drivers/soc/ti/wkup_m3_ipc.c

   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  * @mem_type: memory type value read directly from emif
 222  *
 223  * wkup_m3 must know what memory type is in use to properly suspend
 224  * and resume.
 225  */
 226 static void wkup_m3_set_mem_type(struct wkup_m3_ipc *m3_ipc, int mem_type)
 227 {
 228         m3_ipc->mem_type = mem_type;
 229 }
 230
 231 /**
 232  * wkup_m3_set_resume_address - Pass wkup_m3 resume address
 233  * @addr: Physical address from which resume code should execute
 234  */
 235 static void wkup_m3_set_resume_address(struct wkup_m3_ipc *m3_ipc, void *addr)
 236 {
 237         m3_ipc->resume_addr = (unsigned long)addr;
 238 }
 239
 240 /**
 241  * wkup_m3_request_pm_status - Retrieve wkup_m3 status code after suspend
 242  *
 243  * Returns code representing the status of a low power mode transition.
 244  *      0 - Successful transition
 245  *      1 - Failure to transition to low power state
 246  */
 247 static int wkup_m3_request_pm_status(struct wkup_m3_ipc *m3_ipc)
 248 {
 249         unsigned int i;
 250         int val;
 251
 252         val = wkup_m3_ctrl_ipc_read(m3_ipc, 1);
 253
 254         i = M3_STATUS_RESP_MASK & val;
 255         i >>= __ffs(M3_STATUS_RESP_MASK);
 256
 257         return i;
 258 }
 259
 260 /**
 261  * wkup_m3_prepare_low_power - Request preparation for transition to
 262  *                             low power state
 263  * @state: A kernel suspend state to enter, either MEM or STANDBY
 264  *
 265  * Returns 0 if preparation was successful, otherwise returns error code
 266  */
 267 static int wkup_m3_prepare_low_power(struct wkup_m3_ipc *m3_ipc, int state)
 268 {
 269         struct device *dev = m3_ipc->dev;
 270         int m3_power_state;
 271         int ret = 0;
 272
 273         if (!wkup_m3_is_available(m3_ipc))
 274                 return -ENODEV;
 275
 276         switch (state) {
 277         case WKUP_M3_DEEPSLEEP:
 278                 m3_power_state = IPC_CMD_DS0;
 279                 break;
 280         case WKUP_M3_STANDBY:
 281                 m3_power_state = IPC_CMD_STANDBY;
 282                 break;
 283         case WKUP_M3_IDLE:
 284                 m3_power_state = IPC_CMD_IDLE;
 285                 break;
 286         default:
 287                 return 1;
 288         }
 289
 290         /* Program each required IPC register then write defaults to others */
 291         wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->resume_addr, 0);
 292         wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1);
 293         wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type, 4);
 294
 295         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
 296         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3);
 297         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 5);
 298         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 6);
 299         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 7);
 300
 301         m3_ipc->state = M3_STATE_MSG_FOR_LP;
 302
 303         if (state == WKUP_M3_IDLE)
 304                 ret = wkup_m3_ping_noirq(m3_ipc);
 305         else
 306                 ret = wkup_m3_ping(m3_ipc);
 307
 308         if (ret) {
 309                 dev_err(dev, "Unable to ping CM3\n");
 310                 return ret;
 311         }
 312
 313         return 0;
 314 }
 315
 316 /**
 317  * wkup_m3_finish_low_power - Return m3 to reset state
 318  *
 319  * Returns 0 if reset was successful, otherwise returns error code
 320  */
 321 static int wkup_m3_finish_low_power(struct wkup_m3_ipc *m3_ipc)
 322 {
 323         struct device *dev = m3_ipc->dev;
 324         int ret = 0;
 325
 326         if (!wkup_m3_is_available(m3_ipc))
 327                 return -ENODEV;
 328
 329         wkup_m3_ctrl_ipc_write(m3_ipc, IPC_CMD_RESET, 1);
 330         wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
 331
 332         m3_ipc->state = M3_STATE_MSG_FOR_RESET;
 333
 334         ret = wkup_m3_ping(m3_ipc);
