xref: /openbmc/linux/drivers/tty/hvc/hvc_opal.c (revision 79f08d9e)
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 
65 static const struct hv_ops hvc_opal_raw_ops = {
66 	.get_chars = opal_get_chars,
67 	.put_chars = opal_put_chars,
68 	.notifier_add = notifier_add_irq,
69 	.notifier_del = notifier_del_irq,
70 	.notifier_hangup = notifier_hangup_irq,
71 };
72 
73 static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
74 {
75 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
76 
77 	if (WARN_ON(!pv))
78 		return -ENODEV;
79 
80 	return hvsilib_get_chars(&pv->hvsi, buf, count);
81 }
82 
83 static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
84 {
85 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
86 
87 	if (WARN_ON(!pv))
88 		return -ENODEV;
89 
90 	return hvsilib_put_chars(&pv->hvsi, buf, count);
91 }
92 
93 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
94 {
95 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
96 	int rc;
97 
98 	pr_devel("HVSI@%x: do open !\n", hp->vtermno);
99 
100 	rc = notifier_add_irq(hp, data);
101 	if (rc)
102 		return rc;
103 
104 	return hvsilib_open(&pv->hvsi, hp);
105 }
106 
107 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
108 {
109 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
110 
111 	pr_devel("HVSI@%x: do close !\n", hp->vtermno);
112 
113 	hvsilib_close(&pv->hvsi, hp);
114 
115 	notifier_del_irq(hp, data);
116 }
117 
118 void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
119 {
120 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
121 
122 	pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
123 
124 	hvsilib_close(&pv->hvsi, hp);
125 
126 	notifier_hangup_irq(hp, data);
127 }
128 
129 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
130 {
131 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
132 
133 	if (!pv)
134 		return -EINVAL;
135 	return pv->hvsi.mctrl;
136 }
137 
138 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
139 				unsigned int clear)
140 {
141 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
142 
143 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
144 		 hp->vtermno, set, clear);
145 
146 	if (set & TIOCM_DTR)
147 		hvsilib_write_mctrl(&pv->hvsi, 1);
148 	else if (clear & TIOCM_DTR)
149 		hvsilib_write_mctrl(&pv->hvsi, 0);
150 
151 	return 0;
152 }
153 
154 static const struct hv_ops hvc_opal_hvsi_ops = {
155 	.get_chars = hvc_opal_hvsi_get_chars,
156 	.put_chars = hvc_opal_hvsi_put_chars,
157 	.notifier_add = hvc_opal_hvsi_open,
158 	.notifier_del = hvc_opal_hvsi_close,
159 	.notifier_hangup = hvc_opal_hvsi_hangup,
160 	.tiocmget = hvc_opal_hvsi_tiocmget,
161 	.tiocmset = hvc_opal_hvsi_tiocmset,
162 };
163 
164 static int hvc_opal_probe(struct platform_device *dev)
165 {
166 	const struct hv_ops *ops;
167 	struct hvc_struct *hp;
168 	struct hvc_opal_priv *pv;
169 	hv_protocol_t proto;
170 	unsigned int termno, boot = 0;
171 	const __be32 *reg;
172 
173 	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
174 		proto = HV_PROTOCOL_RAW;
175 		ops = &hvc_opal_raw_ops;
176 	} else if (of_device_is_compatible(dev->dev.of_node,
177 					   "ibm,opal-console-hvsi")) {
178 		proto = HV_PROTOCOL_HVSI;
179 		ops = &hvc_opal_hvsi_ops;
180 	} else {
181 		pr_err("hvc_opal: Unknown protocol for %s\n",
182 		       dev->dev.of_node->full_name);
183 		return -ENXIO;
184 	}
185 
186 	reg = of_get_property(dev->dev.of_node, "reg", NULL);
187 	termno = reg ? be32_to_cpup(reg) : 0;
188 
189 	/* Is it our boot one ? */
190 	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
191 		pv = hvc_opal_privs[termno];
192 		boot = 1;
193 	} else if (hvc_opal_privs[termno] == NULL) {
194 		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
195 		if (!pv)
196 			return -ENOMEM;
197 		pv->proto = proto;
198 		hvc_opal_privs[termno] = pv;
199 		if (proto == HV_PROTOCOL_HVSI)
200 			hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
201 				     termno, 0);
202 
203 		/* Instanciate now to establish a mapping index==vtermno */
204 		hvc_instantiate(termno, termno, ops);
205 	} else {
206 		pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
207 		       dev->dev.of_node->full_name, termno);
208 		return -ENXIO;
209 	}
210 
211 	pr_info("hvc%d: %s protocol on %s%s\n", termno,
212 		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
213 		dev->dev.of_node->full_name,
214 		boot ? " (boot console)" : "");
215 
216 	/* We don't do IRQ yet */
217 	hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
218 	if (IS_ERR(hp))
219 		return PTR_ERR(hp);
220 	dev_set_drvdata(&dev->dev, hp);
221 
222 	return 0;
223 }
224 
225 static int hvc_opal_remove(struct platform_device *dev)
226 {
227 	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
228 	int rc, termno;
229 
230 	termno = hp->vtermno;
231 	rc = hvc_remove(hp);
232 	if (rc == 0) {
233 		if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
234 			kfree(hvc_opal_privs[termno]);
235 		hvc_opal_privs[termno] = NULL;
236 	}
237 	return rc;
238 }
239 
240 static struct platform_driver hvc_opal_driver = {
241 	.probe		= hvc_opal_probe,
242 	.remove		= hvc_opal_remove,
243 	.driver		= {
244 		.name	= hvc_opal_name,
