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