summaryrefslogtreecommitdiffstats
path: root/drivers/tty/hvc/hvc_vio.c
blob: ee307799271a4d3cd362cb131a58490d0d00f18b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
/*
 * vio driver interface to hvc_console.c
 *
 * This code was moved here to allow the remaining code to be reused as a
 * generic polling mode with semi-reliable transport driver core to the
 * console and tty subsystems.
 *
 *
 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
 * Copyright (C) 2004 IBM Corporation
 *
 * Additional Author(s):
 *  Ryan S. Arnold <rsa@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * TODO:
 *
 *   - handle error in sending hvsi protocol packets
 *   - retry nego on subsequent sends ?
 */

#undef DEBUG

#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/console.h>
#include <linux/module.h>

#include <asm/hvconsole.h>
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/hvsi.h>
#include <asm/udbg.h>

#include "hvc_console.h"

static const char hvc_driver_name[] = "hvc_console";

static struct vio_device_id hvc_driver_table[] __devinitdata = {
	{"serial", "hvterm1"},
#ifndef HVC_OLD_HVSI
	{"serial", "hvterm-protocol"},
#endif
	{ "", "" }
};
MODULE_DEVICE_TABLE(vio, hvc_driver_table);

typedef enum hv_protocol {
	HV_PROTOCOL_RAW,
	HV_PROTOCOL_HVSI
} hv_protocol_t;

struct hvterm_priv {
	u32			termno;	/* HV term number */
	hv_protocol_t		proto;	/* Raw data or HVSI packets */
	struct hvsi_priv	hvsi;	/* HVSI specific data */
	spinlock_t		buf_lock;
	char			buf[SIZE_VIO_GET_CHARS];
	int			left;
	int			offset;
};
static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
/* For early boot console */
static struct hvterm_priv hvterm_priv0;

static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
{
	struct hvterm_priv *pv = hvterm_privs[vtermno];
	unsigned long i;
	unsigned long flags;
	int got;

	if (WARN_ON(!pv))
		return 0;

	spin_lock_irqsave(&pv->buf_lock, flags);

	if (pv->left == 0) {
		pv->offset = 0;
		pv->left = hvc_get_chars(pv->termno, pv->buf, count);

		/*
		 * Work around a HV bug where it gives us a null
		 * after every \r.  -- paulus
		 */
		for (i = 1; i < pv->left; ++i) {
			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
				--pv->left;
				if (i < pv->left) {
					memmove(&pv->buf[i], &pv->buf[i+1],
						pv->left - i);
				}
			}
		}
	}

	got = min(count, pv->left);
	memcpy(buf, &pv->buf[pv->offset], got);
	pv->offset += got;
	pv->left -= got;

	spin_unlock_irqrestore(&pv->buf_lock, flags);

	return got;
}

static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
{
	struct hvterm_priv *pv = hvterm_privs[vtermno];

	if (WARN_ON(!pv))
		return 0;

	return hvc_put_chars(pv->termno, buf, count);
}

static const struct hv_ops hvterm_raw_ops = {
	.get_chars = hvterm_raw_get_chars,
	.put_chars = hvterm_raw_put_chars,
	.notifier_add = notifier_add_irq,
	.notifier_del = notifier_del_irq,
	.notifier_hangup = notifier_hangup_irq,
};

static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
{
	struct hvterm_priv *pv = hvterm_privs[vtermno];

	if (WARN_ON(!pv))
		return 0;

	return hvsilib_get_chars(&pv->hvsi, buf, count);
}

static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
{
	struct hvterm_priv *pv = hvterm_privs[vtermno];

	if (WARN_ON(!pv))
		return 0;

	return hvsilib_put_chars(&pv->hvsi, buf, count);
}

static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
{
	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
	int rc;

	pr_devel("HVSI@%x: open !\n", pv->termno);

	rc = notifier_add_irq(hp, data);
	if (rc)
		return rc;

	return hvsilib_open(&pv->hvsi, hp);
}

static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
{
	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];

	pr_devel("HVSI@%x: do close !\n", pv->termno);

	hvsilib_close(&pv->hvsi, hp);

	notifier_del_irq(hp, data);
}

void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
{
	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];

	pr_devel("HVSI@%x: do hangup !\n", pv->termno);

	hvsilib_close(&pv->hvsi, hp);

	notifier_hangup_irq(hp, data);
}

static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
{
	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];

	if (!pv)
		return -EINVAL;
	return pv->hvsi.mctrl;
}

static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
				unsigned int clear)
{
	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];

