1 /* 2 * drivers/rtc/rtc-pl031.c 3 * 4 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC 5 * 6 * Author: Deepak Saxena <dsaxena@plexity.net> 7 * 8 * Copyright 2006 (c) MontaVista Software, Inc. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 #include <linux/module.h> 16 #include <linux/rtc.h> 17 #include <linux/init.h> 18 #include <linux/interrupt.h> 19 #include <linux/amba/bus.h> 20 #include <linux/io.h> 21 22 /* 23 * Register definitions 24 */ 25 #define RTC_DR 0x00 /* Data read register */ 26 #define RTC_MR 0x04 /* Match register */ 27 #define RTC_LR 0x08 /* Data load register */ 28 #define RTC_CR 0x0c /* Control register */ 29 #define RTC_IMSC 0x10 /* Interrupt mask and set register */ 30 #define RTC_RIS 0x14 /* Raw interrupt status register */ 31 #define RTC_MIS 0x18 /* Masked interrupt status register */ 32 #define RTC_ICR 0x1c /* Interrupt clear register */ 33 34 struct pl031_local { 35 struct rtc_device *rtc; 36 void __iomem *base; 37 }; 38 39 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 40 { 41 struct rtc_device *rtc = dev_id; 42 43 rtc_update_irq(rtc, 1, RTC_AF); 44 45 return IRQ_HANDLED; 46 } 47 48 static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 49 { 50 struct pl031_local *ldata = dev_get_drvdata(dev); 51 52 switch (cmd) { 53 case RTC_AIE_OFF: 54 writel(1, ldata->base + RTC_MIS); 55 return 0; 56 case RTC_AIE_ON: 57 writel(0, ldata->base + RTC_MIS); 58 return 0; 59 } 60 61 return -ENOIOCTLCMD; 62 } 63 64 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 65 { 66 struct pl031_local *ldata = dev_get_drvdata(dev); 67 68 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 69 70 return 0; 71 } 72 73 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 74 { 75 unsigned long time; 76 struct pl031_local *ldata = dev_get_drvdata(dev); 77 78 rtc_tm_to_time(tm, &time); 79 writel(time, ldata->base + RTC_LR); 80 81 return 0; 82 } 83 84 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 85 { 86 struct pl031_local *ldata = dev_get_drvdata(dev); 87 88 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 89 alarm->pending = readl(ldata->base + RTC_RIS); 90 alarm->enabled = readl(ldata->base + RTC_IMSC); 91 92 return 0; 93 } 94 95 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 96 { 97 struct pl031_local *ldata = dev_get_drvdata(dev); 98 unsigned long time; 99 100 rtc_tm_to_time(&alarm->time, &time); 101 102 writel(time, ldata->base + RTC_MR); 103 writel(!alarm->enabled, ldata->base + RTC_MIS); 104 105 return 0; 106 } 107 108 static const struct rtc_class_ops pl031_ops = { 109 .ioctl = pl031_ioctl, 110 .read_time = pl031_read_time, 111 .set_time = pl031_set_time, 112 .read_alarm = pl031_read_alarm, 113 .set_alarm = pl031_set_alarm, 114 }; 115 116 static int pl031_remove(struct amba_device *adev) 117 { 118 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 119 120 amba_set_drvdata(adev, NULL); 121 free_irq(adev->irq[0], ldata->rtc); 122 rtc_device_unregister(ldata->rtc); 123 iounmap(ldata->base); 124 kfree(ldata); 125 amba_release_regions(adev); 126 127 return 0; 128 } 129 130 static int pl031_probe(struct amba_device *adev, struct amba_id *id) 131 { 132 int ret; 133 struct pl031_local *ldata; 134 135 ret = amba_request_regions(adev, NULL); 136 if (ret) 137 goto err_req; 138 139 ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL); 140 if (!ldata) { 141 ret = -ENOMEM; 142 goto out; 143 } 144 145 ldata->base = ioremap(adev->res.start, resource_size(&adev->res)); 146 if (!ldata->base) { 147 ret = -ENOMEM; 148 goto out_no_remap; 149 } 150 151 amba_set_drvdata(adev, ldata); 152 153 if (request_irq(adev->irq[0], pl031_interrupt, IRQF_DISABLED, 154 "rtc-pl031", ldata->rtc)) { 155 ret = -EIO; 156 goto out_no_irq; 157 } 158 159 ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops, 160 THIS_MODULE); 161 if (IS_ERR(ldata->rtc)) { 162 ret = PTR_ERR(ldata->rtc); 163 goto out_no_rtc; 164 } 165 166 return 0; 167 168 out_no_rtc: 169 free_irq(adev->irq[0], ldata->rtc); 170 out_no_irq: 171 iounmap(ldata->base); 172 amba_set_drvdata(adev, NULL); 173 out_no_remap: 174 kfree(ldata); 175 out: 176 amba_release_regions(adev); 177 err_req: 178 return ret; 179 } 180 181 static struct amba_id pl031_ids[] __initdata = { 182 { 183 .id = 0x00041031, 184 .mask = 0x000fffff, 185 }, 186 {0, 0}, 187 }; 188 189 static struct amba_driver pl031_driver = { 190 .drv = { 191 .name = "rtc-pl031", 192 }, 193 .id_table = pl031_ids, 194 .probe = pl031_probe, 195 .remove = pl031_remove, 196 }; 197 198 static int __init pl031_init(void) 199 { 200 return amba_driver_register(&pl031_driver); 201 } 202 203 static void __exit pl031_exit(void) 204 { 205 amba_driver_unregister(&pl031_driver); 206 } 207 208 module_init(pl031_init); 209 module_exit(pl031_exit); 210 211 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net"); 212 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 213 MODULE_LICENSE("GPL"); 214