git.librecmc.org Git - oweals/openwrt.git/blob

   1 From c3005e0dbe1f7f6d93833d5a43b12866873a312f Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Wed, 12 Dec 2018 15:51:48 -0800
   4 Subject: [PATCH 561/703] soc: bcm: bcm2835-pm: Add support for power domains
   5  under a new binding.
   6
   7 This provides a free software alternative to raspberrypi-power.c's
   8 firmware calls to manage power domains.  It also exposes a reset line,
   9 where previously the vc4 driver had to try to force power off the
  10 domain in order to trigger a reset.
  11
  12 Signed-off-by: Eric Anholt <eric@anholt.net>
  13 Acked-by: Rob Herring <robh@kernel.org>
  14 Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
  15 Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
  16 (cherry picked from commit 670c672608a1ffcbc7ac0f872734843593bb8b15)
  17 ---
  18  drivers/mfd/bcm2835-pm.c             |  36 +-
  19  drivers/soc/bcm/Kconfig              |  11 +
  20  drivers/soc/bcm/Makefile             |   1 +
  21  drivers/soc/bcm/bcm2835-power.c      | 661 +++++++++++++++++++++++++++
  22  include/dt-bindings/soc/bcm2835-pm.h |  28 ++
  23  include/linux/mfd/bcm2835-pm.h       |   1 +
  24  6 files changed, 734 insertions(+), 4 deletions(-)
  25  create mode 100644 drivers/soc/bcm/bcm2835-power.c
  26  create mode 100644 include/dt-bindings/soc/bcm2835-pm.h
  27
  28 --- a/drivers/mfd/bcm2835-pm.c
  29 +++ b/drivers/mfd/bcm2835-pm.c
  30 @@ -3,7 +3,7 @@
  31   * PM MFD driver for Broadcom BCM2835
  32   *
  33   * This driver binds to the PM block and creates the MFD device for
  34 - * the WDT driver.
  35 + * the WDT and power drivers.
  36   */
  37
  38  #include <linux/delay.h>
  39 @@ -21,11 +21,16 @@ static const struct mfd_cell bcm2835_pm_
  40         { .name = "bcm2835-wdt" },
  41  };
  42
  43 +static const struct mfd_cell bcm2835_power_devs[] = {
  44 +       { .name = "bcm2835-power" },
  45 +};
  46 +
  47  static int bcm2835_pm_probe(struct platform_device *pdev)
  48  {
  49         struct resource *res;
  50         struct device *dev = &pdev->dev;
  51         struct bcm2835_pm *pm;
  52 +       int ret;
  53
  54         pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
  55         if (!pm)
  56 @@ -39,13 +44,36 @@ static int bcm2835_pm_probe(struct platf
  57         if (IS_ERR(pm->base))
  58                 return PTR_ERR(pm->base);
  59
  60 -       return devm_mfd_add_devices(dev, -1,
  61 -                                   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
  62 -                                   NULL, 0, NULL);
  63 +       ret = devm_mfd_add_devices(dev, -1,
  64 +                                  bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
  65 +                                  NULL, 0, NULL);
  66 +       if (ret)
  67 +               return ret;
  68 +
  69 +       /* We'll use the presence of the AXI ASB regs in the
  70 +        * bcm2835-pm binding as the key for whether we can reference
  71 +        * the full PM register range and support power domains.
