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  * @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 void wkup_m3_rproc_boot_thread(struct wkup_m3_ipc *m3_ipc)
 417 {
 418         struct device *dev = m3_ipc->dev;
 419         int ret;
 420
 421         init_completion(&m3_ipc->sync_complete);
 422
 423         ret = rproc_boot(m3_ipc->rproc);
 424         if (ret)
 425                 dev_err(dev, "rproc_boot failed\n");
 426         else
 427                 m3_ipc_state = m3_ipc;
 428
 429         return 0;
 430 }
 431
 432 static int wkup_m3_ipc_probe(struct platform_device *pdev)
 433 {
 434         struct device *dev = &pdev->dev;
 435         int irq, ret;
 436         phandle rproc_phandle;
 437         struct rproc *m3_rproc;
 438         struct resource *res;
 439         struct task_struct *task;
 440         struct wkup_m3_ipc *m3_ipc;
 441
 442         m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL);
 443         if (!m3_ipc)
 444                 return -ENOMEM;
 445
 446         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 447         m3_ipc->ipc_mem_base = devm_ioremap_resource(dev, res);
 448         if (IS_ERR(m3_ipc->ipc_mem_base))
 449                 return PTR_ERR(m3_ipc->ipc_mem_base);
 450
 451         irq = platform_get_irq(pdev, 0);
 452         if (!irq) {
 453                 dev_err(&pdev->dev, "no irq resource\n");
 454                 return -ENXIO;
 455         }
 456
 457         ret = devm_request_irq(dev, irq, wkup_m3_txev_handler,
 458                                0, "wkup_m3_txev", m3_ipc);
 459         if (ret) {
 460                 dev_err(dev, "request_irq failed\n");
 461                 return ret;
 462         }
 463
 464         m3_ipc->mbox_client.dev = dev;
 465         m3_ipc->mbox_client.tx_done = NULL;
 466         m3_ipc->mbox_client.tx_prepare = NULL;
 467         m3_ipc->mbox_client.rx_callback = NULL;
 468         m3_ipc->mbox_client.tx_block = false;
 469         m3_ipc->mbox_client.knows_txdone = false;
 470
 471         m3_ipc->mbox = mbox_request_channel(&m3_ipc->mbox_client, 0);
 472
 473         if (IS_ERR(m3_ipc->mbox)) {
 474                 dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n",
 475                         PTR_ERR(m3_ipc->mbox));
 476                 return PTR_ERR(m3_ipc->mbox);
 477         }
 478
 479         if (of_property_read_u32(dev->of_node, "ti,rproc", &rproc_phandle)) {
 480                 dev_err(&pdev->dev, "could not get rproc phandle\n");
 481                 ret = -ENODEV;
 482                 goto err_free_mbox;
 483         }
 484
 485         m3_rproc = rproc_get_by_phandle(rproc_phandle);
 486         if (!m3_rproc) {
 487                 dev_err(&pdev->dev, "could not get rproc handle\n");
 488                 ret = -EPROBE_DEFER;
 489                 goto err_free_mbox;
 490         }
 491
 492         m3_ipc->rproc = m3_rproc;
 493         m3_ipc->dev = dev;
 494         m3_ipc->state = M3_STATE_RESET;
 495
 496         m3_ipc->ops = &ipc_ops;
 497
 498         /*
 499          * Wait for firmware loading completion in a thread so we
 500          * can boot the wkup_m3 as soon as it's ready without holding
 501          * up kernel boot
 502          */
 503         task = kthread_run((void *)wkup_m3_rproc_boot_thread, m3_ipc,
 504                            "wkup_m3_rproc_loader");
 505
 506         if (IS_ERR(task)) {
 507                 dev_err(dev, "can't create rproc_boot thread\n");
 508                 ret = PTR_ERR(task);
 509                 goto err_put_rproc;
 510         }
 511
 512         return 0;
 513
 514 err_put_rproc:
 515         rproc_put(m3_rproc);
 516 err_free_mbox:
 517         mbox_free_channel(m3_ipc->mbox);
 518         return ret;
 519 }
 520
 521 static int wkup_m3_ipc_remove(struct platform_device *pdev)
 522 {
 523         mbox_free_channel(m3_ipc_state->mbox);
 524
 525         rproc_shutdown(m3_ipc_state->rproc);
 526         rproc_put(m3_ipc_state->rproc);
 527
 528         m3_ipc_state = NULL;
 529
 530         return 0;
 531 }
 532
 533 static int __maybe_unused wkup_m3_ipc_suspend(struct device *dev)
 534 {
 535         /*
 536          * Nothing needs to be done on suspend even with rtc_only flag set
 537          */
 538         return 0;
 539 }
 540
 541 static int __maybe_unused wkup_m3_ipc_resume(struct device *dev)
 542 {
 543         if (m3_ipc_state->is_rtc_only) {
 544                 rproc_shutdown(m3_ipc_state->rproc);
 545                 rproc_boot(m3_ipc_state->rproc);
 546         }
 547
 548         m3_ipc_state->is_rtc_only = false;
 549
 550         return 0;
 551 }
 552
 553 static const struct dev_pm_ops wkup_m3_ipc_pm_ops = {
 554         SET_SYSTEM_SLEEP_PM_OPS(wkup_m3_ipc_suspend, wkup_m3_ipc_resume)
 555 };
 556
 557 static const struct of_device_id wkup_m3_ipc_of_match[] = {
 558         { .compatible = "ti,am3352-wkup-m3-ipc", },
 559         { .compatible = "ti,am4372-wkup-m3-ipc", },
 560         {},
 561 };
 562 MODULE_DEVICE_TABLE(of, wkup_m3_ipc_of_match);
 563
 564 static struct platform_driver wkup_m3_ipc_driver = {
 565         .probe = wkup_m3_ipc_probe,
 566         .remove = wkup_m3_ipc_remove,
 567         .driver = {
 568                 .name = "wkup_m3_ipc",
 569                 .of_match_table = wkup_m3_ipc_of_match,
 570                 .pm = &wkup_m3_ipc_pm_ops,
 571         },
 572 };
 573
 574 module_platform_driver(wkup_m3_ipc_driver);
 575
 576 MODULE_LICENSE("GPL v2");
 577 MODULE_DESCRIPTION("wkup m3 remote processor ipc driver");
 578 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");