xref: /openbmc/linux/drivers/tty/hvc/hvc_opal.c (revision 1c2f87c2)
1 /*
2  * opal driver interface to hvc_console.c
3  *
4  * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #undef DEBUG
23 
24 #include <linux/types.h>
25 #include <linux/init.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/console.h>
29 #include <linux/of.h>
30 #include <linux/of_platform.h>
31 #include <linux/export.h>
32 
33 #include <asm/hvconsole.h>
34 #include <asm/prom.h>
35 #include <asm/firmware.h>
36 #include <asm/hvsi.h>
37 #include <asm/udbg.h>
38 #include <asm/opal.h>
39 
40 #include "hvc_console.h"
41 
42 static const char hvc_opal_name[] = "hvc_opal";
43 
44 static struct of_device_id hvc_opal_match[] = {
45 	{ .name = "serial", .compatible = "ibm,opal-console-raw" },
46 	{ .name = "serial", .compatible = "ibm,opal-console-hvsi" },
47 	{ },
48 };
49 
50 typedef enum hv_protocol {
51 	HV_PROTOCOL_RAW,
52 	HV_PROTOCOL_HVSI
53 } hv_protocol_t;
54 
55 struct hvc_opal_priv {
56 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
57 	struct hvsi_priv	hvsi;	/* HVSI specific data */
58 };
59 static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
60 
61 /* For early boot console */
62 static struct hvc_opal_priv hvc_opal_boot_priv;
63 static u32 hvc_opal_boot_termno;
64 static bool hvc_opal_event_registered;
65 
66 static const struct hv_ops hvc_opal_raw_ops = {
67 	.get_chars = opal_get_chars,
68 	.put_chars = opal_put_chars,
69 	.notifier_add = notifier_add_irq,
70 	.notifier_del = notifier_del_irq,
71 	.notifier_hangup = notifier_hangup_irq,
72 };
73 
74 static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
75 {
76 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
77 
78 	if (WARN_ON(!pv))
79 		return -ENODEV;
80 
81 	return hvsilib_get_chars(&pv->hvsi, buf, count);
82 }
83 
84 static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
85 {
86 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
87 
88 	if (WARN_ON(!pv))
89 		return -ENODEV;
90 
91 	return hvsilib_put_chars(&pv->hvsi, buf, count);
92 }
93 
94 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
95 {
96 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
97 	int rc;
98 
99 	pr_devel("HVSI@%x: do open !\n", hp->vtermno);
100 
101 	rc = notifier_add_irq(hp, data);
102 	if (rc)
103 		return rc;
104 
105 	return hvsilib_open(&pv->hvsi, hp);
106 }
107 
108 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
109 {
110 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
111 
112 	pr_devel("HVSI@%x: do close !\n", hp->vtermno);
113 
114 	hvsilib_close(&pv->hvsi, hp);
115 
116 	notifier_del_irq(hp, data);
117 }
118 
119 void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
120 {
121 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
122 
123 	pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
124 
125 	hvsilib_close(&pv->hvsi, hp);
126 
127 	notifier_hangup_irq(hp, data);
128 }
129 
130 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
131 {
132 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
133 
134 	if (!pv)
135 		return -EINVAL;
136 	return pv->hvsi.mctrl;
137 }
138 
139 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
140 				unsigned int clear)
141 {
142 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
143 
144 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
145 		 hp->vtermno, set, clear);
146 
147 	if (set & TIOCM_DTR)
148 		hvsilib_write_mctrl(&pv->hvsi, 1);
149 	else if (clear & TIOCM_DTR)
150 		hvsilib_write_mctrl(&pv->hvsi, 0);
151 
152 	return 0;
153 }
154 
155 static const struct hv_ops hvc_opal_hvsi_ops = {
156 	.get_chars = hvc_opal_hvsi_get_chars,
157 	.put_chars = hvc_opal_hvsi_put_chars,
158 	.notifier_add = hvc_opal_hvsi_open,
159 	.notifier_del = hvc_opal_hvsi_close,
160 	.notifier_hangup = hvc_opal_hvsi_hangup,
161 	.tiocmget = hvc_opal_hvsi_tiocmget,
162 	.tiocmset = hvc_opal_hvsi_tiocmset,
163 };
164 
165 static int hvc_opal_console_event(struct notifier_block *nb,
166 				  unsigned long events, void *change)