  72 +        */
  73 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  74 +       if (res) {
  75 +               pm->asb = devm_ioremap_resource(dev, res);
  76 +               if (IS_ERR(pm->asb))
  77 +                       return PTR_ERR(pm->asb);
  78 +
  79 +               ret = devm_mfd_add_devices(dev, -1,
  80 +                                          bcm2835_power_devs,
  81 +                                          ARRAY_SIZE(bcm2835_power_devs),
  82 +                                          NULL, 0, NULL);
  83 +               if (ret)
  84 +                       return ret;
  85 +       }
  86 +
  87 +       return 0;
  88  }
  89
  90  static const struct of_device_id bcm2835_pm_of_match[] = {
  91         { .compatible = "brcm,bcm2835-pm-wdt", },
  92 +       { .compatible = "brcm,bcm2835-pm", },
  93         {},
  94  };
  95  MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
  96 --- a/drivers/soc/bcm/Kconfig
  97 +++ b/drivers/soc/bcm/Kconfig
  98 @@ -1,5 +1,16 @@
  99  menu "Broadcom SoC drivers"
 100
 101 +config BCM2835_POWER
 102 +       bool "BCM2835 power domain driver"
 103 +       depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
 104 +       select PM_GENERIC_DOMAINS if PM
 105 +       select RESET_CONTROLLER
 106 +       help
 107 +         This enables support for the BCM2835 power domains and reset
 108 +         controller.  Any usage of power domains by the Raspberry Pi
 109 +         firmware means that Linux usage of the same power domain
 110 +         must be accessed using the RASPBERRYPI_POWER driver
 111 +
 112  config RASPBERRYPI_POWER
 113         bool "Raspberry Pi power domain driver"
 114         depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
 115 --- a/drivers/soc/bcm/Makefile
 116 +++ b/drivers/soc/bcm/Makefile
 117 @@ -1,2 +1,3 @@
 118 +obj-$(CONFIG_BCM2835_POWER)    += bcm2835-power.o
 119  obj-$(CONFIG_RASPBERRYPI_POWER)        += raspberrypi-power.o
 120  obj-$(CONFIG_SOC_BRCMSTB)      += brcmstb/
 121 --- /dev/null
 122 +++ b/drivers/soc/bcm/bcm2835-power.c
 123 @@ -0,0 +1,661 @@
 124 +// SPDX-License-Identifier: GPL-2.0+
 125 +/*
 126 + * Power domain driver for Broadcom BCM2835
 127 + *
 128 + * Copyright (C) 2018 Broadcom
 129 + */
 130 +
 131 +#include <dt-bindings/soc/bcm2835-pm.h>
 132 +#include <linux/clk.h>
 133 +#include <linux/delay.h>
 134 +#include <linux/io.h>
 135 +#include <linux/mfd/bcm2835-pm.h>
 136 +#include <linux/module.h>
 137 +#include <linux/platform_device.h>
 138 +#include <linux/pm_domain.h>
 139 +#include <linux/reset-controller.h>
 140 +#include <linux/types.h>
 141 +
 142 +#define PM_GNRIC                        0x00
 143 +#define PM_AUDIO                        0x04
 144 +#define PM_STATUS                       0x18
 145 +#define PM_RSTC                                0x1c
 146 +#define PM_RSTS                                0x20
 147 +#define PM_WDOG                                0x24
 148 +#define PM_PADS0                       0x28
 149 +#define PM_PADS2                       0x2c
 150 +#define PM_PADS3                       0x30
 151 +#define PM_PADS4                       0x34
 152 +#define PM_PADS5                       0x38
 153 +#define PM_PADS6                       0x3c
 154 +#define PM_CAM0                                0x44
 155 +#define PM_CAM0_LDOHPEN                        BIT(2)
 156 +#define PM_CAM0_LDOLPEN                        BIT(1)
 157 +#define PM_CAM0_CTRLEN                 BIT(0)
 158 +
 159 +#define PM_CAM1                                0x48
 160 +#define PM_CAM1_LDOHPEN                        BIT(2)
 161 +#define PM_CAM1_LDOLPEN                        BIT(1)
 162 +#define PM_CAM1_CTRLEN                 BIT(0)
 163 +
 164 +#define PM_CCP2TX                      0x4c
 165 +#define PM_CCP2TX_LDOEN                        BIT(1)
 166 +#define PM_CCP2TX_CTRLEN               BIT(0)
 167 +
 168 +#define PM_DSI0                                0x50
 169 +#define PM_DSI0_LDOHPEN                        BIT(2)
 170 +#define PM_DSI0_LDOLPEN                        BIT(1)
 171 +#define PM_DSI0_CTRLEN                 BIT(0)
 172 +
 173 +#define PM_DSI1                                0x54
 174 +#define PM_DSI1_LDOHPEN                        BIT(2)
 175 +#define PM_DSI1_LDOLPEN                        BIT(1)
 176 +#define PM_DSI1_CTRLEN                 BIT(0)
 177 +
 178 +#define PM_HDMI                                0x58
 179 +#define PM_HDMI_RSTDR                  BIT(19)
 180 +#define PM_HDMI_LDOPD                  BIT(1)
 181 +#define PM_HDMI_CTRLEN                 BIT(0)
 182 +
 183 +#define PM_USB                         0x5c
 184 +/* The power gates must be enabled with this bit before enabling the LDO in the
 185 + * USB block.
