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_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 38 { 39 return -ENOIOCTLCMD; 40 } 41 42 static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 43 { 44 struct pl030_rtc *rtc = dev_get_drvdata(dev); 45 46 rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time); 47 return 0; 48 } 49 50 static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 51 { 52 struct pl030_rtc *rtc = dev_get_drvdata(dev); 53 unsigned long time; 54 int ret; 55 56 /* 57 * At the moment, we can only deal with non-wildcarded alarm times. 58 */ 59 ret = rtc_valid_tm(&alrm->time); 60 if (ret == 0) 61 ret = rtc_tm_to_time(&alrm->time, &time); 62 if (ret == 0) 63 writel(time, rtc->base + RTC_MR); 64 return ret; 65 } 66 67 static int pl030_read_time(struct device *dev, struct rtc_time *tm) 68 { 69 struct pl030_rtc *rtc = dev_get_drvdata(dev); 70 71 rtc_time_to_tm(readl(rtc->base + RTC_DR), tm); 72 73 return 0; 74 } 75 76 /* 77 * Set the RTC time. Unfortunately, we can't accurately set 78 * the point at which the counter updates. 79 * 80 * Also, since RTC_LR is transferred to RTC_CR on next rising 81 * edge of the 1Hz clock, we must write the time one second 82 * in advance. 83 */ 84 static int pl030_set_time(struct device *dev, struct rtc_time *tm) 85 { 86 struct pl030_rtc *rtc = dev_get_drvdata(dev); 87 unsigned long time; 88 int ret; 89 90 ret = rtc_tm_to_time(tm, &time); 91 if (ret == 0) 92 writel(time + 1, rtc->base + RTC_LR); 93 94 return ret; 95 } 96 97 static const struct rtc_class_ops pl030_ops = { 98 .ioctl = pl030_ioctl, 99 .read_time = pl030_read_time, 100 .set_time = pl030_set_time, 101 .read_alarm = pl030_read_alarm, 102 .set_alarm = pl030_set_alarm, 103 }; 104 105 static int pl030_probe(struct amba_device *dev, struct amba_id *id) 106 { 107 struct pl030_rtc *rtc; 108 int ret; 109 110 ret = amba_request_regions(dev, NULL); 111 if (ret) 112 goto err_req; 113 114 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL); 115 if (!rtc) { 116 ret = -ENOMEM; 117 goto err_rtc; 118 } 119 120 rtc->base = ioremap(dev->res.start, resource_size(&dev->res)); 121 if (!rtc->base) { 122 ret = -ENOMEM; 123 goto err_map; 124 } 125 126 __raw_writel(0, rtc->base + RTC_CR); 127 __raw_writel(0, rtc->base + RTC_EOI); 128 129 amba_set_drvdata(dev, rtc); 130 131 ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED, 132 "rtc-pl030", rtc); 133 if (ret) 134 goto err_irq; 135 136 rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops, 137 THIS_MODULE); 138 if (IS_ERR(rtc->rtc)) { 139 ret = PTR_ERR(rtc->rtc); 140 goto err_reg; 141 } 142 143 return 0; 144 145 err_reg: 146 free_irq(dev->irq[0], rtc); 147 err_irq: 148 iounmap(rtc->base); 149 err_map: 150 kfree(rtc); 151 err_rtc: 152 amba_release_regions(dev); 153 err_req: 154 return ret; 155 } 156 157 static int pl030_remove(struct amba_device *dev) 158 { 159 struct pl030_rtc *rtc = amba_get_drvdata(dev); 160 161 amba_set_drvdata(dev, NULL); 162 163 writel(0, rtc->base + RTC_CR); 164 165 free_irq(dev->irq[0], rtc); 166 rtc_device_unregister(rtc->rtc); 167 iounmap(rtc->base); 168 kfree(rtc); 169 amba_release_regions(dev); 170 171 return 0; 172 } 173 174 static struct amba_id pl030_ids[] = { 175 { 176 .id = 0x00041030, 177 .mask = 0x000fffff, 178 }, 179 { 0, 0 }, 180 }; 181 182 static struct amba_driver pl030_driver = { 183 .drv = { 184 .name = "rtc-pl030", 185 }, 186 .probe = pl030_probe, 187 .remove = pl030_remove, 188 .id_table = pl030_ids, 189 }; 190 191 static int __init pl030_init(void) 192 { 193 return amba_driver_register(&pl030_driver); 194 } 195 196 static void __exit pl030_exit(void) 197 { 198 amba_driver_unregister(&pl030_driver); 199 } 200 201 module_init(pl030_init); 202 module_exit(pl030_exit); 203 204 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 205 MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver"); 206 MODULE_LICENSE("GPL"); 207