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 
52 #include "hvc_console.h"
53 
54 static const char hvc_driver_name[] = "hvc_console";
55 
56 static struct vio_device_id hvc_driver_table[] __devinitdata = {
57 	{"serial", "hvterm1"},
58 #ifndef HVC_OLD_HVSI
59 	{"serial", "hvterm-protocol"},
60 #endif
61 	{ "", "" }
62 };
63 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
64 
65 typedef enum hv_protocol {
66 	HV_PROTOCOL_RAW,
67 	HV_PROTOCOL_HVSI
68 } hv_protocol_t;
69 
70 struct hvterm_priv {
71 	u32			termno;	/* HV term number */
72 	hv_protocol_t		proto;	/* Raw data or HVSI packets */
73 	struct hvsi_priv	hvsi;	/* HVSI specific data */
74 	spinlock_t		buf_lock;
75 	char			buf[SIZE_VIO_GET_CHARS];
76 	int			left;
77 	int			offset;
78 };
79 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
80 /* For early boot console */
81 static struct hvterm_priv hvterm_priv0;
82 
hvterm_raw_get_chars(uint32_t vtermno,char * buf,int count)83 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
84 {
85 	struct hvterm_priv *pv = hvterm_privs[vtermno];
86 	unsigned long i;
87 	unsigned long flags;
88 	int got;
89 
90 	if (WARN_ON(!pv))
91 		return 0;
92 
93 	spin_lock_irqsave(&pv->buf_lock, flags);
94 
95 	if (pv->left == 0) {
96 		pv->offset = 0;
97 		pv->left = hvc_get_chars(pv->termno, pv->buf, count);
98 
99 		/*
100 		 * Work around a HV bug where it gives us a null
101 		 * after every \r.  -- paulus
102 		 */
103 		for (i = 1; i < pv->left; ++i) {
104 			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
105 				--pv->left;
106 				if (i < pv->left) {
107 					memmove(&pv->buf[i], &pv->buf[i+1],
108 						pv->left - i);
109 				}
110 			}
111 		}
112 	}
113 
114 	got = min(count, pv->left);
115 	memcpy(buf, &pv->buf[pv->offset], got);
116 	pv->offset += got;
117 	pv->left -= got;
118 
119 	spin_unlock_irqrestore(&pv->buf_lock, flags);
120 
121 	return got;
122 }
123 
hvterm_raw_put_chars(uint32_t vtermno,const char * buf,int count)124 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
125 {
126 	struct hvterm_priv *pv = hvterm_privs[vtermno];
127 
128 	if (WARN_ON(!pv))
129 		return 0;
130 
131 	return hvc_put_chars(pv->termno, buf, count);
132 }
133 
134 static const struct hv_ops hvterm_raw_ops = {
135 	.get_chars = hvterm_raw_get_chars,
136 	.put_chars = hvterm_raw_put_chars,
137 	.notifier_add = notifier_add_irq,
138 	.notifier_del = notifier_del_irq,
139 	.notifier_hangup = notifier_hangup_irq,
140 };
141 
hvterm_hvsi_get_chars(uint32_t vtermno,char * buf,int count)142 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
143 {
144 	struct hvterm_priv *pv = hvterm_privs[vtermno];
145 
146 	if (WARN_ON(!pv))
147 		return 0;
148 
149 	return hvsilib_get_chars(&pv->hvsi, buf, count);
150 }
151 
hvterm_hvsi_put_chars(uint32_t vtermno,const char * buf,int count)152 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
153 {
154 	struct hvterm_priv *pv = hvterm_privs[vtermno];
155 
156 	if (WARN_ON(!pv))
157 		return 0;
158 
159 	return hvsilib_put_chars(&pv->hvsi, buf, count);
160 }
161 
hvterm_hvsi_open(struct hvc_struct * hp,int data)162 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
163 {
164 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
165 	int rc;
166 
167 	pr_devel("HVSI@%x: open !\n", pv->termno);
168 
169 	rc = notifier_add_irq(hp, data);
170 	if (rc)
171 		return rc;
172 
173 	return hvsilib_open(&pv->hvsi, hp);
174 }
175 
hvterm_hvsi_close(struct hvc_struct * hp,int data)176 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
177 {
178 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
179 
180 	pr_devel("HVSI@%x: do close !\n", pv->termno);
181 
182 	hvsilib_close(&pv->hvsi, hp);
183 
184 	notifier_del_irq(hp, data);
185 }
186 
hvterm_hvsi_hangup(struct hvc_struct * hp,int data)187 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
188 {
189 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
190 
191 	pr_devel("HVSI@%x: do hangup !\n", pv->termno);
192 
193 	hvsilib_close(&pv->hvsi, hp);
194 
195 	notifier_hangup_irq(hp, data);
196 }
197 
hvterm_hvsi_tiocmget(struct hvc_struct * hp)198 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
