;
419 	}
420 
421 #ifdef CONFIG_DM_STDIO
422 	if (!(gd->flags & GD_FLG_RELOC))
423 		return 0;
424 	memset(&sdev, '\0', sizeof(sdev));
425 
426 	strncpy(sdev.name, dev->name, sizeof(sdev.name));
427 	sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
428 	sdev.priv = dev;
429 	sdev.putc = serial_stub_putc;
430 	sdev.puts = serial_stub_puts;
431 	sdev.getc = serial_stub_getc;
432 	sdev.tstc = serial_stub_tstc;
433 
434 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
435 	/* Allocate the RX buffer */
436 	upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
437 #endif
438 
439 	stdio_register_dev(&sdev, &upriv->sdev);
440 #endif
441 	return 0;
442 }
443 
444 static int serial_pre_remove(struct udevice *dev)
445 {
446 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
447 	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
448 
449 	if (stdio_deregister_dev(upriv->sdev, true))
450 		return -EPERM;
451 #endif
452 
453 	return 0;
454 }
455 
456 UCLASS_DRIVER(serial) = {
457 	.id		= UCLASS_SERIAL,
458 	.name		= "serial",
459 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
460 	.post_probe	= serial_post_probe,
461 	.pre_remove	= serial_pre_remove,
462 	.per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
463 };
464 #endif
465