drivers/cpufreq/brcmstb-avs-cpufreq.c

   1 /*
   2  * CPU frequency scaling for Broadcom SoCs with AVS firmware that
   3  * supports DVS or DVFS
   4  *
   5  * Copyright (c) 2016 Broadcom
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation version 2.
  10  *
  11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  12  * kind, whether express or implied; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 /*
  18  * "AVS" is the name of a firmware developed at Broadcom. It derives
  19  * its name from the technique called "Adaptive Voltage Scaling".
  20  * Adaptive voltage scaling was the original purpose of this firmware.
  21  * The AVS firmware still supports "AVS mode", where all it does is
  22  * adaptive voltage scaling. However, on some newer Broadcom SoCs, the
  23  * AVS Firmware, despite its unchanged name, also supports DFS mode and
  24  * DVFS mode.
  25  *
  26  * In the context of this document and the related driver, "AVS" by
  27  * itself always means the Broadcom firmware and never refers to the
  28  * technique called "Adaptive Voltage Scaling".
  29  *
  30  * The Broadcom STB AVS CPUfreq driver provides voltage and frequency
  31  * scaling on Broadcom SoCs using AVS firmware with support for DFS and
  32  * DVFS. The AVS firmware is running on its own co-processor. The
  33  * driver supports both uniprocessor (UP) and symmetric multiprocessor
  34  * (SMP) systems which share clock and voltage across all CPUs.
  35  *
  36  * Actual voltage and frequency scaling is done solely by the AVS
  37  * firmware. This driver does not change frequency or voltage itself.
  38  * It provides a standard CPUfreq interface to the rest of the kernel
  39  * and to userland. It interfaces with the AVS firmware to effect the
  40  * requested changes and to report back the current system status in a
  41  * way that is expected by existing tools.
  42  */
  43
  44 #include <linux/cpufreq.h>
  45 #include <linux/interrupt.h>
  46 #include <linux/io.h>
  47 #include <linux/module.h>
  48 #include <linux/of_address.h>
  49 #include <linux/platform_device.h>
  50 #include <linux/semaphore.h>
  51
  52 /* Max number of arguments AVS calls take */
  53 #define AVS_MAX_CMD_ARGS        4
  54 /*
  55  * This macro is used to generate AVS parameter register offsets. For
  56  * x >= AVS_MAX_CMD_ARGS, it returns 0 to protect against accidental memory
  57  * access outside of the parameter range. (Offset 0 is the first parameter.)
  58  */
  59 #define AVS_PARAM_MULT(x)       ((x) < AVS_MAX_CMD_ARGS ? (x) : 0)
  60
  61 /* AVS Mailbox Register offsets */
  62 #define AVS_MBOX_COMMAND        0x00
  63 #define AVS_MBOX_STATUS         0x04
  64 #define AVS_MBOX_VOLTAGE0       0x08
  65 #define AVS_MBOX_TEMP0          0x0c
  66 #define AVS_MBOX_PV0            0x10
  67 #define AVS_MBOX_MV0            0x14
  68 #define AVS_MBOX_PARAM(x)       (0x18 + AVS_PARAM_MULT(x) * sizeof(u32))
  69 #define AVS_MBOX_REVISION       0x28
  70 #define AVS_MBOX_PSTATE         0x2c
  71 #define AVS_MBOX_HEARTBEAT      0x30
  72 #define AVS_MBOX_MAGIC          0x34
  73 #define AVS_MBOX_SIGMA_HVT      0x38
  74 #define AVS_MBOX_SIGMA_SVT      0x3c
  75 #define AVS_MBOX_VOLTAGE1       0x40
