Root/drivers/tty/hvc/hvc_opal.c

1/*
2 * opal driver interface to hvc_console.c
3 *
4 * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#undef DEBUG
23
24#include <linux/types.h>
25#include <linux/init.h>
26#include <linux/delay.h>
27#include <linux/slab.h>
28#include <linux/console.h>
29#include <linux/of.h>
30#include <linux/of_platform.h>
31#include <linux/export.h>
32
33#include <asm/hvconsole.h>
34#include <asm/prom.h>
35#include <asm/firmware.h>
36#include <asm/hvsi.h>
37#include <asm/udbg.h>
38#include <asm/opal.h>
39
40#include "hvc_console.h"
41
42static const char hvc_opal_name[] = "hvc_opal";
43
44static struct of_device_id hvc_opal_match[] = {
45    { .name = "serial", .compatible = "ibm,opal-console-raw" },
46    { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
47    { },
48};
49
50typedef enum hv_protocol {
51    HV_PROTOCOL_RAW,
52    HV_PROTOCOL_HVSI
53} hv_protocol_t;
54
55struct hvc_opal_priv {
56    hv_protocol_t proto; /* Raw data or HVSI packets */
57    struct hvsi_priv hvsi; /* HVSI specific data */
58};
59static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
60
61/* For early boot console */
62static struct hvc_opal_priv hvc_opal_boot_priv;
63static u32 hvc_opal_boot_termno;
64
65static const struct hv_ops hvc_opal_raw_ops = {
66    .get_chars = opal_get_chars,
67    .put_chars = opal_put_chars,
68    .notifier_add = notifier_add_irq,
69    .notifier_del = notifier_del_irq,
70    .notifier_hangup = notifier_hangup_irq,
71};
72
73static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
74{
75    struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
76
77    if (WARN_ON(!pv))
78        return -ENODEV;
79
80    return hvsilib_get_chars(&pv->hvsi, buf, count);
81}
82
83static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
84{
85    struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
86
87    if (WARN_ON(!pv))
88        return -ENODEV;
89
90    return hvsilib_put_chars(&pv->hvsi, buf, count);
91}
92
93static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
94{
95    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
96    int rc;
97
98    pr_devel("HVSI@%x: do open !\n", hp->vtermno);
99
100    rc = notifier_add_irq(hp, data);
101    if (rc)
102        return rc;
103
104    return hvsilib_open(&pv->hvsi, hp);
105}
106
107static void hvc_opal_hvsi_close(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 close !\n", hp->vtermno);
112
113    hvsilib_close(&pv->hvsi, hp);
114
115    notifier_del_irq(hp, data);
116}
117
118void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
119{
120    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
121
122    pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
123
124    hvsilib_close(&pv->hvsi, hp);
125
126    notifier_hangup_irq(hp, data);
127}
128
129static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
130{
131    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
132
133    if (!pv)
134        return -EINVAL;
135    return pv->hvsi.mctrl;
136}
137
138static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
139                unsigned int clear)
140{
141    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
142
143    pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
144         hp->vtermno, set, clear);
145
146    if (set & TIOCM_DTR)
147        hvsilib_write_mctrl(&pv->hvsi, 1);
148    else if (clear & TIOCM_DTR)
149        hvsilib_write_mctrl(&pv->hvsi, 0);
150
151    return 0;
152}
153
154static const struct hv_ops hvc_opal_hvsi_ops = {
155    .get_chars = hvc_opal_hvsi_get_chars,
156    .put_chars = hvc_opal_hvsi_put_chars,
157    .notifier_add = hvc_opal_hvsi_open,
158    .notifier_del = hvc_opal_hvsi_close,
159    .notifier_hangup = hvc_opal_hvsi_hangup,
160    .tiocmget = hvc_opal_hvsi_tiocmget,
161    .tiocmset = hvc_opal_hvsi_tiocmset,
162};
163
164static int hvc_opal_probe(struct platform_device *dev)
165{
166    const struct hv_ops *ops;
167    struct hvc_struct *hp;
168    struct hvc_opal_priv *pv;
169    hv_protocol_t proto;
