1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMx3 Wkup M3 IPC driver 4 * 5 * Copyright (C) 2015 Texas Instruments, Inc. 6 * 7 * Dave Gerlach <d-gerlach@ti.com> 8 */ 9 10 #include <linux/err.h> 11 #include <linux/kernel.h> 12 #include <linux/kthread.h> 13 #include <linux/interrupt.h> 14 #include <linux/irq.h> 15 #include <linux/module.h> 16 #include <linux/of.h> 17 #include <linux/omap-mailbox.h> 18 #include <linux/platform_device.h> 19 #include <linux/remoteproc.h> 20 #include <linux/suspend.h> 21 #include <linux/wkup_m3_ipc.h> 22 23 #define AM33XX_CTRL_IPC_REG_COUNT 0x8 24 #define AM33XX_CTRL_IPC_REG_OFFSET(m) (0x4 + 4 * (m)) 25 26 /* AM33XX M3_TXEV_EOI register */ 27 #define AM33XX_CONTROL_M3_TXEV_EOI 0x00 28 29 #define AM33XX_M3_TXEV_ACK (0x1 << 0) 30 #define AM33XX_M3_TXEV_ENABLE (0x0 << 0) 31 32 #define IPC_CMD_DS0 0x4 33 #define IPC_CMD_STANDBY 0xc 34 #define IPC_CMD_IDLE 0x10 35 #define IPC_CMD_RESET 0xe 36 #define DS_IPC_DEFAULT 0xffffffff 37 #define M3_VERSION_UNKNOWN 0x0000ffff 38 #define M3_BASELINE_VERSION 0x191 39 #define M3_STATUS_RESP_MASK (0xffff << 16) 40 #define M3_FW_VERSION_MASK 0xffff 41 #define M3_WAKE_SRC_MASK 0xff 42 43 #define M3_STATE_UNKNOWN 0 44 #define M3_STATE_RESET 1 45 #define M3_STATE_INITED 2 46 #define M3_STATE_MSG_FOR_LP 3 47 #define M3_STATE_MSG_FOR_RESET 4 48 49 static struct wkup_m3_ipc *m3_ipc_state; 50 51 static const struct wkup_m3_wakeup_src wakeups[] = { 52 {.irq_nr = 16, .src = "PRCM"}, 53 {.irq_nr = 35, .src = "USB0_PHY"}, 54 {.irq_nr = 36, .src = "USB1_PHY"}, 55 {.irq_nr = 40, .src = "I2C0"}, 56 {.irq_nr = 41, .src = "RTC Timer"}, 57 {.irq_nr = 42, .src = "RTC Alarm"}, 58 {.irq_nr = 43, .src = "Timer0"}, 59 {.irq_nr = 44, .src = "Timer1"}, 60 {.irq_nr = 45, .src = "UART"}, 61 {.irq_nr = 46, .src = "GPIO0"}, 62 {.irq_nr = 48, .src = "MPU_WAKE"}, 63 {.irq_nr = 49, .src = "WDT0"}, 64 {.irq_nr = 50, .src = "WDT1"}, 65 {.irq_nr = 51, .src = "ADC_TSC"}, 66 {.irq_nr = 0, .src = "Unknown"}, 67 }; 68 69 static void am33xx_txev_eoi(struct wkup_m3_ipc *m3_ipc) 70 { 71 writel(AM33XX_M3_TXEV_ACK, 72 m3_ipc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI); 73 } 74 75 static void am33xx_txev_enable(struct wkup_m3_ipc *m3_ipc) 76 { 77 writel(AM33XX_M3_TXEV_ENABLE, 78 m3_ipc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI); 79 } 80 81 static void wkup_m3_ctrl_ipc_write(struct wkup_m3_ipc *m3_ipc, 82 u32 val, int ipc_reg_num) 83 { 84 if (WARN(ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT, 85 "ipc register operation out of range")) 86 return; 87 88 writel(val, m3_ipc->ipc_mem_base + 89 AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num)); 90 } 91 92 static unsigned int wkup_m3_ctrl_ipc_read(struct wkup_m3_ipc *m3_ipc, 93 int ipc_reg_num) 94 { 95 if (WARN(ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT, 96 "ipc register operation out of range")) 97 return 0; 98 99 return readl(m3_ipc->ipc_mem_base + 100 AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num)); 101 } 102 103 static int wkup_m3_fw_version_read(struct wkup_m3_ipc *m3_ipc) 104 { 105 int val; 106 107 val = wkup_m3_ctrl_ipc_read(m3_ipc, 2); 108 109 return val & M3_FW_VERSION_MASK; 