  76 #define AVS_MBOX_TEMP1          0x44
  77 #define AVS_MBOX_PV1            0x48
  78 #define AVS_MBOX_MV1            0x4c
  79 #define AVS_MBOX_FREQUENCY      0x50
  80
  81 /* AVS Commands */
  82 #define AVS_CMD_AVAILABLE       0x00
  83 #define AVS_CMD_DISABLE         0x10
  84 #define AVS_CMD_ENABLE          0x11
  85 #define AVS_CMD_S2_ENTER        0x12
  86 #define AVS_CMD_S2_EXIT         0x13
  87 #define AVS_CMD_BBM_ENTER       0x14
  88 #define AVS_CMD_BBM_EXIT        0x15
  89 #define AVS_CMD_S3_ENTER        0x16
  90 #define AVS_CMD_S3_EXIT         0x17
  91 #define AVS_CMD_BALANCE         0x18
  92 /* PMAP and P-STATE commands */
  93 #define AVS_CMD_GET_PMAP        0x30
  94 #define AVS_CMD_SET_PMAP        0x31
  95 #define AVS_CMD_GET_PSTATE      0x40
  96 #define AVS_CMD_SET_PSTATE      0x41
  97
  98 /* Different modes AVS supports (for GET_PMAP/SET_PMAP) */
  99 #define AVS_MODE_AVS            0x0
 100 #define AVS_MODE_DFS            0x1
 101 #define AVS_MODE_DVS            0x2
 102 #define AVS_MODE_DVFS           0x3
 103
 104 /*
 105  * PMAP parameter p1
 106  * unused:31-24, mdiv_p0:23-16, unused:15-14, pdiv:13-10 , ndiv_int:9-0
 107  */
 108 #define NDIV_INT_SHIFT          0
 109 #define NDIV_INT_MASK           0x3ff
 110 #define PDIV_SHIFT              10
 111 #define PDIV_MASK               0xf
 112 #define MDIV_P0_SHIFT           16
 113 #define MDIV_P0_MASK            0xff
 114 /*
 115  * PMAP parameter p2
 116  * mdiv_p4:31-24, mdiv_p3:23-16, mdiv_p2:15:8, mdiv_p1:7:0
 117  */
 118 #define MDIV_P1_SHIFT           0
 119 #define MDIV_P1_MASK            0xff
 120 #define MDIV_P2_SHIFT           8
 121 #define MDIV_P2_MASK            0xff
 122 #define MDIV_P3_SHIFT           16
 123 #define MDIV_P3_MASK            0xff
 124 #define MDIV_P4_SHIFT           24
 125 #define MDIV_P4_MASK            0xff
 126
 127 /* Different P-STATES AVS supports (for GET_PSTATE/SET_PSTATE) */
 128 #define AVS_PSTATE_P0           0x0
 129 #define AVS_PSTATE_P1           0x1
 130 #define AVS_PSTATE_P2           0x2
 131 #define AVS_PSTATE_P3           0x3
 132 #define AVS_PSTATE_P4           0x4
 133 #define AVS_PSTATE_MAX          AVS_PSTATE_P4
 134
 135 /* CPU L2 Interrupt Controller Registers */
 136 #define AVS_CPU_L2_SET0         0x04
 137 #define AVS_CPU_L2_INT_MASK     BIT(31)
 138
 139 /* AVS Command Status Values */
 140 #define AVS_STATUS_CLEAR        0x00
 141 /* Command/notification accepted */
 142 #define AVS_STATUS_SUCCESS      0xf0
 143 /* Command/notification rejected */
 144 #define AVS_STATUS_FAILURE      0xff
 145 /* Invalid command/notification (unknown) */
 146 #define AVS_STATUS_INVALID      0xf1
 147 /* Non-AVS modes are not supported */
 148 #define AVS_STATUS_NO_SUPP      0xf2
 149 /* Cannot set P-State until P-Map supplied */
 150 #define AVS_STATUS_NO_MAP       0xf3
 151 /* Cannot change P-Map after initial P-Map set */
 152 #define AVS_STATUS_MAP_SET      0xf4
 153 /* Max AVS status; higher numbers are used for debugging */
 154 #define AVS_STATUS_MAX          0xff
 155
 156 /* Other AVS related constants */
 157 #define AVS_LOOP_LIMIT          10000
 158 #define AVS_TIMEOUT             300 /* in ms; expected completion is < 10ms */
 159 #define AVS_FIRMWARE_MAGIC      0xa11600d1
 160
 161 #define BRCM_AVS_CPUFREQ_PREFIX "brcmstb-avs"
 162 #define BRCM_AVS_CPUFREQ_NAME   BRCM_AVS_CPUFREQ_PREFIX "-cpufreq"
 163 #define BRCM_AVS_CPU_DATA       "brcm,avs-cpu-data-mem"
 164 #define BRCM_AVS_CPU_INTR       "brcm,avs-cpu-l2-intr"
 165 #define BRCM_AVS_HOST_INTR      "sw_intr"
 166
 167 struct pmap {
 168         unsigned int mode;
 169         unsigned int p1;
 170         unsigned int p2;
 171         unsigned int state;
 172 };
 173
 174 struct private_data {
 175         void __iomem *base;
 176         void __iomem *avs_intr_base;
 177         struct device *dev;
 178         struct completion done;
 179         struct semaphore sem;
 180         struct pmap pmap;
 181 };
 182
 183 static void __iomem *__map_region(const char *name)
 184 {
 185         struct device_node *np;
 186         void __iomem *ptr;
 187
 188         np = of_find_compatible_node(NULL, NULL, name);
 189         if (!np)
 190                 return NULL;
 191
 192         ptr = of_iomap(np, 0);
 193         of_node_put(np);
 194
 195         return ptr;
 196 }
 197
 198 static int __issue_avs_command(struct private_data *priv, int cmd, bool is_send,
 199                                u32 args[])
 200 {
 201         unsigned long time_left = msecs_to_jiffies(AVS_TIMEOUT);
 202         void __iomem *base = priv->base;
 203         unsigned int i;
 204         int ret;
 205         u32 val;
 206
 207         ret = down_interruptible(&priv->sem);
 208         if (ret)
 209                 return ret;
 210
 211         /*
 212          * Make sure no other command is currently running: cmd is 0 if AVS
 213          * co-processor is idle. Due to the guard above, we should almost never
 214          * have to wait here.
 215          */
 216         for (i = 0, val = 1; val != 0 && i < AVS_LOOP_LIMIT; i++)
 217                 val = readl(base + AVS_MBOX_COMMAND);
 218
 219         /* Give the caller a chance to retry if AVS is busy. */
 220         if (i == AVS_LOOP_LIMIT) {
 221                 ret = -EAGAIN;
 222                 goto out;
 223         }
 224
 225         /* Clear status before we begin. */
 226         writel(AVS_STATUS_CLEAR, base + AVS_MBOX_STATUS);
 227
 228         /* We need to send arguments for this command. */
 229         if (args && is_send) {
 230                 for (i = 0; i < AVS_MAX_CMD_ARGS; i++)
 231                         writel(args[i], base + AVS_MBOX_PARAM(i));
 232         }
 233
 234         /* Protect from spurious interrupts. */
 235         reinit_completion(&priv->done);
 236
 237         /* Now issue the command & tell firmware to wake up to process it. */
 238         writel(cmd, base + AVS_MBOX_COMMAND);
 239         writel(AVS_CPU_L2_INT_MASK, priv->avs_intr_base + AVS_CPU_L2_SET0);
 240
 241         /* Wait for AVS co-processor to finish processing the command. */
 242         time_left = wait_for_completion_timeout(&priv->done, time_left);
 243
 244         /*
 245          * If the AVS status is not in the expected range, it means AVS didn't
 246          * complete our command in time, and we return an error. Also, if there
 247          * is no "time left", we timed out waiting for the interrupt.
 248          */
 249         val = readl(base + AVS_MBOX_STATUS);
 250         if (time_left == 0 || val == 0 || val > AVS_STATUS_MAX) {
 251                 dev_err(priv->dev, "AVS command %#x didn't complete in time\n",
 252                         cmd);
 253                 dev_err(priv->dev, "    Time left: %u ms, AVS status: %#x\n",
 254                         jiffies_to_msecs(time_left), val);
 255                 ret = -ETIMEDOUT;
 256                 goto out;
 257         }
 258
 259         /* This command returned arguments, so we read them back. */
 260         if (args && !is_send) {
 261                 for (i = 0; i < AVS_MAX_CMD_ARGS; i++)
 262                         args[i] = readl(base + AVS_MBOX_PARAM(i));
 263         }
 264
 265         /* Clear status to tell AVS co-processor we are done. */
 266         writel(AVS_STATUS_CLEAR, base + AVS_MBOX_STATUS);
 267
 268         /* Convert firmware errors to errno's as much as possible. */
 269         switch (val) {
 270         case AVS_STATUS_INVALID:
 271                 ret = -EINVAL;
 272                 break;
 273         case AVS_STATUS_NO_SUPP:
 274                 ret = -ENOTSUPP;
 275                 break;
 276         case AVS_STATUS_NO_MAP:
 277                 ret = -ENOENT;
 278                 break;
 279         case AVS_STATUS_MAP_SET:
 280                 ret = -EEXIST;
 281                 break;
 282         case AVS_STATUS_FAILURE:
 283                 ret = -EIO;
 284                 break;
 285         }
 286
 287 out:
 288         up(&priv->sem);
 289
 290         return ret;
 291 }
 292
 293 static irqreturn_t irq_handler(int irq, void *data)
 294 {
 295         struct private_data *priv = data;
 296
 297         /* AVS command completed execution. Wake up __issue_avs_command(). */
 298         complete(&priv->done);
 299
 300         return IRQ_HANDLED;
 301 }
 302
 303 static char *brcm_avs_mode_to_string(unsigned int mode)
 304 {
 305         switch (mode) {
 306         case AVS_MODE_AVS:
 307                 return "AVS";
 308         case AVS_MODE_DFS:
 309                 return "DFS";
 310         case AVS_MODE_DVS:
 311                 return "DVS";
 312         case AVS_MODE_DVFS:
 313                 return "DVFS";
 314         }
 315         return NULL;
 316 }
 317
 318 static void brcm_avs_parse_p1(u32 p1, unsigned int *mdiv_p0, unsigned int *pdiv,
 319                               unsigned int *ndiv)
 320 {
 321         *mdiv_p0 = (p1 >> MDIV_P0_SHIFT) & MDIV_P0_MASK;
 322         *pdiv = (p1 >> PDIV_SHIFT) & PDIV_MASK;
 323         *ndiv = (p1 >> NDIV_INT_SHIFT) & NDIV_INT_MASK;
 324 }
 325
 326 static void brcm_avs_parse_p2(u32 p2, unsigned int *mdiv_p1,
 327                               unsigned int *mdiv_p2, unsigned int *mdiv_p3,
 328                               unsigned int *mdiv_p4)
 329 {
 330         *mdiv_p4 = (p2 >> MDIV_P4_SHIFT) & MDIV_P4_MASK;
 331         *mdiv_p3 = (p2 >> MDIV_P3_SHIFT) & MDIV_P3_MASK;
 332         *mdiv_p2 = (p2 >> MDIV_P2_SHIFT) & MDIV_P2_MASK;
 333         *mdiv_p1 = (p2 >> MDIV_P1_SHIFT) & MDIV_P1_MASK;
 334 }
 335
 336 static int brcm_avs_get_pmap(struct private_data *priv, struct pmap *pmap)
 337 {
 338         u32 args[AVS_MAX_CMD_ARGS];
 339         int ret;
 340
 341         ret = __issue_avs_command(priv, AVS_CMD_GET_PMAP, false, args);
 342         if (ret || !pmap)
 343                 return ret;
 344
 345         pmap->mode = args[0];
 346         pmap->p1 = args[1];
 347         pmap->p2 = args[2];
 348         pmap->state = args[3];
 349
 350         return 0;
 351 }
 352
 353 static int brcm_avs_set_pmap(struct private_data *priv, struct pmap *pmap)
 354 {
 355         u32 args[AVS_MAX_CMD_ARGS];
 356
 357         args[0] = pmap->mode;
 358         args[1] = pmap->p1;
 359         args[2] = pmap->p2;
 360         args[3] = pmap->state;
 361
 362         return __issue_avs_command(priv, AVS_CMD_SET_PMAP, true, args);
 363 }
 364
 365 static int brcm_avs_get_pstate(struct private_data *priv, unsigned int *pstate)
 366 {
 367         u32 args[AVS_MAX_CMD_ARGS];
 368         int ret;
 369
 370         ret = __issue_avs_command(priv, AVS_CMD_GET_PSTATE, false, args);
 371         if (ret)
 372                 return ret;
 373         *pstate = args[0];
 374
 375         return 0;
 376 }
 377
 378 static int brcm_avs_set_pstate(struct private_data *priv, unsigned int pstate)
 379 {
 380         u32 args[AVS_MAX_CMD_ARGS];
 381
 382         args[0] = pstate;
 383
 384         return __issue_avs_command(priv, AVS_CMD_SET_PSTATE, true, args);
 385 }
 386
 387 static u32 brcm_avs_get_voltage(void __iomem *base)
 388 {
 389         return readl(base + AVS_MBOX_VOLTAGE1);
 390 }
 391
 392 static u32 brcm_avs_get_frequency(void __iomem *base)
 393 {
 394         return readl(base + AVS_MBOX_FREQUENCY) * 1000; /* in kHz */
 395 }
 396
 397 /*
 398  * We determine which frequencies are supported by cycling through all P-states
 399  * and reading back what frequency we are running at for each P-state.
 400  */
 401 static struct cpufreq_frequency_table *
 402 brcm_avs_get_freq_table(struct device *dev, struct private_data *priv)
 403 {
 404         struct cpufreq_frequency_table *table;
 405         unsigned int pstate;
 406         int i, ret;
 407
 408         /* Remember P-state for later */
 409         ret = brcm_avs_get_pstate(priv, &pstate);
 410         if (ret)
 411                 return ERR_PTR(ret);
 412
 413         table = devm_kcalloc(dev, AVS_PSTATE_MAX + 1, sizeof(*table),
 414                              GFP_KERNEL);
 415         if (!table)
 416                 return ERR_PTR(-ENOMEM);
 417
 418         for (i = AVS_PSTATE_P0; i <= AVS_PSTATE_MAX; i++) {
 419                 ret = brcm_avs_set_pstate(priv, i);
 420                 if (ret)
 421                         return ERR_PTR(ret);
 422                 table[i].frequency = brcm_avs_get_frequency(priv->base);
 423                 table[i].driver_data = i;
 424         }
 425         table[i].frequency = CPUFREQ_TABLE_END;
 426
 427         /* Restore P-state */
 428         ret = brcm_avs_set_pstate(priv, pstate);
 429         if (ret)
 430                 return ERR_PTR(ret);
 431
 432         return table;
 433 }
 434
 435 /*
 436  * To ensure the right firmware is running we need to
 437  *    - check the MAGIC matches what we expect
 438  *    - brcm_avs_get_pmap() doesn't return -ENOTSUPP or -EINVAL
 439  * We need to set up our interrupt handling before calling brcm_avs_get_pmap()!
 440  */
 441 static bool brcm_avs_is_firmware_loaded(struct private_data *priv)
 442 {
 443         u32 magic;
 444         int rc;
 445
 446         rc = brcm_avs_get_pmap(priv, NULL);
 447         magic = readl(priv->base + AVS_MBOX_MAGIC);
 448
 449         return (magic == AVS_FIRMWARE_MAGIC) && ((rc != -ENOTSUPP) ||
 450                 (rc != -EINVAL));
 451 }
 452
 453 static unsigned int brcm_avs_cpufreq_get(unsigned int cpu)
 454 {
 455         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 456         struct private_data *priv = policy->driver_data;
 457
 458         cpufreq_cpu_put(policy);
 459
 460         return brcm_avs_get_frequency(priv->base);
 461 }
 462
 463 static int brcm_avs_target_index(struct cpufreq_policy *policy,
 464                                  unsigned int index)
 465 {
 466         return brcm_avs_set_pstate(policy->driver_data,
 467                                   policy->freq_table[index].driver_data);
 468 }
 469
 470 static int brcm_avs_suspend(struct cpufreq_policy *policy)
 471 {
 472         struct private_data *priv = policy->driver_data;
 473         int ret;
 474
 475         ret = brcm_avs_get_pmap(priv, &priv->pmap);
 476         if (ret)
 477                 return ret;
 478
 479         /*
 480          * We can't use the P-state returned by brcm_avs_get_pmap(), since
 481          * that's the initial P-state from when the P-map was downloaded to the
 482          * AVS co-processor, not necessarily the P-state we are running at now.
 483          * So, we get the current P-state explicitly.
 484          */
 485         return brcm_avs_get_pstate(priv, &priv->pmap.state);
 486 }
 487
 488 static int brcm_avs_resume(struct cpufreq_policy *policy)
 489 {
 490         struct private_data *priv = policy->driver_data;
 491         int ret;
 492
 493         ret = brcm_avs_set_pmap(priv, &priv->pmap);
 494         if (ret == -EEXIST) {
 495                 struct platform_device *pdev  = cpufreq_get_driver_data();
 496                 struct device *dev = &pdev->dev;
 497
 498                 dev_warn(dev, "PMAP was already set\n");
 499                 ret = 0;
 500         }
 501
 502         return ret;
 503 }
 504
 505 /*
 506  * All initialization code that we only want to execute once goes here. Setup
 507  * code that can be re-tried on every core (if it failed before) can go into
 508  * brcm_avs_cpufreq_init().
 509  */
 510 static int brcm_avs_prepare_init(struct platform_device *pdev)
 511 {
 512         struct private_data *priv;
 513         struct device *dev;
 514         int host_irq, ret;
 515
 516         dev = &pdev->dev;
 517         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 518         if (!priv)
 519                 return -ENOMEM;
 520
 521         priv->dev = dev;
 522         sema_init(&priv->sem, 1);
 523         init_completion(&priv->done);
 524         platform_set_drvdata(pdev, priv);
 525
 526         priv->base = __map_region(BRCM_AVS_CPU_DATA);
 527         if (!priv->base) {
 528                 dev_err(dev, "Couldn't find property %s in device tree.\n",
 529                         BRCM_AVS_CPU_DATA);
 530                 return -ENOENT;
 531         }
 532
 533         priv->avs_intr_base = __map_region(BRCM_AVS_CPU_INTR);
 534         if (!priv->avs_intr_base) {
 535                 dev_err(dev, "Couldn't find property %s in device tree.\n",
 536                         BRCM_AVS_CPU_INTR);
 537                 ret = -ENOENT;
 538                 goto unmap_base;
 539         }
 540
 541         host_irq = platform_get_irq_byname(pdev, BRCM_AVS_HOST_INTR);
 542         if (host_irq < 0) {
 543                 dev_err(dev, "Couldn't find interrupt %s -- %d\n",
 544                         BRCM_AVS_HOST_INTR, host_irq);
 545                 ret = host_irq;
 546                 goto unmap_intr_base;
 547         }
 548
 549         ret = devm_request_irq(dev, host_irq, irq_handler, IRQF_TRIGGER_RISING,
 550                                BRCM_AVS_HOST_INTR, priv);
 551         if (ret) {
 552                 dev_err(dev, "IRQ request failed: %s (%d) -- %d\n",
 553                         BRCM_AVS_HOST_INTR, host_irq, ret);
 554                 goto unmap_intr_base;
 555         }
 556
 557         if (brcm_avs_is_firmware_loaded(priv))
 558                 return 0;
 559
 560         dev_err(dev, "AVS firmware is not loaded or doesn't support DVFS\n");
 561         ret = -ENODEV;
 562
 563 unmap_intr_base:
 564         iounmap(priv->avs_intr_base);
 565 unmap_base:
 566         iounmap(priv->base);
 567
 568         return ret;
 569 }
 570
 571 static int brcm_avs_cpufreq_init(struct cpufreq_policy *policy)
 572 {
 573         struct cpufreq_frequency_table *freq_table;
 574         struct platform_device *pdev;
 575         struct private_data *priv;
 576         struct device *dev;
 577         int ret;
 578
 579         pdev = cpufreq_get_driver_data();
 580         priv = platform_get_drvdata(pdev);
 581         policy->driver_data = priv;
 582         dev = &pdev->dev;
 583
 584         freq_table = brcm_avs_get_freq_table(dev, priv);
 585         if (IS_ERR(freq_table)) {
 586                 ret = PTR_ERR(freq_table);
 587                 dev_err(dev, "Couldn't determine frequency table (%d).\n", ret);
 588                 return ret;
 589         }
 590
 591         policy->freq_table = freq_table;
 592
 593         /* All cores share the same clock and thus the same policy. */
 594         cpumask_setall(policy->cpus);
 595
 596         ret = __issue_avs_command(priv, AVS_CMD_ENABLE, false, NULL);
 597         if (!ret) {
 598                 unsigned int pstate;
 599
 600                 ret = brcm_avs_get_pstate(priv, &pstate);
 601                 if (!ret) {
 602                         policy->cur = freq_table[pstate].frequency;
 603                         dev_info(dev, "registered\n");
 604                         return 0;
 605                 }
 606         }
 607
 608         dev_err(dev, "couldn't initialize driver (%d)\n", ret);
 609
 610         return ret;
 611 }
 612
 613 static ssize_t show_brcm_avs_pstate(struct cpufreq_policy *policy, char *buf)
 614 {
 615         struct private_data *priv = policy->driver_data;
 616         unsigned int pstate;
 617
 618         if (brcm_avs_get_pstate(priv, &pstate))
 619                 return sprintf(buf, "<unknown>\n");
 620
 621         return sprintf(buf, "%u\n", pstate);
 622 }
 623
 624 static ssize_t show_brcm_avs_mode(struct cpufreq_policy *policy, char *buf)
 625 {
 626         struct private_data *priv = policy->driver_data;
 627         struct pmap pmap;
 628
 629         if (brcm_avs_get_pmap(priv, &pmap))
 630                 return sprintf(buf, "<unknown>\n");
 631
 632         return sprintf(buf, "%s %u\n", brcm_avs_mode_to_string(pmap.mode),
 633                 pmap.mode);
 634 }
 635
 636 static ssize_t show_brcm_avs_pmap(struct cpufreq_policy *policy, char *buf)
 637 {
 638         unsigned int mdiv_p0, mdiv_p1, mdiv_p2, mdiv_p3, mdiv_p4;
 639         struct private_data *priv = policy->driver_data;
 640         unsigned int ndiv, pdiv;
 641         struct pmap pmap;
 642
 643         if (brcm_avs_get_pmap(priv, &pmap))
