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
42static const char hvc_opal_name[] = "hvc_opal";
43
44static const 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
50typedef enum hv_protocol {
51	HV_PROTOCOL_RAW,
52	HV_PROTOCOL_HVSI
53} hv_protocol_t;
54
55struct hvc_opal_priv {
56	hv_protocol_t		proto;	/* Raw data or HVSI packets */
57	struct hvsi_priv	hvsi;	/* HVSI specific data */
58};
59static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
60
61/* For early boot console */
62static struct hvc_opal_priv hvc_opal_boot_priv;
63static u32 hvc_opal_boot_termno;
64static bool hvc_opal_event_registered;
65
66static 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
74static 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
84static 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
94static 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
108static 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
119void 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
130static 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
139static 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
155static 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
165static 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
173static struct notifier_block hvc_opal_console_nb = {
174	.notifier_call	= hvc_opal_console_event,
175};
176
177static 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
245static 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
260static struct platform_driver hvc_opal_driver = {
261	.probe		= hvc_opal_probe,
262	.remove		= hvc_opal_remove,
263	.driver		= {
264		.name	= hvc_opal_name,
265		.of_match_table	= hvc_opal_match,
266	}
267};
268
269static int __init hvc_opal_init(void)
270{
271	if (!firmware_has_feature(FW_FEATURE_OPAL))
272		return -ENODEV;
273
274	/* Register as a vio device to receive callbacks */
275	return platform_driver_register(&hvc_opal_driver);
276}
277device_initcall(hvc_opal_init);
278
279static void udbg_opal_putc(char c)
280{
281	unsigned int termno = hvc_opal_boot_termno;
282	int count = -1;
283
284	if (c == '\n')
285		udbg_opal_putc('\r');
286
287	do {
288		switch(hvc_opal_boot_priv.proto) {
289		case HV_PROTOCOL_RAW:
290			count = opal_put_chars(termno, &c, 1);
291			break;
292		case HV_PROTOCOL_HVSI:
293			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
294			break;
295		}
296	} while(count == 0 || count == -EAGAIN);
297}
298
299static int udbg_opal_getc_poll(void)
300{
301	unsigned int termno = hvc_opal_boot_termno;
302	int rc = 0;
303	char c;
304
305	switch(hvc_opal_boot_priv.proto) {
306	case HV_PROTOCOL_RAW:
307		rc = opal_get_chars(termno, &c, 1);
308		break;
309	case HV_PROTOCOL_HVSI:
310		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
311		break;
312	}
313	if (!rc)
314		return -1;
315	return c;
316}
317
318static int udbg_opal_getc(void)
319{
320	int ch;
321	for (;;) {
322		ch = udbg_opal_getc_poll();
323		if (ch == -1) {
324			/* This shouldn't be needed...but... */
325			volatile unsigned long delay;
326			for (delay=0; delay < 2000000; delay++)
327				;
328		} else {
329			return ch;
330		}
331	}
332}
333
334static void udbg_init_opal_common(void)
335{
336	udbg_putc = udbg_opal_putc;
337	udbg_getc = udbg_opal_getc;
338	udbg_getc_poll = udbg_opal_getc_poll;
339	tb_ticks_per_usec = 0x200; /* Make udelay not suck */
340}
341
342void __init hvc_opal_init_early(void)
343{
344	struct device_node *stdout_node = of_node_get(of_stdout);
345	const __be32 *termno;
346	const struct hv_ops *ops;
347	u32 index;
348
349	/* If the console wasn't in /chosen, try /ibm,opal */
350	if (!stdout_node) {
351		struct device_node *opal, *np;
352
353		/* Current OPAL takeover doesn't provide the stdout
354		 * path, so we hard wire it
355		 */
356		opal = of_find_node_by_path("/ibm,opal/consoles");
357		if (opal)
358			pr_devel("hvc_opal: Found consoles in new location\n");
359		if (!opal) {
360			opal = of_find_node_by_path("/ibm,opal");
361			if (opal)
362				pr_devel("hvc_opal: "
363					 "Found consoles in old location\n");
364		}
365		if (!opal)
366			return;
367		for_each_child_of_node(opal, np) {
368			if (!strcmp(np->name, "serial")) {
369				stdout_node = np;
370				break;
371			}
372		}
373		of_node_put(opal);
374	}
375	if (!stdout_node)
376		return;
377	termno = of_get_property(stdout_node, "reg", NULL);
378	index = termno ? be32_to_cpup(termno) : 0;
379	if (index >= MAX_NR_HVC_CONSOLES)
380		return;
381	hvc_opal_privs[index] = &hvc_opal_boot_priv;
382
383	/* Check the protocol */
384	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
385		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
386		ops = &hvc_opal_raw_ops;
387		pr_devel("hvc_opal: Found RAW console\n");
388	}
389	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
390		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
391		ops = &hvc_opal_hvsi_ops;
392		hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
393			     opal_put_chars, index, 1);
394		/* HVSI, perform the handshake now */
395		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
396		pr_devel("hvc_opal: Found HVSI console\n");
397	} else
398		goto out;
399	hvc_opal_boot_termno = index;
400	udbg_init_opal_common();
401	add_preferred_console("hvc", index, NULL);
402	hvc_instantiate(index, index, ops);
403out:
404	of_node_put(stdout_node);
405}
406
407#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
408void __init udbg_init_debug_opal_raw(void)
409{
410	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
411	hvc_opal_privs[index] = &hvc_opal_boot_priv;
412	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
413	hvc_opal_boot_termno = index;
414	udbg_init_opal_common();
415}
416#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
417
418#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
419void __init udbg_init_debug_opal_hvsi(void)
420{
421	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
422	hvc_opal_privs[index] = &hvc_opal_boot_priv;
423	hvc_opal_boot_termno = index;
424	udbg_init_opal_common();
425	hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
426		     index, 1);
427	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
428}
429#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
430