199 {
200 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
201 
202 	if (!pv)
203 		return -EINVAL;
204 	return pv->hvsi.mctrl;
205 }
206 
hvterm_hvsi_tiocmset(struct hvc_struct * hp,unsigned int set,unsigned int clear)207 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
208 				unsigned int clear)
209 {
210 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
211 
212 	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
213 		 pv->termno, set, clear);
214 
215 	if (set & TIOCM_DTR)
216 		hvsilib_write_mctrl(&pv->hvsi, 1);
217 	else if (clear & TIOCM_DTR)
218 		hvsilib_write_mctrl(&pv->hvsi, 0);
219 
220 	return 0;
221 }
222 
223 static const struct hv_ops hvterm_hvsi_ops = {
224 	.get_chars = hvterm_hvsi_get_chars,
225 	.put_chars = hvterm_hvsi_put_chars,
226 	.notifier_add = hvterm_hvsi_open,
227 	.notifier_del = hvterm_hvsi_close,
228 	.notifier_hangup = hvterm_hvsi_hangup,
229 	.tiocmget = hvterm_hvsi_tiocmget,
230 	.tiocmset = hvterm_hvsi_tiocmset,
231 };
232 
hvc_vio_probe(struct vio_dev * vdev,const struct vio_device_id * id)233 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
234 				   const struct vio_device_id *id)
235 {
236 	const struct hv_ops *ops;
237 	struct hvc_struct *hp;
238 	struct hvterm_priv *pv;
239 	hv_protocol_t proto;
240 	int i, termno = -1;
241 
242 	/* probed with invalid parameters. */
243 	if (!vdev || !id)
244 		return -EPERM;
245 
246 	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
247 		proto = HV_PROTOCOL_RAW;
248 		ops = &hvterm_raw_ops;
249 	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
250 		proto = HV_PROTOCOL_HVSI;
251 		ops = &hvterm_hvsi_ops;
252 	} else {
253 		pr_err("hvc_vio: Unkown protocol for %s\n", vdev->dev.of_node->full_name);
254 		return -ENXIO;
255 	}
256 
257 	pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
258 		 vdev->dev.of_node->full_name,
259 		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
260 
261 	/* Is it our boot one ? */
262 	if (hvterm_privs[0] == &hvterm_priv0 &&
263 	    vdev->unit_address == hvterm_priv0.termno) {
264 		pv = hvterm_privs[0];
265 		termno = 0;
266 		pr_devel("->boot console, using termno 0\n");
267 	}
268 	/* nope, allocate a new one */
269 	else {
270 		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
271 			if (!hvterm_privs[i])
272 				termno = i;
273 		pr_devel("->non-boot console, using termno %d\n", termno);
274 		if (termno < 0)
275 			return -ENODEV;
276 		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
277 		if (!pv)
278 			return -ENOMEM;
279 		pv->termno = vdev->unit_address;
280 		pv->proto = proto;
281 		spin_lock_init(&pv->buf_lock);
282 		hvterm_privs[termno] = pv;
283 		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
284 			     pv->termno, 0);
285 	}
286 
287 	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
288 	if (IS_ERR(hp))
289 		return PTR_ERR(hp);
290 	dev_set_drvdata(&vdev->dev, hp);
291 
292 	return 0;
293 }
294 
hvc_vio_remove(struct vio_dev * vdev)295 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
296 {
297 	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
298 	int rc, termno;
299 
300 	termno = hp->vtermno;
301 	rc = hvc_remove(hp);
302 	if (rc == 0) {
303 		if (hvterm_privs[termno] != &hvterm_priv0)
304 			kfree(hvterm_privs[termno]);
305 		hvterm_privs[termno] = NULL;
306 	}
307 	return rc;
308 }
309 
310 static struct vio_driver hvc_vio_driver = {
311 	.id_table	= hvc_driver_table,
312 	.probe		= hvc_vio_probe,
313 	.remove		= hvc_vio_remove,
314 	.name		= hvc_driver_name,
315 };
316 
hvc_vio_init(void)317 static int __init hvc_vio_init(void)
318 {
319 	int rc;
320 
321 	/* Register as a vio device to receive callbacks */
322 	rc = vio_register_driver(&hvc_vio_driver);
323 
324 	return rc;
325 }
326 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
327 
hvc_vio_exit(void)328 static void __exit hvc_vio_exit(void)
329 {
330 	vio_unregister_driver(&hvc_vio_driver);
331 }
332 module_exit(hvc_vio_exit);
333 
udbg_hvc_putc(char c)334 static void udbg_hvc_putc(char c)
335 {
336 	int count = -1;
337 
338 	if (c == '\n')
339 		udbg_hvc_putc('\r');
340 
341 	do {