245 		.owner	= THIS_MODULE,
246 		.of_match_table	= hvc_opal_match,
247 	}
248 };
249 
250 static int __init hvc_opal_init(void)
251 {
252 	if (!firmware_has_feature(FW_FEATURE_OPAL))
253 		return -ENODEV;
254 
255 	/* Register as a vio device to receive callbacks */
256 	return platform_driver_register(&hvc_opal_driver);
257 }
258 module_init(hvc_opal_init);
259 
260 static void __exit hvc_opal_exit(void)
261 {
262 	platform_driver_unregister(&hvc_opal_driver);
263 }
264 module_exit(hvc_opal_exit);
265 
266 static void udbg_opal_putc(char c)
267 {
268 	unsigned int termno = hvc_opal_boot_termno;
269 	int count = -1;
270 
271 	if (c == '\n')
272 		udbg_opal_putc('\r');
273 
274 	do {
275 		switch(hvc_opal_boot_priv.proto) {
276 		case HV_PROTOCOL_RAW:
277 			count = opal_put_chars(termno, &c, 1);
278 			break;
279 		case HV_PROTOCOL_HVSI:
280 			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
281 			break;
282 		}
283 	} while(count == 0 || count == -EAGAIN);
284 }
285 
286 static int udbg_opal_getc_poll(void)
287 {
288 	unsigned int termno = hvc_opal_boot_termno;
289 	int rc = 0;
290 	char c;
291 
292 	switch(hvc_opal_boot_priv.proto) {
293 	case HV_PROTOCOL_RAW:
294 		rc = opal_get_chars(termno, &c, 1);
295 		break;
296 	case HV_PROTOCOL_HVSI:
297 		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
298 		break;
299 	}
300 	if (!rc)
301 		return -1;
302 	return c;
303 }
304 
305 static int udbg_opal_getc(void)
306 {
307 	int ch;
308 	for (;;) {
309 		ch = udbg_opal_getc_poll();
310 		if (ch == -1) {
311 			/* This shouldn't be needed...but... */
312 			volatile unsigned long delay;
313 			for (delay=0; delay < 2000000; delay++)
314 				;
315 		} else {
316 			return ch;
317 		}
318 	}
319 }
320 
321 static void udbg_init_opal_common(void)
322 {
323 	udbg_putc = udbg_opal_putc;
324 	udbg_getc = udbg_opal_getc;
325 	udbg_getc_poll = udbg_opal_getc_poll;
326 	tb_ticks_per_usec = 0x200; /* Make udelay not suck */
327 }
328 
329 void __init hvc_opal_init_early(void)
330 {
331 	struct device_node *stdout_node = NULL;
332 	const __be32 *termno;
333 	const char *name = NULL;
334 	const struct hv_ops *ops;
335 	u32 index;
336 
337 	/* find the boot console from /chosen/stdout */
338 	if (of_chosen)
339 		name = of_get_property(of_chosen, "linux,stdout-path", NULL);
340 	if (name) {
341 		stdout_node = of_find_node_by_path(name);
342 		if (!stdout_node) {
343 			pr_err("hvc_opal: Failed to locate default console!\n");
344 			return;
345 		}
346 	} else {
347 		struct device_node *opal, *np;
348 
349 		/* Current OPAL takeover doesn't provide the stdout
350 		 * path, so we hard wire it
351 		 */
352 		opal = of_find_node_by_path("/ibm,opal/consoles");
353 		if (opal)
354 			pr_devel("hvc_opal: Found consoles in new location\n");
355 		if (!opal) {
356 			opal = of_find_node_by_path("/ibm,opal");
357 			if (opal)
358 				pr_devel("hvc_opal: "
359 					 "Found consoles in old location\n");
360 		}
361 		if (!opal)
362 			return;
363 		for_each_child_of_node(opal, np) {
364 			if (!strcmp(np->name, "serial")) {
365 				stdout_node = np;
366 				break;
367 			}
368 		}
369 		of_node_put(opal);
370 	}
371 	if (!stdout_node)
372 		return;
373 	termno = of_get_property(stdout_node, "reg", NULL);
374 	index = termno ? be32_to_cpup(termno) : 0;
375 	if (index >= MAX_NR_HVC_CONSOLES)
376 		return;
377 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
378 
379 	/* Check the protocol */
380 	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
381 		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
382 		ops = &hvc_opal_raw_ops;
383 		pr_devel("hvc_opal: Found RAW console\n");
384 	}
385 	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
386 		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
387 		ops = &hvc_opal_hvsi_ops;
388 		hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
389 			     opal_put_chars, index, 1);
390 		/* HVSI, perform the handshake now */
391 		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
392 		pr_devel("hvc_opal: Found HVSI console\n");
393 	} else
394 		goto out;
395 	hvc_opal_boot_termno = index;
396 	udbg_init_opal_common();
397 	add_preferred_console("hvc", index, NULL);
398 	hvc_instantiate(index, index, ops);
399 out:
400 	of_node_put(stdout_node);
401 }
402 
403 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
404 void __init udbg_init_debug_opal_raw(void)
405 {
406 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
407 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
408 	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
409 	hvc_opal_boot_termno = index;
410 	udbg_init_opal_common();
411 }
412 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
413 
414 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
415 void __init udbg_init_debug_opal_hvsi(void)
416 {
417 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
418 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
419 	hvc_opal_boot_termno = index;
420 	udbg_init_opal_common();
421 	hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
422 		     index, 1);
423 	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
424 }
425 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
426