 186 + */
 187 +#define PM_USB_CTRLEN                  BIT(0)
 188 +
 189 +#define PM_PXLDO                       0x60
 190 +#define PM_PXBG                                0x64
 191 +#define PM_DFT                         0x68
 192 +#define PM_SMPS                                0x6c
 193 +#define PM_XOSC                                0x70
 194 +#define PM_SPAREW                      0x74
 195 +#define PM_SPARER                      0x78
 196 +#define PM_AVS_RSTDR                   0x7c
 197 +#define PM_AVS_STAT                    0x80
 198 +#define PM_AVS_EVENT                   0x84
 199 +#define PM_AVS_INTEN                   0x88
 200 +#define PM_DUMMY                       0xfc
 201 +
 202 +#define PM_IMAGE                       0x108
 203 +#define PM_GRAFX                       0x10c
 204 +#define PM_PROC                                0x110
 205 +#define PM_ENAB                                BIT(12)
 206 +#define PM_ISPRSTN                     BIT(8)
 207 +#define PM_H264RSTN                    BIT(7)
 208 +#define PM_PERIRSTN                    BIT(6)
 209 +#define PM_V3DRSTN                     BIT(6)
 210 +#define PM_ISFUNC                      BIT(5)
 211 +#define PM_MRDONE                      BIT(4)
 212 +#define PM_MEMREP                      BIT(3)
 213 +#define PM_ISPOW                       BIT(2)
 214 +#define PM_POWOK                       BIT(1)
 215 +#define PM_POWUP                       BIT(0)
 216 +#define PM_INRUSH_SHIFT                        13
 217 +#define PM_INRUSH_3_5_MA               0
 218 +#define PM_INRUSH_5_MA                 1
 219 +#define PM_INRUSH_10_MA                        2
 220 +#define PM_INRUSH_20_MA                        3
 221 +#define PM_INRUSH_MASK                 (3 << PM_INRUSH_SHIFT)
 222 +
 223 +#define PM_PASSWORD                    0x5a000000
 224 +
 225 +#define PM_WDOG_TIME_SET               0x000fffff
 226 +#define PM_RSTC_WRCFG_CLR              0xffffffcf
 227 +#define PM_RSTS_HADWRH_SET             0x00000040
 228 +#define PM_RSTC_WRCFG_SET              0x00000030
 229 +#define PM_RSTC_WRCFG_FULL_RESET       0x00000020
 230 +#define PM_RSTC_RESET                  0x00000102
 231 +
 232 +#define PM_READ(reg) readl(power->base + (reg))
 233 +#define PM_WRITE(reg, val) writel(PM_PASSWORD | (val), power->base + (reg))
 234 +
 235 +#define ASB_BRDG_VERSION                0x00
 236 +#define ASB_CPR_CTRL                    0x04
 237 +
 238 +#define ASB_V3D_S_CTRL                 0x08
 239 +#define ASB_V3D_M_CTRL                 0x0c
 240 +#define ASB_ISP_S_CTRL                 0x10
 241 +#define ASB_ISP_M_CTRL                 0x14
 242 +#define ASB_H264_S_CTRL                        0x18
 243 +#define ASB_H264_M_CTRL                        0x1c
 244 +
 245 +#define ASB_REQ_STOP                    BIT(0)
 246 +#define ASB_ACK                         BIT(1)
 247 +#define ASB_EMPTY                       BIT(2)
 248 +#define ASB_FULL                        BIT(3)
 249 +
 250 +#define ASB_AXI_BRDG_ID                        0x20
 251 +
 252 +#define ASB_READ(reg) readl(power->asb + (reg))
 253 +#define ASB_WRITE(reg, val) writel(PM_PASSWORD | (val), power->asb + (reg))
 254 +
 255 +struct bcm2835_power_domain {
 256 +       struct generic_pm_domain base;
 257 +       struct bcm2835_power *power;
 258 +       u32 domain;
 259 +       struct clk *clk;
 260 +};
 261 +
 262 +struct bcm2835_power {
 263 +       struct device           *dev;
 264 +       /* PM registers. */
 265 +       void __iomem            *base;
 266 +       /* AXI Async bridge registers. */
 267 +       void __iomem            *asb;
 268 +
 269 +       struct genpd_onecell_data pd_xlate;
 270 +       struct bcm2835_power_domain domains[BCM2835_POWER_DOMAIN_COUNT];
 271 +       struct reset_controller_dev reset;
 272 +};
 273 +
 274 +static int bcm2835_asb_enable(struct bcm2835_power *power, u32 reg)
 275 +{
 276 +       u64 start = ktime_get_ns();
 277 +
 278 +       /* Enable the module's async AXI bridges. */
 279 +       ASB_WRITE(reg, ASB_READ(reg) & ~ASB_REQ_STOP);
 280 +       while (ASB_READ(reg) & ASB_ACK) {
 281 +               cpu_relax();
 282 +               if (ktime_get_ns() - start >= 1000)
 283 +                       return -ETIMEDOUT;
 284 +       }
 285 +
 286 +       return 0;
 287 +}
 288 +
 289 +static int bcm2835_asb_disable(struct bcm2835_power *power, u32 reg)
 290 +{
 291 +       u64 start = ktime_get_ns();
 292 +
 293 +       /* Enable the module's async AXI bridges. */
