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/suspend.h> 18 #include <linux/delay.h> 19 #include <linux/device.h> 20 #include <linux/of_platform.h> 21 22 struct pmc_regs { 23 __be32 devdisr; 24 __be32 devdisr2; 25 __be32 :32; 26 __be32 :32; 27 __be32 pmcsr; 28 #define PMCSR_SLP (1 << 17) 29 }; 30 31 static struct device *pmc_dev; 32 static struct pmc_regs __iomem *pmc_regs; 33 34 static int pmc_suspend_enter(suspend_state_t state) 35 { 36 int ret; 37 38 setbits32(&pmc_regs->pmcsr, PMCSR_SLP); 39 /* At this point, the CPU is asleep. */ 40 41 /* Upon resume, wait for SLP bit to be clear. */ 42 ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0, 43 10000, 10) ? 0 : -ETIMEDOUT; 44 if (ret) 45 dev_err(pmc_dev, "tired waiting for SLP bit to clear\n"); 46 return ret; 47 } 48 49 static int pmc_suspend_valid(suspend_state_t state) 50 { 51 if (state != PM_SUSPEND_STANDBY) 52 return 0; 53 return 1; 54 } 55 56 static const struct platform_suspend_ops pmc_suspend_ops = { 57 .valid = pmc_suspend_valid, 58 .enter = pmc_suspend_enter, 59 }; 60 61 static int pmc_probe(struct platform_device *ofdev) 62 { 63 pmc_regs = of_iomap(ofdev->dev.of_node, 0); 64 if (!pmc_regs) 65 return -ENOMEM; 66 67 pmc_dev = &ofdev->dev; 68 suspend_set_ops(&pmc_suspend_ops); 69 return 0; 70 } 71 72 static const struct of_device_id pmc_ids[] = { 73 { .compatible = "fsl,mpc8548-pmc", }, 74 { .compatible = "fsl,mpc8641d-pmc", }, 75 { }, 76 }; 77 78 static struct platform_driver pmc_driver = { 79 .driver = { 80 .name = "fsl-pmc", 81 .owner = THIS_MODULE, 82 .of_match_table = pmc_ids, 83 }, 84 .probe = pmc_probe, 85 }; 86 87 static int __init pmc_init(void) 88 { 89 return platform_driver_register(&pmc_driver); 90 } 91 device_initcall(pmc_init); 92