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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Thunderbolt/USB4 retimer support.
4 *
5 * Copyright (C) 2020, Intel Corporation
6 * Authors: Kranthi Kuntala <kranthi.kuntala@intel.com>
7 * Mika Westerberg <mika.westerberg@linux.intel.com>
8 */
9
10#include <linux/delay.h>
11#include <linux/pm_runtime.h>
12#include <linux/sched/signal.h>
13
14#include "sb_regs.h"
15#include "tb.h"
16
17#define TB_MAX_RETIMER_INDEX 6
18
19static int tb_retimer_nvm_read(void *priv, unsigned int offset, void *val,
20 size_t bytes)
21{
22 struct tb_nvm *nvm = priv;
23 struct tb_retimer *rt = tb_to_retimer(nvm->dev);
24 int ret;
25
26 pm_runtime_get_sync(&rt->dev);
27
28 if (!mutex_trylock(&rt->tb->lock)) {
29 ret = restart_syscall();
30 goto out;
31 }
32
33 ret = usb4_port_retimer_nvm_read(rt->port, rt->index, offset, val, bytes);
34 mutex_unlock(&rt->tb->lock);
35
36out:
37 pm_runtime_mark_last_busy(&rt->dev);
38 pm_runtime_put_autosuspend(&rt->dev);
39
40 return ret;
41}
42
43static int tb_retimer_nvm_write(void *priv, unsigned int offset, void *val,
44 size_t bytes)
45{
46 struct tb_nvm *nvm = priv;
47 struct tb_retimer *rt = tb_to_retimer(nvm->dev);
48 int ret = 0;
49
50 if (!mutex_trylock(&rt->tb->lock))
51 return restart_syscall();
52
53 ret = tb_nvm_write_buf(nvm, offset, val, bytes);
54 mutex_unlock(&rt->tb->lock);
55
56 return ret;
57}
58
59static int tb_retimer_nvm_add(struct tb_retimer *rt)
60{
61 struct tb_nvm *nvm;
62 u32 val, nvm_size;
63 int ret;
64
65 nvm = tb_nvm_alloc(&rt->dev);
66 if (IS_ERR(nvm))
67 return PTR_ERR(nvm);
68
69 ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_VERSION, &val,
70 sizeof(val));
71 if (ret)
72 goto err_nvm;
73
74 nvm->major = val >> 16;
75 nvm->minor = val >> 8;
76
77 ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_FLASH_SIZE,
78 &val, sizeof(val));
79 if (ret)
80 goto err_nvm;
81
82 nvm_size = (SZ_1M << (val & 7)) / 8;
83 nvm_size = (nvm_size - SZ_16K) / 2;
84
85 ret = tb_nvm_add_active(nvm, nvm_size, tb_retimer_nvm_read);
86 if (ret)
87 goto err_nvm;
88
89 ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE, tb_retimer_nvm_write);
90 if (ret)
91 goto err_nvm;
92
93 rt->nvm = nvm;
94 return 0;
95
96err_nvm:
97 tb_nvm_free(nvm);
98 return ret;
99}
100
101static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
102{
103 unsigned int image_size, hdr_size;
104 const u8 *buf = rt->nvm->buf;
105 u16 ds_size, device;
106
107 image_size = rt->nvm->buf_data_size;
108 if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
109 return -EINVAL;
110
111 /*
112 * FARB pointer must point inside the image and must at least
113 * contain parts of the digital section we will be reading here.
114 */
115 hdr_size = (*(u32 *)buf) & 0xffffff;
116 if (hdr_size + NVM_DEVID + 2 >= image_size)
117 return -EINVAL;
118
119 /* Digital section start should be aligned to 4k page */
120 if (!IS_ALIGNED(hdr_size, SZ_4K))
121 return -EINVAL;
122
123 /*
124 * Read digital section size and check that it also fits inside
125 * the image.
126 */
127 ds_size = *(u16 *)(buf + hdr_size);
128 if (ds_size >= image_size)
129 return -EINVAL;
130
131 /*
132 * Make sure the device ID in the image matches the retimer
133 * hardware.