 294 +       ASB_WRITE(reg, ASB_READ(reg) | ASB_REQ_STOP);
 295 +       while (!(ASB_READ(reg) & ASB_ACK)) {
 296 +               cpu_relax();
 297 +               if (ktime_get_ns() - start >= 1000)
 298 +                       return -ETIMEDOUT;
 299 +       }
 300 +
 301 +       return 0;
 302 +}
 303 +
 304 +static int bcm2835_power_power_off(struct bcm2835_power_domain *pd, u32 pm_reg)
 305 +{
 306 +       struct bcm2835_power *power = pd->power;
 307 +
 308 +       /* Enable functional isolation */
 309 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISFUNC);
 310 +
 311 +       /* Enable electrical isolation */
 312 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
 313 +
 314 +       /* Open the power switches. */
 315 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_POWUP);
 316 +
 317 +       return 0;
 318 +}
 319 +
 320 +static int bcm2835_power_power_on(struct bcm2835_power_domain *pd, u32 pm_reg)
 321 +{
 322 +       struct bcm2835_power *power = pd->power;
 323 +       struct device *dev = power->dev;
 324 +       u64 start;
 325 +       int ret;
 326 +       int inrush;
 327 +       bool powok;
 328 +
 329 +       /* If it was already powered on by the fw, leave it that way. */
 330 +       if (PM_READ(pm_reg) & PM_POWUP)
 331 +               return 0;
 332 +
 333 +       /* Enable power.  Allowing too much current at once may result
 334 +        * in POWOK never getting set, so start low and ramp it up as
 335 +        * necessary to succeed.
 336 +        */
 337 +       powok = false;
 338 +       for (inrush = PM_INRUSH_3_5_MA; inrush <= PM_INRUSH_20_MA; inrush++) {
 339 +               PM_WRITE(pm_reg,
 340 +                        (PM_READ(pm_reg) & ~PM_INRUSH_MASK) |
 341 +                        (inrush << PM_INRUSH_SHIFT) |
 342 +                        PM_POWUP);
 343 +
 344 +               start = ktime_get_ns();
 345 +               while (!(powok = !!(PM_READ(pm_reg) & PM_POWOK))) {
 346 +                       cpu_relax();
 347 +                       if (ktime_get_ns() - start >= 3000)
 348 +                               break;
 349 +               }
 350 +       }
 351 +       if (!powok) {
 352 +               dev_err(dev, "Timeout waiting for %s power OK\n",
 353 +                       pd->base.name);
 354 +               ret = -ETIMEDOUT;
 355 +               goto err_disable_powup;
 356 +       }
 357 +
 358 +       /* Disable electrical isolation */
 359 +       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISPOW);
 360 +
 361 +       /* Repair memory */
 362 +       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_MEMREP);
 363 +       start = ktime_get_ns();
 364 +       while (!(PM_READ(pm_reg) & PM_MRDONE)) {
 365 +               cpu_relax();
 366 +               if (ktime_get_ns() - start >= 1000) {
 367 +                       dev_err(dev, "Timeout waiting for %s memory repair\n",
 368 +                               pd->base.name);
 369 +                       ret = -ETIMEDOUT;
 370 +                       goto err_disable_ispow;
 371 +               }
 372 +       }
 373 +
 374 +       /* Disable functional isolation */
 375 +       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISFUNC);
 376 +
 377 +       return 0;
 378 +
 379 +err_disable_ispow:
 380 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
 381 +err_disable_powup:
 382 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~(PM_POWUP | PM_INRUSH_MASK));
 383 +       return ret;
 384 +}
 385 +
 386 +static int bcm2835_asb_power_on(struct bcm2835_power_domain *pd,
 387 +                               u32 pm_reg,
 388 +                               u32 asb_m_reg,
 389 +                               u32 asb_s_reg,
 390 +                               u32 reset_flags)
 391 +{
 392 +       struct bcm2835_power *power = pd->power;
 393 +       int ret;
 394 +
 395 +       ret = clk_prepare_enable(pd->clk);
 396 +       if (ret) {
 397 +               dev_err(power->dev, "Failed to enable clock for %s\n",
 398 +                       pd->base.name);
 399 +               return ret;
 400 +       }
 401 +
 402 +       /* Wait 32 clocks for reset to propagate, 1 us will be enough */
 403 +       udelay(1);
 404 +
 405 +       clk_disable_unprepare(pd->clk);
 406 +
 407 +       /* Deassert the resets. */
 408 +       PM_WRITE(pm_reg, PM_READ(pm_reg) | reset_flags);
 409 +
 410 +       ret = clk_prepare_enable(pd->clk);
 411 +       if (ret) {
 412 +               dev_err(power->dev, "Failed to enable clock for %s\n",
 413 +                       pd->base.name);
 414 +               goto err_enable_resets;
 415 +       }
 416 +
 417 +       ret = bcm2835_asb_enable(power, asb_m_reg);
 418 +       if (ret) {
 419 +               dev_err(power->dev, "Failed to enable ASB master for %s\n",
 420 +                       pd->base.name);
 421 +               goto err_disable_clk;
 422 +       }
 423 +       ret = bcm2835_asb_enable(power, asb_s_reg);
 424 +       if (ret) {
 425 +               dev_err(power->dev, "Failed to enable ASB slave for %s\n",
 426 +                       pd->base.name);
 427 +               goto err_disable_asb_master;
 428 +       }
 429 +
 430 +       return 0;
 431 +
 432 +err_disable_asb_master:
 433 +       bcm2835_asb_disable(power, asb_m_reg);
 434 +err_disable_clk:
 435 +       clk_disable_unprepare(pd->clk);
 436 +err_enable_resets:
 437 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
 438 +       return ret;
 439 +}
 440 +
 441 +static int bcm2835_asb_power_off(struct bcm2835_power_domain *pd,
 442 +                                u32 pm_reg,
 443 +                                u32 asb_m_reg,
 444 +                                u32 asb_s_reg,
 445 +                                u32 reset_flags)
 446 +{
 447 +       struct bcm2835_power *power = pd->power;
 448 +       int ret;
 449 +
 450 +       ret = bcm2835_asb_disable(power, asb_s_reg);
 451 +       if (ret) {
 452 +               dev_warn(power->dev, "Failed to disable ASB slave for %s\n",
 453 +                        pd->base.name);
 454 +               return ret;
 455 +       }
 456 +       ret = bcm2835_asb_disable(power, asb_m_reg);
 457 +       if (ret) {
 458 +               dev_warn(power->dev, "Failed to disable ASB master for %s\n",
 459 +                        pd->base.name);
 460 +               bcm2835_asb_enable(power, asb_s_reg);
 461 +               return ret;
 462 +       }
 463 +
 464 +       clk_disable_unprepare(pd->clk);
 465 +
 466 +       /* Assert the resets. */
 467 +       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
 468 +
 469 +       return 0;
 470 +}
 471 +
 472 +static int bcm2835_power_pd_power_on(struct generic_pm_domain *domain)
 473 +{
 474 +       struct bcm2835_power_domain *pd =
 475 +               container_of(domain, struct bcm2835_power_domain, base);
 476 +       struct bcm2835_power *power = pd->power;
 477 +
 478 +       switch (pd->domain) {
 479 +       case BCM2835_POWER_DOMAIN_GRAFX:
 480 +               return bcm2835_power_power_on(pd, PM_GRAFX);
 481 +
 482 +       case BCM2835_POWER_DOMAIN_GRAFX_V3D:
 483 +               return bcm2835_asb_power_on(pd, PM_GRAFX,
 484 +                                           ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
 485 +                                           PM_V3DRSTN);
 486 +
 487 +       case BCM2835_POWER_DOMAIN_IMAGE:
 488 +               return bcm2835_power_power_on(pd, PM_IMAGE);
 489 +
 490 +       case BCM2835_POWER_DOMAIN_IMAGE_PERI:
 491 +               return bcm2835_asb_power_on(pd, PM_IMAGE,
 492 +                                           0, 0,
 493 +                                           PM_PERIRSTN);
 494 +
 495 +       case BCM2835_POWER_DOMAIN_IMAGE_ISP:
 496 +               return bcm2835_asb_power_on(pd, PM_IMAGE,
 497 +                                           ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
 498 +                                           PM_ISPRSTN);
 499 +
 500 +       case BCM2835_POWER_DOMAIN_IMAGE_H264:
 501 +               return bcm2835_asb_power_on(pd, PM_IMAGE,
 502 +                                           ASB_H264_M_CTRL, ASB_H264_S_CTRL,
 503 +                                           PM_H264RSTN);
 504 +
 505 +       case BCM2835_POWER_DOMAIN_USB:
 506 +               PM_WRITE(PM_USB, PM_USB_CTRLEN);
 507 +               return 0;
 508 +
 509 +       case BCM2835_POWER_DOMAIN_DSI0:
 510 +               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
 511 +               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN | PM_DSI0_LDOHPEN);
 512 +               return 0;
 513 +
 514 +       case BCM2835_POWER_DOMAIN_DSI1:
 515 +               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
 516 +               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN | PM_DSI1_LDOHPEN);
 517 +               return 0;
 518 +
 519 +       case BCM2835_POWER_DOMAIN_CCP2TX:
 520 +               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
 521 +               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN | PM_CCP2TX_LDOEN);
 522 +               return 0;
 523 +
 524 +       case BCM2835_POWER_DOMAIN_HDMI:
 525 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_RSTDR);
 526 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_CTRLEN);
 527 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_LDOPD);
 528 +               usleep_range(100, 200);
 529 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_RSTDR);
 530 +               return 0;
 531 +
 532 +       default:
 533 +               dev_err(power->dev, "Invalid domain %d\n", pd->domain);
 534 +               return -EINVAL;
 535 +       }
 536 +}
 537 +
 538 +static int bcm2835_power_pd_power_off(struct generic_pm_domain *domain)
 539 +{
 540 +       struct bcm2835_power_domain *pd =
 541 +               container_of(domain, struct bcm2835_power_domain, base);
 542 +       struct bcm2835_power *power = pd->power;
 543 +
 544 +       switch (pd->domain) {
 545 +       case BCM2835_POWER_DOMAIN_GRAFX:
 546 +               return bcm2835_power_power_off(pd, PM_GRAFX);
 547 +
 548 +       case BCM2835_POWER_DOMAIN_GRAFX_V3D:
 549 +               return bcm2835_asb_power_off(pd, PM_GRAFX,
 550 +                                            ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
 551 +                                            PM_V3DRSTN);
 552 +
 553 +       case BCM2835_POWER_DOMAIN_IMAGE:
 554 +               return bcm2835_power_power_off(pd, PM_IMAGE);
 555 +
 556 +       case BCM2835_POWER_DOMAIN_IMAGE_PERI:
 557 +               return bcm2835_asb_power_off(pd, PM_IMAGE,
 558 +                                            0, 0,
 559 +                                            PM_PERIRSTN);
 560 +
 561 +       case BCM2835_POWER_DOMAIN_IMAGE_ISP:
 562 +               return bcm2835_asb_power_off(pd, PM_IMAGE,
 563 +                                            ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
 564 +                                            PM_ISPRSTN);
 565 +
 566 +       case BCM2835_POWER_DOMAIN_IMAGE_H264:
 567 +               return bcm2835_asb_power_off(pd, PM_IMAGE,
 568 +                                            ASB_H264_M_CTRL, ASB_H264_S_CTRL,
 569 +                                            PM_H264RSTN);
 570 +
 571 +       case BCM2835_POWER_DOMAIN_USB:
 572 +               PM_WRITE(PM_USB, 0);
 573 +               return 0;
 574 +
 575 +       case BCM2835_POWER_DOMAIN_DSI0:
 576 +               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
 577 +               PM_WRITE(PM_DSI0, 0);
 578 +               return 0;
 579 +
 580 +       case BCM2835_POWER_DOMAIN_DSI1:
 581 +               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
 582 +               PM_WRITE(PM_DSI1, 0);
 583 +               return 0;
 584 +
 585 +       case BCM2835_POWER_DOMAIN_CCP2TX:
 586 +               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
 587 +               PM_WRITE(PM_CCP2TX, 0);
 588 +               return 0;
 589 +
 590 +       case BCM2835_POWER_DOMAIN_HDMI:
 591 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_LDOPD);
 592 +               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_CTRLEN);
 593 +               return 0;
 594 +
 595 +       default:
 596 +               dev_err(power->dev, "Invalid domain %d\n", pd->domain);
 597 +               return -EINVAL;
 598 +       }
 599 +}
 600 +
 601 +static void
 602 +bcm2835_init_power_domain(struct bcm2835_power *power,
 603 +                         int pd_xlate_index, const char *name)
 604 +{
 605 +       struct device *dev = power->dev;
 606 +       struct bcm2835_power_domain *dom = &power->domains[pd_xlate_index];
 607 +
 608 +       dom->clk = devm_clk_get(dev->parent, name);
 609 +
 610 +       dom->base.name = name;
 611 +       dom->base.power_on = bcm2835_power_pd_power_on;
 612 +       dom->base.power_off = bcm2835_power_pd_power_off;
 613 +
 614 +       dom->domain = pd_xlate_index;
 615 +       dom->power = power;
 616 +
 617 +       /* XXX: on/off at boot? */
 618 +       pm_genpd_init(&dom->base, NULL, true);
 619 +
 620 +       power->pd_xlate.domains[pd_xlate_index] = &dom->base;
 621 +}
 622 +
 623 +/** bcm2835_reset_reset - Resets a block that has a reset line in the
 624 + * PM block.
 625 + *
 626 + * The consumer of the reset controller must have the power domain up
 627 + * -- there's no reset ability with the power domain down.  To reset
 628 + * the sub-block, we just disable its access to memory through the
 629 + * ASB, reset, and re-enable.
 630 + */
 631 +static int bcm2835_reset_reset(struct reset_controller_dev *rcdev,
 632 +                              unsigned long id)
 633 +{
 634 +       struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
 635 +                                                  reset);
 636 +       struct bcm2835_power_domain *pd;
 637 +       int ret;
 638 +
 639 +       switch (id) {
 640 +       case BCM2835_RESET_V3D:
 641 +               pd = &power->domains[BCM2835_POWER_DOMAIN_GRAFX_V3D];
 642 +               break;
 643 +       case BCM2835_RESET_H264:
 644 +               pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_H264];
 645 +               break;
 646 +       case BCM2835_RESET_ISP:
 647 +               pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_ISP];
 648 +               break;
 649 +       default:
 650 +               dev_err(power->dev, "Bad reset id %ld\n", id);
 651 +               return -EINVAL;
 652 +       }
 653 +
 654 +       ret = bcm2835_power_pd_power_off(&pd->base);
 655 +       if (ret)
 656 +               return ret;
 657 +
 658 +       return bcm2835_power_pd_power_on(&pd->base);
 659 +}
 660 +
 661 +static int bcm2835_reset_status(struct reset_controller_dev *rcdev,
 662 +                               unsigned long id)
 663 +{
 664 +       struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
 665 +                                                  reset);
 666 +
 667 +       switch (id) {
 668 +       case BCM2835_RESET_V3D:
 669 +               return !PM_READ(PM_GRAFX & PM_V3DRSTN);
 670 +       case BCM2835_RESET_H264:
 671 +               return !PM_READ(PM_IMAGE & PM_H264RSTN);
 672 +       case BCM2835_RESET_ISP:
 673 +               return !PM_READ(PM_IMAGE & PM_ISPRSTN);
 674 +       default:
 675 +               return -EINVAL;
 676 +       }
 677 +}
 678 +
 679 +const struct reset_control_ops bcm2835_reset_ops = {
 680 +       .reset = bcm2835_reset_reset,
 681 +       .status = bcm2835_reset_status,
 682 +};
 683 +
 684 +static const char *const power_domain_names[] = {
 685 +       [BCM2835_POWER_DOMAIN_GRAFX] = "grafx",
 686 +       [BCM2835_POWER_DOMAIN_GRAFX_V3D] = "v3d",
 687 +
 688 +       [BCM2835_POWER_DOMAIN_IMAGE] = "image",
 689 +       [BCM2835_POWER_DOMAIN_IMAGE_PERI] = "peri_image",
 690 +       [BCM2835_POWER_DOMAIN_IMAGE_H264] = "h264",
 691 +       [BCM2835_POWER_DOMAIN_IMAGE_ISP] = "isp",
 692 +
 693 +       [BCM2835_POWER_DOMAIN_USB] = "usb",
 694 +       [BCM2835_POWER_DOMAIN_DSI0] = "dsi0",
 695 +       [BCM2835_POWER_DOMAIN_DSI1] = "dsi1",
 696 +       [BCM2835_POWER_DOMAIN_CAM0] = "cam0",
 697 +       [BCM2835_POWER_DOMAIN_CAM1] = "cam1",
 698 +       [BCM2835_POWER_DOMAIN_CCP2TX] = "ccp2tx",
 699 +       [BCM2835_POWER_DOMAIN_HDMI] = "hdmi",
 700 +};
 701 +
 702 +static int bcm2835_power_probe(struct platform_device *pdev)
 703 +{
 704 +       struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
 705 +       struct device *dev = &pdev->dev;
 706 +       struct bcm2835_power *power;
 707 +       static const struct {
 708 +               int parent, child;
 709 +       } domain_deps[] = {
 710 +               { BCM2835_POWER_DOMAIN_GRAFX, BCM2835_POWER_DOMAIN_GRAFX_V3D },
 711 +               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_PERI },
 712 +               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_H264 },
 713 +               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_ISP },
 714 +               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_USB },
 715 +               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM0 },
 716 +               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM1 },
 717 +       };
 718 +       int ret, i;
 719 +       u32 id;
 720 +
 721 +       power = devm_kzalloc(dev, sizeof(*power), GFP_KERNEL);