	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
		 pv->termno, set, clear);

	if (set & TIOCM_DTR)
		hvsilib_write_mctrl(&pv->hvsi, 1);
	else if (clear & TIOCM_DTR)
		hvsilib_write_mctrl(&pv->hvsi, 0);

	return 0;
}

static const struct hv_ops hvterm_hvsi_ops = {
	.get_chars = hvterm_hvsi_get_chars,
	.put_chars = hvterm_hvsi_put_chars,
	.notifier_add = hvterm_hvsi_open,
	.notifier_del = hvterm_hvsi_close,
	.notifier_hangup = hvterm_hvsi_hangup,
	.tiocmget = hvterm_hvsi_tiocmget,
	.tiocmset = hvterm_hvsi_tiocmset,
};

static int __devinit hvc_vio_probe(struct vio_dev *vdev,
				   const struct vio_device_id *id)
{
	const struct hv_ops *ops;
	struct hvc_struct *hp;
	struct hvterm_priv *pv;
	hv_protocol_t proto;
	int i, termno = -1;

	/* probed with invalid parameters. */
	if (!vdev || !id)
		return -EPERM;

	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
		proto = HV_PROTOCOL_RAW;
		ops = &hvterm_raw_ops;
	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
		proto = HV_PROTOCOL_HVSI;
		ops = &hvterm_hvsi_ops;
	} else {
		pr_err("hvc_vio: Unkown protocol for %s\n", vdev->dev.of_node->full_name);
		return -ENXIO;
	}

	pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
		 vdev->dev.of_node->full_name,
		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");

	/* Is it our boot one ? */
	if (hvterm_privs[0] == &hvterm_priv0 &&
	    vdev->unit_address == hvterm_priv0.termno) {
		pv = hvterm_privs[0];
		termno = 0;
		pr_devel("->boot console, using termno 0\n");
	}
	/* nope, allocate a new one */
	else {
		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
			if (!hvterm_privs[i])
				termno = i;
		pr_devel("->non-boot console, using termno %d\n", termno);
		if (termno < 0)
			return -ENODEV;
		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
		if (!pv)
			return -ENOMEM;
		pv->termno = vdev->unit_address;
		pv->proto = proto;
		spin_lock_init(&pv->buf_lock);
		hvterm_privs[termno] = pv;
		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
			     pv->termno, 0);
	}

	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
	if (IS_ERR(hp))
		return PTR_ERR(hp);
	dev_set_drvdata(&vdev->dev, hp);

	return 0;
}

static int __devexit hvc_vio_remove(struct vio_dev *vdev)
{
	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
	int rc, termno;

	termno = hp->vtermno;
	rc = hvc_remove(hp);
	if (rc == 0) {
		if (hvterm_privs[termno] != &hvterm_priv0)
			kfree(hvterm_privs[termno]);
		hvterm_privs[termno] = NULL;
	}
	return rc;
}

static struct vio_driver hvc_vio_driver = {
	.id_table	= hvc_driver_table,
	.probe		= hvc_vio_probe,
	.remove		= hvc_vio_remove,
	.name		= hvc_driver_name,
};

static int __init hvc_vio_init(void)
{
	int rc;