 644                 return sprintf(buf, "<unknown>\n");
 645
 646         brcm_avs_parse_p1(pmap.p1, &mdiv_p0, &pdiv, &ndiv);
 647         brcm_avs_parse_p2(pmap.p2, &mdiv_p1, &mdiv_p2, &mdiv_p3, &mdiv_p4);
 648
 649         return sprintf(buf, "0x%08x 0x%08x %u %u %u %u %u %u %u %u %u\n",
 650                 pmap.p1, pmap.p2, ndiv, pdiv, mdiv_p0, mdiv_p1, mdiv_p2,
 651                 mdiv_p3, mdiv_p4, pmap.mode, pmap.state);
 652 }
 653
 654 static ssize_t show_brcm_avs_voltage(struct cpufreq_policy *policy, char *buf)
 655 {
 656         struct private_data *priv = policy->driver_data;
 657
 658         return sprintf(buf, "0x%08x\n", brcm_avs_get_voltage(priv->base));
 659 }
 660
 661 static ssize_t show_brcm_avs_frequency(struct cpufreq_policy *policy, char *buf)
 662 {
 663         struct private_data *priv = policy->driver_data;
 664
 665         return sprintf(buf, "0x%08x\n", brcm_avs_get_frequency(priv->base));
 666 }
 667
 668 cpufreq_freq_attr_ro(brcm_avs_pstate);
 669 cpufreq_freq_attr_ro(brcm_avs_mode);
 670 cpufreq_freq_attr_ro(brcm_avs_pmap);
 671 cpufreq_freq_attr_ro(brcm_avs_voltage);
 672 cpufreq_freq_attr_ro(brcm_avs_frequency);
 673
 674 static struct freq_attr *brcm_avs_cpufreq_attr[] = {
 675         &cpufreq_freq_attr_scaling_available_freqs,
 676         &brcm_avs_pstate,
 677         &brcm_avs_mode,
 678         &brcm_avs_pmap,
 679         &brcm_avs_voltage,
 680         &brcm_avs_frequency,
 681         NULL
 682 };
 683
 684 static struct cpufreq_driver brcm_avs_driver = {
 685         .flags          = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 686         .verify         = cpufreq_generic_frequency_table_verify,
 687         .target_index   = brcm_avs_target_index,
 688         .get            = brcm_avs_cpufreq_get,
 689         .suspend        = brcm_avs_suspend,
 690         .resume         = brcm_avs_resume,
 691         .init           = brcm_avs_cpufreq_init,
 692         .attr           = brcm_avs_cpufreq_attr,
 693         .name           = BRCM_AVS_CPUFREQ_PREFIX,
 694 };
 695
 696 static int brcm_avs_cpufreq_probe(struct platform_device *pdev)
 697 {
 698         int ret;
 699
 700         ret = brcm_avs_prepare_init(pdev);
 701         if (ret)
 702                 return ret;
 703
 704         brcm_avs_driver.driver_data = pdev;
 705
 706         return cpufreq_register_driver(&brcm_avs_driver);
 707 }
 708
 709 static int brcm_avs_cpufreq_remove(struct platform_device *pdev)
 710 {
 711         struct private_data *priv;
 712         int ret;
 713
 714         ret = cpufreq_unregister_driver(&brcm_avs_driver);
 715         if (ret)
 716                 return ret;
 717
 718         priv = platform_get_drvdata(pdev);
 719         iounmap(priv->base);
 720         iounmap(priv->avs_intr_base);
 721
 722         return 0;
 723 }
 724
 725 static const struct of_device_id brcm_avs_cpufreq_match[] = {
 726         { .compatible = BRCM_AVS_CPU_DATA },
 727         { }
 728 };
 729 MODULE_DEVICE_TABLE(of, brcm_avs_cpufreq_match);
 730
 731 static struct platform_driver brcm_avs_cpufreq_platdrv = {
 732         .driver = {
 733                 .name   = BRCM_AVS_CPUFREQ_NAME,
 734                 .of_match_table = brcm_avs_cpufreq_match,
 735         },
 736         .probe          = brcm_avs_cpufreq_probe,
 737         .remove         = brcm_avs_cpufreq_remove,
 738 };
 739 module_platform_driver(brcm_avs_cpufreq_platdrv);
 740
 741 MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
 742 MODULE_DESCRIPTION("CPUfreq driver for Broadcom STB AVS");
 743 MODULE_LICENSE("GPL");