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(&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 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, 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; 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(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); 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(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 irq_flag = 0, rc; 292 293 pci_set_drvdata(pci_dev, privdata); 294 295 rc = pcim_enable_device(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(pci_dev, 1 << 2, pci_name(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(pci_dev)[2]; 307 308 pci_set_master(pci_dev); 309 310 rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64)); 311 if (rc) 312 goto err_dma_mask; 313 314 /* request and enable interrupt */ 315 writel(0, privdata->mmio + AMD_P2C_MSG_INTEN); 316 rc = pci_alloc_irq_vectors(pci_dev, 1, 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(pci_dev, 0); 323 if (!pci_dev->msix_enabled && !pci_dev->msi_enabled) 324 irq_flag = IRQF_SHARED; 325 326 rc = devm_request_irq(&pci_dev->dev, privdata->dev_irq, 327 amd_mp2_irq_isr, irq_flag, dev_name(&pci_dev->dev), 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(pci_dev); 339 err_pci_enable: 340 pci_set_drvdata(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(&pci_dev->dev, 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(&pci_dev->dev, 1000); 362 pm_runtime_use_autosuspend(&pci_dev->dev); 363 pm_runtime_put_autosuspend(&pci_dev->dev); 364 pm_runtime_allow(&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(pci_dev); 375 376 pm_runtime_forbid(&pci_dev->dev); 377 pm_runtime_get_noresume(&pci_dev->dev); 378 379 free_irq(privdata->dev_irq, privdata); 380 pci_clear_master(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(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(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(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(pci_dev); 414 struct amd_i2c_common *i2c_common; 415 unsigned int bus_id; 416 int ret = 0; 417 418 pci_restore_state(pci_dev); 419 ret = pci_enable_device(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(&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(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