 722 +       if (!power)
 723 +               return -ENOMEM;
 724 +       platform_set_drvdata(pdev, power);
 725 +
 726 +       power->dev = dev;
 727 +       power->base = pm->base;
 728 +       power->asb = pm->asb;
 729 +
 730 +       id = ASB_READ(ASB_AXI_BRDG_ID);
 731 +       if (id != 0x62726467 /* "BRDG" */) {
 732 +               dev_err(dev, "ASB register ID returned 0x%08x\n", id);
 733 +               return -ENODEV;
 734 +       }
 735 +
 736 +       power->pd_xlate.domains = devm_kcalloc(dev,
 737 +                                              ARRAY_SIZE(power_domain_names),
 738 +                                              sizeof(*power->pd_xlate.domains),
 739 +                                              GFP_KERNEL);
 740 +       if (!power->pd_xlate.domains)
 741 +               return -ENOMEM;
 742 +
 743 +       power->pd_xlate.num_domains = ARRAY_SIZE(power_domain_names);
 744 +
 745 +       for (i = 0; i < ARRAY_SIZE(power_domain_names); i++)
 746 +               bcm2835_init_power_domain(power, i, power_domain_names[i]);
 747 +
 748 +       for (i = 0; i < ARRAY_SIZE(domain_deps); i++) {
 749 +               pm_genpd_add_subdomain(&power->domains[domain_deps[i].parent].base,
 750 +                                      &power->domains[domain_deps[i].child].base);
 751 +       }
 752 +
 753 +       power->reset.owner = THIS_MODULE;
 754 +       power->reset.nr_resets = BCM2835_RESET_COUNT;
 755 +       power->reset.ops = &bcm2835_reset_ops;
 756 +       power->reset.of_node = dev->parent->of_node;
 757 +
 758 +       ret = devm_reset_controller_register(dev, &power->reset);
 759 +       if (ret)
 760 +               return ret;
 761 +
 762 +       of_genpd_add_provider_onecell(dev->parent->of_node, &power->pd_xlate);
 763 +
 764 +       dev_info(dev, "Broadcom BCM2835 power domains driver");
 765 +       return 0;
 766 +}
 767 +
 768 +static int bcm2835_power_remove(struct platform_device *pdev)
 769 +{
 770 +       return 0;
 771 +}
 772 +
 773 +static struct platform_driver bcm2835_power_driver = {
 774 +       .probe          = bcm2835_power_probe,
 775 +       .remove         = bcm2835_power_remove,
 776 +       .driver = {
 777 +               .name = "bcm2835-power",
 778 +       },
 779 +};
 780 +module_platform_driver(bcm2835_power_driver);
 781 +
 782 +MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 783 +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM power domains and reset");
 784 +MODULE_LICENSE("GPL");
 785 --- /dev/null
 786 +++ b/include/dt-bindings/soc/bcm2835-pm.h
 787 @@ -0,0 +1,28 @@
 788 +/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
 789 +
 790 +#ifndef _DT_BINDINGS_ARM_BCM2835_PM_H
 791 +#define _DT_BINDINGS_ARM_BCM2835_PM_H
 792 +
 793 +#define BCM2835_POWER_DOMAIN_GRAFX             0
 794 +#define BCM2835_POWER_DOMAIN_GRAFX_V3D         1
 795 +#define BCM2835_POWER_DOMAIN_IMAGE             2
 796 +#define BCM2835_POWER_DOMAIN_IMAGE_PERI                3
 797 +#define BCM2835_POWER_DOMAIN_IMAGE_ISP         4
 798 +#define BCM2835_POWER_DOMAIN_IMAGE_H264                5
 799 +#define BCM2835_POWER_DOMAIN_USB               6
 800 +#define BCM2835_POWER_DOMAIN_DSI0              7
 801 +#define BCM2835_POWER_DOMAIN_DSI1              8
 802 +#define BCM2835_POWER_DOMAIN_CAM0              9
 803 +#define BCM2835_POWER_DOMAIN_CAM1              10
 804 +#define BCM2835_POWER_DOMAIN_CCP2TX            11
 805 +#define BCM2835_POWER_DOMAIN_HDMI              12
 806 +
 807 +#define BCM2835_POWER_DOMAIN_COUNT             13
 808 +
 809 +#define BCM2835_RESET_V3D                      0
 810 +#define BCM2835_RESET_ISP                      1
 811 +#define BCM2835_RESET_H264                     2
 812 +
 813 +#define BCM2835_RESET_COUNT                    3
 814 +
 815 +#endif /* _DT_BINDINGS_ARM_BCM2835_PM_H */
 816 --- a/include/linux/mfd/bcm2835-pm.h
 817 +++ b/include/linux/mfd/bcm2835-pm.h
 818 @@ -8,6 +8,7 @@
 819  struct bcm2835_pm {
 820         struct device *dev;
 821         void __iomem *base;
 822 +       void __iomem *asb;
 823  };
 824
 825  #endif /* BCM2835_MFD_PM_H */