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/platform_device.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
29static const char hvc_opal_name[] = "hvc_opal";
30
31static 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
37typedef enum hv_protocol {
38	HV_PROTOCOL_RAW,
39	HV_PROTOCOL_HVSI
40} hv_protocol_t;
41
42struct hvc_opal_priv {
43	hv_protocol_t		proto;	/* Raw data or HVSI packets */
44	struct hvsi_priv	hvsi;	/* HVSI specific data */
45};
46static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
47
48/* For early boot console */
49static struct hvc_opal_priv hvc_opal_boot_priv;
50static u32 hvc_opal_boot_termno;
51
52static 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
61static ssize_t hvc_opal_hvsi_get_chars(uint32_t vtermno, u8 *buf, size_t 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
71static ssize_t hvc_opal_hvsi_put_chars(uint32_t vtermno, const u8 *buf,
72				       size_t count)
73{
74	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
75
76	if (WARN_ON(!pv))
77		return -ENODEV;
78
79	return hvsilib_put_chars(&pv->hvsi, buf, count);
80}
81
82static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
83{
84	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
85	int rc;
86
87	pr_devel("HVSI@%x: do open !\n", hp->vtermno);
88
89	rc = notifier_add_irq(hp, data);
90	if (rc)
91		return rc;
92
93	return hvsilib_open(&pv->hvsi, hp);
94}
95
96static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
97{
98	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
99
100	pr_devel("HVSI@%x: do close !\n", hp->vtermno);
101
102	hvsilib_close(&pv->hvsi, hp);
103
104	notifier_del_irq(hp, data);
105}
106
107static void hvc_opal_hvsi_hangup(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 hangup !\n", hp->vtermno);
112
113	hvsilib_close(&pv->hvsi, hp);
114
115	notifier_hangup_irq(hp, data);
116}
117
118static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
119{
120	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
121
122	if (!pv)
123		return -EINVAL;
124	return pv->hvsi.mctrl;
125}
126
127static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
128				unsigned int clear)
129{
130	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
131
132	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
133		 hp->vtermno, set, clear);
134
135	if (set & TIOCM_DTR)
136		hvsilib_write_mctrl(&pv->hvsi, 1);
137	else if (clear & TIOCM_DTR)
138		hvsilib_write_mctrl(&pv->hvsi, 0);
139
140	return 0;
141}
142
143static const struct hv_ops hvc_opal_hvsi_ops = {
144	.get_chars = hvc_opal_hvsi_get_chars,
145	.put_chars = hvc_opal_hvsi_put_chars,
146	.flush = opal_flush_chars,
147	.notifier_add = hvc_opal_hvsi_open,
148	.notifier_del = hvc_opal_hvsi_close,
149	.notifier_hangup = hvc_opal_hvsi_hangup,
150	.tiocmget = hvc_opal_hvsi_tiocmget,
151	.tiocmset = hvc_opal_hvsi_tiocmset,
152};
153
154static int hvc_opal_probe(struct platform_device *dev)
155{
156	const struct hv_ops *ops;
157	struct hvc_struct *hp;
158	struct hvc_opal_priv *pv;
159	hv_protocol_t proto;
160	unsigned int termno, irq, boot = 0;
161	const __be32 *reg;
162
163	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
164		proto = HV_PROTOCOL_RAW;
165		ops = &hvc_opal_raw_ops;
166	} else if (of_device_is_compatible(dev->dev.of_node,
167					   "ibm,opal-console-hvsi")) {
168		proto = HV_PROTOCOL_HVSI;
169		ops = &hvc_opal_hvsi_ops;
170	} else {
171		pr_err("hvc_opal: Unknown protocol for %pOF\n",
172		       dev->dev.of_node);
173		return -ENXIO;
174	}
175
176	reg = of_get_property(dev->dev.of_node, "reg", NULL);
177	termno = reg ? be32_to_cpup(reg) : 0;
178
179	/* Is it our boot one ? */
180	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
181		pv = hvc_opal_privs[termno];
182		boot = 1;
183	} else if (hvc_opal_privs[termno] == NULL) {
184		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
185		if (!pv)
186			return -ENOMEM;
187		pv->proto = proto;
188		hvc_opal_privs[termno] = pv;
189		if (proto == HV_PROTOCOL_HVSI) {
190			/*
191			 * We want put_chars to be atomic to avoid mangling of
192			 * hvsi packets.
