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529766e0 EM |
1 | // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
2 | /* | |
3 | * AMD MP2 PCIe communication driver | |
4 | * | |
5 | * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> | |
6 | * Elie Morisse <syniurge@gmail.com> | |
7 | */ | |
8 | ||
9 | #include <linux/dma-mapping.h> | |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/pci.h> | |
13 | #include <linux/slab.h> | |
14 | ||
15 | #include "i2c-amd-mp2.h" | |
16 | ||
17 | #include <linux/io-64-nonatomic-lo-hi.h> | |
18 | ||
19 | static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common) | |
20 | { | |
21 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
22 | ||
23 | /* there is only one data mailbox for two i2c adapters */ | |
24 | mutex_lock(&privdata->c2p_lock); | |
25 | privdata->c2p_lock_busid = i2c_common->bus_id; | |
26 | } | |
27 | ||
28 | static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common) | |
29 | { | |
30 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
31 | ||
32 | if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) { | |
267e82b9 | 33 | pci_warn(privdata->pci_dev, |
529766e0 EM |
34 | "bus %d attempting to unlock C2P locked by bus %d\n", |
35 | i2c_common->bus_id, privdata->c2p_lock_busid); | |
36 | return; | |
37 | } | |
38 | ||
39 | mutex_unlock(&privdata->c2p_lock); | |
40 | } | |
41 | ||
42 | static int amd_mp2_cmd(struct amd_i2c_common *i2c_common, | |
43 | union i2c_cmd_base i2c_cmd_base) | |
44 | { | |
45 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
46 | void __iomem *reg; | |
47 | ||
48 | i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd; | |
49 | ||
50 | reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ? | |
51 | AMD_C2P_MSG1 : AMD_C2P_MSG0); | |
52 | writel(i2c_cmd_base.ul, reg); | |
53 | ||
54 | return 0; | |
55 | } | |
56 | ||
57 | int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable) | |
58 | { | |
59 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
60 | union i2c_cmd_base i2c_cmd_base; | |
61 | ||
267e82b9 | 62 | pci_dbg(privdata->pci_dev, "id: %d\n", i2c_common->bus_id); |
529766e0 EM |
63 | |
64 | i2c_cmd_base.ul = 0; | |
65 | i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable; | |
66 | i2c_cmd_base.s.bus_id = i2c_common->bus_id; | |
67 | i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed; | |
68 | ||
69 | amd_mp2_c2p_mutex_lock(i2c_common); | |
70 | ||
71 | return amd_mp2_cmd(i2c_common, i2c_cmd_base); | |
72 | } | |
73 | EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set); | |
74 | ||
75 | static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common, | |
76 | union i2c_cmd_base *i2c_cmd_base, | |
77 | enum i2c_cmd reqcmd) | |
78 | { | |
79 | i2c_cmd_base->s.i2c_cmd = reqcmd; | |
80 | i2c_cmd_base->s.bus_id = i2c_common->bus_id; | |
81 | i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed; | |
82 | i2c_cmd_base->s.slave_addr = i2c_common->msg->addr; | |
83 | i2c_cmd_base->s.length = i2c_common->msg->len; | |
84 | } | |
85 | ||
86 | int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd) | |
87 | { | |
88 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
89 | union i2c_cmd_base i2c_cmd_base; | |
90 | ||
