xref: /openbmc/linux/drivers/tty/hvc/hvc_opal.c (revision 293d5b43)
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 #include <linux/interrupt.h>
33 
34 #include <asm/hvconsole.h>
35 #include <asm/prom.h>
36 #include <asm/firmware.h>
37 #include <asm/hvsi.h>
38 #include <asm/udbg.h>
39 #include <asm/opal.h>
40 
41 #include "hvc_console.h"
42 
43 static const char hvc_opal_name[] = "hvc_opal";
44 
45 static const struct of_device_id hvc_opal_match[] = {
46 	{ .name = "serial", .compatible = "ibm,opal-console-raw" },
47 	{ .name = "serial", .compatible = "ibm,opal-console-hvsi" },
48 	{ },
49 };
50 
51 typedef enum hv_protocol {
52 	HV_PROTOCOL_RAW,
53 	HV_PROTOCOL_HVSI
54 } hv_protocol_t;
55 
56 struct hvc_opal_priv {
57 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
58 	struct hvsi_priv	hvsi;	/* HVSI specific data */
59 };
60 static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
61 
62 /* For early boot console */
63 static struct hvc_opal_priv hvc_opal_boot_priv;
64 static u32 hvc_opal_boot_termno;
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_probe(struct platform_device *dev)
166 {
167 	const struct hv_ops *ops;
168 	struct hvc_struct *hp;
169 	struct hvc_opal_priv *pv;
170 	hv_protocol_t proto;
171 	unsigned int termno, irq, boot = 0;
172 	const __be32 *reg;
173 
174 	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
175 		proto = HV_PROTOCOL_RAW;
176 		ops = &hvc_opal_raw_ops;
177 	} else if (of_device_is_compatible(dev->dev.of_node,
178 					   "ibm,opal-console-hvsi")) {
179 		proto = HV_PROTOCOL_HVSI;
180 		ops = &hvc_opal_hvsi_ops;
181 	} else {
182 		pr_err("hvc_opal: Unknown protocol for %s\n",
183 		       dev->dev.of_node->full_name);
184 		return -ENXIO;
185 	}
186 
187 	reg = of_get_property(dev->dev.of_node, "reg", NULL);
188 	termno = reg ? be32_to_cpup(reg) : 0;
189 
190 	/* Is it our boot one ? */
191 	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
192 		pv = hvc_opal_privs[termno];
193 		boot = 1;
194 	} else if (hvc_opal_privs[termno] == NULL) {
195 		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
196 		if (!pv)
197 			return -ENOMEM;
198 		pv->proto = proto;
199 		hvc_opal_privs[termno] = pv;
200 		if (proto == HV_PROTOCOL_HVSI)
201 			hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
202 				     termno, 0);
203 
204 		/* Instanciate now to establish a mapping index==vtermno */
205 		hvc_instantiate(termno, termno, ops);
206 	} else {
207 		pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
208 		       dev->dev.of_node->full_name, termno);
209 		return -ENXIO;
210 	}
211 
212 	pr_info("hvc%d: %s protocol on %s%s\n", termno,
213 		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
214 		dev->dev.of_node->full_name,
215 		boot ? " (boot console)" : "");
216 
217 	irq = irq_of_parse_and_map(dev->dev.of_node, 0);
218 	if (!irq) {
219 		pr_info("hvc%d: No interrupts property, using OPAL event\n",
220 				termno);
221 		irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
222 	}
223 
224 	if (!irq) {
225 		pr_err("hvc_opal: Unable to map interrupt for device %s\n",
226 			dev->dev.of_node->full_name);
227 		return irq;
228 	}
229 
230 	hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
231 	if (IS_ERR(hp))
232 		return PTR_ERR(hp);
233 
234 	/* hvc consoles on powernv may need to share a single irq */
235 	hp->flags = IRQF_SHARED;
236 	dev_set_drvdata(&dev->dev, hp);
237 
238 	return 0;
239 }
240 
241 static int hvc_opal_remove(struct platform_device *dev)
242 {
243 	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
244 	int rc, termno;
245 
246 	termno = hp->vtermno;
247 	rc = hvc_remove(hp);
248 	if (rc == 0) {
249 		if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
250 			kfree(hvc_opal_privs[termno]);
251 		hvc_opal_privs[termno] = NULL;
252 	}
253 	return rc;
254 }
255 
256 static struct platform_driver hvc_opal_driver = {
257 	.probe		= hvc_opal_probe,
258 	.remove		= hvc_opal_remove,
259 	.driver		= {
260 		.name	= hvc_opal_name,
261 		.of_match_table	= hvc_opal_match,
262 	}
263 };
264 
265 static int __init hvc_opal_init(void)
266 {
267 	if (!firmware_has_feature(FW_FEATURE_OPAL))
268 		return -ENODEV;
269 
270 	/* Register as a vio device to receive callbacks */
271 	return platform_driver_register(&hvc_opal_driver);
272 }
273 device_initcall(hvc_opal_init);
274 
275 static void udbg_opal_putc(char c)
276 {
277 	unsigned int termno = hvc_opal_boot_termno;
278 	int count = -1;
279 
280 	if (c == '\n')
281 		udbg_opal_putc('\r');
282 
283 	do {
284 		switch(hvc_opal_boot_priv.proto) {
285 		case HV_PROTOCOL_RAW:
286 			count = opal_put_chars(termno, &c, 1);
287 			break;
288 		case HV_PROTOCOL_HVSI:
289 			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
290 			break;
291 		}
292 	} while(count == 0 || count == -EAGAIN);
293 }
294 
295 static int udbg_opal_getc_poll(void)
296 {
297 	unsigned int termno = hvc_opal_boot_termno;
298 	int rc = 0;
299 	char c;
300 
301 	switch(hvc_opal_boot_priv.proto) {
302 	case HV_PROTOCOL_RAW:
303 		rc = opal_get_chars(termno, &c, 1);
304 		break;
305 	case HV_PROTOCOL_HVSI:
306 		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
307 		break;
308 	}
309 	if (!rc)
310 		return -1;
311 	return c;
312 }
313 
314 static int udbg_opal_getc(void)
315 {
316 	int ch;
317 	for (;;) {
318 		ch = udbg_opal_getc_poll();
319 		if (ch == -1) {
320 			/* This shouldn't be needed...but... */
321 			volatile unsigned long delay;
322 			for (delay=0; delay < 2000000; delay++)
323 				;
324 		} else {
325 			return ch;
326 		}
327 	}
328 }
329 
330 static void udbg_init_opal_common(void)
331 {
332 	udbg_putc = udbg_opal_putc;
333 	udbg_getc = udbg_opal_getc;
334 	udbg_getc_poll = udbg_opal_getc_poll;
335 	tb_ticks_per_usec = 0x200; /* Make udelay not suck */
336 }
337 
338 void __init hvc_opal_init_early(void)
339 {
340 	struct device_node *stdout_node = of_node_get(of_stdout);
341 	const __be32 *termno;
342 	const struct hv_ops *ops;
343 	u32 index;
344 
345 	/* If the console wasn't in /chosen, try /ibm,opal */
346 	if (!stdout_node) {
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