 335         if (ret) {
 336                 dev_err(dev, "Unable to ping CM3\n");
 337                 return ret;
 338         }
 339
 340         return 0;
 341 }
 342
 343 /**
 344  * wkup_m3_request_wake_src - Get the wakeup source info passed from wkup_m3
 345  * @m3_ipc: Pointer to wkup_m3_ipc context
 346  */
 347 static const char *wkup_m3_request_wake_src(struct wkup_m3_ipc *m3_ipc)
 348 {
 349         unsigned int wakeup_src_idx;
 350         int j, val;
 351
 352         val = wkup_m3_ctrl_ipc_read(m3_ipc, 6);
 353
 354         wakeup_src_idx = val & M3_WAKE_SRC_MASK;
 355
 356         for (j = 0; j < ARRAY_SIZE(wakeups) - 1; j++) {
 357                 if (wakeups[j].irq_nr == wakeup_src_idx)
 358                         return wakeups[j].src;
 359         }
 360         return wakeups[j].src;
 361 }
 362
 363 /**
 364  * wkup_m3_set_rtc_only - Set the rtc_only flag
 365  * @wkup_m3_wakeup: struct wkup_m3_wakeup_src * gets assigned the
 366  *                  wakeup src value
 367  */
 368 static void wkup_m3_set_rtc_only(struct wkup_m3_ipc *m3_ipc)
 369 {
 370         if (m3_ipc_state)
 371                 m3_ipc_state->is_rtc_only = true;
 372 }
 373
 374 static struct wkup_m3_ipc_ops ipc_ops = {
 375         .set_mem_type = wkup_m3_set_mem_type,
 376         .set_resume_address = wkup_m3_set_resume_address,
 377         .prepare_low_power = wkup_m3_prepare_low_power,
 378         .finish_low_power = wkup_m3_finish_low_power,
 379         .request_pm_status = wkup_m3_request_pm_status,
 380         .request_wake_src = wkup_m3_request_wake_src,
 381         .set_rtc_only = wkup_m3_set_rtc_only,
 382 };
 383
 384 /**
 385  * wkup_m3_ipc_get - Return handle to wkup_m3_ipc
 386  *
 387  * Returns NULL if the wkup_m3 is not yet available, otherwise returns
 388  * pointer to wkup_m3_ipc struct.
 389  */
 390 struct wkup_m3_ipc *wkup_m3_ipc_get(void)
 391 {
 392         if (m3_ipc_state)
 393                 get_device(m3_ipc_state->dev);
 394         else
 395                 return NULL;
 396
 397         return m3_ipc_state;
 398 }
 399 EXPORT_SYMBOL_GPL(wkup_m3_ipc_get);
 400
 401 /**
 402  * wkup_m3_ipc_put - Free handle to wkup_m3_ipc returned from wkup_m3_ipc_get
 403  * @m3_ipc: A pointer to wkup_m3_ipc struct returned by wkup_m3_ipc_get
 404  */
 405 void wkup_m3_ipc_put(struct wkup_m3_ipc *m3_ipc)
 406 {
 407         if (m3_ipc_state)
 408                 put_device(m3_ipc_state->dev);
 409 }
 410 EXPORT_SYMBOL_GPL(wkup_m3_ipc_put);
 411
 412 static void wkup_m3_rproc_boot_thread(struct wkup_m3_ipc *m3_ipc)
 413 {
 414         struct device *dev = m3_ipc->dev;
 415         int ret;
 416
 417         init_completion(&m3_ipc->sync_complete);
 418
 419         ret = rproc_boot(m3_ipc->rproc);
 420         if (ret)
 421                 dev_err(dev, "rproc_boot failed\n");
 422         else
 423                 m3_ipc_state = m3_ipc;
 424
 425         do_exit(0);
 426 }
 427
 428 static int wkup_m3_ipc_probe(struct platform_device *pdev)
 429 {
 430         struct device *dev = &pdev->dev;
 431         int irq, ret;
 432         phandle rproc_phandle;
 433         struct rproc *m3_rproc;
 434         struct resource *res;
 435         struct task_struct *task;
 436         struct wkup_m3_ipc *m3_ipc;
 437
 438         m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL);
 439         if (!m3_ipc)
 440                 return -ENOMEM;
 441
 442         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 443         m3_ipc->ipc_mem_base = devm_ioremap_resource(dev, res);
 444         if (IS_ERR(m3_ipc->ipc_mem_base)) {
 445                 dev_err(dev, "could not ioremap ipc_mem\n");
 446                 return PTR_ERR(m3_ipc->ipc_mem_base);
 447         }
 448
 449         irq = platform_get_irq(pdev, 0);
 450         if (!irq) {
 451                 dev_err(&pdev->dev, "no irq resource\n");
 452                 return -ENXIO;
 453         }
 454
 455         ret = devm_request_irq(dev, irq, wkup_m3_txev_handler,
 456                                0, "wkup_m3_txev", m3_ipc);
