1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * opal driver interface to hvc_console.c
4  *
5  * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
6  */
7 
8 #undef DEBUG
9 
10 #include <linux/types.h>
11 #include <linux/init.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/console.h>
15 #include <linux/of.h>
16 #include <linux/of_irq.h>
17 #include <linux/of_platform.h>
18 #include <linux/export.h>
19 #include <linux/interrupt.h>
20 
21 #include <asm/hvconsole.h>
22 #include <asm/firmware.h>
23 #include <asm/hvsi.h>
24 #include <asm/udbg.h>
25 #include <asm/opal.h>
26 
27 #include "hvc_console.h"
28 
29 static const char hvc_opal_name[] = "hvc_opal";
30 
31 static const struct of_device_id hvc_opal_match[] = {
32 	{ .name = "serial", .compatible = "ibm,opal-console-raw" },
33 	{ .name = "serial", .compatible = "ibm,opal-console-hvsi" },
34 	{ },
35 };
36 
37 typedef enum hv_protocol {
38 	HV_PROTOCOL_RAW,
39 	HV_PROTOCOL_HVSI
40 } hv_protocol_t;
41 
42 struct hvc_opal_priv {
43 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
44 	struct hvsi_priv	hvsi;	/* HVSI specific data */
45 };
46 static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
47 
48 /* For early boot console */
49 static struct hvc_opal_priv hvc_opal_boot_priv;
50 static u32 hvc_opal_boot_termno;
51 
52 static const struct hv_ops hvc_opal_raw_ops = {
53 	.get_chars = opal_get_chars,
54 	.put_chars = opal_put_chars,
55 	.flush = opal_flush_chars,
56 	.notifier_add = notifier_add_irq,
57 	.notifier_del = notifier_del_irq,
58 	.notifier_hangup = notifier_hangup_irq,
59 };
60 
hvc_opal_hvsi_get_chars(uint32_t vtermno,char * buf,int count)61 static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
62 {
63 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
64 
65 	if (WARN_ON(!pv))
66 		return -ENODEV;
67 
68 	return hvsilib_get_chars(&pv->hvsi, buf, count);
69 }
70 
hvc_opal_hvsi_put_chars(uint32_t vtermno,const char * buf,int count)71 static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
72 {
73 	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
74 
75 	if (WARN_ON(!pv))
76 		return -ENODEV;
77 
78 	return hvsilib_put_chars(&pv->hvsi, buf, count);
79 }
80 
hvc_opal_hvsi_open(struct hvc_struct * hp,int data)81 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
82 {
83 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
84 	int rc;
85 
86 	pr_devel("HVSI@%x: do open !\n", hp->vtermno);
87 
88 	rc = notifier_add_irq(hp, data);
89 	if (rc)
90 		return rc;
91 
92 	return hvsilib_open(&pv->hvsi, hp);
93 }
94 
hvc_opal_hvsi_close(struct hvc_struct * hp,int data)95 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
96 {
97 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
98 
99 	pr_devel("HVSI@%x: do close !\n", hp->vtermno);
100 
101 	hvsilib_close(&pv->hvsi, hp);
102 
103 	notifier_del_irq(hp, data);
104 }
105 
hvc_opal_hvsi_hangup(struct hvc_struct * hp,int data)106 static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
107 {
108 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
109 
110 	pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
111 
112 	hvsilib_close(&pv->hvsi, hp);
113 
114 	notifier_hangup_irq(hp, data);
115 }
116 
hvc_opal_hvsi_tiocmget(struct hvc_struct * hp)117 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
118 {
119 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
120 
121 	if (!pv)
122 		return -EINVAL;
123 	return pv->hvsi.mctrl;
124 }
125 
hvc_opal_hvsi_tiocmset(struct hvc_struct * hp,unsigned int set,unsigned int clear)126 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
127 				unsigned int clear)
128 {
129 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
130 
131 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
132 		 hp->vtermno, set, clear);
133 
134 	if (set & TIOCM_DTR)
135 		hvsilib_write_mctrl(&pv->hvsi, 1);
136 	else if (clear & TIOCM_DTR)
137 		hvsilib_write_mctrl(&pv->hvsi, 0);
138 
139 	return 0;
140 }
141 
142 static const struct hv_ops hvc_opal_hvsi_ops = {
143 	.get_chars = hvc_opal_hvsi_get_chars,
144 	.put_chars = hvc_opal_hvsi_put_chars,
145 	.flush = opal_flush_chars,
146 	.notifier_add = hvc_opal_hvsi_open,
