xref: /linux/drivers/tty/hvc/hvc_vio.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * vio driver interface to hvc_console.c
3  *
4  * This code was moved here to allow the remaining code to be reused as a
5  * generic polling mode with semi-reliable transport driver core to the
6  * console and tty subsystems.
7  *
8  *
9  * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
10  * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
11  * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
12  * Copyright (C) 2004 IBM Corporation
13  *
14  * Additional Author(s):
15  *  Ryan S. Arnold <rsa@us.ibm.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License as published by
19  * the Free Software Foundation; either version 2 of the License, or
20  * (at your option) any later version.
21  *
22  * This program is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
30  *
31  * TODO:
32  *
33  *   - handle error in sending hvsi protocol packets
34  *   - retry nego on subsequent sends ?
35  */
36 
37 #undef DEBUG
38 
39 #include <linux/types.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/slab.h>
43 #include <linux/console.h>
44 #include <linux/module.h>
45 
46 #include <asm/hvconsole.h>
47 #include <asm/vio.h>
48 #include <asm/prom.h>
49 #include <asm/hvsi.h>
50 #include <asm/udbg.h>
51 #include <asm/machdep.h>
52 
53 #include "hvc_console.h"
54 
55 static const char hvc_driver_name[] = "hvc_console";
56 
57 static struct vio_device_id hvc_driver_table[] = {
58 	{"serial", "hvterm1"},
59 #ifndef HVC_OLD_HVSI
60 	{"serial", "hvterm-protocol"},
61 #endif
62 	{ "", "" }
63 };
64 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
65 
66 typedef enum hv_protocol {
67 	HV_PROTOCOL_RAW,
68 	HV_PROTOCOL_HVSI
69 } hv_protocol_t;
70 
71 struct hvterm_priv {
72 	u32			termno;	/* HV term number */
73 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
74 	struct hvsi_priv	hvsi;	/* HVSI specific data */
75 	spinlock_t		buf_lock;
76 	char			buf[SIZE_VIO_GET_CHARS];
77 	int			left;
78 	int			offset;
79 };
80 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
81 /* For early boot console */
82 static struct hvterm_priv hvterm_priv0;
83 
84 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
85 {
86 	struct hvterm_priv *pv = hvterm_privs[vtermno];
87 	unsigned long i;
88 	unsigned long flags;
89 	int got;
90 
91 	if (WARN_ON(!pv))
92 		return 0;
93 
94 	spin_lock_irqsave(&pv->buf_lock, flags);
95 
96 	if (pv->left == 0) {
97 		pv->offset = 0;
98 		pv->left = hvc_get_chars(pv->termno, pv->buf, count);
99 
100 		/*
101 		 * Work around a HV bug where it gives us a null
102 		 * after every \r.  -- paulus
103 		 */
104 		for (i = 1; i < pv->left; ++i) {
105 			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
106 				--pv->left;
107 				if (i < pv->left) {
108 					memmove(&pv->buf[i], &pv->buf[i+1],
109 						pv->left - i);
110 				}
111 			}
112 		}
113 	}
114 
115 	got = min(count, pv->left);
116 	memcpy(buf, &pv->buf[pv->offset], got);
117 	pv->offset += got;
118 	pv->left -= got;
119 
120 	spin_unlock_irqrestore(&pv->buf_lock, flags);
121 
122 	return got;
123 }
124 
125 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
126 {
127 	struct hvterm_priv *pv = hvterm_privs[vtermno];
128 
129 	if (WARN_ON(!pv))
130 		return 0;
131 
132 	return hvc_put_chars(pv->termno, buf, count);
133 }
134 
135 static const struct hv_ops hvterm_raw_ops = {
136 	.get_chars = hvterm_raw_get_chars,
137 	.put_chars = hvterm_raw_put_chars,
138 	.notifier_add = notifier_add_irq,
139 	.notifier_del = notifier_del_irq,
140 	.notifier_hangup = notifier_hangup_irq,
141 };
142 
143 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
144 {
145 	struct hvterm_priv *pv = hvterm_privs[vtermno];
146 
147 	if (WARN_ON(!pv))
148 		return 0;
149 
150 	return hvsilib_get_chars(&pv->hvsi, buf, count);
151 }
152 
153 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
154 {
155 	struct hvterm_priv *pv = hvterm_privs[vtermno];
156 
157 	if (WARN_ON(!pv))
158 		return 0;
159 
160 	return hvsilib_put_chars(&pv->hvsi, buf, count);
161 }
162 
163 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
164 {
165 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
166 	int rc;
167 
168 	pr_devel("HVSI@%x: open !\n", pv->termno);
169 
170 	rc = notifier_add_irq(hp, data);
171 	if (rc)
172 		return rc;
173 
174 	return hvsilib_open(&pv->hvsi, hp);