91 | amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd); | |
92 | amd_mp2_c2p_mutex_lock(i2c_common); | |
93 | ||
94 | if (i2c_common->msg->len <= 32) { | |
95 | i2c_cmd_base.s.mem_type = use_c2pmsg; | |
96 | if (reqcmd == i2c_write) | |
97 | memcpy_toio(privdata->mmio + AMD_C2P_MSG2, | |
98 | i2c_common->msg->buf, | |
99 | i2c_common->msg->len); | |
100 | } else { | |
101 | i2c_cmd_base.s.mem_type = use_dram; | |
102 | writeq((u64)i2c_common->dma_addr, | |
103 | privdata->mmio + AMD_C2P_MSG2); | |
104 | } | |
105 | ||
106 | return amd_mp2_cmd(i2c_common, i2c_cmd_base); | |
107 | } | |
108 | EXPORT_SYMBOL_GPL(amd_mp2_rw); | |
109 | ||
110 | static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common) | |
111 | { | |
112 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
267e82b9 | 113 | struct pci_dev *pdev = privdata->pci_dev; |
529766e0 EM |
114 | int len = i2c_common->eventval.r.length; |
115 | u32 slave_addr = i2c_common->eventval.r.slave_addr; | |
116 | bool err = false; | |
117 | ||
118 | if (unlikely(len != i2c_common->msg->len)) { | |
267e82b9 | 119 | pci_err(pdev, "length %d in event doesn't match buffer length %d!\n", |
529766e0 EM |
120 | len, i2c_common->msg->len); |
121 | err = true; | |
122 | } | |
123 | ||
124 | if (unlikely(slave_addr != i2c_common->msg->addr)) { | |
267e82b9 | 125 | pci_err(pdev, "unexpected slave address %x (expected: %x)!\n", |
529766e0 EM |
126 | slave_addr, i2c_common->msg->addr); |
127 | err = true; | |
128 | } | |
129 | ||
130 | if (!err) | |
131 | i2c_common->cmd_success = true; | |
132 | } | |
133 | ||
134 | static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common) | |
135 | { | |
136 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
267e82b9 | 137 | struct pci_dev *pdev = privdata->pci_dev; |
529766e0 EM |
138 | enum status_type sts = i2c_common->eventval.r.status; |
139 | enum response_type res = i2c_common->eventval.r.response; | |
140 | int len = i2c_common->eventval.r.length; | |
141 | ||
142 | if (res != command_success) { | |
143 | if (res != command_failed) | |
267e82b9 | 144 | pci_err(pdev, "invalid response to i2c command!\n"); |
529766e0 EM |
145 | return; |
146 | } | |
147 | ||
148 | switch (i2c_common->reqcmd) { | |
149 | case i2c_read: | |
150 | if (sts == i2c_readcomplete_event) { | |
151 | amd_mp2_pci_check_rw_event(i2c_common); | |
152 | if (len <= 32) | |
153 | memcpy_fromio(i2c_common->msg->buf, | |
154 | privdata->mmio + AMD_C2P_MSG2, | |
155 | len); | |
156 | } else if (sts != i2c_readfail_event) { | |
267e82b9 | 157 | pci_err(pdev, "invalid i2c status after read (%d)!\n", sts); |
529766e0 EM |
158 | } |
159 | break; | |
160 | case i2c_write: | |
161 | if (sts == i2c_writecomplete_event) | |
162 | amd_mp2_pci_check_rw_event(i2c_common); | |
163 | else if (sts != i2c_writefail_event) | |
267e82b9 | 164 | pci_err(pdev, "invalid i2c status after write (%d)!\n", sts); |
529766e0 EM |
165 | break; |
166 | case i2c_enable: | |
167 | if (sts == i2c_busenable_complete) | |
168 | i2c_common->cmd_success = true; | |
169 | else if (sts != i2c_busenable_failed) | |
267e82b9 | 170 | pci_err(pdev, "invalid i2c status after bus enable (%d)!\n", sts); |
529766e0 EM |
171 | break; |
172 | case i2c_disable: | |
173 | if (sts == i2c_busdisable_complete) | |