147 	.notifier_del = hvc_opal_hvsi_close,
148 	.notifier_hangup = hvc_opal_hvsi_hangup,
149 	.tiocmget = hvc_opal_hvsi_tiocmget,
150 	.tiocmset = hvc_opal_hvsi_tiocmset,
151 };
152 
hvc_opal_probe(struct platform_device * dev)153 static int hvc_opal_probe(struct platform_device *dev)
154 {
155 	const struct hv_ops *ops;
156 	struct hvc_struct *hp;
157 	struct hvc_opal_priv *pv;
158 	hv_protocol_t proto;
159 	unsigned int termno, irq, boot = 0;
160 	const __be32 *reg;
161 
162 	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
163 		proto = HV_PROTOCOL_RAW;
164 		ops = &hvc_opal_raw_ops;
165 	} else if (of_device_is_compatible(dev->dev.of_node,
166 					   "ibm,opal-console-hvsi")) {
167 		proto = HV_PROTOCOL_HVSI;
168 		ops = &hvc_opal_hvsi_ops;
169 	} else {
170 		pr_err("hvc_opal: Unknown protocol for %pOF\n",
171 		       dev->dev.of_node);
172 		return -ENXIO;
173 	}
174 
175 	reg = of_get_property(dev->dev.of_node, "reg", NULL);
176 	termno = reg ? be32_to_cpup(reg) : 0;
177 
178 	/* Is it our boot one ? */
179 	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
180 		pv = hvc_opal_privs[termno];
181 		boot = 1;
182 	} else if (hvc_opal_privs[termno] == NULL) {
183 		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
184 		if (!pv)
185 			return -ENOMEM;
186 		pv->proto = proto;
187 		hvc_opal_privs[termno] = pv;
188 		if (proto == HV_PROTOCOL_HVSI) {
189 			/*
190 			 * We want put_chars to be atomic to avoid mangling of
191 			 * hvsi packets.
192 			 */
193 			hvsilib_init(&pv->hvsi,
194 				     opal_get_chars, opal_put_chars_atomic,
195 				     termno, 0);
196 		}
197 
198 		/* Instanciate now to establish a mapping index==vtermno */
199 		hvc_instantiate(termno, termno, ops);
200 	} else {
201 		pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
202 		       dev->dev.of_node, termno);
203 		return -ENXIO;
204 	}
205 
206 	pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
207 		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
208 		dev->dev.of_node,
209 		boot ? " (boot console)" : "");
210 
211 	irq = irq_of_parse_and_map(dev->dev.of_node, 0);
212 	if (!irq) {
213 		pr_info("hvc%d: No interrupts property, using OPAL event\n",
214 				termno);
215 		irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
216 	}
217 
218 	if (!irq) {
219 		pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
220 			dev->dev.of_node);
221 		return irq;
222 	}
223 
224 	hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
225 	if (IS_ERR(hp))
226 		return PTR_ERR(hp);
227 
228 	/* hvc consoles on powernv may need to share a single irq */
229 	hp->flags = IRQF_SHARED;
230 	dev_set_drvdata(&dev->dev, hp);
231 
232 	return 0;
233 }
234 
hvc_opal_remove(struct platform_device * dev)235 static int hvc_opal_remove(struct platform_device *dev)
236 {
237 	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
238 	int rc, termno;
239 
240 	termno = hp->vtermno;
241 	rc = hvc_remove(hp);
242 	if (rc == 0) {
243 		if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
244 			kfree(hvc_opal_privs[termno]);
245 		hvc_opal_privs[termno] = NULL;
246 	}
247 	return rc;
248 }
249 
250 static struct platform_driver hvc_opal_driver = {
251 	.probe		= hvc_opal_probe,
252 	.remove		= hvc_opal_remove,
253 	.driver		= {
254 		.name	= hvc_opal_name,
255 		.of_match_table	= hvc_opal_match,
256 	}
257 };
258 
hvc_opal_init(void)259 static int __init hvc_opal_init(void)
260 {
261 	if (!firmware_has_feature(FW_FEATURE_OPAL))
262 		return -ENODEV;
263 
264 	/* Register as a vio device to receive callbacks */
265 	return platform_driver_register(&hvc_opal_driver);
266 }
267 device_initcall(hvc_opal_init);
268 
udbg_opal_putc(char c)269 static void udbg_opal_putc(char c)
270 {
271 	unsigned int termno = hvc_opal_boot_termno;
272 	int count = -1;
273 
274 	if (c == '\n')
275 		udbg_opal_putc('\r');
276 
277 	do {
278 		switch(hvc_opal_boot_priv.proto) {
279 		case HV_PROTOCOL_RAW:
280 			count = opal_put_chars(termno, &c, 1);
281 			break;
282 		case HV_PROTOCOL_HVSI:
283 			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
284 			break;
285 		}
286 
287 		/* This is needed for the cosole to flush
288 		 * when there aren't any interrupts.