175 }
176 
177 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
178 {
179 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
180 
181 	pr_devel("HVSI@%x: do close !\n", pv->termno);
182 
183 	hvsilib_close(&pv->hvsi, hp);
184 
185 	notifier_del_irq(hp, data);
186 }
187 
188 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
189 {
190 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
191 
192 	pr_devel("HVSI@%x: do hangup !\n", pv->termno);
193 
194 	hvsilib_close(&pv->hvsi, hp);
195 
196 	notifier_hangup_irq(hp, data);
197 }
198 
199 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
200 {
201 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
202 
203 	if (!pv)
204 		return -EINVAL;
205 	return pv->hvsi.mctrl;
206 }
207 
208 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
209 				unsigned int clear)
210 {
211 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
212 
213 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
214 		 pv->termno, set, clear);
215 
216 	if (set & TIOCM_DTR)
217 		hvsilib_write_mctrl(&pv->hvsi, 1);
218 	else if (clear & TIOCM_DTR)
219 		hvsilib_write_mctrl(&pv->hvsi, 0);
220 
221 	return 0;
222 }
223 
224 static const struct hv_ops hvterm_hvsi_ops = {
225 	.get_chars = hvterm_hvsi_get_chars,
226 	.put_chars = hvterm_hvsi_put_chars,
227 	.notifier_add = hvterm_hvsi_open,
228 	.notifier_del = hvterm_hvsi_close,
229 	.notifier_hangup = hvterm_hvsi_hangup,
230 	.tiocmget = hvterm_hvsi_tiocmget,
231 	.tiocmset = hvterm_hvsi_tiocmset,
232 };
233 
234 static void udbg_hvc_putc(char c)
235 {
236 	int count = -1;
237 
238 	if (!hvterm_privs[0])
239 		return;
240 
241 	if (c == '\n')
242 		udbg_hvc_putc('\r');
243 
244 	do {
245 		switch(hvterm_privs[0]->proto) {
246 		case HV_PROTOCOL_RAW:
247 			count = hvterm_raw_put_chars(0, &c, 1);
248 			break;
249 		case HV_PROTOCOL_HVSI:
250 			count = hvterm_hvsi_put_chars(0, &c, 1);
251 			break;
252 		}
253 	} while(count == 0);
254 }
255 
256 static int udbg_hvc_getc_poll(void)
257 {
258 	int rc = 0;
259 	char c;
260 
261 	if (!hvterm_privs[0])
262 		return -1;
263 
264 	switch(hvterm_privs[0]->proto) {
265 	case HV_PROTOCOL_RAW:
266 		rc = hvterm_raw_get_chars(0, &c, 1);
267 		break;
268 	case HV_PROTOCOL_HVSI:
269 		rc = hvterm_hvsi_get_chars(0, &c, 1);
270 		break;
271 	}
272 	if (!rc)
273 		return -1;
274 	return c;
275 }
276 
277 static int udbg_hvc_getc(void)
278 {
279 	int ch;
280 
281 	if (!hvterm_privs[0])
282 		return -1;
283 
284 	for (;;) {
285 		ch = udbg_hvc_getc_poll();
286 		if (ch == -1) {
287 			/* This shouldn't be needed...but... */
288 			volatile unsigned long delay;
289 			for (delay=0; delay < 2000000; delay++)
290 				;
291 		} else {
292 			return ch;
293 		}
294 	}
295 }
296 
297 static int hvc_vio_probe(struct vio_dev *vdev,
298 				   const struct vio_device_id *id)
299 {
300 	const struct hv_ops *ops;
301 	struct hvc_struct *hp;
302 	struct hvterm_priv *pv;
303 	hv_protocol_t proto;
304 	int i, termno = -1;
305 
306 	/* probed with invalid parameters. */
307 	if (!vdev || !id)
308 		return -EPERM;
309 
310 	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
311 		proto = HV_PROTOCOL_RAW;
312 		ops = &hvterm_raw_ops;
313 	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
314 		proto = HV_PROTOCOL_HVSI;
315 		ops = &hvterm_hvsi_ops;
316 	} else {
317 		pr_err("hvc_vio: Unknown protocol for %s\n", vdev->dev.of_node->full_name);
318 		return -ENXIO;
319 	}
320 
321 	pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
322 		 vdev->dev.of_node->full_name,
323 		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
324 
325 	/* Is it our boot one ? */
326 	if (hvterm_privs[0] == &hvterm_priv0 &&
327 	    vdev->unit_address == hvterm_priv0.termno) {
328 		pv = hvterm_privs[0];
329 		termno = 0;
330 		pr_devel("->boot console, using termno 0\n");
331 	}
332 	/* nope, allocate a new one */
333 	else {
334 		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
335 			if (!hvterm_privs[i])
336 				termno = i;
337 		pr_devel("->non-boot console, using termno %d\n", termno);
338 		if (termno < 0)
339 			return -ENODEV;
340 		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
341 		if (!pv)
342 			return -ENOMEM;
343 		pv->termno = vdev->unit_address;
344 		pv->proto = proto;
345 		spin_lock_init(&pv->buf_lock);
346 		hvterm_privs[termno] = pv;
