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_open(struct device *dev) 49 { 50 /* 51 * We request IRQ in pl031_probe, so nothing to do here... 52 */ 53 return 0; 54 } 55 56 static void pl031_release(struct device *dev) 57 { 58 } 59 60 static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 61 { 62 struct pl031_local *ldata = dev_get_drvdata(dev); 63 64 switch (cmd) { 65 case RTC_AIE_OFF: 66 __raw_writel(1, ldata->base + RTC_MIS); 67 return 0; 68 case RTC_AIE_ON: 69 __raw_writel(0, ldata->base + RTC_MIS); 70 return 0; 71 } 72 73 return -ENOIOCTLCMD; 74 } 75 76 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 77 { 78 struct pl031_local *ldata = dev_get_drvdata(dev); 79 80 rtc_time_to_tm(__raw_readl(ldata->base + RTC_DR), tm); 81 82 return 0; 83 } 84 85 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 86 { 87 unsigned long time; 88 struct pl031_local *ldata = dev_get_drvdata(dev); 89 90 rtc_tm_to_time(tm, &time); 91 __raw_writel(time, ldata->base + RTC_LR); 92 93 return 0; 94 } 95 96 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 97 { 98 struct pl031_local *ldata = dev_get_drvdata(dev); 99 100 rtc_time_to_tm(__raw_readl(ldata->base + RTC_MR), &alarm->time); 101 alarm->pending = __raw_readl(ldata->base + RTC_RIS); 102 alarm->enabled = __raw_readl(ldata->base + RTC_IMSC); 103 104 return 0; 105 } 106 107 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 108 { 109 struct pl031_local *ldata = dev_get_drvdata(dev); 110 unsigned long time; 111 112 rtc_tm_to_time(&alarm->time, &time); 113 114 __raw_writel(time, ldata->base + RTC_MR); 115 __raw_writel(!alarm->enabled, ldata->base + RTC_MIS); 116 117 return 0; 118 } 119 120 static const struct rtc_class_ops pl031_ops = { 121 .open = pl031_open, 122 .release = pl031_release, 123 .ioctl = pl031_ioctl, 124 .read_time = pl031_read_time, 125 .set_time = pl031_set_time, 126 .read_alarm = pl031_read_alarm, 127 .set_alarm = pl031_set_alarm, 128 }; 129 130 static int pl031_remove(struct amba_device *adev) 131 { 132 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 133 134 amba_set_drvdata(adev, NULL); 135 free_irq(adev->irq[0], ldata->rtc); 136 rtc_device_unregister(ldata->rtc); 137 iounmap(ldata->base); 138 kfree(ldata); 139 amba_release_regions(adev); 140 141 return 0; 142 } 143 144 static int pl031_probe(struct amba_device *adev, void *id) 145 { 146 int ret; 147 struct pl031_local *ldata; 148 149 ret = amba_request_regions(adev, NULL); 150 if (ret) 151 goto err_req; 152 153 ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL); 154 if (!ldata) { 155 ret = -ENOMEM; 156 goto out; 157 } 158 159 ldata->base = ioremap(adev->res.start, 160 adev->res.end - adev->res.start + 1); 161 if (!ldata->base) { 162 ret = -ENOMEM; 163 goto out_no_remap; 164 } 165 166 amba_set_drvdata(adev, ldata); 167 168 if (request_irq(adev->irq[0], pl031_interrupt, IRQF_DISABLED, 169 "rtc-pl031", ldata->rtc)) { 170 ret = -EIO; 171 goto out_no_irq; 172 } 173 174 ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops, 175 THIS_MODULE); 176 if (IS_ERR(ldata->rtc)) { 177 ret = PTR_ERR(ldata->rtc); 178 goto out_no_rtc; 179 } 180 181 return 0; 182 183 out_no_rtc: 184 free_irq(adev->irq[0], ldata->rtc); 185 out_no_irq: 186 iounmap(ldata->base); 187 amba_set_drvdata(adev, NULL); 188 out_no_remap: 189 kfree(ldata); 190 out: 191 amba_release_regions(adev); 192 err_req: 193 return ret; 194 } 195 196 static struct amba_id pl031_ids[] __initdata = { 197 { 198 .id = 0x00041031, 199 .mask = 0x000fffff, }, 200 {0, 0}, 201 }; 202 203 static struct amba_driver pl031_driver = { 204 .drv = { 205 .name = "rtc-pl031", 206 }, 207 .id_table = pl031_ids, 208 .probe = pl031_probe, 209 .remove = pl031_remove, 210 }; 211 212 static int __init pl031_init(void) 213 { 214 return amba_driver_register(&pl031_driver); 215 } 216 217 static void __exit pl031_exit(void) 218 { 219 amba_driver_unregister(&pl031_driver); 220 } 221 222 module_init(pl031_init); 223 module_exit(pl031_exit); 224 225 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net"); 226 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 227 MODULE_LICENSE("GPL"); 228