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)) { |
33 | pci_warn(privdata->pci_dev, |
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(lock: &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(val: i2c_cmd_base.ul, addr: 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 | |
62 | pci_dbg(privdata->pci_dev, "id: %d\n" , i2c_common->bus_id); |
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: &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(val: (u64)i2c_common->dma_addr, |
103 | addr: 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; |
113 | struct pci_dev *pdev = privdata->pci_dev; |
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)) { |
119 | pci_err(pdev, "length %d in event doesn't match buffer length %d!\n" , |
120 | len, i2c_common->msg->len); |
121 | err = true; |
122 | } |
123 | |
124 | if (unlikely(slave_addr != i2c_common->msg->addr)) { |
125 | pci_err(pdev, "unexpected slave address %x (expected: %x)!\n" , |
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; |
137 | struct pci_dev *pdev = privdata->pci_dev; |
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) |
144 | pci_err(pdev, "invalid response to i2c command!\n" ); |
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) { |
157 | pci_err(pdev, "invalid i2c status after read (%d)!\n" , sts); |
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) |
164 | pci_err(pdev, "invalid i2c status after write (%d)!\n" , sts); |
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) |
170 | pci_err(pdev, "invalid i2c status after bus enable (%d)!\n" , sts); |
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) |
176 | pci_err(pdev, "invalid i2c status after bus disable (%d)!\n" , sts); |
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; |
186 | struct pci_dev *pdev = privdata->pci_dev; |
187 | |
188 | if (unlikely(i2c_common->reqcmd == i2c_none)) { |
189 | pci_warn(pdev, "received msg but no cmd was sent (bus = %d)!\n" , |
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; |
204 | struct pci_dev *pdev = privdata->pci_dev; |
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(addr: reg); |
219 | if (val != 0) { |
220 | writel(val: 0, addr: reg); |
221 | writel(val: 0, addr: 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(addr: privdata->mmio + AMD_P2C_MSG_INTEN); |
231 | if (val != 0) { |
232 | writel(val: 0, addr: privdata->mmio + AMD_P2C_MSG_INTEN); |
233 | pci_warn(pdev, "received irq without message\n" ); |
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; |
251 | struct pci_dev *pdev = privdata->pci_dev; |
252 | |
253 | if (i2c_common->bus_id > 1) |
254 | return -EINVAL; |
255 | |
256 | if (privdata->busses[i2c_common->bus_id]) { |
257 | pci_err(pdev, "Bus %d already taken!\n" , i2c_common->bus_id); |
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(val: 0, addr: privdata->mmio + reg); |
283 | |
284 | for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4) |
285 | writel(val: 0, addr: 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 irq_flag = 0, rc; |
292 | |
293 | pci_set_drvdata(pdev: pci_dev, data: privdata); |
294 | |
295 | rc = pcim_enable_device(pdev: pci_dev); |
296 | if (rc) { |
297 | pci_err(pci_dev, "Failed to enable MP2 PCI device\n" ); |
298 | goto err_pci_enable; |
299 | } |
300 | |
301 | rc = pcim_iomap_regions(pdev: pci_dev, mask: 1 << 2, name: pci_name(pdev: pci_dev)); |
302 | if (rc) { |
303 | pci_err(pci_dev, "I/O memory remapping failed\n" ); |
304 | goto err_pci_enable; |
305 | } |
306 | privdata->mmio = pcim_iomap_table(pdev: pci_dev)[2]; |
307 | |
308 | pci_set_master(dev: pci_dev); |
309 | |
310 | rc = dma_set_mask(dev: &pci_dev->dev, DMA_BIT_MASK(64)); |
311 | if (rc) |
312 | goto err_dma_mask; |
313 | |
314 | /* request and enable interrupt */ |
315 | writel(val: 0, addr: privdata->mmio + AMD_P2C_MSG_INTEN); |
316 | rc = pci_alloc_irq_vectors(dev: pci_dev, min_vecs: 1, max_vecs: 1, PCI_IRQ_ALL_TYPES); |
317 | if (rc < 0) { |
318 | dev_err(&pci_dev->dev, "Failed to allocate single IRQ err=%d\n" , rc); |
319 | goto err_dma_mask; |
320 | } |
321 | |
322 | privdata->dev_irq = pci_irq_vector(dev: pci_dev, nr: 0); |
323 | if (!pci_dev->msix_enabled && !pci_dev->msi_enabled) |
324 | irq_flag = IRQF_SHARED; |
325 | |
326 | rc = devm_request_irq(dev: &pci_dev->dev, irq: privdata->dev_irq, |
327 | handler: amd_mp2_irq_isr, irqflags: irq_flag, devname: dev_name(dev: &pci_dev->dev), dev_id: privdata); |
328 | if (rc) { |
329 | pci_err(pci_dev, "Failure requesting irq %i: %d\n" , privdata->dev_irq, rc); |