347 		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
348 			     pv->termno, 0);
349 	}
350 
351 	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
352 	if (IS_ERR(hp))
353 		return PTR_ERR(hp);
354 	dev_set_drvdata(&vdev->dev, hp);
355 
356 	/* register udbg if it's not there already for console 0 */
357 	if (hp->index == 0 && !udbg_putc) {
358 		udbg_putc = udbg_hvc_putc;
359 		udbg_getc = udbg_hvc_getc;
360 		udbg_getc_poll = udbg_hvc_getc_poll;
361 	}
362 
363 	return 0;
364 }
365 
366 static int hvc_vio_remove(struct vio_dev *vdev)
367 {
368 	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
369 	int rc, termno;
370 
371 	termno = hp->vtermno;
372 	rc = hvc_remove(hp);
373 	if (rc == 0) {
374 		if (hvterm_privs[termno] != &hvterm_priv0)
375 			kfree(hvterm_privs[termno]);
376 		hvterm_privs[termno] = NULL;
377 	}
378 	return rc;
379 }
380 
381 static struct vio_driver hvc_vio_driver = {
382 	.id_table	= hvc_driver_table,
383 	.probe		= hvc_vio_probe,
384 	.remove		= hvc_vio_remove,
385 	.name		= hvc_driver_name,
386 };
387 
388 static int __init hvc_vio_init(void)
389 {
390 	int rc;
391 
392 	/* Register as a vio device to receive callbacks */
393 	rc = vio_register_driver(&hvc_vio_driver);
394 
395 	return rc;
396 }
397 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
398 
399 static void __exit hvc_vio_exit(void)
400 {
401 	vio_unregister_driver(&hvc_vio_driver);
402 }
403 module_exit(hvc_vio_exit);
404 
405 void __init hvc_vio_init_early(void)
406 {
407 	const __be32 *termno;
408 	const char *name;
409 	const struct hv_ops *ops;
410 
411 	/* find the boot console from /chosen/stdout */
412 	if (!of_stdout)
413 		return;
414 	name = of_get_property(of_stdout, "name", NULL);
415 	if (!name) {
416 		printk(KERN_WARNING "stdout node missing 'name' property!\n");
417 		return;
418 	}
419 
420 	/* Check if it's a virtual terminal */
421 	if (strncmp(name, "vty", 3) != 0)
422 		return;
423 	termno = of_get_property(of_stdout, "reg", NULL);
424 	if (termno == NULL)
425 		return;
426 	hvterm_priv0.termno = of_read_number(termno, 1);
427 	spin_lock_init(&hvterm_priv0.buf_lock);
428 	hvterm_privs[0] = &hvterm_priv0;
429 
430 	/* Check the protocol */
431 	if (of_device_is_compatible(of_stdout, "hvterm1")) {
432 		hvterm_priv0.proto = HV_PROTOCOL_RAW;
433 		ops = &hvterm_raw_ops;
434 	}
435 	else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
436 		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
437 		ops = &hvterm_hvsi_ops;
438 		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
439 			     hvterm_priv0.termno, 1);
440 		/* HVSI, perform the handshake now */
441 		hvsilib_establish(&hvterm_priv0.hvsi);
442 	} else
443 		return;
444 	udbg_putc = udbg_hvc_putc;
445 	udbg_getc = udbg_hvc_getc;
446 	udbg_getc_poll = udbg_hvc_getc_poll;
447 #ifdef HVC_OLD_HVSI
448 	/* When using the old HVSI driver don't register the HVC
449 	 * backend for HVSI, only do udbg
450 	 */
451 	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
452 		return;
453 #endif
454 	/* Check whether the user has requested a different console. */
455 	if (!strstr(boot_command_line, "console="))
456 		add_preferred_console("hvc", 0, NULL);
457 	hvc_instantiate(0, 0, ops);
458 }
459 
460 /* call this from early_init() for a working debug console on
461  * vterm capable LPAR machines
462  */
463 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
464 void __init udbg_init_debug_lpar(void)
465 {
466 	hvterm_privs[0] = &hvterm_priv0;
467 	hvterm_priv0.termno = 0;
468 	hvterm_priv0.proto = HV_PROTOCOL_RAW;
469 	spin_lock_init(&hvterm_priv0.buf_lock);
470 	udbg_putc = udbg_hvc_putc;
471 	udbg_getc = udbg_hvc_getc;
472 	udbg_getc_poll = udbg_hvc_getc_poll;
473 }
474 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
475 
476 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
477 void __init udbg_init_debug_lpar_hvsi(void)
478 {
479 	hvterm_privs[0] = &hvterm_priv0;
480 	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
481 	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
482 	spin_lock_init(&hvterm_priv0.buf_lock);
483 	udbg_putc = udbg_hvc_putc;
484 	udbg_getc = udbg_hvc_getc;
485 	udbg_getc_poll = udbg_hvc_getc_poll;
486 	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
487 		     hvterm_priv0.termno, 1);
488 	hvsilib_establish(&hvterm_priv0.hvsi);
489 }
490 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
491