drivers/remoteproc/keystone_remoteproc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TI Keystone DSP remoteproc driver
   4  *
   5  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/io.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/pm_runtime.h>
  14 #include <linux/workqueue.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of_reserved_mem.h>
  17 #include <linux/gpio/consumer.h>
  18 #include <linux/regmap.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/remoteproc.h>
  21 #include <linux/reset.h>
  22
  23 #include "remoteproc_internal.h"
  24
  25 #define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK       (SZ_16M - 1)
  26
  27 /**
  28  * struct keystone_rproc_mem - internal memory structure
  29  * @cpu_addr: MPU virtual address of the memory region
  30  * @bus_addr: Bus address used to access the memory region
  31  * @dev_addr: Device address of the memory region from DSP view
  32  * @size: Size of the memory region
  33  */
  34 struct keystone_rproc_mem {
  35         void __iomem *cpu_addr;
  36         phys_addr_t bus_addr;
  37         u32 dev_addr;
  38         size_t size;
  39 };
  40
  41 /**
  42  * struct keystone_rproc - keystone remote processor driver structure
  43  * @dev: cached device pointer
  44  * @rproc: remoteproc device handle
  45  * @mem: internal memory regions data
  46  * @num_mems: number of internal memory regions
  47  * @dev_ctrl: device control regmap handle
  48  * @reset: reset control handle
  49  * @boot_offset: boot register offset in @dev_ctrl regmap
  50  * @irq_ring: irq entry for vring
  51  * @irq_fault: irq entry for exception
  52  * @kick_gpio: gpio used for virtio kicks
  53  * @workqueue: workqueue for processing virtio interrupts
  54  */
  55 struct keystone_rproc {
  56         struct device *dev;
  57         struct rproc *rproc;
  58         struct keystone_rproc_mem *mem;
  59         int num_mems;
  60         struct regmap *dev_ctrl;
  61         struct reset_control *reset;
  62         struct gpio_desc *kick_gpio;
  63         u32 boot_offset;
  64         int irq_ring;
  65         int irq_fault;
  66         struct work_struct workqueue;
  67 };
  68
  69 /* Put the DSP processor into reset */
  70 static void keystone_rproc_dsp_reset(struct keystone_rproc *ksproc)
  71 {
  72         reset_control_assert(ksproc->reset);
  73 }
  74
  75 /* Configure the boot address and boot the DSP processor */
  76 static int keystone_rproc_dsp_boot(struct keystone_rproc *ksproc, u32 boot_addr)
  77 {
  78         int ret;
  79
  80         if (boot_addr & (SZ_1K - 1)) {
  81                 dev_err(ksproc->dev, "invalid boot address 0x%x, must be aligned on a 1KB boundary\n",
  82                         boot_addr);
  83                 return -EINVAL;
  84         }
  85
  86         ret = regmap_write(ksproc->dev_ctrl, ksproc->boot_offset, boot_addr);
  87         if (ret) {
  88                 dev_err(ksproc->dev, "regmap_write of boot address failed, status = %d\n",
  89                         ret);
  90                 return ret;
  91         }
  92
  93         reset_control_deassert(ksproc->reset);
  94
  95         return 0;
  96 }
  97
  98 /*
  99  * Process the remoteproc exceptions
 100  *
 101  * The exception reporting on Keystone DSP remote processors is very simple
 102  * compared to the equivalent processors on the OMAP family, it is notified
 103  * through a software-designed specific interrupt source in the IPC interrupt
 104  * generation register.
 105  *
 106  * This function just invokes the rproc_report_crash to report the exception
 107  * to the remoteproc driver core, to trigger a recovery.
 108  */
 109 static irqreturn_t keystone_rproc_exception_interrupt(int irq, void *dev_id)
 110 {
 111         struct keystone_rproc *ksproc = dev_id;
 112
 113         rproc_report_crash(ksproc->rproc, RPROC_FATAL_ERROR);
 114
 115         return IRQ_HANDLED;
 116 }
 117
 118 /*
 119  * Main virtqueue message workqueue function
 120  *
 121  * This function is executed upon scheduling of the keystone remoteproc
 122  * driver's workqueue. The workqueue is scheduled by the vring ISR handler.
 123  *
 124  * There is no payload message indicating the virtqueue index as is the
 125  * case with mailbox-based implementations on OMAP family. As such, this
 126  * handler processes both the Tx and Rx virtqueue indices on every invocation.
 127  * The rproc_vq_interrupt function can detect if there are new unprocessed
 128  * messages or not (returns IRQ_NONE vs IRQ_HANDLED), but there is no need
 129  * to check for these return values. The index 0 triggering will process all
 130  * pending Rx buffers, and the index 1 triggering will process all newly
 131  * available Tx buffers and will wakeup any potentially blocked senders.
 132  *
 133  * NOTE:
 134  * 1. A payload could be added by using some of the source bits in the
 135  *    IPC interrupt generation registers, but this would need additional
 136  *    changes to the overall IPC stack, and currently there are no benefits
 137  *    of adapting that approach.
 138  * 2. The current logic is based on an inherent design assumption of supporting
 139  *    only 2 vrings, but this can be changed if needed.
 140  */
 141 static void handle_event(struct work_struct *work)
 142 {
 143         struct keystone_rproc *ksproc =
 144                 container_of(work, struct keystone_rproc, workqueue);
 145
 146         rproc_vq_interrupt(ksproc->rproc, 0);
 147         rproc_vq_interrupt(ksproc->rproc, 1);
 148 }
 149
 150 /*
 151  * Interrupt handler for processing vring kicks from remote processor
 152  */
 153 static irqreturn_t keystone_rproc_vring_interrupt(int irq, void *dev_id)
 154 {
 155         struct keystone_rproc *ksproc = dev_id;
 156
 157         schedule_work(&ksproc->workqueue);
 158
 159         return IRQ_HANDLED;
 160 }
 161
 162 /*
 163  * Power up the DSP remote processor.
 164  *
 165  * This function will be invoked only after the firmware for this rproc
 166  * was loaded, parsed successfully, and all of its resource requirements
 167  * were met.
 168  */
 169 static int keystone_rproc_start(struct rproc *rproc)
 170 {
 171         struct keystone_rproc *ksproc = rproc->priv;
 172         int ret;
 173
 174         INIT_WORK(&ksproc->workqueue, handle_event);
 175
 176         ret = request_irq(ksproc->irq_ring, keystone_rproc_vring_interrupt, 0,
 177                           dev_name(ksproc->dev), ksproc);
 178         if (ret) {
 179                 dev_err(ksproc->dev, "failed to enable vring interrupt, ret = %d\n",
 180                         ret);
 181                 goto out;
 182         }
 183
 184         ret = request_irq(ksproc->irq_fault, keystone_rproc_exception_interrupt,
 185                           0, dev_name(ksproc->dev), ksproc);
 186         if (ret) {
 187                 dev_err(ksproc->dev, "failed to enable exception interrupt, ret = %d\n",
 188                         ret);
 189                 goto free_vring_irq;
 190         }
 191
 192         ret = keystone_rproc_dsp_boot(ksproc, rproc->bootaddr);
 193         if (ret)
 194                 goto free_exc_irq;
 195
 196         return 0;
 197
 198 free_exc_irq:
 199         free_irq(ksproc->irq_fault, ksproc);
 200 free_vring_irq:
 201         free_irq(ksproc->irq_ring, ksproc);
 202         flush_work(&ksproc->workqueue);
 203 out:
 204         return ret;
 205 }
 206
 207 /*
 208  * Stop the DSP remote processor.
 209  *
 210  * This function puts the DSP processor into reset, and finishes processing
 211  * of any pending messages.
 212  */
 213 static int keystone_rproc_stop(struct rproc *rproc)
 214 {
 215         struct keystone_rproc *ksproc = rproc->priv;
 216
 217         keystone_rproc_dsp_reset(ksproc);
 218         free_irq(ksproc->irq_fault, ksproc);
 219         free_irq(ksproc->irq_ring, ksproc);
 220         flush_work(&ksproc->workqueue);
 221
 222         return 0;
 223 }
 224
 225 /*
 226  * Kick the remote processor to notify about pending unprocessed messages.
 227  * The vqid usage is not used and is inconsequential, as the kick is performed
 228  * through a simulated GPIO (a bit in an IPC interrupt-triggering register),
 229  * the remote processor is expected to process both its Tx and Rx virtqueues.
 230  */
 231 static void keystone_rproc_kick(struct rproc *rproc, int vqid)
 232 {
 233         struct keystone_rproc *ksproc = rproc->priv;
 234
 235         if (!ksproc->kick_gpio)
 236                 return;
 237
 238         gpiod_set_value(ksproc->kick_gpio, 1);
 239 }
 240
 241 /*
 242  * Custom function to translate a DSP device address (internal RAMs only) to a
 243  * kernel virtual address.  The DSPs can access their RAMs at either an internal
 244  * address visible only from a DSP, or at the SoC-level bus address. Both these
 245  * addresses need to be looked through for translation. The translated addresses
 246  * can be used either by the remoteproc core for loading (when using kernel
 247  * remoteproc loader), or by any rpmsg bus drivers.
 248  */
 249 static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
 250 {
 251         struct keystone_rproc *ksproc = rproc->priv;
 252         void __iomem *va = NULL;
 253         phys_addr_t bus_addr;
 254         u32 dev_addr, offset;
 255         size_t size;
 256         int i;
 257
 258         if (len == 0)
 259                 return NULL;
 260
 261         for (i = 0; i < ksproc->num_mems; i++) {
 262                 bus_addr = ksproc->mem[i].bus_addr;
 263                 dev_addr = ksproc->mem[i].dev_addr;
 264                 size = ksproc->mem[i].size;
 265
 266                 if (da < KEYSTONE_RPROC_LOCAL_ADDRESS_MASK) {
 267                         /* handle DSP-view addresses */
 268                         if ((da >= dev_addr) &&
 269                             ((da + len) <= (dev_addr + size))) {
 270                                 offset = da - dev_addr;
 271                                 va = ksproc->mem[i].cpu_addr + offset;
 272                                 break;
 273                         }
 274                 } else {
 275                         /* handle SoC-view addresses */
 276                         if ((da >= bus_addr) &&
 277                             (da + len) <= (bus_addr + size)) {
 278                                 offset = da - bus_addr;
 279                                 va = ksproc->mem[i].cpu_addr + offset;
 280                                 break;
 281                         }
 282                 }
 283         }
 284
 285         return (__force void *)va;
 286 }
 287
 288 static const struct rproc_ops keystone_rproc_ops = {
 289         .start          = keystone_rproc_start,
 290         .stop           = keystone_rproc_stop,
 291         .kick           = keystone_rproc_kick,
 292         .da_to_va       = keystone_rproc_da_to_va,
 293 };
 294
 295 static int keystone_rproc_of_get_memories(struct platform_device *pdev,
 296                                           struct keystone_rproc *ksproc)
 297 {
 298         static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
 299         struct device *dev = &pdev->dev;
 300         struct resource *res;
 301         int num_mems = 0;
 302         int i;
 303
 304         num_mems = ARRAY_SIZE(mem_names);
 305         ksproc->mem = devm_kcalloc(ksproc->dev, num_mems,
 306                                    sizeof(*ksproc->mem), GFP_KERNEL);
 307         if (!ksproc->mem)
 308                 return -ENOMEM;
 309
 310         for (i = 0; i < num_mems; i++) {
 311                 res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 312                                                    mem_names[i]);
 313                 ksproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
 314                 if (IS_ERR(ksproc->mem[i].cpu_addr)) {
 315                         dev_err(dev, "failed to parse and map %s memory\n",
 316                                 mem_names[i]);
 317                         return PTR_ERR(ksproc->mem[i].cpu_addr);
 318                 }
 319                 ksproc->mem[i].bus_addr = res->start;
 320                 ksproc->mem[i].dev_addr =
 321                                 res->start & KEYSTONE_RPROC_LOCAL_ADDRESS_MASK;
 322                 ksproc->mem[i].size = resource_size(res);
 323
 324                 /* zero out memories to start in a pristine state */
 325                 memset((__force void *)ksproc->mem[i].cpu_addr, 0,
 326                        ksproc->mem[i].size);
 327         }
 328         ksproc->num_mems = num_mems;
 329
 330         return 0;
 331 }
 332
 333 static int keystone_rproc_of_get_dev_syscon(struct platform_device *pdev,
 334                                             struct keystone_rproc *ksproc)
 335 {
 336         struct device_node *np = pdev->dev.of_node;
 337         struct device *dev = &pdev->dev;
 338         int ret;
 339
 340         if (!of_property_read_bool(np, "ti,syscon-dev")) {
 341                 dev_err(dev, "ti,syscon-dev property is absent\n");
 342                 return -EINVAL;
 343         }
 344
 345         ksproc->dev_ctrl =
 346                 syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
 347         if (IS_ERR(ksproc->dev_ctrl)) {
 348                 ret = PTR_ERR(ksproc->dev_ctrl);
 349                 return ret;
 350         }
 351
 352         if (of_property_read_u32_index(np, "ti,syscon-dev", 1,
 353                                        &ksproc->boot_offset)) {
 354                 dev_err(dev, "couldn't read the boot register offset\n");
 355                 return -EINVAL;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int keystone_rproc_probe(struct platform_device *pdev)
 362 {
 363         struct device *dev = &pdev->dev;
 364         struct device_node *np = dev->of_node;
 365         struct keystone_rproc *ksproc;
 366         struct rproc *rproc;
 367         int dsp_id;
 368         char *fw_name = NULL;
 369         int ret = 0;
 370
 371         if (!np) {
 372                 dev_err(dev, "only DT-based devices are supported\n");
 373                 return -ENODEV;
 374         }
 375
 376         dsp_id = of_alias_get_id(np, "rproc");
 377         if (dsp_id < 0) {
 378                 dev_warn(dev, "device does not have an alias id\n");
 379                 return dsp_id;
 380         }
 381
 382         /* construct a custom default fw name - subject to change in future */
 383         fw_name = devm_kasprintf(dev, GFP_KERNEL, "keystone-dsp%d-fw", dsp_id);
 384         if (!fw_name)
 385                 return -ENOMEM;
 386
 387         rproc = devm_rproc_alloc(dev, dev_name(dev), &keystone_rproc_ops,
 388                                  fw_name, sizeof(*ksproc));
 389         if (!rproc)
 390                 return -ENOMEM;
 391
 392         rproc->has_iommu = false;
 393         ksproc = rproc->priv;
 394         ksproc->rproc = rproc;
 395         ksproc->dev = dev;
 396
 397         ret = keystone_rproc_of_get_dev_syscon(pdev, ksproc);
 398         if (ret)
 399                 return ret;
 400
 401         ksproc->reset = devm_reset_control_get_exclusive(dev, NULL);
 402         if (IS_ERR(ksproc->reset))
 403                 return PTR_ERR(ksproc->reset);
 404
 405         /* enable clock for accessing DSP internal memories */
 406         pm_runtime_enable(dev);
 407         ret = pm_runtime_resume_and_get(dev);
 408         if (ret < 0) {
 409                 dev_err(dev, "failed to enable clock, status = %d\n", ret);
 410                 goto disable_rpm;
 411         }
 412
 413         ret = keystone_rproc_of_get_memories(pdev, ksproc);
 414         if (ret)
 415                 goto disable_clk;
 416
 417         ksproc->irq_ring = platform_get_irq_byname(pdev, "vring");
 418         if (ksproc->irq_ring < 0) {
 419                 ret = ksproc->irq_ring;
 420                 goto disable_clk;
 421         }
 422
 423         ksproc->irq_fault = platform_get_irq_byname(pdev, "exception");
 424         if (ksproc->irq_fault < 0) {
 425                 ret = ksproc->irq_fault;
 426                 goto disable_clk;
 427         }
 428
 429         ksproc->kick_gpio = gpiod_get(dev, "kick", GPIOD_ASIS);
 430         ret = PTR_ERR_OR_ZERO(ksproc->kick_gpio);
 431         if (ret) {
 432                 dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
 433                         ret);
 434                 goto disable_clk;
 435         }
 436
 437         if (of_reserved_mem_device_init(dev))
 438                 dev_warn(dev, "device does not have specific CMA pool\n");
 439
 440         /* ensure the DSP is in reset before loading firmware */
 441         ret = reset_control_status(ksproc->reset);
 442         if (ret < 0) {
 443                 dev_err(dev, "failed to get reset status, status = %d\n", ret);
 444                 goto release_mem;
 445         } else if (ret == 0) {
 446                 WARN(1, "device is not in reset\n");
 447                 keystone_rproc_dsp_reset(ksproc);
 448         }
 449
 450         ret = rproc_add(rproc);
 451         if (ret) {
 452                 dev_err(dev, "failed to add register device with remoteproc core, status = %d\n",
 453                         ret);
 454                 goto release_mem;
 455         }
 456
 457         platform_set_drvdata(pdev, ksproc);
 458
 459         return 0;
 460
 461 release_mem:
 462         of_reserved_mem_device_release(dev);
 463         gpiod_put(ksproc->kick_gpio);
 464 disable_clk:
 465         pm_runtime_put_sync(dev);
 466 disable_rpm:
 467         pm_runtime_disable(dev);
 468         return ret;
 469 }
 470
 471 static void keystone_rproc_remove(struct platform_device *pdev)
 472 {
 473         struct keystone_rproc *ksproc = platform_get_drvdata(pdev);
 474
 475         rproc_del(ksproc->rproc);
 476         gpiod_put(ksproc->kick_gpio);
 477         pm_runtime_put_sync(&pdev->dev);
 478         pm_runtime_disable(&pdev->dev);
 479         of_reserved_mem_device_release(&pdev->dev);
 480 }
 481
 482 static const struct of_device_id keystone_rproc_of_match[] = {
 483         { .compatible = "ti,k2hk-dsp", },
 484         { .compatible = "ti,k2l-dsp", },
 485         { .compatible = "ti,k2e-dsp", },
 486         { .compatible = "ti,k2g-dsp", },
 487         { /* sentinel */ },
 488 };
 489 MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);
 490
 491 static struct platform_driver keystone_rproc_driver = {
 492         .probe  = keystone_rproc_probe,
 493         .remove = keystone_rproc_remove,
 494         .driver = {
 495                 .name = "keystone-rproc",
 496                 .of_match_table = keystone_rproc_of_match,
 497         },
 498 };
 499
 500 module_platform_driver(keystone_rproc_driver);
 501
 502 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
 503 MODULE_LICENSE("GPL v2");
 504 MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");