134 */
135 device = *(u16 *)(buf + hdr_size + NVM_DEVID);
136 if (device != rt->device)
137 return -EINVAL;
138
139 /* Skip headers in the image */
140 buf += hdr_size;
141 image_size -= hdr_size;
142
143 return usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
144 image_size);
145}
146
147static ssize_t device_show(struct device *dev, struct device_attribute *attr,
148 char *buf)
149{
150 struct tb_retimer *rt = tb_to_retimer(dev);
151
152 return sprintf(buf, "%#x\n", rt->device);
153}
154static DEVICE_ATTR_RO(device);
155
156static ssize_t nvm_authenticate_show(struct device *dev,
157 struct device_attribute *attr, char *buf)
158{
159 struct tb_retimer *rt = tb_to_retimer(dev);
160 int ret;
161
162 if (!mutex_trylock(&rt->tb->lock))
163 return restart_syscall();
164
165 if (!rt->nvm)
166 ret = -EAGAIN;
167 else
168 ret = sprintf(buf, "%#x\n", rt->auth_status);
169
170 mutex_unlock(&rt->tb->lock);
171
172 return ret;
173}
174
175static ssize_t nvm_authenticate_store(struct device *dev,
176 struct device_attribute *attr, const char *buf, size_t count)
177{
178 struct tb_retimer *rt = tb_to_retimer(dev);
179 bool val;
180 int ret;
181
182 pm_runtime_get_sync(&rt->dev);
183
184 if (!mutex_trylock(&rt->tb->lock)) {
185 ret = restart_syscall();
186 goto exit_rpm;
187 }
188
189 if (!rt->nvm) {
190 ret = -EAGAIN;
191 goto exit_unlock;
192 }
193
194 ret = kstrtobool(buf, &val);
195 if (ret)
196 goto exit_unlock;
197
198 /* Always clear status */
199 rt->auth_status = 0;
200
201 if (val) {
202 if (!rt->nvm->buf) {
203 ret = -EINVAL;
204 goto exit_unlock;
205 }
206
207 ret = tb_retimer_nvm_validate_and_write(rt);
208 if (ret)
209 goto exit_unlock;
210
211 ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
212 }
213
214exit_unlock:
215 mutex_unlock(&rt->tb->lock);
216exit_rpm:
217 pm_runtime_mark_last_busy(&rt->dev);
218 pm_runtime_put_autosuspend(&rt->dev);
219
220 if (ret)
221 return ret;
222 return count;
223}
224static DEVICE_ATTR_RW(nvm_authenticate);
225
226static ssize_t nvm_version_show(struct device *dev,
227 struct device_attribute *attr, char *buf)
228{
229 struct tb_retimer *rt = tb_to_retimer(dev);
230 int ret;
231
232 if (!mutex_trylock(&rt->tb->lock))
233 return restart_syscall();
234
235 if (!rt->nvm)
236 ret = -EAGAIN;
237 else
238 ret = sprintf(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);
239
240 mutex_unlock(&rt->tb->lock);
241 return ret;
242}
243static DEVICE_ATTR_RO(nvm_version);
244
245static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
246 char *buf)
247{
248 struct tb_retimer *rt = tb_to_retimer(dev);
249
250 return sprintf(buf, "%#x\n", rt->vendor);
251}
252static DEVICE_ATTR_RO(vendor);
253
254static struct attribute *retimer_attrs[] = {
255 &dev_attr_device.attr,
256 &dev_attr_nvm_authenticate.attr,
257 &dev_attr_nvm_version.attr,
258 &dev_attr_vendor.attr,
259 NULL
260};
261
262static const struct attribute_group retimer_group = {
263 .attrs = retimer_attrs,
264};
265
266static const struct attribute_group *retimer_groups[] = {
267 &retimer_group,
268 NULL
269};
270
271static void tb_retimer_release(struct device *dev)
272{
273 struct tb_retimer *rt = tb_to_retimer(dev);
274
275 kfree(rt);
276}
277
278struct device_type tb_retimer_type = {
279 .name = "thunderbolt_retimer",
280 .groups = retimer_groups,
281 .release = tb_retimer_release,
282};
283
284static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status)
285{
286 struct tb_retimer *rt;
287 u32 vendor, device;
288 int ret;
289
290 if (!port->cap_usb4)
291 return -EINVAL;
292
293 ret = usb4_port_retimer_read(port, index, USB4_SB_VENDOR_ID, &vendor,
294 sizeof(vendor));
295 if (ret) {
296 if (ret != -ENODEV)
297 tb_port_warn(port, "failed read retimer VendorId: %d\n", ret);
298 return ret;
299 }
300
301 ret = usb4_port_retimer_read(port, index, USB4_SB_PRODUCT_ID, &device,
302 sizeof(device));
303 if (ret) {
304 if (ret != -ENODEV)
305 tb_port_warn(port, "failed read retimer ProductId: %d\n", ret);
306 return ret;
307 }
308
309 if (vendor != PCI_VENDOR_ID_INTEL && vendor != 0x8087) {
310 tb_port_info(port, "retimer NVM format of vendor %#x is not supported\n",
311 vendor);
312 return -EOPNOTSUPP;
313 }
314
315 /*
316 * Check that it supports NVM operations. If not then don't add
317 * the device at all.