167 {
168 	if (events & OPAL_EVENT_CONSOLE_INPUT)
169 		hvc_kick();
170 	return 0;
171 }
172 
173 static struct notifier_block hvc_opal_console_nb = {
174 	.notifier_call	= hvc_opal_console_event,
175 };
176 
177 static int hvc_opal_probe(struct platform_device *dev)
178 {
179 	const struct hv_ops *ops;
180 	struct hvc_struct *hp;
181 	struct hvc_opal_priv *pv;
182 	hv_protocol_t proto;
183 	unsigned int termno, boot = 0;
184 	const __be32 *reg;
185 
186 
187 	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
188 		proto = HV_PROTOCOL_RAW;
189 		ops = &hvc_opal_raw_ops;
190 	} else if (of_device_is_compatible(dev->dev.of_node,
191 					   "ibm,opal-console-hvsi")) {
192 		proto = HV_PROTOCOL_HVSI;
193 		ops = &hvc_opal_hvsi_ops;
194 	} else {
195 		pr_err("hvc_opal: Unknown protocol for %s\n",
196 		       dev->dev.of_node->full_name);
197 		return -ENXIO;
198 	}
199 
200 	reg = of_get_property(dev->dev.of_node, "reg", NULL);
201 	termno = reg ? be32_to_cpup(reg) : 0;
202 
203 	/* Is it our boot one ? */
204 	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
205 		pv = hvc_opal_privs[termno];
206 		boot = 1;
207 	} else if (hvc_opal_privs[termno] == NULL) {
208 		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
209 		if (!pv)
210 			return -ENOMEM;
211 		pv->proto = proto;
212 		hvc_opal_privs[termno] = pv;
213 		if (proto == HV_PROTOCOL_HVSI)
214 			hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
215 				     termno, 0);
216 
217 		/* Instanciate now to establish a mapping index==vtermno */
218 		hvc_instantiate(termno, termno, ops);
219 	} else {
220 		pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
221 		       dev->dev.of_node->full_name, termno);
222 		return -ENXIO;
223 	}
224 
225 	pr_info("hvc%d: %s protocol on %s%s\n", termno,
226 		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
227 		dev->dev.of_node->full_name,
228 		boot ? " (boot console)" : "");
229 
230 	/* We don't do IRQ ... */
231 	hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
232 	if (IS_ERR(hp))
233 		return PTR_ERR(hp);
234 	dev_set_drvdata(&dev->dev, hp);
235 
236 	/* ...  but we use OPAL event to kick the console */
237 	if (!hvc_opal_event_registered) {
238 		opal_notifier_register(&hvc_opal_console_nb);
239 		hvc_opal_event_registered = true;
240 	}
241 
242 	return 0;
243 }
244 
245 static int hvc_opal_remove(struct platform_device *dev)
246 {
247 	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
248 	int rc, termno;
249 
250 	termno = hp->vtermno;
251 	rc = hvc_remove(hp);
252 	if (rc == 0) {
253 		if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
254 			kfree(hvc_opal_privs[termno]);
255 		hvc_opal_privs[termno] = NULL;
256 	}
257 	return rc;
258 }
259 
260 static struct platform_driver hvc_opal_driver = {
261 	.probe		= hvc_opal_probe,
262 	.remove		= hvc_opal_remove,
263 	.driver		= {
264 		.name	= hvc_opal_name,
265 		.owner	= THIS_MODULE,
266 		.of_match_table	= hvc_opal_match,
267 	}
268 };
269 
270 static int __init hvc_opal_init(void)
271 {
272 	if (!firmware_has_feature(FW_FEATURE_OPAL))
273 		return -ENODEV;
274 
275 	/* Register as a vio device to receive callbacks */
276 	return platform_driver_register(&hvc_opal_driver);
277 }
278 device_initcall(hvc_opal_init);
279 
280 static void udbg_opal_putc(char c)
281 {
282 	unsigned int termno = hvc_opal_boot_termno;
283 	int count = -1;
284 
285 	if (c == '\n')
286 		udbg_opal_putc('\r');
287 
288 	do {
289 		switch(hvc_opal_boot_priv.proto) {
290 		case HV_PROTOCOL_RAW:
291 			count = opal_put_chars(termno, &c, 1);
292 			break;
293 		case HV_PROTOCOL_HVSI:
294 			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
295 			break;
296 		}
297 	} while(count == 0 || count == -EAGAIN);
298 }
299 
300 static int udbg_opal_getc_poll(void)
301 {
302 	unsigned int termno = hvc_opal_boot_termno;
303 	int rc = 0;
304 	char c;
305 
306 	switch(hvc_opal_boot_priv.proto) {
307 	case HV_PROTOCOL_RAW:
308 		rc = opal_get_chars(termno, &c, 1);