	/* Register as a vio device to receive callbacks */
	rc = vio_register_driver(&hvc_vio_driver);

	return rc;
}
module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */

static void __exit hvc_vio_exit(void)
{
	vio_unregister_driver(&hvc_vio_driver);
}
module_exit(hvc_vio_exit);

static void udbg_hvc_putc(char c)
{
	int count = -1;

	if (c == '\n')
		udbg_hvc_putc('\r');

	do {
		switch(hvterm_priv0.proto) {
		case HV_PROTOCOL_RAW:
			count = hvterm_raw_put_chars(0, &c, 1);
			break;
		case HV_PROTOCOL_HVSI:
			count = hvterm_hvsi_put_chars(0, &c, 1);
			break;
		}
	} while(count == 0);
}

static int udbg_hvc_getc_poll(void)
{
	int rc = 0;
	char c;

	switch(hvterm_priv0.proto) {
	case HV_PROTOCOL_RAW:
		rc = hvterm_raw_get_chars(0, &c, 1);
		break;
	case HV_PROTOCOL_HVSI:
		rc = hvterm_hvsi_get_chars(0, &c, 1);
		break;
	}
	if (!rc)
		return -1;
	return c;
}

static int udbg_hvc_getc(void)
{
	int ch;
	for (;;) {
		ch = udbg_hvc_getc_poll();
		if (ch == -1) {
			/* This shouldn't be needed...but... */
			volatile unsigned long delay;
			for (delay=0; delay < 2000000; delay++)
				;
		} else {
			return ch;
		}
	}
}

void __init hvc_vio_init_early(void)
{
	struct device_node *stdout_node;
	const u32 *termno;
	const char *name;
	const struct hv_ops *ops;

	/* find the boot console from /chosen/stdout */
	if (!of_chosen)
		return;
	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
	if (name == NULL)
		return;
	stdout_node = of_find_node_by_path(name);
	if (!stdout_node)
		return;
	name = of_get_property(stdout_node, "name", NULL);
	if (!name) {
		printk(KERN_WARNING "stdout node missing 'name' property!\n");
		goto out;
	}

	/* Check if it's a virtual terminal */
	if (strncmp(name, "vty", 3) != 0)
		goto out;
	termno = of_get_property(stdout_node, "reg", NULL);
	if (termno == NULL)
		goto out;
	hvterm_priv0.termno = *termno;
	spin_lock_init(&hvterm_priv0.buf_lock);
	hvterm_privs[0] = &hvterm_priv0;

	/* Check the protocol */
	if (of_device_is_compatible(stdout_node, "hvterm1")) {
		hvterm_priv0.proto = HV_PROTOCOL_RAW;
		ops = &hvterm_raw_ops;
	}
	else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
		ops = &hvterm_hvsi_ops;
		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
			     hvterm_priv0.termno, 1);
		/* HVSI, perform the handshake now */
		hvsilib_establish(&hvterm_priv0.hvsi);
	} else
		goto out;
	udbg_putc = udbg_hvc_putc;
	udbg_getc = udbg_hvc_getc;
	udbg_getc_poll = udbg_hvc_getc_poll;
#ifdef HVC_OLD_HVSI
	/* When using the old HVSI driver don't register the HVC
	 * backend for HVSI, only do udbg
	 */
	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
		goto out;
#endif
	add_preferred_console("hvc", 0, NULL);
	hvc_instantiate(0, 0, ops);
out:
	of_node_put(stdout_node);
}

/* call this from early_init() for a working debug console on
 * vterm capable LPAR machines
 */
#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
void __init udbg_init_debug_lpar(void)
{
	hvterm_privs[0] = &hvterm_priv0;
	hvterm_priv0.termno = 0;
	hvterm_priv0.proto = HV_PROTOCOL_RAW;
	spin_lock_init(&hvterm_priv0.buf_lock);
	udbg_putc = udbg_hvc_putc;
	udbg_getc = udbg_hvc_getc;
	udbg_getc_poll = udbg_hvc_getc_poll;
}
#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */

#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
void __init udbg_init_debug_lpar_hvsi(void)
{
	hvterm_privs[0] = &hvterm_priv0;
	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
	spin_lock_init(&hvterm_priv0.buf_lock);
	udbg_putc = udbg_hvc_putc;
	udbg_getc = udbg_hvc_getc;
	udbg_getc_poll = udbg_hvc_getc_poll;
	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
		     hvterm_priv0.termno, 1);
	hvsilib_establish(&hvterm_priv0.hvsi);
}
#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */