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Commit | Line | Data |
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c90553b3 AN |
1 | /* |
2 | * Thunderbolt Cactus Ridge driver - eeprom access | |
3 | * | |
4 | * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> | |
5 | */ | |
6 | ||
cd22e73b | 7 | #include <linux/crc32.h> |
c9cc3aaa | 8 | #include <linux/property.h> |
2b35404e | 9 | #include <linux/slab.h> |
c90553b3 AN |
10 | #include "tb.h" |
11 | ||
12 | /** | |
13 | * tb_eeprom_ctl_write() - write control word | |
14 | */ | |
15 | static int tb_eeprom_ctl_write(struct tb_switch *sw, struct tb_eeprom_ctl *ctl) | |
16 | { | |
17 | return tb_sw_write(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1); | |
18 | } | |
19 | ||
20 | /** | |
21 | * tb_eeprom_ctl_write() - read control word | |
22 | */ | |
23 | static int tb_eeprom_ctl_read(struct tb_switch *sw, struct tb_eeprom_ctl *ctl) | |
24 | { | |
25 | return tb_sw_read(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1); | |
26 | } | |
27 | ||
28 | enum tb_eeprom_transfer { | |
29 | TB_EEPROM_IN, | |
30 | TB_EEPROM_OUT, | |
31 | }; | |
32 | ||
33 | /** | |
34 | * tb_eeprom_active - enable rom access | |
35 | * | |
36 | * WARNING: Always disable access after usage. Otherwise the controller will | |
37 | * fail to reprobe. | |
38 | */ | |
39 | static int tb_eeprom_active(struct tb_switch *sw, bool enable) | |
40 | { | |
41 | struct tb_eeprom_ctl ctl; | |
42 | int res = tb_eeprom_ctl_read(sw, &ctl); | |
43 | if (res) | |
44 | return res; | |
45 | if (enable) { | |
46 | ctl.access_high = 1; | |
47 | res = tb_eeprom_ctl_write(sw, &ctl); | |
48 | if (res) | |
49 | return res; | |
50 | ctl.access_low = 0; | |
51 | return tb_eeprom_ctl_write(sw, &ctl); | |
52 | } else { | |
53 | ctl.access_low = 1; | |
54 | res = tb_eeprom_ctl_write(sw, &ctl); | |
55 | if (res) | |
56 | return res; | |
57 | ctl.access_high = 0; | |
58 | return tb_eeprom_ctl_write(sw, &ctl); | |
59 | } | |
60 | } | |
61 | ||
62 | /** | |
63 | * tb_eeprom_transfer - transfer one bit | |
64 | * | |
65 | * If TB_EEPROM_IN is passed, then the bit can be retrieved from ctl->data_in. | |
66 | * If TB_EEPROM_OUT is passed, then ctl->data_out will be written. | |
67 | */ | |
68 | static int tb_eeprom_transfer(struct tb_switch *sw, struct tb_eeprom_ctl *ctl, | |
69 | enum tb_eeprom_transfer direction) | |
70 | { | |
71 | int res; | |
72 | if (direction == TB_EEPROM_OUT) { | |
73 | res = tb_eeprom_ctl_write(sw, ctl); | |
74 | if (res) | |
75 | return res; | |
76 | } | |
77 | ctl->clock = 1; | |
78 | res = tb_eeprom_ctl_write(sw, ctl); | |
79 | if (res) | |
80 | return res; | |
81 | if (direction == TB_EEPROM_IN) { | |
82 | res = tb_eeprom_ctl_read(sw, ctl); | |
83 | if (res) | |
84 | return res; | |
85 | } | |
86 | ctl->clock = 0; | |
87 | return tb_eeprom_ctl_write(sw, ctl); | |
88 | } | |
89 | ||
90 | /** | |
91 | * tb_eeprom_out - write one byte to the bus | |
92 | */ | |
93 | static int tb_eeprom_out(struct tb_switch *sw, u8 val) | |
94 | { | |
95 | struct tb_eeprom_ctl ctl; | |
96 | int i; | |
97 | int res = tb_eeprom_ctl_read(sw, &ctl); | |
98 | if (res) | |
99 | return res; | |
100 | for (i = 0; i < 8; i++) { | |
101 | ctl.data_out = val & 0x80; | |
102 | res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_OUT); | |
103 | if (res) | |
104 | return res; | |
105 | val <<= 1; | |
106 | } | |
107 | return 0; | |
108 | } | |
109 | ||
110 | /** | |
111 | * tb_eeprom_in - read one byte from the bus | |
112 | */ | |
113 | static int tb_eeprom_in(struct tb_switch *sw, u8 *val) | |
114 | { | |
115 | struct tb_eeprom_ctl ctl; | |
116 | int i; | |
117 | int res = tb_eeprom_ctl_read(sw, &ctl); | |
118 | if (res) | |
119 | return res; | |
120 | *val = 0; | |
121 | for (i = 0; i < 8; i++) { | |
122 | *val <<= 1; | |
123 | res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_IN); | |
124 | if (res) | |
125 | return res; | |
126 | *val |= ctl.data_in; | |
127 | } | |
128 | return 0; | |
129 | } | |
130 | ||
131 | /** | |
132 | * tb_eeprom_read_n - read count bytes from offset into val | |
133 | */ | |
134 | static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val, | |
135 | size_t count) | |
136 | { | |
137 | int i, res; | |
138 | res = tb_eeprom_active(sw, true); | |
139 | if (res) | |
140 | return res; | |
141 | res = tb_eeprom_out(sw, 3); | |
142 | if (res) | |
143 | return res; | |
144 | res = tb_eeprom_out(sw, offset >> 8); | |
145 | if (res) | |
146 | return res; | |
147 | res = tb_eeprom_out(sw, offset); | |
148 | if (res) | |
149 | return res; | |
150 | for (i = 0; i < count; i++) { | |
151 | res = tb_eeprom_in(sw, val + i); | |
152 | if (res) | |
153 | return res; | |
154 | } | |
155 | return tb_eeprom_active(sw, false); | |
156 | } | |
157 | ||
cd22e73b AN |
158 | static u8 tb_crc8(u8 *data, int len) |
159 | { | |
160 | int i, j; | |
161 | u8 val = 0xff; | |
162 | for (i = 0; i < len; i++) { | |
163 | val ^= data[i]; | |
164 | for (j = 0; j < 8; j++) | |
165 | val = (val << 1) ^ ((val & 0x80) ? 7 : 0); | |
166 | } | |
167 | return val; | |
168 | } | |
169 | ||
170 | static u32 tb_crc32(void *data, size_t len) | |
171 | { | |
172 | return ~__crc32c_le(~0, data, len); | |
173 | } | |
174 | ||
175 | #define TB_DROM_DATA_START 13 | |
176 | struct tb_drom_header { | |
177 | /* BYTE 0 */ | |
178 | u8 uid_crc8; /* checksum for uid */ | |
179 | /* BYTES 1-8 */ | |
180 | u64 uid; | |
181 | /* BYTES 9-12 */ | |
182 | u32 data_crc32; /* checksum for data_len bytes starting at byte 13 */ | |
183 | /* BYTE 13 */ | |
184 | u8 device_rom_revision; /* should be <= 1 */ | |
185 | u16 data_len:10; | |
186 | u8 __unknown1:6; | |
187 | /* BYTES 16-21 */ | |
188 | u16 vendor_id; | |
189 | u16 model_id; | |
190 | u8 model_rev; | |
191 | u8 eeprom_rev; | |
192 | } __packed; | |
193 | ||
194 | enum tb_drom_entry_type { | |
e7120778 AN |
195 | /* force unsigned to prevent "one-bit signed bitfield" warning */ |
196 | TB_DROM_ENTRY_GENERIC = 0U, | |
cd22e73b AN |
197 | TB_DROM_ENTRY_PORT, |
198 | }; | |
199 | ||
200 | struct tb_drom_entry_header { | |
201 | u8 len; | |
202 | u8 index:6; | |
203 | bool port_disabled:1; /* only valid if type is TB_DROM_ENTRY_PORT */ | |
204 | enum tb_drom_entry_type type:1; | |
205 | } __packed; | |
206 | ||
207 | struct tb_drom_entry_port { | |
208 | /* BYTES 0-1 */ | |
209 | struct tb_drom_entry_header header; | |
210 | /* BYTE 2 */ | |
211 | u8 dual_link_port_rid:4; | |
212 | u8 link_nr:1; | |
213 | u8 unknown1:2; | |
214 | bool has_dual_link_port:1; | |
215 | ||
216 | /* BYTE 3 */ | |
217 | u8 dual_link_port_nr:6; | |
218 | u8 unknown2:2; | |
219 | ||
220 | /* BYTES 4 - 5 TODO decode */ | |
221 | u8 micro2:4; | |
222 | u8 micro1:4; | |
223 | u8 micro3; | |
224 | ||
aae20bb6 | 225 | /* BYTES 6-7, TODO: verify (find hardware that has these set) */ |
cd22e73b AN |
226 | u8 peer_port_rid:4; |
227 | u8 unknown3:3; | |
228 | bool has_peer_port:1; | |
229 | u8 peer_port_nr:6; | |
230 | u8 unknown4:2; | |
231 | } __packed; | |
232 | ||
233 | ||
234 | /** | |
235 | * tb_eeprom_get_drom_offset - get drom offset within eeprom | |
236 | */ | |
e0f55014 | 237 | static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset) |
c90553b3 | 238 | { |
c90553b3 AN |
239 | struct tb_cap_plug_events cap; |
240 | int res; | |
241 | if (!sw->cap_plug_events) { | |
242 | tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n"); | |
243 | return -ENOSYS; | |
244 | } | |
245 | res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events, | |
246 | sizeof(cap) / 4); | |
247 | if (res) | |
248 | return res; | |
cd22e73b | 249 | |
c90553b3 AN |
250 | if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) { |
251 | tb_sw_warn(sw, "no NVM\n"); | |
252 | return -ENOSYS; | |
253 | } | |
254 | ||
255 | if (cap.drom_offset > 0xffff) { | |
256 | tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n", | |
257 | cap.drom_offset); | |
258 | return -ENXIO; | |
259 | } | |
cd22e73b AN |
260 | *offset = cap.drom_offset; |
261 | return 0; | |
262 | } | |
263 | ||
264 | /** | |
265 | * tb_drom_read_uid_only - read uid directly from drom | |
266 | * | |
267 | * Does not use the cached copy in sw->drom. Used during resume to check switch | |
268 | * identity. | |
269 | */ | |
270 | int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid) | |
271 | { | |
272 | u8 data[9]; | |
273 | u16 drom_offset; | |
274 | u8 crc; | |
275 | int res = tb_eeprom_get_drom_offset(sw, &drom_offset); | |
276 | if (res) | |
277 | return res; | |
c90553b3 AN |
278 | |
279 | /* read uid */ | |
cd22e73b | 280 | res = tb_eeprom_read_n(sw, drom_offset, data, 9); |
c90553b3 AN |
281 | if (res) |
282 | return res; | |
cd22e73b AN |
283 | |
284 | crc = tb_crc8(data + 1, 8); | |
285 | if (crc != data[0]) { | |
286 | tb_sw_warn(sw, "uid crc8 missmatch (expected: %#x, got: %#x)\n", | |
287 | data[0], crc); | |
288 | return -EIO; | |
289 | } | |
290 | ||
c90553b3 AN |
291 | *uid = *(u64 *)(data+1); |
292 | return 0; | |
293 | } | |
294 | ||
cd22e73b AN |
295 | static void tb_drom_parse_port_entry(struct tb_port *port, |
296 | struct tb_drom_entry_port *entry) | |
297 | { | |
298 | port->link_nr = entry->link_nr; | |
299 | if (entry->has_dual_link_port) | |
300 | port->dual_link_port = | |
301 | &port->sw->ports[entry->dual_link_port_nr]; | |
302 | } | |
303 | ||
304 | static int tb_drom_parse_entry(struct tb_switch *sw, | |
