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 builtin_platform_driver(pmc_driver); 89