170    unsigned int termno, boot = 0;
171    const __be32 *reg;
172
173    if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
174        proto = HV_PROTOCOL_RAW;
175        ops = &hvc_opal_raw_ops;
176    } else if (of_device_is_compatible(dev->dev.of_node,
177                       "ibm,opal-console-hvsi")) {
178        proto = HV_PROTOCOL_HVSI;
179        ops = &hvc_opal_hvsi_ops;
180    } else {
181        pr_err("hvc_opal: Unknown protocol for %s\n",
182               dev->dev.of_node->full_name);
183        return -ENXIO;
184    }
185
186    reg = of_get_property(dev->dev.of_node, "reg", NULL);
187    termno = reg ? be32_to_cpup(reg) : 0;
188
189    /* Is it our boot one ? */
190    if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
191        pv = hvc_opal_privs[termno];
192        boot = 1;
193    } else if (hvc_opal_privs[termno] == NULL) {
194        pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
195        if (!pv)
196            return -ENOMEM;
197        pv->proto = proto;
198        hvc_opal_privs[termno] = pv;
199        if (proto == HV_PROTOCOL_HVSI)
200            hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
201                     termno, 0);
202
203        /* Instanciate now to establish a mapping index==vtermno */
204        hvc_instantiate(termno, termno, ops);
205    } else {
206        pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
207               dev->dev.of_node->full_name, termno);
208        return -ENXIO;
209    }
210
211    pr_info("hvc%d: %s protocol on %s%s\n", termno,
212        proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
213        dev->dev.of_node->full_name,
214        boot ? " (boot console)" : "");
215
216    /* We don't do IRQ yet */
217    hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
218    if (IS_ERR(hp))
219        return PTR_ERR(hp);
220    dev_set_drvdata(&dev->dev, hp);
221
222    return 0;
223}
224
225static int hvc_opal_remove(struct platform_device *dev)
226{
227    struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
228    int rc, termno;
229
230    termno = hp->vtermno;
231    rc = hvc_remove(hp);
232    if (rc == 0) {
233        if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
234            kfree(hvc_opal_privs[termno]);
235        hvc_opal_privs[termno] = NULL;
236    }
237    return rc;
238}
239
240static struct platform_driver hvc_opal_driver = {
241    .probe = hvc_opal_probe,
242    .remove = hvc_opal_remove,
243    .driver = {
244        .name = hvc_opal_name,
245        .owner = THIS_MODULE,
246        .of_match_table = hvc_opal_match,
247    }
248};
249
250static int __init hvc_opal_init(void)
251{
252    if (!firmware_has_feature(FW_FEATURE_OPAL))
253        return -ENODEV;
254
255    /* Register as a vio device to receive callbacks */
256    return platform_driver_register(&hvc_opal_driver);
257}
258module_init(hvc_opal_init);
259
260static void __exit hvc_opal_exit(void)
261{
262    platform_driver_unregister(&hvc_opal_driver);
263}
264module_exit(hvc_opal_exit);
265
266static void udbg_opal_putc(char c)
267{
268    unsigned int termno = hvc_opal_boot_termno;
269    int count = -1;
270
271    if (c == '\n')
272        udbg_opal_putc('\r');
273
274    do {
275        switch(hvc_opal_boot_priv.proto) {
276        case HV_PROTOCOL_RAW:
277            count = opal_put_chars(termno, &c, 1);
278            break;
279        case HV_PROTOCOL_HVSI:
280            count = hvc_opal_hvsi_put_chars(termno, &c, 1);
281            break;
282        }
283    } while(count == 0 || count == -EAGAIN);
284}
285
286static int udbg_opal_getc_poll(void)
287{
288    unsigned int termno = hvc_opal_boot_termno;
289    int rc = 0;
290    char c;
291
292    switch(hvc_opal_boot_priv.proto) {
293    case HV_PROTOCOL_RAW:
294        rc = opal_get_chars(termno, &c, 1);
295        break;
296    case HV_PROTOCOL_HVSI:
297        rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
298        break;
299    }
300    if (!rc)
301        return -1;
302    return c;
303}
304
