| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * Suspend/resume support |
| 3 | * |
| 4 | * Copyright 2009 MontaVista Software, Inc. |
| 5 | * |
| 6 | * Author: Anton Vorontsov <avorontsov@ru.mvista.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/types.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/export.h> |
| 18 | #include <linux/suspend.h> |
| 19 | #include <linux/delay.h> |
| 20 | #include <linux/device.h> |
| 21 | #include <linux/of_address.h> |
| 22 | #include <linux/of_platform.h> |
| 23 | |
| 24 | struct pmc_regs { |
| 25 | __be32 devdisr; |
| 26 | __be32 devdisr2; |
| 27 | __be32 :32; |
| 28 | __be32 :32; |
| 29 | __be32 pmcsr; |
| 30 | #define PMCSR_SLP (1 << 17) |
| 31 | }; |
| 32 | |
| 33 | static struct device *pmc_dev; |
| 34 | static struct pmc_regs __iomem *pmc_regs; |
| 35 | |
| 36 | static int pmc_suspend_enter(suspend_state_t state) |
| 37 | { |
| 38 | int ret; |
| 39 | |
| 40 | setbits32(&pmc_regs->pmcsr, PMCSR_SLP); |
| 41 | /* At this point, the CPU is asleep. */ |
| 42 | |
| 43 | /* Upon resume, wait for SLP bit to be clear. */ |
| 44 | ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0, |
| 45 | 10000, 10) ? 0 : -ETIMEDOUT; |
| 46 | if (ret) |
| 47 | dev_err(pmc_dev, "tired waiting for SLP bit to clear\n"); |
| 48 | return ret; |
| 49 | } |
| 50 | |
| 51 | static int pmc_suspend_valid(suspend_state_t state) |
| 52 | { |
| 53 | if (state != PM_SUSPEND_STANDBY) |
| 54 | return 0; |
| 55 | return 1; |
| 56 | } |
| 57 | |
| 58 | static const struct platform_suspend_ops pmc_suspend_ops = { |
| 59 | .valid = pmc_suspend_valid, |
| 60 | .enter = pmc_suspend_enter, |
| 61 | }; |
| 62 | |
| 63 | static int pmc_probe(struct platform_device *ofdev) |
| 64 | { |
| 65 | pmc_regs = of_iomap(ofdev->dev.of_node, 0); |
| 66 | if (!pmc_regs) |
| 67 | return -ENOMEM; |
| 68 | |
| 69 | pmc_dev = &ofdev->dev; |
| 70 | suspend_set_ops(&pmc_suspend_ops); |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | static const struct of_device_id pmc_ids[] = { |
| 75 | { .compatible = "fsl,mpc8548-pmc", }, |
| 76 | { .compatible = "fsl,mpc8641d-pmc", }, |
| 77 | { }, |
| 78 | }; |
| 79 | |
| 80 | static struct platform_driver pmc_driver = { |
| 81 | .driver = { |
| 82 | .name = "fsl-pmc", |
| 83 | .of_match_table = pmc_ids, |
| 84 | }, |
| 85 | .probe = pmc_probe, |
| 86 | }; |
| 87 | |
| 88 | static int __init pmc_init(void) |
| 89 | { |
| 90 | return platform_driver_register(&pmc_driver); |
| 91 | } |
| 92 | device_initcall(pmc_init); |