GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / tty / hvc / hvc_opal.c
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_platform.h>
17 #include <linux/export.h>
18 #include <linux/interrupt.h>
19
20 #include <asm/hvconsole.h>
21 #include <asm/prom.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
29 static const char hvc_opal_name[] = "hvc_opal";
30
31 static 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
37 typedef enum hv_protocol {
38         HV_PROTOCOL_RAW,
39         HV_PROTOCOL_HVSI
40 } hv_protocol_t;
41
42 struct hvc_opal_priv {
43         hv_protocol_t           proto;  /* Raw data or HVSI packets */
44         struct hvsi_priv        hvsi;   /* HVSI specific data */
45 };
46 static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
47
48 /* For early boot console */
49 static struct hvc_opal_priv hvc_opal_boot_priv;
50 static u32 hvc_opal_boot_termno;
51
52 static 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
61 static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int 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
71 static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
72 {
73         struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
74
75         if (WARN_ON(!pv))
76                 return -ENODEV;
77
78         return hvsilib_put_chars(&pv->hvsi, buf, count);
79 }
80
81 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
82 {
83         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
84         int rc;
85
86         pr_devel("HVSI@%x: do open !\n", hp->vtermno);
87
88         rc = notifier_add_irq(hp, data);
89         if (rc)
90                 return rc;
91
92         return hvsilib_open(&pv->hvsi, hp);
93 }
94
95 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
96 {
97         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
98
99         pr_devel("HVSI@%x: do close !\n", hp->vtermno);
100
101         hvsilib_close(&pv->hvsi, hp);
102
103         notifier_del_irq(hp, data);
104 }
105
106 void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
107 {
108         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
109
110         pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
111
112         hvsilib_close(&pv->hvsi, hp);
113
114         notifier_hangup_irq(hp, data);
115 }
116
117 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
118 {
119         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
120
121         if (!pv)
122                 return -EINVAL;
123         return pv->hvsi.mctrl;
124 }
125
126 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
127                                 unsigned int clear)
128 {
129         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
130
131         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
132                  hp->vtermno, set, clear);
133
134         if (set & TIOCM_DTR)
135                 hvsilib_write_mctrl(&pv->hvsi, 1);
136         else if (clear & TIOCM_DTR)
137                 hvsilib_write_mctrl(&pv->hvsi, 0);
138
139         return 0;
140 }
141
142 static const struct hv_ops hvc_opal_hvsi_ops = {
143         .get_chars = hvc_opal_hvsi_get_chars,
144         .put_chars = hvc_opal_hvsi_put_chars,
145         .flush = opal_flush_chars,
146         .notifier_add = hvc_opal_hvsi_open,
147         .notifier_del = hvc_opal_hvsi_close,
148         .notifier_hangup = hvc_opal_hvsi_hangup,
149         .tiocmget = hvc_opal_hvsi_tiocmget,
150         .tiocmset = hvc_opal_hvsi_tiocmset,
151 };
152
153 static int hvc_opal_probe(struct platform_device *dev)
154 {
155         const struct hv_ops *ops;
156         struct hvc_struct *hp;
157         struct hvc_opal_priv *pv;
158         hv_protocol_t proto;
159         unsigned int termno, irq, boot = 0;
160         const __be32 *reg;
161
162         if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
163                 proto = HV_PROTOCOL_RAW;
164                 ops = &hvc_opal_raw_ops;
165         } else if (of_device_is_compatible(dev->dev.of_node,
166                                            "ibm,opal-console-hvsi")) {
167                 proto = HV_PROTOCOL_HVSI;
168                 ops = &hvc_opal_hvsi_ops;
169         } else {
170                 pr_err("hvc_opal: Unknown protocol for %pOF\n",
171                        dev->dev.of_node);
172                 return -ENXIO;
173         }
174
175         reg = of_get_property(dev->dev.of_node, "reg", NULL);
176         termno = reg ? be32_to_cpup(reg) : 0;
177
178         /* Is it our boot one ? */
179         if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
180                 pv = hvc_opal_privs[termno];
181                 boot = 1;
182         } else if (hvc_opal_privs[termno] == NULL) {
183                 pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
184                 if (!pv)
185                         return -ENOMEM;
186                 pv->proto = proto;
187                 hvc_opal_privs[termno] = pv;
188                 if (proto == HV_PROTOCOL_HVSI) {
189                         /*
190                          * We want put_chars to be atomic to avoid mangling of
191                          * hvsi packets.