 457         if (ret) {
 458                 dev_err(dev, "request_irq failed\n");
 459                 return ret;
 460         }
 461
 462         m3_ipc->mbox_client.dev = dev;
 463         m3_ipc->mbox_client.tx_done = NULL;
 464         m3_ipc->mbox_client.tx_prepare = NULL;
 465         m3_ipc->mbox_client.rx_callback = NULL;
 466         m3_ipc->mbox_client.tx_block = false;
 467         m3_ipc->mbox_client.knows_txdone = false;
 468
 469         m3_ipc->mbox = mbox_request_channel(&m3_ipc->mbox_client, 0);
 470
 471         if (IS_ERR(m3_ipc->mbox)) {
 472                 dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n",
 473                         PTR_ERR(m3_ipc->mbox));
 474                 return PTR_ERR(m3_ipc->mbox);
 475         }
 476
 477         if (of_property_read_u32(dev->of_node, "ti,rproc", &rproc_phandle)) {
 478                 dev_err(&pdev->dev, "could not get rproc phandle\n");
 479                 ret = -ENODEV;
 480                 goto err_free_mbox;
 481         }
 482
 483         m3_rproc = rproc_get_by_phandle(rproc_phandle);
 484         if (!m3_rproc) {
 485                 dev_err(&pdev->dev, "could not get rproc handle\n");
 486                 ret = -EPROBE_DEFER;
 487                 goto err_free_mbox;
 488         }
 489
 490         m3_ipc->rproc = m3_rproc;
 491         m3_ipc->dev = dev;
 492         m3_ipc->state = M3_STATE_RESET;
 493
 494         m3_ipc->ops = &ipc_ops;
 495
 496         /*
 497          * Wait for firmware loading completion in a thread so we
 498          * can boot the wkup_m3 as soon as it's ready without holding
 499          * up kernel boot
 500          */
 501         task = kthread_run((void *)wkup_m3_rproc_boot_thread, m3_ipc,
 502                            "wkup_m3_rproc_loader");
 503
 504         if (IS_ERR(task)) {
 505                 dev_err(dev, "can't create rproc_boot thread\n");
 506                 ret = PTR_ERR(task);
 507                 goto err_put_rproc;
 508         }
 509
 510         return 0;
 511
 512 err_put_rproc:
 513         rproc_put(m3_rproc);
 514 err_free_mbox:
 515         mbox_free_channel(m3_ipc->mbox);
 516         return ret;
 517 }
 518
 519 static int wkup_m3_ipc_remove(struct platform_device *pdev)
 520 {
 521         mbox_free_channel(m3_ipc_state->mbox);
 522
 523         rproc_shutdown(m3_ipc_state->rproc);
 524         rproc_put(m3_ipc_state->rproc);
 525
 526         m3_ipc_state = NULL;
 527
 528         return 0;
 529 }
 530
 531 static int __maybe_unused wkup_m3_ipc_suspend(struct device *dev)
 532 {
 533         /*
 534          * Nothing needs to be done on suspend even with rtc_only flag set
 535          */
 536         return 0;
 537 }
 538
 539 static int __maybe_unused wkup_m3_ipc_resume(struct device *dev)
 540 {
 541         if (m3_ipc_state->is_rtc_only) {
 542                 rproc_shutdown(m3_ipc_state->rproc);
 543                 rproc_boot(m3_ipc_state->rproc);
 544         }
 545
 546         m3_ipc_state->is_rtc_only = false;
 547
 548         return 0;
 549 }
 550
 551 static const struct dev_pm_ops wkup_m3_ipc_pm_ops = {
 552         SET_SYSTEM_SLEEP_PM_OPS(wkup_m3_ipc_suspend, wkup_m3_ipc_resume)
 553 };
 554
 555 static const struct of_device_id wkup_m3_ipc_of_match[] = {
 556         { .compatible = "ti,am3352-wkup-m3-ipc", },
 557         { .compatible = "ti,am4372-wkup-m3-ipc", },
 558         {},
 559 };
 560 MODULE_DEVICE_TABLE(of, wkup_m3_ipc_of_match);
 561
 562 static struct platform_driver wkup_m3_ipc_driver = {
 563         .probe = wkup_m3_ipc_probe,
 564         .remove = wkup_m3_ipc_remove,
 565         .driver = {
 566                 .name = "wkup_m3_ipc",
 567                 .of_match_table = wkup_m3_ipc_of_match,
 568                 .pm = &wkup_m3_ipc_pm_ops,
 569         },
 570 };
 571
 572 module_platform_driver(wkup_m3_ipc_driver);
 573
 574 MODULE_LICENSE("GPL v2");
 575 MODULE_DESCRIPTION("wkup m3 remote processor ipc driver");
 576 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");