305 | struct tb_drom_entry_header *header) | |
306 | { | |
307 | struct tb_port *port; | |
308 | int res; | |
309 | enum tb_port_type type; | |
c90553b3 | 310 | |
cd22e73b AN |
311 | if (header->type != TB_DROM_ENTRY_PORT) |
312 | return 0; | |
c90553b3 | 313 | |
cd22e73b AN |
314 | port = &sw->ports[header->index]; |
315 | port->disabled = header->port_disabled; | |
316 | if (port->disabled) | |
317 | return 0; | |
318 | ||
319 | res = tb_port_read(port, &type, TB_CFG_PORT, 2, 1); | |
320 | if (res) | |
321 | return res; | |
322 | type &= 0xffffff; | |
323 | ||
324 | if (type == TB_TYPE_PORT) { | |
325 | struct tb_drom_entry_port *entry = (void *) header; | |
326 | if (header->len != sizeof(*entry)) { | |
327 | tb_sw_warn(sw, | |
3543fb77 | 328 | "port entry has size %#x (expected %#zx)\n", |
cd22e73b AN |
329 | header->len, sizeof(struct tb_drom_entry_port)); |
330 | return -EIO; | |
331 | } | |
332 | tb_drom_parse_port_entry(port, entry); | |
333 | } | |
334 | return 0; | |
335 | } | |
336 | ||
337 | /** | |
338 | * tb_drom_parse_entries - parse the linked list of drom entries | |
339 | * | |
340 | * Drom must have been copied to sw->drom. | |
341 | */ | |
342 | static int tb_drom_parse_entries(struct tb_switch *sw) | |
343 | { | |
344 | struct tb_drom_header *header = (void *) sw->drom; | |
345 | u16 pos = sizeof(*header); | |
346 | u16 drom_size = header->data_len + TB_DROM_DATA_START; | |
347 | ||
348 | while (pos < drom_size) { | |
349 | struct tb_drom_entry_header *entry = (void *) (sw->drom + pos); | |
350 | if (pos + 1 == drom_size || pos + entry->len > drom_size | |
351 | || !entry->len) { | |
352 | tb_sw_warn(sw, "drom buffer overrun, aborting\n"); | |
353 | return -EIO; | |
354 | } | |
355 | ||
356 | tb_drom_parse_entry(sw, entry); | |
357 | ||
358 | pos += entry->len; | |
359 | } | |
360 | return 0; | |
361 | } | |
362 | ||
c9cc3aaa LW |
363 | /** |
364 | * tb_drom_copy_efi - copy drom supplied by EFI to sw->drom if present | |
365 | */ | |
366 | static int tb_drom_copy_efi(struct tb_switch *sw, u16 *size) | |
367 | { | |
368 | struct device *dev = &sw->tb->nhi->pdev->dev; | |
369 | int len, res; | |
370 | ||
371 | len = device_property_read_u8_array(dev, "ThunderboltDROM", NULL, 0); | |
372 | if (len < 0 || len < sizeof(struct tb_drom_header)) | |
373 | return -EINVAL; | |
374 | ||
375 | sw->drom = kmalloc(len, GFP_KERNEL); | |
376 | if (!sw->drom) | |
377 | return -ENOMEM; | |
378 | ||
379 | res = device_property_read_u8_array(dev, "ThunderboltDROM", sw->drom, | |
380 | len); | |
381 | if (res) | |
382 | goto err; | |
383 | ||
384 | *size = ((struct tb_drom_header *)sw->drom)->data_len + | |
385 | TB_DROM_DATA_START; | |
386 | if (*size > len) | |
387 | goto err; | |
388 | ||
389 | return 0; | |
390 | ||
391 | err: | |
392 | kfree(sw->drom); | |
393 | sw->drom = NULL; | |
394 | return -EINVAL; | |
395 | } | |
396 | ||
cd22e73b AN |
397 | /** |
398 | * tb_drom_read - copy drom to sw->drom and parse it | |
399 | */ | |
400 | int tb_drom_read(struct tb_switch *sw) | |
401 | { | |
402 | u16 drom_offset; | |
403 | u16 size; | |
404 | u32 crc; | |
405 | struct tb_drom_header *header; | |
406 | int res; | |
407 | if (sw->drom) | |
408 | return 0; | |
409 | ||
410 | if (tb_route(sw) == 0) { | |
c9cc3aaa LW |
411 | /* |
412 | * Apple's NHI EFI driver supplies a DROM for the root switch | |
413 | * in a device property. Use it if available. | |
414 | */ | |
415 | if (tb_drom_copy_efi(sw, &size) == 0) | |
416 | goto parse; | |
417 | ||
cd22e73b AN |
418 | /* |
419 | * The root switch contains only a dummy drom (header only, | |
420 | * no entries). Hardcode the configuration here. | |
421 | */ | |
422 | tb_drom_read_uid_only(sw, &sw->uid); | |
423 | ||
424 | sw->ports[1].link_nr = 0; | |
425 | sw->ports[2].link_nr = 1; | |
426 | sw->ports[1].dual_link_port = &sw->ports[2]; | |
427 | sw->ports[2].dual_link_port = &sw->ports[1]; | |
428 | ||
429 | sw->ports[3].link_nr = 0; | |
430 | sw->ports[4].link_nr = 1; | |
431 | sw->ports[3].dual_link_port = &sw->ports[4]; | |
432 | sw->ports[4].dual_link_port = &sw->ports[3]; | |
19bf4d4f LW |
433 | |
434 | /* Port 5 is inaccessible on this gen 1 controller */ | |
435 | if (sw->config.device_id == PCI_DEVICE_ID_INTEL_LIGHT_RIDGE) | |
436 | sw->ports[5].disabled = true; | |
437 | ||
cd22e73b AN |
438 | return 0; |
439 | } | |
440 | ||
441 | res = tb_eeprom_get_drom_offset(sw, &drom_offset); | |
442 | if (res) | |
443 | return res; | |
444 | ||
445 | res = tb_eeprom_read_n(sw, drom_offset + 14, (u8 *) &size, 2); | |
446 | if (res) | |
447 | return res; | |
448 | size &= 0x3ff; | |
449 | size += TB_DROM_DATA_START; | |
450 | tb_sw_info(sw, "reading drom (length: %#x)\n", size); | |
451 | if (size < sizeof(*header)) { | |
452 | tb_sw_warn(sw, "drom too small, aborting\n"); | |
453 | return -EIO; | |
454 | } | |
455 | ||
456 | sw->drom = kzalloc(size, GFP_KERNEL); | |
457 | if (!sw->drom) | |
458 | return -ENOMEM; | |
459 | res = tb_eeprom_read_n(sw, drom_offset, sw->drom, size); | |
460 | if (res) | |
461 | goto err; | |
462 | ||
c9cc3aaa | 463 | parse: |
cd22e73b AN |
464 | header = (void *) sw->drom; |
465 | ||
466 | if (header->data_len + TB_DROM_DATA_START != size) { | |
467 | tb_sw_warn(sw, "drom size mismatch, aborting\n"); | |
468 | goto err; | |
469 | } | |
470 | ||
471 | crc = tb_crc8((u8 *) &header->uid, 8); | |
472 | if (crc != header->uid_crc8) { | |
473 | tb_sw_warn(sw, | |
474 | "drom uid crc8 mismatch (expected: %#x, got: %#x), aborting\n", | |
475 | header->uid_crc8, crc); | |
476 | goto err; | |
477 | } | |
478 | sw->uid = header->uid; | |
479 | ||
480 | crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len); | |
481 | if (crc != header->data_crc32) { | |
482 | tb_sw_warn(sw, | |
483 | "drom data crc32 mismatch (expected: %#x, got: %#x), aborting\n", | |
484 | header->data_crc32, crc); | |
485 | goto err; | |
486 | } | |
487 | ||
488 | if (header->device_rom_revision > 1) | |
489 | tb_sw_warn(sw, "drom device_rom_revision %#x unknown\n", | |
490 | header->device_rom_revision); | |
491 | ||
492 | return tb_drom_parse_entries(sw); | |
493 | err: | |
494 | kfree(sw->drom); | |
2ffa9a5d | 495 | sw->drom = NULL; |
cd22e73b AN |
496 | return -EIO; |
497 | ||
498 | } |