305static int udbg_opal_getc(void)
306{
307    int ch;
308    for (;;) {
309        ch = udbg_opal_getc_poll();
310        if (ch == -1) {
311            /* This shouldn't be needed...but... */
312            volatile unsigned long delay;
313            for (delay=0; delay < 2000000; delay++)
314                ;
315        } else {
316            return ch;
317        }
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    tb_ticks_per_usec = 0x200; /* Make udelay not suck */
327}
328
329void __init hvc_opal_init_early(void)
330{
331    struct device_node *stdout_node = NULL;
332    const u32 *termno;
333    const char *name = NULL;
334    const struct hv_ops *ops;
335    u32 index;
336
337    /* find the boot console from /chosen/stdout */
338    if (of_chosen)
339        name = of_get_property(of_chosen, "linux,stdout-path", NULL);
340    if (name) {
341        stdout_node = of_find_node_by_path(name);
342        if (!stdout_node) {
343            pr_err("hvc_opal: Failed to locate default console!\n");
344            return;
345        }
346    } else {
347        struct device_node *opal, *np;
348
349        /* Current OPAL takeover doesn't provide the stdout
350         * path, so we hard wire it
351         */
352        opal = of_find_node_by_path("/ibm,opal/consoles");
353        if (opal)
354            pr_devel("hvc_opal: Found consoles in new location\n");
355        if (!opal) {
356            opal = of_find_node_by_path("/ibm,opal");
357            if (opal)
358                pr_devel("hvc_opal: "
359                     "Found consoles in old location\n");
360        }
361        if (!opal)
362            return;
363        for_each_child_of_node(opal, np) {
364            if (!strcmp(np->name, "serial")) {
365                stdout_node = np;
366                break;
367            }
368        }
369        of_node_put(opal);
370    }
371    if (!stdout_node)
372        return;
373    termno = of_get_property(stdout_node, "reg", NULL);
374    index = termno ? *termno : 0;
375    if (index >= MAX_NR_HVC_CONSOLES)
376        return;
377    hvc_opal_privs[index] = &hvc_opal_boot_priv;
378
379    /* Check the protocol */
380    if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
381        hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
382        ops = &hvc_opal_raw_ops;
383        pr_devel("hvc_opal: Found RAW console\n");
384    }
385    else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
386        hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
387        ops = &hvc_opal_hvsi_ops;
388        hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
389                 opal_put_chars, index, 1);
390        /* HVSI, perform the handshake now */
391        hvsilib_establish(&hvc_opal_boot_priv.hvsi);
392        pr_devel("hvc_opal: Found HVSI console\n");
393    } else
394        goto out;
395    hvc_opal_boot_termno = index;
396    udbg_init_opal_common();
397    add_preferred_console("hvc", index, NULL);
398    hvc_instantiate(index, index, ops);
399out:
400    of_node_put(stdout_node);
401}
402
403#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
404void __init udbg_init_debug_opal_raw(void)
405{
406    u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
407    hvc_opal_privs[index] = &hvc_opal_boot_priv;
408    hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
409    hvc_opal_boot_termno = index;
410    udbg_init_opal_common();
411}
412#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
413
414#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
415void __init udbg_init_debug_opal_hvsi(void)
416{
417    u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
418    hvc_opal_privs[index] = &hvc_opal_boot_priv;
419    hvc_opal_boot_termno = index;
420    udbg_init_opal_common();
421    hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
422             index, 1);
423    hvsilib_establish(&hvc_opal_boot_priv.hvsi);
424}
425#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
426

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