192                          */
193                         hvsilib_init(&pv->hvsi,
194                                      opal_get_chars, opal_put_chars_atomic,
195                                      termno, 0);
196                 }
197
198                 /* Instanciate now to establish a mapping index==vtermno */
199                 hvc_instantiate(termno, termno, ops);
200         } else {
201                 pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
202                        dev->dev.of_node, termno);
203                 return -ENXIO;
204         }
205
206         pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
207                 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
208                 dev->dev.of_node,
209                 boot ? " (boot console)" : "");
210
211         irq = irq_of_parse_and_map(dev->dev.of_node, 0);
212         if (!irq) {
213                 pr_info("hvc%d: No interrupts property, using OPAL event\n",
214                                 termno);
215                 irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
216         }
217
218         if (!irq) {
219                 pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
220                         dev->dev.of_node);
221                 return irq;
222         }
223
224         hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
225         if (IS_ERR(hp))
226                 return PTR_ERR(hp);
227
228         /* hvc consoles on powernv may need to share a single irq */
229         hp->flags = IRQF_SHARED;
230         dev_set_drvdata(&dev->dev, hp);
231
232         return 0;
233 }
234
235 static int hvc_opal_remove(struct platform_device *dev)
236 {
237         struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
238         int rc, termno;
239
240         termno = hp->vtermno;
241         rc = hvc_remove(hp);
242         if (rc == 0) {
243                 if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
244                         kfree(hvc_opal_privs[termno]);
245                 hvc_opal_privs[termno] = NULL;
246         }
247         return rc;
248 }
249
250 static struct platform_driver hvc_opal_driver = {
251         .probe          = hvc_opal_probe,
252         .remove         = hvc_opal_remove,
253         .driver         = {
254                 .name   = hvc_opal_name,
255                 .of_match_table = hvc_opal_match,
256         }
257 };
258
259 static int __init hvc_opal_init(void)
260 {
261         if (!firmware_has_feature(FW_FEATURE_OPAL))
262                 return -ENODEV;
263
264         /* Register as a vio device to receive callbacks */
265         return platform_driver_register(&hvc_opal_driver);
266 }
267 device_initcall(hvc_opal_init);
268
269 static void udbg_opal_putc(char c)
270 {
271         unsigned int termno = hvc_opal_boot_termno;
272         int count = -1;
273
274         if (c == '\n')
275                 udbg_opal_putc('\r');
276
277         do {
278                 switch(hvc_opal_boot_priv.proto) {
279                 case HV_PROTOCOL_RAW:
280                         count = opal_put_chars(termno, &c, 1);
281                         break;
282                 case HV_PROTOCOL_HVSI:
283                         count = hvc_opal_hvsi_put_chars(termno, &c, 1);
284                         break;
285                 }
286
287                 /* This is needed for the cosole to flush
288                  * when there aren't any interrupts.
289                  */
290                 opal_flush_console(termno);
291         } while(count == 0 || count == -EAGAIN);
292 }
293
294 static int udbg_opal_getc_poll(void)
295 {
296         unsigned int termno = hvc_opal_boot_termno;
297         int rc = 0;
298         char c;
299
300         switch(hvc_opal_boot_priv.proto) {
301         case HV_PROTOCOL_RAW:
302                 rc = opal_get_chars(termno, &c, 1);
303                 break;
304         case HV_PROTOCOL_HVSI:
305                 rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
306                 break;
307         }
308         if (!rc)
309                 return -1;
310         return c;
311 }
312
313 static int udbg_opal_getc(void)
314 {
315         int ch;
316         for (;;) {
317                 ch = udbg_opal_getc_poll();
318                 if (ch != -1)
319                         return ch;
320         }
321 }
322
323 static void udbg_init_opal_common(void)
324 {
325         udbg_putc = udbg_opal_putc;
326         udbg_getc = udbg_opal_getc;
327         udbg_getc_poll = udbg_opal_getc_poll;
328 }
329
330 void __init hvc_opal_init_early(void)
331 {
332         struct device_node *stdout_node = of_node_get(of_stdout);
333         const __be32 *termno;
334         const struct hv_ops *ops;
335         u32 index;
336
337         /* If the console wasn't in /chosen, try /ibm,opal */
338         if (!stdout_node) {
339                 struct device_node *opal, *np;
340
341                 /* Current OPAL takeover doesn't provide the stdout
342                  * path, so we hard wire it
343                  */
344                 opal = of_find_node_by_path("/ibm,opal/consoles");
345                 if (opal)
346                         pr_devel("hvc_opal: Found consoles in new location\n");
347                 if (!opal) {
348                         opal = of_find_node_by_path("/ibm,opal");
349                         if (opal)
350                                 pr_devel("hvc_opal: "
351                                          "Found consoles in old location\n");
352                 }
353                 if (!opal)
354                         return;
355                 for_each_child_of_node(opal, np) {
356                         if (of_node_name_eq(np, "serial")) {
357                                 stdout_node = np;
358                                 break;
359                         }
360                 }
361                 of_node_put(opal);
362         }
363         if (!stdout_node)
364                 return;
365         termno = of_get_property(stdout_node, "reg", NULL);
366         index = termno ? be32_to_cpup(termno) : 0;
367         if (index >= MAX_NR_HVC_CONSOLES)
368                 return;
369         hvc_opal_privs[index] = &hvc_opal_boot_priv;
370
371         /* Check the protocol */
372         if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
373                 hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
374                 ops = &hvc_opal_raw_ops;
375                 pr_devel("hvc_opal: Found RAW console\n");
376         }
377         else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
378                 hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
379                 ops = &hvc_opal_hvsi_ops;
380                 hvsilib_init(&hvc_opal_boot_priv.hvsi,
381                              opal_get_chars, opal_put_chars_atomic,
382                              index, 1);
383                 /* HVSI, perform the handshake now */
384                 hvsilib_establish(&hvc_opal_boot_priv.hvsi);
385                 pr_devel("hvc_opal: Found HVSI console\n");
386         } else
387                 goto out;
388         hvc_opal_boot_termno = index;
389         udbg_init_opal_common();
390         add_preferred_console("hvc", index, NULL);
391         hvc_instantiate(index, index, ops);
392 out:
393         of_node_put(stdout_node);
394 }
395
396 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
397 void __init udbg_init_debug_opal_raw(void)
398 {
399         u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
400         hvc_opal_privs[index] = &hvc_opal_boot_priv;
401         hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
402         hvc_opal_boot_termno = index;
403         udbg_init_opal_common();
404 }
405 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
406
407 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
408 void __init udbg_init_debug_opal_hvsi(void)
409 {
410         u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
411         hvc_opal_privs[index] = &hvc_opal_boot_priv;
412         hvc_opal_boot_termno = index;
413         udbg_init_opal_common();
414         hvsilib_init(&hvc_opal_boot_priv.hvsi,
415                      opal_get_chars, opal_put_chars_atomic,
416                      index, 1);
417         hvsilib_establish(&hvc_opal_boot_priv.hvsi);
418 }
419 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */