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 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 rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32)); 313 if (rc) 314 goto err_dma_mask; 315 } 316 317 /* Set up intx irq */ 318 writel(0, privdata->mmio + AMD_P2C_MSG_INTEN); 319 pci_intx(pci_dev, 1); 320 rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr, 321 IRQF_SHARED, dev_name(&pci_dev->dev), privdata); 322 if (rc) 323 pci_err(pci_dev, "Failure requesting irq %i: %d\n", 324 pci_dev->irq, rc); 325 326 return rc; 327 328 err_dma_mask: 329 pci_clear_master(pci_dev); 330 err_pci_enable: 331 pci_set_drvdata(pci_dev, NULL); 332 return rc; 333 } 334 335 static int amd_mp2_pci_probe(struct pci_dev *pci_dev, 336 const struct pci_device_id *id) 337 { 338 struct amd_mp2_dev *privdata; 339 int rc; 340 341 privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL); 342 if (!privdata) 343 return -ENOMEM; 344 345 privdata->pci_dev = pci_dev; 346 rc = amd_mp2_pci_init(privdata, pci_dev); 347 if (rc) 348 return rc; 349 350 mutex_init(&privdata->c2p_lock); 351 352 pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000); 353 pm_runtime_use_autosuspend(&pci_dev->dev); 354 pm_runtime_put_autosuspend(&pci_dev->dev); 355 pm_runtime_allow(&pci_dev->dev); 356 357 privdata->probed = true; 358 359 pci_info(pci_dev, "MP2 device registered.\n"); 360 return 0; 361 } 362 363 static void amd_mp2_pci_remove(struct pci_dev *pci_dev) 364 { 365 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); 366 367 pm_runtime_forbid(&pci_dev->dev); 368 pm_runtime_get_noresume(&pci_dev->dev); 369 370 pci_intx(pci_dev, 0); 371 pci_clear_master(pci_dev); 372 373 amd_mp2_clear_reg(privdata); 374 } 375 376 #ifdef CONFIG_PM 377 static int amd_mp2_pci_suspend(struct device *dev) 378 { 379 struct pci_dev *pci_dev = to_pci_dev(dev); 380 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); 381 struct amd_i2c_common *i2c_common; 382 unsigned int bus_id; 383 int ret = 0; 384 385 for (bus_id = 0; bus_id < 2; bus_id++) { 386 i2c_common = privdata->busses[bus_id]; 387 if (i2c_common) 388 i2c_common->suspend(i2c_common); 389 } 390 391 ret = pci_save_state(pci_dev); 392 if (ret) { 393 pci_err(pci_dev, "pci_save_state failed = %d\n", ret); 394 return ret; 395 } 396 397 pci_disable_device(pci_dev); 398 return ret; 399 } 400 401 static int amd_mp2_pci_resume(struct device *dev) 402 { 403 struct pci_dev *pci_dev = to_pci_dev(dev); 404 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev); 405 struct amd_i2c_common *i2c_common; 406 unsigned int bus_id; 407 int ret = 0; 408 409 pci_restore_state(pci_dev); 410 ret = pci_enable_device(pci_dev); 411 if (ret < 0) { 412 pci_err(pci_dev, "pci_enable_device failed = %d\n", ret); 413 return ret; 414 } 415 416 for (bus_id = 0; bus_id < 2; bus_id++) { 417 i2c_common = privdata->busses[bus_id]; 418 if (i2c_common) { 419 ret = i2c_common->resume(i2c_common); 420 if (ret < 0) 421 return ret; 422 } 423 } 424 425 return ret; 426 } 427 428 static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend, 429 amd_mp2_pci_resume, NULL); 430 #endif /* CONFIG_PM */ 431 432 static const struct pci_device_id amd_mp2_pci_tbl[] = { 433 {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)}, 434 {0} 435 }; 436 MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl); 437 438 static struct pci_driver amd_mp2_pci_driver = { 439 .name = "i2c_amd_mp2", 440 .id_table = amd_mp2_pci_tbl, 441 .probe = amd_mp2_pci_probe, 442 .remove = amd_mp2_pci_remove, 443 #ifdef CONFIG_PM 444 .driver = { 445 .pm = &amd_mp2_pci_pm_ops, 446 }, 447 #endif 448 }; 449 module_pci_driver(amd_mp2_pci_driver); 450 451 struct amd_mp2_dev *amd_mp2_find_device(void) 452 { 453 struct device *dev; 454 struct pci_dev *pci_dev; 455 456 dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL); 457 if (!dev) 458 return NULL; 459 460 pci_dev = to_pci_dev(dev); 461 return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); 462 } 463 EXPORT_SYMBOL_GPL(amd_mp2_find_device); 464 465 MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver"); 466 MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>"); 467 MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>"); 468 MODULE_LICENSE("Dual BSD/GPL"); 469