318 */
319 ret = usb4_port_retimer_nvm_sector_size(port, index);
320 if (ret < 0)
321 return ret;
322
323 rt = kzalloc(sizeof(*rt), GFP_KERNEL);
324 if (!rt)
325 return -ENOMEM;
326
327 rt->index = index;
328 rt->vendor = vendor;
329 rt->device = device;
330 rt->auth_status = auth_status;
331 rt->port = port;
332 rt->tb = port->sw->tb;
333
334 rt->dev.parent = &port->sw->dev;
335 rt->dev.bus = &tb_bus_type;
336 rt->dev.type = &tb_retimer_type;
337 dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev),
338 port->port, index);
339
340 ret = device_register(&rt->dev);
341 if (ret) {
342 dev_err(&rt->dev, "failed to register retimer: %d\n", ret);
343 put_device(&rt->dev);
344 return ret;
345 }
346
347 ret = tb_retimer_nvm_add(rt);
348 if (ret) {
349 dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret);
350 device_del(&rt->dev);
351 return ret;
352 }
353
354 dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n",
355 rt->vendor, rt->device);
356
357 pm_runtime_no_callbacks(&rt->dev);
358 pm_runtime_set_active(&rt->dev);
359 pm_runtime_enable(&rt->dev);
360 pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY);
361 pm_runtime_mark_last_busy(&rt->dev);
362 pm_runtime_use_autosuspend(&rt->dev);
363
364 return 0;
365}
366
367static void tb_retimer_remove(struct tb_retimer *rt)
368{
369 dev_info(&rt->dev, "retimer disconnected\n");
370 tb_nvm_free(rt->nvm);
371 device_unregister(&rt->dev);
372}
373
374struct tb_retimer_lookup {
375 const struct tb_port *port;
376 u8 index;
377};
378
379static int retimer_match(struct device *dev, void *data)
380{
381 const struct tb_retimer_lookup *lookup = data;
382 struct tb_retimer *rt = tb_to_retimer(dev);
383
384 return rt && rt->port == lookup->port && rt->index == lookup->index;
385}
386
387static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
388{
389 struct tb_retimer_lookup lookup = { .port = port, .index = index };
390 struct device *dev;
391
392 dev = device_find_child(&port->sw->dev, &lookup, retimer_match);
393 if (dev)
394 return tb_to_retimer(dev);
395
396 return NULL;
397}
398
399/**
400 * tb_retimer_scan() - Scan for on-board retimers under port
401 * @port: USB4 port to scan
402 *
403 * Tries to enumerate on-board retimers connected to @port. Found
404 * retimers are registered as children of @port. Does not scan for cable
405 * retimers for now.
406 */
407int tb_retimer_scan(struct tb_port *port)
408{
409 u32 status[TB_MAX_RETIMER_INDEX] = {};
410 int ret, i, last_idx = 0;
411
412 if (!port->cap_usb4)
413 return 0;
414
415 /*
416 * Send broadcast RT to make sure retimer indices facing this
417 * port are set.
418 */
419 ret = usb4_port_enumerate_retimers(port);
420 if (ret)
421 return ret;
422
423 /*
424 * Before doing anything else, read the authentication status.
425 * If the retimer has it set, store it for the new retimer
426 * device instance.
427 */
428 for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
429 usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]);
430
431 for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
432 /*
433 * Last retimer is true only for the last on-board
434 * retimer (the one connected directly to the Type-C
435 * port).
436 */
437 ret = usb4_port_retimer_is_last(port, i);
438 if (ret > 0)
439 last_idx = i;
440 else if (ret < 0)
441 break;
442 }
443
444 if (!last_idx)
445 return 0;
446
447 /* Add on-board retimers if they do not exist already */
448 for (i = 1; i <= last_idx; i++) {
449 struct tb_retimer *rt;
450
451 rt = tb_port_find_retimer(port, i);
452 if (rt) {
453 put_device(&rt->dev);
454 } else {
455 ret = tb_retimer_add(port, i, status[i]);
456 if (ret && ret != -EOPNOTSUPP)
457 return ret;
458 }
459 }
460
461 return 0;
462}
463
464static int remove_retimer(struct device *dev, void *data)
465{
466 struct tb_retimer *rt = tb_to_retimer(dev);
467 struct tb_port *port = data;
468
469 if (rt && rt->port == port)
470 tb_retimer_remove(rt);
471 return 0;
472}
473
474/**
475 * tb_retimer_remove_all() - Remove all retimers under port
476 * @port: USB4 port whose retimers to remove
477 *
478 * This removes all previously added retimers under @port.
479 */
480void tb_retimer_remove_all(struct tb_port *port)
481{
482 if (port->cap_usb4)
483 device_for_each_child_reverse(&port->sw->dev, port,
484 remove_retimer);
485}