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 20 struct 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 29 static struct device *pmc_dev; 30 static struct pmc_regs __iomem *pmc_regs; 31 32 static 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 47 static int pmc_suspend_valid(suspend_state_t state) 48 { 49 if (state != PM_SUSPEND_STANDBY) 50 return 0; 51 return 1; 52 } 53 54 static const struct platform_suspend_ops pmc_suspend_ops = { 55 .valid = pmc_suspend_valid, 56 .enter = pmc_suspend_enter, 57 }; 58 59 static 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 70 static const struct of_device_id pmc_ids[] = { 71 { .compatible = "fsl,mpc8548-pmc", }, 72 { .compatible = "fsl,mpc8641d-pmc", }, 73 { }, 74 }; 75 76 static struct platform_driver pmc_driver = { 77 .driver = { 78 .name = "fsl-pmc", 79 .of_match_table = pmc_ids, 80 }, 81 .probe = pmc_probe, 82 }; 83 84 builtin_platform_driver(pmc_driver); 85