342 		switch(hvterm_priv0.proto) {
343 		case HV_PROTOCOL_RAW:
344 			count = hvterm_raw_put_chars(0, &c, 1);
345 			break;
346 		case HV_PROTOCOL_HVSI:
347 			count = hvterm_hvsi_put_chars(0, &c, 1);
348 			break;
349 		}
350 	} while(count == 0);
351 }
352 
udbg_hvc_getc_poll(void)353 static int udbg_hvc_getc_poll(void)
354 {
355 	int rc = 0;
356 	char c;
357 
358 	switch(hvterm_priv0.proto) {
359 	case HV_PROTOCOL_RAW:
360 		rc = hvterm_raw_get_chars(0, &c, 1);
361 		break;
362 	case HV_PROTOCOL_HVSI:
363 		rc = hvterm_hvsi_get_chars(0, &c, 1);
364 		break;
365 	}
366 	if (!rc)
367 		return -1;
368 	return c;
369 }
370 
udbg_hvc_getc(void)371 static int udbg_hvc_getc(void)
372 {
373 	int ch;
374 	for (;;) {
375 		ch = udbg_hvc_getc_poll();
376 		if (ch == -1) {
377 			/* This shouldn't be needed...but... */
378 			volatile unsigned long delay;
379 			for (delay=0; delay < 2000000; delay++)
380 				;
381 		} else {
382 			return ch;
383 		}
384 	}
385 }
386 
hvc_vio_init_early(void)387 void __init hvc_vio_init_early(void)
388 {
389 	struct device_node *stdout_node;
390 	const u32 *termno;
391 	const char *name;
392 	const struct hv_ops *ops;
393 
394 	/* find the boot console from /chosen/stdout */
395 	if (!of_chosen)
396 		return;
397 	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
398 	if (name == NULL)
399 		return;
400 	stdout_node = of_find_node_by_path(name);
401 	if (!stdout_node)
402 		return;
403 	name = of_get_property(stdout_node, "name", NULL);
404 	if (!name) {
405 		printk(KERN_WARNING "stdout node missing 'name' property!\n");
406 		goto out;
407 	}
408 
409 	/* Check if it's a virtual terminal */
410 	if (strncmp(name, "vty", 3) != 0)
411 		goto out;
412 	termno = of_get_property(stdout_node, "reg", NULL);
413 	if (termno == NULL)
414 		goto out;
415 	hvterm_priv0.termno = *termno;
416 	spin_lock_init(&hvterm_priv0.buf_lock);
417 	hvterm_privs[0] = &hvterm_priv0;
418 
419 	/* Check the protocol */
420 	if (of_device_is_compatible(stdout_node, "hvterm1")) {
421 		hvterm_priv0.proto = HV_PROTOCOL_RAW;
422 		ops = &hvterm_raw_ops;
423 	}
424 	else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
425 		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
426 		ops = &hvterm_hvsi_ops;
427 		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
428 			     hvterm_priv0.termno, 1);
429 		/* HVSI, perform the handshake now */
430 		hvsilib_establish(&hvterm_priv0.hvsi);
431 	} else
432 		goto out;
433 	udbg_putc = udbg_hvc_putc;
434 	udbg_getc = udbg_hvc_getc;
435 	udbg_getc_poll = udbg_hvc_getc_poll;
436 #ifdef HVC_OLD_HVSI
437 	/* When using the old HVSI driver don't register the HVC
438 	 * backend for HVSI, only do udbg
439 	 */
440 	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
441 		goto out;
442 #endif
443 	add_preferred_console("hvc", 0, NULL);
444 	hvc_instantiate(0, 0, ops);
445 out:
446 	of_node_put(stdout_node);
447 }
448 
449 /* call this from early_init() for a working debug console on
450  * vterm capable LPAR machines
451  */
452 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
udbg_init_debug_lpar(void)453 void __init udbg_init_debug_lpar(void)
454 {
455 	hvterm_privs[0] = &hvterm_priv0;
456 	hvterm_priv0.termno = 0;
457 	hvterm_priv0.proto = HV_PROTOCOL_RAW;
458 	spin_lock_init(&hvterm_priv0.buf_lock);
459 	udbg_putc = udbg_hvc_putc;
460 	udbg_getc = udbg_hvc_getc;
461 	udbg_getc_poll = udbg_hvc_getc_poll;
462 }
463 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
464 
465 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
udbg_init_debug_lpar_hvsi(void)466 void __init udbg_init_debug_lpar_hvsi(void)
467 {
468 	hvterm_privs[0] = &hvterm_priv0;
469 	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
470 	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
471 	spin_lock_init(&hvterm_priv0.buf_lock);
472 	udbg_putc = udbg_hvc_putc;
473 	udbg_getc = udbg_hvc_getc;
474 	udbg_getc_poll = udbg_hvc_getc_poll;
475 	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
476 		     hvterm_priv0.termno, 1);
477 	hvsilib_establish(&hvterm_priv0.hvsi);
478 }
479 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
480