LXR linux/arch/powerpc/sysdev/fsl

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Suspend/resume support
   4 *
   5 * Copyright 2009  MontaVista Software, Inc.
   6 *
   7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   8 */
   9
  10#include <linux/init.h>
  11#include <linux/types.h>
  12#include <linux/errno.h>
  13#include <linux/export.h>
  14#include <linux/suspend.h>
  15#include <linux/delay.h>
  16#include <linux/device.h>
  17#include <linux/of_address.h>
  18#include <linux/of_platform.h>
  19
  20struct pmc_regs {
  21        __be32 devdisr;
  22        __be32 devdisr2;
  23        __be32 :32;
  24        __be32 :32;
  25        __be32 pmcsr;
  26#define PMCSR_SLP       (1 << 17)
  27};
  28
  29static struct device *pmc_dev;
  30static struct pmc_regs __iomem *pmc_regs;
  31
  32static int pmc_suspend_enter(suspend_state_t state)
  33{
  34        int ret;
  35
  36        setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
  37        /* At this point, the CPU is asleep. */
  38
  39        /* Upon resume, wait for SLP bit to be clear. */
  40        ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
  41                                 10000, 10) ? 0 : -ETIMEDOUT;
  42        if (ret)
  43                dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
  44        return ret;
  45}
  46
  47static int pmc_suspend_valid(suspend_state_t state)
  48{
  49        if (state != PM_SUSPEND_STANDBY)
  50                return 0;
  51        return 1;
  52}
  53
  54static const struct platform_suspend_ops pmc_suspend_ops = {
  55        .valid = pmc_suspend_valid,
  56        .enter = pmc_suspend_enter,
  57};
  58
  59static int pmc_probe(struct platform_device *ofdev)
  60{
  61        pmc_regs = of_iomap(ofdev->dev.of_node, 0);
  62        if (!pmc_regs)
  63                return -ENOMEM;
  64
  65        pmc_dev = &ofdev->dev;
  66        suspend_set_ops(&pmc_suspend_ops);
  67        return 0;
  68}
  69
  70static const struct of_device_id pmc_ids[] = {
  71        { .compatible = "fsl,mpc8548-pmc", },
  72        { .compatible = "fsl,mpc8641d-pmc", },
  73        { },
  74};
  75
  76static struct platform_driver pmc_driver = {
  77        .driver = {
  78                .name = "fsl-pmc",
  79                .of_match_table = pmc_ids,
  80        },
  81        .probe = pmc_probe,
  82};
  83
  84builtin_platform_driver(pmc_driver);
  85