174 | i2c_common->cmd_success = true; | |
175 | else if (sts != i2c_busdisable_failed) | |
267e82b9 | 176 | pci_err(pdev, "invalid i2c status after bus disable (%d)!\n", sts); |
529766e0 EM |
177 | break; |
178 | default: | |
179 | break; | |
180 | } | |
181 | } | |
182 | ||
183 | void amd_mp2_process_event(struct amd_i2c_common *i2c_common) | |
184 | { | |
185 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
267e82b9 | 186 | struct pci_dev *pdev = privdata->pci_dev; |
529766e0 EM |
187 | |
188 | if (unlikely(i2c_common->reqcmd == i2c_none)) { | |
267e82b9 | 189 | pci_warn(pdev, "received msg but no cmd was sent (bus = %d)!\n", |
529766e0 EM |
190 | i2c_common->bus_id); |
191 | return; | |
192 | } | |
193 | ||
194 | __amd_mp2_process_event(i2c_common); | |
195 | ||
196 | i2c_common->reqcmd = i2c_none; | |
197 | amd_mp2_c2p_mutex_unlock(i2c_common); | |
198 | } | |
199 | EXPORT_SYMBOL_GPL(amd_mp2_process_event); | |
200 | ||
201 | static irqreturn_t amd_mp2_irq_isr(int irq, void *dev) | |
202 | { | |
203 | struct amd_mp2_dev *privdata = dev; | |
267e82b9 | 204 | struct pci_dev *pdev = privdata->pci_dev; |
529766e0 EM |
205 | struct amd_i2c_common *i2c_common; |
206 | u32 val; | |
207 | unsigned int bus_id; | |
208 | void __iomem *reg; | |
209 | enum irqreturn ret = IRQ_NONE; | |
210 | ||
211 | for (bus_id = 0; bus_id < 2; bus_id++) { | |
212 | i2c_common = privdata->busses[bus_id]; | |
213 | if (!i2c_common) | |
214 | continue; | |
215 | ||
216 | reg = privdata->mmio + ((bus_id == 0) ? | |
217 | AMD_P2C_MSG1 : AMD_P2C_MSG2); | |
218 | val = readl(reg); | |
219 | if (val != 0) { | |
220 | writel(0, reg); | |
221 | writel(0, privdata->mmio + AMD_P2C_MSG_INTEN); | |
222 | i2c_common->eventval.ul = val; | |
223 | i2c_common->cmd_completion(i2c_common); | |
224 | ||
225 | ret = IRQ_HANDLED; | |
226 | } | |
227 | } | |
228 | ||
229 | if (ret != IRQ_HANDLED) { | |
230 | val = readl(privdata->mmio + AMD_P2C_MSG_INTEN); | |
231 | if (val != 0) { | |
232 | writel(0, privdata->mmio + AMD_P2C_MSG_INTEN); | |
267e82b9 | 233 | pci_warn(pdev, "received irq without message\n"); |
529766e0 EM |
234 | ret = IRQ_HANDLED; |
235 | } | |
236 | } | |
237 | ||
238 | return ret; | |
239 | } | |
240 | ||
241 | void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common) | |
242 | { | |
243 | i2c_common->reqcmd = i2c_none; | |
244 | amd_mp2_c2p_mutex_unlock(i2c_common); | |
245 | } | |
246 | EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout); | |
247 | ||
248 | int amd_mp2_register_cb(struct amd_i2c_common *i2c_common) | |
249 | { | |
250 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
267e82b9 | 251 | struct pci_dev *pdev = privdata->pci_dev; |
529766e0 EM |
252 | |
253 | if (i2c_common->bus_id > 1) | |
254 | return -EINVAL; | |
255 | ||
256 | if (privdata->busses[i2c_common->bus_id]) { | |
267e82b9 | 257 | pci_err(pdev, "Bus %d already taken!\n", i2c_common->bus_id); |
529766e0 EM |
258 | return -EINVAL; |
259 | } | |
260 | ||
261 | privdata->busses[i2c_common->bus_id] = i2c_common; | |
262 | ||
263 | return 0; | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(amd_mp2_register_cb); | |
266 | ||
267 | int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common) | |
268 | { | |
