1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * MPIC timer wakeup driver 4 * 5 * Copyright 2013 Freescale Semiconductor, Inc. 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/slab.h> 10 #include <linux/errno.h> 11 #include <linux/module.h> 12 #include <linux/interrupt.h> 13 #include <linux/device.h> 14 15 #include <asm/mpic_timer.h> 16 #include <asm/mpic.h> 17 18 struct fsl_mpic_timer_wakeup { 19 struct mpic_timer *timer; 20 struct work_struct free_work; 21 }; 22 23 static struct fsl_mpic_timer_wakeup *fsl_wakeup; 24 static DEFINE_MUTEX(sysfs_lock); 25 26 static void fsl_free_resource(struct work_struct *ws) 27 { 28 struct fsl_mpic_timer_wakeup *wakeup = 29 container_of(ws, struct fsl_mpic_timer_wakeup, free_work); 30 31 mutex_lock(&sysfs_lock); 32 33 if (wakeup->timer) { 34 disable_irq_wake(wakeup->timer->irq); 35 mpic_free_timer(wakeup->timer); 36 } 37 38 wakeup->timer = NULL; 39 mutex_unlock(&sysfs_lock); 40 } 41 42 static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id) 43 { 44 struct fsl_mpic_timer_wakeup *wakeup = dev_id; 45 46 schedule_work(&wakeup->free_work); 47 48 return wakeup->timer ? IRQ_HANDLED : IRQ_NONE; 49 } 50 51 static ssize_t fsl_timer_wakeup_show(struct device *dev, 52 struct device_attribute *attr, 53 char *buf) 54 { 55 time64_t interval = 0; 56 57 mutex_lock(&sysfs_lock); 58 if (fsl_wakeup->timer) { 59 mpic_get_remain_time(fsl_wakeup->timer, &interval); 60 interval++; 61 } 62 mutex_unlock(&sysfs_lock); 63 64 return sprintf(buf, "%lld\n", interval); 65 } 66 67 static ssize_t fsl_timer_wakeup_store(struct device *dev, 68 struct device_attribute *attr, 69 const char *buf, 70 size_t count) 71 { 72 time64_t interval; 73 int ret; 74 75 if (kstrtoll(buf, 0, &interval)) 76 return -EINVAL; 77 78 mutex_lock(&sysfs_lock); 79 80 if (fsl_wakeup->timer) { 81 disable_irq_wake(fsl_wakeup->timer->irq); 82 mpic_free_timer(fsl_wakeup->timer); 83 fsl_wakeup->timer = NULL; 84 } 85 86 if (!interval) { 87 mutex_unlock(&sysfs_lock); 88 return count; 89 } 90 91 fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq, 92 fsl_wakeup, interval); 93 if (!fsl_wakeup->timer) { 94 mutex_unlock(&sysfs_lock); 95 return -EINVAL; 96 } 97 98 ret = enable_irq_wake(fsl_wakeup->timer->irq); 99 if (ret) { 100 mpic_free_timer(fsl_wakeup->timer); 101 fsl_wakeup->timer = NULL; 102 mutex_unlock(&sysfs_lock); 103 104 return ret; 105 } 106 107 mpic_start_timer(fsl_wakeup->timer); 108 109 mutex_unlock(&sysfs_lock); 110 111 return count; 112 } 113 114 static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644, 115 fsl_timer_wakeup_show, fsl_timer_wakeup_store); 116 117 static int __init fsl_wakeup_sys_init(void) 118 { 119 struct device *dev_root; 120 int ret = -EINVAL; 121 122 fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL); 123 if (!fsl_wakeup) 124 return -ENOMEM; 125 126 INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource); 127 128 dev_root = bus_get_dev_root(&mpic_subsys); 129 if (dev_root) { 130 ret = device_create_file(dev_root, &mpic_attributes); 131 put_device(dev_root); 132 if (ret) 133 kfree(fsl_wakeup); 134 } 135 136 return ret; 137 } 138 139 static void __exit fsl_wakeup_sys_exit(void) 140 { 141 struct device *dev_root; 142 143 dev_root = bus_get_dev_root(&mpic_subsys); 144 if (dev_root) { 145 device_remove_file(dev_root, &mpic_attributes); 146 put_device(dev_root); 147 } 148 149 mutex_lock(&sysfs_lock); 150 151 if (fsl_wakeup->timer) { 152 disable_irq_wake(fsl_wakeup->timer->irq); 153 mpic_free_timer(fsl_wakeup->timer); 154 } 155 156 kfree(fsl_wakeup); 157 158 mutex_unlock(&sysfs_lock); 159 } 160 161 module_init(fsl_wakeup_sys_init); 162 module_exit(fsl_wakeup_sys_exit); 163 164 MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver"); 165 MODULE_LICENSE("GPL v2"); 166 MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>"); 167