110 } 111 112 static irqreturn_t wkup_m3_txev_handler(int irq, void *ipc_data) 113 { 114 struct wkup_m3_ipc *m3_ipc = ipc_data; 115 struct device *dev = m3_ipc->dev; 116 int ver = 0; 117 118 am33xx_txev_eoi(m3_ipc); 119 120 switch (m3_ipc->state) { 121 case M3_STATE_RESET: 122 ver = wkup_m3_fw_version_read(m3_ipc); 123 124 if (ver == M3_VERSION_UNKNOWN || 125 ver < M3_BASELINE_VERSION) { 126 dev_warn(dev, "CM3 Firmware Version %x not supported\n", 127 ver); 128 } else { 129 dev_info(dev, "CM3 Firmware Version = 0x%x\n", ver); 130 } 131 132 m3_ipc->state = M3_STATE_INITED; 133 complete(&m3_ipc->sync_complete); 134 break; 135 case M3_STATE_MSG_FOR_RESET: 136 m3_ipc->state = M3_STATE_INITED; 137 complete(&m3_ipc->sync_complete); 138 break; 139 case M3_STATE_MSG_FOR_LP: 140 complete(&m3_ipc->sync_complete); 141 break; 142 case M3_STATE_UNKNOWN: 143 dev_warn(dev, "Unknown CM3 State\n"); 144 } 145 146 am33xx_txev_enable(m3_ipc); 147 148 return IRQ_HANDLED; 149 } 150 151 static int wkup_m3_ping(struct wkup_m3_ipc *m3_ipc) 152 { 153 struct device *dev = m3_ipc->dev; 154 mbox_msg_t dummy_msg = 0; 155 int ret; 156 157 if (!m3_ipc->mbox) { 158 dev_err(dev, 159 "No IPC channel to communicate with wkup_m3!\n"); 160 return -EIO; 161 } 162 163 /* 164 * Write a dummy message to the mailbox in order to trigger the RX 165 * interrupt to alert the M3 that data is available in the IPC 166 * registers. We must enable the IRQ here and disable it after in 167 * the RX callback to avoid multiple interrupts being received 168 * by the CM3. 169 */ 170 ret = mbox_send_message(m3_ipc->mbox, &dummy_msg); 171 if (ret < 0) { 172 dev_err(dev, "%s: mbox_send_message() failed: %d\n", 173 __func__, ret); 174 return ret; 175 } 176 177 ret = wait_for_completion_timeout(&m3_ipc->sync_complete, 178 msecs_to_jiffies(500)); 179 if (!ret) { 180 dev_err(dev, "MPU<->CM3 sync failure\n"); 181 m3_ipc->state = M3_STATE_UNKNOWN; 182 return -EIO; 183 } 184 185 mbox_client_txdone(m3_ipc->mbox, 0); 186 return 0; 187 } 188 189 static int wkup_m3_ping_noirq(struct wkup_m3_ipc *m3_ipc) 190 { 191 struct device *dev = m3_ipc->dev; 192 mbox_msg_t dummy_msg = 0; 193 int ret; 194 195 if (!m3_ipc->mbox) { 196 dev_err(dev, 197 "No IPC channel to communicate with wkup_m3!\n"); 198 return -EIO; 199 } 200 201 ret = mbox_send_message(m3_ipc->mbox, &dummy_msg); 202 if (ret < 0) { 203 dev_err(dev, "%s: mbox_send_message() failed: %d\n", 204 __func__, ret); 205 return ret; 206 } 207 208 mbox_client_txdone(m3_ipc->mbox, 0); 209 return 0; 210 } 211 212 static int wkup_m3_is_available(struct wkup_m3_ipc *m3_ipc) 213 { 214 return ((m3_ipc->state != M3_STATE_RESET) && 215 (m3_ipc->state != M3_STATE_UNKNOWN)); 216 } 217 218 /* Public functions */ 219 /** 220 * wkup_m3_set_mem_type - Pass wkup_m3 which type of memory is in use 221 * @m3_ipc: Pointer to wkup_m3_ipc context 222 * @mem_type: memory type value read directly from emif 223 * 224 * wkup_m3 must know what memory type is in use to properly suspend 225 * and resume. 226 */ 227 static void wkup_m3_set_mem_type(struct wkup_m3_ipc *m3_ipc, int mem_type) 228 { 229 m3_ipc->mem_type = mem_type; 230 } 231 232 /** 233 * wkup_m3_set_resume_address - Pass wkup_m3 resume address 234 * @m3_ipc: Pointer to wkup_m3_ipc context 235 * @addr: Physical address from which resume code should execute 236 */ 237 static void wkup_m3_set_resume_address(struct wkup_m3_ipc *m3_ipc, void *addr) 238 { 239 m3_ipc->resume_addr = (unsigned long)addr; 240 } 241 242 /** 243 * wkup_m3_request_pm_status - Retrieve wkup_m3 status code after suspend 244 * @m3_ipc: Pointer to wkup_m3_ipc context 245 * 246 * Returns code representing the status of a low power mode transition. 247 * 0 - Successful transition 248 * 1 - Failure to transition to low power state 249 */ 250 static int wkup_m3_request_pm_status(struct wkup_m3_ipc *m3_ipc) 251 { 252 unsigned int i; 253 int val; 254 255 val = wkup_m3_ctrl_ipc_read(m3_ipc, 1); 256 257 i = M3_STATUS_RESP_MASK & val; 258 i >>= __ffs(M3_STATUS_RESP_MASK); 259 260 return i; 261 } 262 263 /** 264 * wkup_m3_prepare_low_power - Request preparation for transition to 265 * low power state 266 * @m3_ipc: Pointer to wkup_m3_ipc context 267 * @state: A kernel suspend state to enter, either MEM or STANDBY 268 * 269 * Returns 0 if preparation was successful, otherwise returns error code 270 */ 271 static int wkup_m3_prepare_low_power(struct wkup_m3_ipc *m3_ipc, int state) 272 { 273 struct device *dev = m3_ipc->dev; 274 int m3_power_state; 275 int ret = 0; 276 277 if (!wkup_m3_is_available(m3_ipc)) 278 return -ENODEV; 279 280 switch (state) { 281 case WKUP_M3_DEEPSLEEP: 282 m3_power_state = IPC_CMD_DS0; 283 break; 284 case WKUP_M3_STANDBY: 285 m3_power_state = IPC_CMD_STANDBY; 286 break; 287 case WKUP_M3_IDLE: 288 m3_power_state = IPC_CMD_IDLE; 289 break; 290 default: 291 return 1; 292 } 293 294 /* Program each required IPC register then write defaults to others */ 295 wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->resume_addr, 0); 296 wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1); 297 wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type, 4); 298 299 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2); 300 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3); 301 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 5); 302 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 6); 303 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 7); 304 305 m3_ipc->state = M3_STATE_MSG_FOR_LP; 306 307 if (state == WKUP_M3_IDLE) 308 ret = wkup_m3_ping_noirq(m3_ipc); 309 else 310 ret = wkup_m3_ping(m3_ipc); 311 312 if (ret) { 313 dev_err(dev, "Unable to ping CM3\n"); 314 return ret; 315 } 316 317 return 0; 318 } 319 320 /** 321 * wkup_m3_finish_low_power - Return m3 to reset state 322 * @m3_ipc: Pointer to wkup_m3_ipc context 323 * 324 * Returns 0 if reset was successful, otherwise returns error code 325 */ 326 static int wkup_m3_finish_low_power(struct wkup_m3_ipc *m3_ipc) 327 { 328 struct device *dev = m3_ipc->dev; 329 int ret = 0; 330 331 if (!wkup_m3_is_available(m3_ipc)) 332 return -ENODEV; 333 334 wkup_m3_ctrl_ipc_write(m3_ipc, IPC_CMD_RESET, 1); 335 wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2); 336 337 m3_ipc->state = M3_STATE_MSG_FOR_RESET; 338 339 ret = wkup_m3_ping(m3_ipc); 340 if (ret) { 341 dev_err(dev, "Unable to ping CM3\n"); 342 return ret; 343 } 344 345 return 0; 346 } 347 348 /** 349 * wkup_m3_request_wake_src - Get the wakeup source info passed from wkup_m3 350 * @m3_ipc: Pointer to wkup_m3_ipc context 351 */ 352 static const char *wkup_m3_request_wake_src(struct wkup_m3_ipc *m3_ipc) 353 { 354 unsigned int wakeup_src_idx; 355 int j, val; 356 357 val = wkup_m3_ctrl_ipc_read(m3_ipc, 6); 358 359 wakeup_src_idx = val & M3_WAKE_SRC_MASK; 360 361 for (j = 0; j < ARRAY_SIZE(wakeups) - 1; j++) { 362 if (wakeups[j].irq_nr == wakeup_src_idx) 363 return wakeups[j].src; 364 } 365 return wakeups[j].src; 366 } 367 368 /** 369 * wkup_m3_set_rtc_only - Set the rtc_only flag 370 * @m3_ipc: Pointer to wkup_m3_ipc context 371 */ 372 static void wkup_m3_set_rtc_only(struct wkup_m3_ipc *m3_ipc) 373 { 374 if (m3_ipc_state) 375 m3_ipc_state->is_rtc_only = true; 376 } 377 378 static struct wkup_m3_ipc_ops ipc_ops = { 379 .set_mem_type = wkup_m3_set_mem_type, 380 .set_resume_address = wkup_m3_set_resume_address, 381 .prepare_low_power = wkup_m3_prepare_low_power, 382 .finish_low_power = wkup_m3_finish_low_power, 383 .request_pm_status = wkup_m3_request_pm_status, 384 .request_wake_src = wkup_m3_request_wake_src, 385 .set_rtc_only = wkup_m3_set_rtc_only, 386 }; 387 388 /** 389 * wkup_m3_ipc_get - Return handle to wkup_m3_ipc 390 * 391 * Returns NULL if the wkup_m3 is not yet available, otherwise returns 392 * pointer to wkup_m3_ipc struct. 393 */ 394 struct wkup_m3_ipc *wkup_m3_ipc_get(void) 395 { 396 if (m3_ipc_state) 397 get_device(m3_ipc_state->dev); 398 else 399 return NULL; 400 401 return m3_ipc_state; 402 } 403 EXPORT_SYMBOL_GPL(wkup_m3_ipc_get); 404 405 /** 406 * wkup_m3_ipc_put - Free handle to wkup_m3_ipc returned from wkup_m3_ipc_get 407 * @m3_ipc: A pointer to wkup_m3_ipc struct returned by wkup_m3_ipc_get 408 */ 409 void wkup_m3_ipc_put(struct wkup_m3_ipc *m3_ipc) 410 { 411 if (m3_ipc_state) 412 put_device(m3_ipc_state->dev); 413 } 414 EXPORT_SYMBOL_GPL(wkup_m3_ipc_put); 415 416 static int wkup_m3_rproc_boot_thread(void *arg) 417 { 418 struct wkup_m3_ipc *m3_ipc = arg; 419 struct device *dev = m3_ipc->dev; 420 int ret; 421 422 init_completion(&m3_ipc->sync_complete); 423 424 ret = rproc_boot(m3_ipc->rproc); 425 if (ret) 426 dev_err(dev, "rproc_boot failed\n"); 427 else 428 m3_ipc_state = m3_ipc; 429 430 return 0; 431 } 432 433 static int wkup_m3_ipc_probe(struct platform_device *pdev) 434 { 435 struct device *dev = &pdev->dev; 436 int irq, ret; 437 phandle rproc_phandle; 438 struct rproc *m3_rproc; 439 struct resource *res; 440 struct task_struct *task; 441 struct wkup_m3_ipc *m3_ipc; 442 443 m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL); 444 if (!m3_ipc) 445 return -ENOMEM; 446 447 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 448 m3_ipc->ipc_mem_base = devm_ioremap_resource(dev, res); 449 if (IS_ERR(m3_ipc->ipc_mem_base)) 450 return PTR_ERR(m3_ipc->ipc_mem_base); 451 452 irq = platform_get_irq(pdev, 0); 453 if (!irq) { 454 dev_err(&pdev->dev, "no irq resource\n"); 455 return -ENXIO; 456 } 457 458 ret = devm_request_irq(dev, irq, wkup_m3_txev_handler, 459 0, "wkup_m3_txev", m3_ipc); 460 if (ret) { 461 dev_err(dev, "request_irq failed\n"); 462 return ret; 463 } 464 465 m3_ipc->mbox_client.dev = dev; 466 m3_ipc->mbox_client.tx_done = NULL; 467 m3_ipc->mbox_client.tx_prepare = NULL; 468 m3_ipc->mbox_client.rx_callback = NULL; 469 m3_ipc->mbox_client.tx_block = false; 470 m3_ipc->mbox_client.knows_txdone = false; 471 472 m3_ipc->mbox = mbox_request_channel(&m3_ipc->mbox_client, 0); 473 474 if (IS_ERR(m3_ipc->mbox)) { 475 dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n", 476 PTR_ERR(m3_ipc->mbox)); 477 return PTR_ERR(m3_ipc->mbox); 478 } 479 480 if (of_property_read_u32(dev->of_node, "ti,rproc", &rproc_phandle)) { 481 dev_err(&pdev->dev, "could not get rproc phandle\n"); 482 ret = -ENODEV; 483 goto err_free_mbox; 484 } 485 486 m3_rproc = rproc_get_by_phandle(rproc_phandle); 487 if (!m3_rproc) { 488 dev_err(&pdev->dev, "could not get rproc handle\n"); 489 ret = -EPROBE_DEFER; 490 goto err_free_mbox; 491 } 492 493 m3_ipc->rproc = m3_rproc; 494 m3_ipc->dev = dev; 495 m3_ipc->state = M3_STATE_RESET; 496 497 m3_ipc->ops = &ipc_ops; 498 499 /* 500 * Wait for firmware loading completion in a thread so we 501 * can boot the wkup_m3 as soon as it's ready without holding 502 * up kernel boot 503 */ 504 task = kthread_run(wkup_m3_rproc_boot_thread, m3_ipc, 505 "wkup_m3_rproc_loader"); 506 507 if (IS_ERR(task)) { 508 dev_err(dev, "can't create rproc_boot thread\n"); 509 ret = PTR_ERR(task); 510 goto err_put_rproc; 511 } 512 513 return 0; 514 515 err_put_rproc: 516 rproc_put(m3_rproc); 517 err_free_mbox: 518 mbox_free_channel(m3_ipc->mbox); 519 return ret; 520 } 521 522 static int wkup_m3_ipc_remove(struct platform_device *pdev) 523 { 524 mbox_free_channel(m3_ipc_state->mbox); 525 526 rproc_shutdown(m3_ipc_state->rproc); 527 rproc_put(m3_ipc_state->rproc); 528 529 m3_ipc_state = NULL; 530 531 return 0; 532 } 533 534 static int __maybe_unused wkup_m3_ipc_suspend(struct device *dev) 535 { 536 /* 537 * Nothing needs to be done on suspend even with rtc_only flag set 538 */ 539 return 0; 540 } 541 542 static int __maybe_unused wkup_m3_ipc_resume(struct device *dev) 543 { 544 if (m3_ipc_state->is_rtc_only) { 545 rproc_shutdown(m3_ipc_state->rproc); 546 rproc_boot(m3_ipc_state->rproc); 547 } 548 549 m3_ipc_state->is_rtc_only = false; 550 551 return 0; 552 } 553 554 static const struct dev_pm_ops wkup_m3_ipc_pm_ops = { 555 SET_SYSTEM_SLEEP_PM_OPS(wkup_m3_ipc_suspend, wkup_m3_ipc_resume) 556 }; 557 558 static const struct of_device_id wkup_m3_ipc_of_match[] = { 559 { .compatible = "ti,am3352-wkup-m3-ipc", }, 560 { .compatible = "ti,am4372-wkup-m3-ipc", }, 561 {}, 562 }; 563 MODULE_DEVICE_TABLE(of, wkup_m3_ipc_of_match); 564 565 static struct platform_driver wkup_m3_ipc_driver = { 566 .probe = wkup_m3_ipc_probe, 567 .remove = wkup_m3_ipc_remove, 568 .driver = { 569 .name = "wkup_m3_ipc", 570 .of_match_table = wkup_m3_ipc_of_match, 571 .pm = &wkup_m3_ipc_pm_ops, 572 }, 573 }; 574 575 module_platform_driver(wkup_m3_ipc_driver); 576 577 MODULE_LICENSE("GPL v2"); 578 MODULE_DESCRIPTION("wkup m3 remote processor ipc driver"); 579 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>"); 580