269 | struct amd_mp2_dev *privdata = i2c_common->mp2_dev; | |
270 | ||
271 | privdata->busses[i2c_common->bus_id] = NULL; | |
272 | ||
273 | return 0; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb); | |
276 | ||
277 | static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata) | |
278 | { | |
279 | int reg; | |
280 | ||
281 | for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4) | |
282 | writel(0, privdata->mmio + reg); | |
283 | ||
284 | for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4) | |
285 | writel(0, privdata->mmio + reg); | |
286 | } | |
287 | ||
288 | static int amd_mp2_pci_init(struct amd_mp2_dev *privdata, | |
289 | struct pci_dev *pci_dev) | |
290 | { | |
291 | int rc; | |
292 | ||
293 | pci_set_drvdata(pci_dev, privdata); | |
294 | ||
295 | rc = pcim_enable_device(pci_dev); | |
296 | if (rc) { | |
267e82b9 | 297 | pci_err(pci_dev, "Failed to enable MP2 PCI device\n"); |
529766e0 EM |
298 | goto err_pci_enable; |
299 | } | |
300 | ||
301 | rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev)); | |
302 | if (rc) { | |
267e82b9 | 303 | pci_err(pci_dev, "I/O memory remapping failed\n"); |
529766e0 EM |
304 | goto err_pci_enable; |
305 | } | |
306 | privdata->mmio = pcim_iomap_table(pci_dev)[2]; | |
307 | ||
308 | pci_set_master(pci_dev); | |
309 | ||
d56baf6e | 310 | rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64)); |
951285e5 CJ |
311 | if (rc) |
312 | goto err_dma_mask; | |
529766e0 EM |
313 | |
314 | /* Set up intx irq */ | |
315 | writel(0, privdata->mmio + AMD_P2C_MSG_INTEN); | |
316 | pci_intx(pci_dev, 1); | |
317 | rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr, | |
318 | IRQF_SHARED, dev_name(&pci_dev->dev), privdata); | |
319 | if (rc) | |
267e82b9 | 320 | pci_err(pci_dev, "Failure requesting irq %i: %d\n", |
529766e0 EM |
321 | pci_dev->irq, rc); |
322 | ||
323 | return rc; | |
324 | ||
325 | err_dma_mask: | |
326 | pci_clear_master(pci_dev); | |
327 | err_pci_enable: | |
328 | pci_set_drvdata(pci_dev, NULL); | |
329 | return rc; | |
330 | } | |
331 | ||
332 | static int amd_mp2_pci_probe(struct pci_dev *pci_dev, | |
333 | const struct pci_device_id *id) | |
334 | { | |
335 | struct amd_mp2_dev *privdata; | |
336 | int rc; | |
337 | ||
338 | privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL); | |
339 | if (!privdata) | |
340 | return -ENOMEM; | |
341 | ||
ac2b0813 | 342 | privdata->pci_dev = pci_dev; |
529766e0 EM |
343 | rc = amd_mp2_pci_init(privdata, pci_dev); |
344 | if (rc) | |
345 | return rc; | |
346 | ||
347 | mutex_init(&privdata->c2p_lock); | |
529766e0 EM |
348 | |
349 | pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000); | |
350 | pm_runtime_use_autosuspend(&pci_dev->dev); | |
351 | pm_runtime_put_autosuspend(&pci_dev->dev); | |
352 | pm_runtime_allow(&pci_dev->dev); | |
353 | ||
354 | privdata->probed = true; | |
355 | ||
267e82b9 | 356 | pci_info(pci_dev, "MP2 device registered.\n"); |
529766e0 EM |
357 | return 0; |
358 | } | |
359 | ||
360 | static void amd_mp2_pci_remove(struct pci_dev *pci_dev) | |
361 | { | |
362 | struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); | |
363 | ||
364 | pm_runtime_forbid(&pci_dev->dev); | |
365 | pm_runtime_get_noresume(&pci_dev->dev); | |
366 | ||
367 | pci_intx(pci_dev, 0); | |
