1 /* 2 * linux/drivers/rtc/rtc-pl030.c 3 * 4 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/module.h> 11 #include <linux/rtc.h> 12 #include <linux/init.h> 13 #include <linux/interrupt.h> 14 #include <linux/amba/bus.h> 15 #include <linux/io.h> 16 17 #define RTC_DR (0) 18 #define RTC_MR (4) 19 #define RTC_STAT (8) 20 #define RTC_EOI (8) 21 #define RTC_LR (12) 22 #define RTC_CR (16) 23 #define RTC_CR_MIE (1 << 0) 24 25 struct pl030_rtc { 26 struct rtc_device *rtc; 27 void __iomem *base; 28 }; 29 30 static irqreturn_t pl030_interrupt(int irq, void *dev_id) 31 { 32 struct pl030_rtc *rtc = dev_id; 33 writel(0, rtc->base + RTC_EOI); 34 return IRQ_HANDLED; 35 } 36 37 static int pl030_open(struct device *dev) 38 { 39 return 0; 40 } 41 42 static void pl030_release(struct device *dev) 43 { 44 } 45 46 static int pl030_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 47 { 48 return -ENOIOCTLCMD; 49 } 50 51 static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 52 { 53 struct pl030_rtc *rtc = dev_get_drvdata(dev); 54 55 rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time); 56 return 0; 57 } 58 59 static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 60 { 61 struct pl030_rtc *rtc = dev_get_drvdata(dev); 62 unsigned long time; 63 int ret; 64 65 /* 66 * At the moment, we can only deal with non-wildcarded alarm times. 67 */ 68 ret = rtc_valid_tm(&alrm->time); 69 if (ret == 0) 70 ret = rtc_tm_to_time(&alrm->time, &time); 71 if (ret == 0) 72 writel(time, rtc->base + RTC_MR); 73 return ret; 74 } 75 76 static int pl030_read_time(struct device *dev, struct rtc_time *tm) 77 { 78 struct pl030_rtc *rtc = dev_get_drvdata(dev); 79 80 rtc_time_to_tm(readl(rtc->base + RTC_DR), tm); 81 82 return 0; 83 } 84 85 /* 86 * Set the RTC time. Unfortunately, we can't accurately set 87 * the point at which the counter updates. 88 * 89 * Also, since RTC_LR is transferred to RTC_CR on next rising 90 * edge of the 1Hz clock, we must write the time one second 91 * in advance. 92 */ 93 static int pl030_set_time(struct device *dev, struct rtc_time *tm) 94 { 95 struct pl030_rtc *rtc = dev_get_drvdata(dev); 96 unsigned long time; 97 int ret; 98 99 ret = rtc_tm_to_time(tm, &time); 100 if (ret == 0) 101 writel(time + 1, rtc->base + RTC_LR); 102 103 return ret; 104 } 105 106 static const struct rtc_class_ops pl030_ops = { 107 .open = pl030_open, 108 .release = pl030_release, 109 .ioctl = pl030_ioctl, 110 .read_time = pl030_read_time, 111 .set_time = pl030_set_time, 112 .read_alarm = pl030_read_alarm, 113 .set_alarm = pl030_set_alarm, 114 }; 115 116 static int pl030_probe(struct amba_device *dev, void *id) 117 { 118 struct pl030_rtc *rtc; 119 int ret; 120 121 ret = amba_request_regions(dev, NULL); 122 if (ret) 123 goto err_req; 124 125 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL); 126 if (!rtc) { 127 ret = -ENOMEM; 128 goto err_rtc; 129 } 130 131 rtc->base = ioremap(dev->res.start, SZ_4K); 132 if (!rtc->base) { 133 ret = -ENOMEM; 134 goto err_map; 135 } 136 137 __raw_writel(0, rtc->base + RTC_CR); 138 __raw_writel(0, rtc->base + RTC_EOI); 139 140 amba_set_drvdata(dev, rtc); 141 142 ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED, 143 "rtc-pl030", rtc); 144 if (ret) 145 goto err_irq; 146 147 rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops, 148 THIS_MODULE); 149 if (IS_ERR(rtc->rtc)) { 150 ret = PTR_ERR(rtc->rtc); 151 goto err_reg; 152 } 153 154 return 0; 155 156 err_reg: 157 free_irq(dev->irq[0], rtc); 158 err_irq: 159 iounmap(rtc->base); 160 err_map: 161 kfree(rtc); 162 err_rtc: 163 amba_release_regions(dev); 164 err_req: 165 return ret; 166 } 167 168 static int pl030_remove(struct amba_device *dev) 169 { 170 struct pl030_rtc *rtc = amba_get_drvdata(dev); 171 172 amba_set_drvdata(dev, NULL); 173 174 writel(0, rtc->base + RTC_CR); 175 176 free_irq(dev->irq[0], rtc); 177 rtc_device_unregister(rtc->rtc); 178 iounmap(rtc->base); 179 kfree(rtc); 180 amba_release_regions(dev); 181 182 return 0; 183 } 184 185 static struct amba_id pl030_ids[] = { 186 { 187 .id = 0x00041030, 188 .mask = 0x000fffff, 189 }, 190 { 0, 0 }, 191 }; 192 193 static struct amba_driver pl030_driver = { 194 .drv = { 195 .name = "rtc-pl030", 196 }, 197 .probe = pl030_probe, 198 .remove = pl030_remove, 199 .id_table = pl030_ids, 200 }; 201 202 static int __init pl030_init(void) 203 { 204 return amba_driver_register(&pl030_driver); 205 } 206 207 static void __exit pl030_exit(void) 208 { 209 amba_driver_unregister(&pl030_driver); 210 } 211 212 module_init(pl030_init); 213 module_exit(pl030_exit); 214 215 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 216 MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver"); 217 MODULE_LICENSE("GPL"); 218