309 		break;
310 	case HV_PROTOCOL_HVSI:
311 		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
312 		break;
313 	}
314 	if (!rc)
315 		return -1;
316 	return c;
317 }
318 
319 static int udbg_opal_getc(void)
320 {
321 	int ch;
322 	for (;;) {
323 		ch = udbg_opal_getc_poll();
324 		if (ch == -1) {
325 			/* This shouldn't be needed...but... */
326 			volatile unsigned long delay;
327 			for (delay=0; delay < 2000000; delay++)
328 				;
329 		} else {
330 			return ch;
331 		}
332 	}
333 }
334 
335 static void udbg_init_opal_common(void)
336 {
337 	udbg_putc = udbg_opal_putc;
338 	udbg_getc = udbg_opal_getc;
339 	udbg_getc_poll = udbg_opal_getc_poll;
340 	tb_ticks_per_usec = 0x200; /* Make udelay not suck */
341 }
342 
343 void __init hvc_opal_init_early(void)
344 {
345 	struct device_node *stdout_node = NULL;
346 	const __be32 *termno;
347 	const char *name = NULL;
348 	const struct hv_ops *ops;
349 	u32 index;
350 
351 	/* find the boot console from /chosen/stdout */
352 	if (of_chosen)
353 		name = of_get_property(of_chosen, "linux,stdout-path", NULL);
354 	if (name) {
355 		stdout_node = of_find_node_by_path(name);
356 		if (!stdout_node) {
357 			pr_err("hvc_opal: Failed to locate default console!\n");
358 			return;
359 		}
360 	} else {
361 		struct device_node *opal, *np;
362 
363 		/* Current OPAL takeover doesn't provide the stdout
364 		 * path, so we hard wire it
365 		 */
366 		opal = of_find_node_by_path("/ibm,opal/consoles");
367 		if (opal)
368 			pr_devel("hvc_opal: Found consoles in new location\n");
369 		if (!opal) {
370 			opal = of_find_node_by_path("/ibm,opal");
371 			if (opal)
372 				pr_devel("hvc_opal: "
373 					 "Found consoles in old location\n");
374 		}
375 		if (!opal)
376 			return;
377 		for_each_child_of_node(opal, np) {
378 			if (!strcmp(np->name, "serial")) {
379 				stdout_node = np;
380 				break;
381 			}
382 		}
383 		of_node_put(opal);
384 	}
385 	if (!stdout_node)
386 		return;
387 	termno = of_get_property(stdout_node, "reg", NULL);
388 	index = termno ? be32_to_cpup(termno) : 0;
389 	if (index >= MAX_NR_HVC_CONSOLES)
390 		return;
391 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
392 
393 	/* Check the protocol */
394 	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
395 		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
396 		ops = &hvc_opal_raw_ops;
397 		pr_devel("hvc_opal: Found RAW console\n");
398 	}
399 	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
400 		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
401 		ops = &hvc_opal_hvsi_ops;
402 		hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
403 			     opal_put_chars, index, 1);
404 		/* HVSI, perform the handshake now */
405 		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
406 		pr_devel("hvc_opal: Found HVSI console\n");
407 	} else
408 		goto out;
409 	hvc_opal_boot_termno = index;
410 	udbg_init_opal_common();
411 	add_preferred_console("hvc", index, NULL);
412 	hvc_instantiate(index, index, ops);
413 out:
414 	of_node_put(stdout_node);
415 }
416 
417 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
418 void __init udbg_init_debug_opal_raw(void)
419 {
420 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
421 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
422 	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
423 	hvc_opal_boot_termno = index;
424 	udbg_init_opal_common();
425 }
426 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
427 
428 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
429 void __init udbg_init_debug_opal_hvsi(void)
430 {
431 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
432 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
433 	hvc_opal_boot_termno = index;
434 	udbg_init_opal_common();
435 	hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
436 		     index, 1);
437 	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
438 }
439 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
440