368 | pci_clear_master(pci_dev); | |
369 | ||
370 | amd_mp2_clear_reg(privdata); | |
371 | } | |
372 | ||
373 | #ifdef CONFIG_PM | |
374 | static int amd_mp2_pci_suspend(struct device *dev) | |
375 | { | |
376 | struct pci_dev *pci_dev = to_pci_dev(dev); | |
377 | struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); | |
378 | struct amd_i2c_common *i2c_common; | |
379 | unsigned int bus_id; | |
380 | int ret = 0; | |
381 | ||
382 | for (bus_id = 0; bus_id < 2; bus_id++) { | |
383 | i2c_common = privdata->busses[bus_id]; | |
384 | if (i2c_common) | |
385 | i2c_common->suspend(i2c_common); | |
386 | } | |
387 | ||
388 | ret = pci_save_state(pci_dev); | |
389 | if (ret) { | |
267e82b9 | 390 | pci_err(pci_dev, "pci_save_state failed = %d\n", ret); |
529766e0 EM |
391 | return ret; |
392 | } | |
393 | ||
394 | pci_disable_device(pci_dev); | |
395 | return ret; | |
396 | } | |
397 | ||
398 | static int amd_mp2_pci_resume(struct device *dev) | |
399 | { | |
400 | struct pci_dev *pci_dev = to_pci_dev(dev); | |
401 | struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); | |
402 | struct amd_i2c_common *i2c_common; | |
403 | unsigned int bus_id; | |
404 | int ret = 0; | |
405 | ||
406 | pci_restore_state(pci_dev); | |
407 | ret = pci_enable_device(pci_dev); | |
408 | if (ret < 0) { | |
267e82b9 | 409 | pci_err(pci_dev, "pci_enable_device failed = %d\n", ret); |
529766e0 EM |
410 | return ret; |
411 | } | |
412 | ||
413 | for (bus_id = 0; bus_id < 2; bus_id++) { | |
414 | i2c_common = privdata->busses[bus_id]; | |
415 | if (i2c_common) { | |
416 | ret = i2c_common->resume(i2c_common); | |
417 | if (ret < 0) | |
418 | return ret; | |
419 | } | |
420 | } | |
421 | ||
422 | return ret; | |
423 | } | |
424 | ||
425 | static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend, | |
426 | amd_mp2_pci_resume, NULL); | |
427 | #endif /* CONFIG_PM */ | |
428 | ||
429 | static const struct pci_device_id amd_mp2_pci_tbl[] = { | |
430 | {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)}, | |
431 | {0} | |
432 | }; | |
433 | MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl); | |
434 | ||
435 | static struct pci_driver amd_mp2_pci_driver = { | |
436 | .name = "i2c_amd_mp2", | |
437 | .id_table = amd_mp2_pci_tbl, | |
438 | .probe = amd_mp2_pci_probe, | |
439 | .remove = amd_mp2_pci_remove, | |
440 | #ifdef CONFIG_PM | |
441 | .driver = { | |
442 | .pm = &amd_mp2_pci_pm_ops, | |
443 | }, | |
444 | #endif | |
445 | }; | |
446 | module_pci_driver(amd_mp2_pci_driver); | |
447 | ||
529766e0 EM |
448 | struct amd_mp2_dev *amd_mp2_find_device(void) |
449 | { | |
450 | struct device *dev; | |
451 | struct pci_dev *pci_dev; | |
452 | ||
6bf85ba9 | 453 | dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL); |
529766e0 EM |
454 | if (!dev) |
455 | return NULL; | |
456 | ||
457 | pci_dev = to_pci_dev(dev); | |
458 | return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); | |
459 | } | |
460 | EXPORT_SYMBOL_GPL(amd_mp2_find_device); | |
461 | ||
462 | MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver"); | |
463 | MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>"); | |
464 | MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>"); | |
465 | MODULE_LICENSE("Dual BSD/GPL"); |