330 | goto free_irq_vectors; |
331 | } |
332 | |
333 | return rc; |
334 | |
335 | free_irq_vectors: |
336 | free_irq(privdata->dev_irq, privdata); |
337 | err_dma_mask: |
338 | pci_clear_master(dev: pci_dev); |
339 | err_pci_enable: |
340 | pci_set_drvdata(pdev: pci_dev, NULL); |
341 | return rc; |
342 | } |
343 | |
344 | static int amd_mp2_pci_probe(struct pci_dev *pci_dev, |
345 | const struct pci_device_id *id) |
346 | { |
347 | struct amd_mp2_dev *privdata; |
348 | int rc; |
349 | |
350 | privdata = devm_kzalloc(dev: &pci_dev->dev, size: sizeof(*privdata), GFP_KERNEL); |
351 | if (!privdata) |
352 | return -ENOMEM; |
353 | |
354 | privdata->pci_dev = pci_dev; |
355 | rc = amd_mp2_pci_init(privdata, pci_dev); |
356 | if (rc) |
357 | return rc; |
358 | |
359 | mutex_init(&privdata->c2p_lock); |
360 | |
361 | pm_runtime_set_autosuspend_delay(dev: &pci_dev->dev, delay: 1000); |
362 | pm_runtime_use_autosuspend(dev: &pci_dev->dev); |
363 | pm_runtime_put_autosuspend(dev: &pci_dev->dev); |
364 | pm_runtime_allow(dev: &pci_dev->dev); |
365 | |
366 | privdata->probed = true; |
367 | |
368 | pci_info(pci_dev, "MP2 device registered.\n" ); |
369 | return 0; |
370 | } |
371 | |
372 | static void amd_mp2_pci_remove(struct pci_dev *pci_dev) |
373 | { |
374 | struct amd_mp2_dev *privdata = pci_get_drvdata(pdev: pci_dev); |
375 | |
376 | pm_runtime_forbid(dev: &pci_dev->dev); |
377 | pm_runtime_get_noresume(dev: &pci_dev->dev); |
378 | |
379 | free_irq(privdata->dev_irq, privdata); |
380 | pci_clear_master(dev: pci_dev); |
381 | |
382 | amd_mp2_clear_reg(privdata); |
383 | } |
384 | |
385 | #ifdef CONFIG_PM |
386 | static int amd_mp2_pci_suspend(struct device *dev) |
387 | { |
388 | struct pci_dev *pci_dev = to_pci_dev(dev); |
389 | struct amd_mp2_dev *privdata = pci_get_drvdata(pdev: pci_dev); |
390 | struct amd_i2c_common *i2c_common; |
391 | unsigned int bus_id; |
392 | int ret = 0; |
393 | |
394 | for (bus_id = 0; bus_id < 2; bus_id++) { |
395 | i2c_common = privdata->busses[bus_id]; |
396 | if (i2c_common) |
397 | i2c_common->suspend(i2c_common); |
398 | } |
399 | |
400 | ret = pci_save_state(dev: pci_dev); |
401 | if (ret) { |
402 | pci_err(pci_dev, "pci_save_state failed = %d\n" , ret); |
403 | return ret; |
404 | } |
405 | |
406 | pci_disable_device(dev: pci_dev); |
407 | return ret; |
408 | } |
409 | |
410 | static int amd_mp2_pci_resume(struct device *dev) |
411 | { |
412 | struct pci_dev *pci_dev = to_pci_dev(dev); |
413 | struct amd_mp2_dev *privdata = pci_get_drvdata(pdev: pci_dev); |
414 | struct amd_i2c_common *i2c_common; |
415 | unsigned int bus_id; |
416 | int ret = 0; |
417 | |
418 | pci_restore_state(dev: pci_dev); |
419 | ret = pci_enable_device(dev: pci_dev); |
420 | if (ret < 0) { |
421 | pci_err(pci_dev, "pci_enable_device failed = %d\n" , ret); |
422 | return ret; |
423 | } |
424 | |
425 | for (bus_id = 0; bus_id < 2; bus_id++) { |
426 | i2c_common = privdata->busses[bus_id]; |
427 | if (i2c_common) { |
428 | ret = i2c_common->resume(i2c_common); |
429 | if (ret < 0) |
430 | return ret; |
431 | } |
432 | } |
433 | |
434 | return ret; |
435 | } |
436 | |
437 | static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend, |
438 | amd_mp2_pci_resume, NULL); |
439 | #endif /* CONFIG_PM */ |
440 | |
441 | static const struct pci_device_id amd_mp2_pci_tbl[] = { |
442 | {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)}, |
443 | {0} |
444 | }; |
445 | MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl); |
446 | |
447 | static struct pci_driver amd_mp2_pci_driver = { |
448 | .name = "i2c_amd_mp2" , |
449 | .id_table = amd_mp2_pci_tbl, |
450 | .probe = amd_mp2_pci_probe, |
451 | .remove = amd_mp2_pci_remove, |
452 | #ifdef CONFIG_PM |
453 | .driver = { |
454 | .pm = &amd_mp2_pci_pm_ops, |
455 | }, |
456 | #endif |
457 | }; |
458 | module_pci_driver(amd_mp2_pci_driver); |
459 | |
460 | struct amd_mp2_dev *amd_mp2_find_device(void) |
461 | { |
462 | struct device *dev; |
463 | struct pci_dev *pci_dev; |
464 | |
465 | dev = driver_find_next_device(drv: &amd_mp2_pci_driver.driver, NULL); |
466 | if (!dev) |
467 | return NULL; |
468 | |
469 | pci_dev = to_pci_dev(dev); |
470 | return (struct amd_mp2_dev *)pci_get_drvdata(pdev: pci_dev); |
471 | } |
472 | EXPORT_SYMBOL_GPL(amd_mp2_find_device); |
473 | |
474 | MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver" ); |
475 | MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>" ); |
476 | MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>" ); |
477 | MODULE_LICENSE("Dual BSD/GPL" ); |
478 | |