289 		 */
290 		opal_flush_console(termno);
291 	} while(count == 0 || count == -EAGAIN);
292 }
293 
udbg_opal_getc_poll(void)294 static int udbg_opal_getc_poll(void)
295 {
296 	unsigned int termno = hvc_opal_boot_termno;
297 	int rc = 0;
298 	char c;
299 
300 	switch(hvc_opal_boot_priv.proto) {
301 	case HV_PROTOCOL_RAW:
302 		rc = opal_get_chars(termno, &c, 1);
303 		break;
304 	case HV_PROTOCOL_HVSI:
305 		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
306 		break;
307 	}
308 	if (!rc)
309 		return -1;
310 	return c;
311 }
312 
udbg_opal_getc(void)313 static int udbg_opal_getc(void)
314 {
315 	int ch;
316 	for (;;) {
317 		ch = udbg_opal_getc_poll();
318 		if (ch != -1)
319 			return ch;
320 	}
321 }
322 
udbg_init_opal_common(void)323 static void udbg_init_opal_common(void)
324 {
325 	udbg_putc = udbg_opal_putc;
326 	udbg_getc = udbg_opal_getc;
327 	udbg_getc_poll = udbg_opal_getc_poll;
328 }
329 
hvc_opal_init_early(void)330 void __init hvc_opal_init_early(void)
331 {
332 	struct device_node *stdout_node = of_node_get(of_stdout);
333 	const __be32 *termno;
334 	const struct hv_ops *ops;
335 	u32 index;
336 
337 	/* If the console wasn't in /chosen, try /ibm,opal */
338 	if (!stdout_node) {
339 		struct device_node *opal, *np;
340 
341 		/* Current OPAL takeover doesn't provide the stdout
342 		 * path, so we hard wire it
343 		 */
344 		opal = of_find_node_by_path("/ibm,opal/consoles");
345 		if (opal) {
346 			pr_devel("hvc_opal: Found consoles in new location\n");
347 		} else {
348 			opal = of_find_node_by_path("/ibm,opal");
349 			if (opal)
350 				pr_devel("hvc_opal: "
351 					 "Found consoles in old location\n");
352 		}
353 		if (!opal)
354 			return;
355 		for_each_child_of_node(opal, np) {
356 			if (of_node_name_eq(np, "serial")) {
357 				stdout_node = np;
358 				break;
359 			}
360 		}
361 		of_node_put(opal);
362 	}
363 	if (!stdout_node)
364 		return;
365 	termno = of_get_property(stdout_node, "reg", NULL);
366 	index = termno ? be32_to_cpup(termno) : 0;
367 	if (index >= MAX_NR_HVC_CONSOLES)
368 		return;
369 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
370 
371 	/* Check the protocol */
372 	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
373 		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
374 		ops = &hvc_opal_raw_ops;
375 		pr_devel("hvc_opal: Found RAW console\n");
376 	}
377 	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
378 		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
379 		ops = &hvc_opal_hvsi_ops;
380 		hvsilib_init(&hvc_opal_boot_priv.hvsi,
381 			     opal_get_chars, opal_put_chars_atomic,
382 			     index, 1);
383 		/* HVSI, perform the handshake now */
384 		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
385 		pr_devel("hvc_opal: Found HVSI console\n");
386 	} else
387 		goto out;
388 	hvc_opal_boot_termno = index;
389 	udbg_init_opal_common();
390 	add_preferred_console("hvc", index, NULL);
391 	hvc_instantiate(index, index, ops);
392 out:
393 	of_node_put(stdout_node);
394 }
395 
396 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
udbg_init_debug_opal_raw(void)397 void __init udbg_init_debug_opal_raw(void)
398 {
399 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
400 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
401 	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
402 	hvc_opal_boot_termno = index;
403 	udbg_init_opal_common();
404 }
405 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
406 
407 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
udbg_init_debug_opal_hvsi(void)408 void __init udbg_init_debug_opal_hvsi(void)
409 {
410 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
411 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
412 	hvc_opal_boot_termno = index;
413 	udbg_init_opal_common();
414 	hvsilib_init(&hvc_opal_boot_priv.hvsi,
415 		     opal_get_chars, opal_put_chars_atomic,
416 		     index, 1);
417 	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
418 }
419 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
420