193			 */
194			hvsilib_init(&pv->hvsi,
195				     opal_get_chars, opal_put_chars_atomic,
196				     termno, 0);
197		}
198
199		/* Instanciate now to establish a mapping index==vtermno */
200		hvc_instantiate(termno, termno, ops);
201	} else {
202		pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
203		       dev->dev.of_node, termno);
204		return -ENXIO;
205	}
206
207	pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
208		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
209		dev->dev.of_node,
210		boot ? " (boot console)" : "");
211
212	irq = irq_of_parse_and_map(dev->dev.of_node, 0);
213	if (!irq) {
214		pr_info("hvc%d: No interrupts property, using OPAL event\n",
215				termno);
216		irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
217	}
218
219	if (!irq) {
220		pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
221			dev->dev.of_node);
222		return irq;
223	}
224
225	hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
226	if (IS_ERR(hp))
227		return PTR_ERR(hp);
228
229	/* hvc consoles on powernv may need to share a single irq */
230	hp->flags = IRQF_SHARED;
231	dev_set_drvdata(&dev->dev, hp);
232
233	return 0;
234}
235
236static void hvc_opal_remove(struct platform_device *dev)
237{
238	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
239	int termno;
240
241	termno = hp->vtermno;
242	hvc_remove(hp);
243	if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
244		kfree(hvc_opal_privs[termno]);
245	hvc_opal_privs[termno] = NULL;
246}
247
248static struct platform_driver hvc_opal_driver = {
249	.probe		= hvc_opal_probe,
250	.remove_new	= hvc_opal_remove,
251	.driver		= {
252		.name	= hvc_opal_name,
253		.of_match_table	= hvc_opal_match,
254	}
255};
256
257static int __init hvc_opal_init(void)
258{
259	if (!firmware_has_feature(FW_FEATURE_OPAL))
260		return -ENODEV;
261
262	/* Register as a vio device to receive callbacks */
263	return platform_driver_register(&hvc_opal_driver);
264}
265device_initcall(hvc_opal_init);
266
267static void udbg_opal_putc(char c)
268{
269	unsigned int termno = hvc_opal_boot_termno;
270	int count = -1;
271
272	if (c == '\n')
273		udbg_opal_putc('\r');
274
275	do {
276		switch(hvc_opal_boot_priv.proto) {
277		case HV_PROTOCOL_RAW:
278			count = opal_put_chars(termno, &c, 1);
279			break;
280		case HV_PROTOCOL_HVSI:
281			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
282			break;
283		}
284
285		/* This is needed for the cosole to flush
286		 * when there aren't any interrupts.
287		 */
288		opal_flush_console(termno);
289	} while(count == 0 || count == -EAGAIN);
290}
291
292static int udbg_opal_getc_poll(void)
293{
294	unsigned int termno = hvc_opal_boot_termno;
295	int rc = 0;
296	char c;
297
298	switch(hvc_opal_boot_priv.proto) {
299	case HV_PROTOCOL_RAW:
300		rc = opal_get_chars(termno, &c, 1);
301		break;
302	case HV_PROTOCOL_HVSI:
303		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
304		break;
305	}
306	if (!rc)
307		return -1;
308	return c;
309}
310
311static int udbg_opal_getc(void)
312{
313	int ch;
314	for (;;) {
315		ch = udbg_opal_getc_poll();
316		if (ch != -1)
317			return ch;
318	}
319}
320
321static 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}
327
328void __init hvc_opal_init_early(void)
329{
330	struct device_node *stdout_node = of_node_get(of_stdout);
331	const __be32 *termno;
332	const struct hv_ops *ops;
333	u32 index;
334
335	/* If the console wasn't in /chosen, try /ibm,opal */
336	if (!stdout_node) {
337		struct device_node *opal, *np;
338
339		/* Current OPAL takeover doesn't provide the stdout
340		 * path, so we hard wire it
341		 */
342		opal = of_find_node_by_path("/ibm,opal/consoles");
343		if (opal) {
344			pr_devel("hvc_opal: Found consoles in new location\n");
345		} else {
346			opal = of_find_node_by_path("/ibm,opal");
347			if (opal)
348				pr_devel("hvc_opal: "
349					 "Found consoles in old location\n");
350		}
351		if (!opal)
352			return;
353		for_each_child_of_node(opal, np) {
354			if (of_node_name_eq(np, "serial")) {
355				stdout_node = np;
356				break;
357			}
358		}
359		of_node_put(opal);
360	}
361	if (!stdout_node)
362		return;
363	termno = of_get_property(stdout_node, "reg", NULL);
364	index = termno ? be32_to_cpup(termno) : 0;
365	if (index >= MAX_NR_HVC_CONSOLES)
366		return;
367	hvc_opal_privs[index] = &hvc_opal_boot_priv;
368
369	/* Check the protocol */
370	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
371		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
372		ops = &hvc_opal_raw_ops;
373		pr_devel("hvc_opal: Found RAW console\n");
374	}
375	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
376		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
377		ops = &hvc_opal_hvsi_ops;
378		hvsilib_init(&hvc_opal_boot_priv.hvsi,
379			     opal_get_chars, opal_put_chars_atomic,
380			     index, 1);
381		/* HVSI, perform the handshake now */
382		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
383		pr_devel("hvc_opal: Found HVSI console\n");
384	} else
385		goto out;
386	hvc_opal_boot_termno = index;
387	udbg_init_opal_common();
388	add_preferred_console("hvc", index, NULL);
389	hvc_instantiate(index, index, ops);
390out:
391	of_node_put(stdout_node);
392}
393
394#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
395void __init udbg_init_debug_opal_raw(void)
396{
397	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
398	hvc_opal_privs[index] = &hvc_opal_boot_priv;
399	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
400	hvc_opal_boot_termno = index;
401	udbg_init_opal_common();
402}
403#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
404
405#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
406void __init udbg_init_debug_opal_hvsi(void)
407{
408	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
409	hvc_opal_privs[index] = &hvc_opal_boot_priv;
410	hvc_opal_boot_termno = index;
411	udbg_init_opal_common();
412	hvsilib_init(&hvc_opal_boot_priv.hvsi,
413		     opal_get_chars, opal_put_chars_atomic,
414		     index, 1);
415	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
416}
417#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
418