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 #include <linux/slab.h> 17 18 #define RTC_DR (0) 19 #define RTC_MR (4) 20 #define RTC_STAT (8) 21 #define RTC_EOI (8) 22 #define RTC_LR (12) 23 #define RTC_CR (16) 24 #define RTC_CR_MIE (1 << 0) 25 26 struct pl030_rtc { 27 struct rtc_device *rtc; 28 void __iomem *base; 29 }; 30 31 static irqreturn_t pl030_interrupt(int irq, void *dev_id) 32 { 33 struct pl030_rtc *rtc = dev_id; 34 writel(0, rtc->base + RTC_EOI); 35 return IRQ_HANDLED; 36 } 37 38 static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 39 { 40 struct pl030_rtc *rtc = dev_get_drvdata(dev); 41 42 rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time); 43 return 0; 44 } 45 46 static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 47 { 48 struct pl030_rtc *rtc = dev_get_drvdata(dev); 49 unsigned long time; 50 int ret; 51 52 /* 53 * At the moment, we can only deal with non-wildcarded alarm times. 54 */ 55 ret = rtc_valid_tm(&alrm->time); 56 if (ret == 0) 57 ret = rtc_tm_to_time(&alrm->time, &time); 58 if (ret == 0) 59 writel(time, rtc->base + RTC_MR); 60 return ret; 61 } 62 63 static int pl030_read_time(struct device *dev, struct rtc_time *tm) 64 { 65 struct pl030_rtc *rtc = dev_get_drvdata(dev); 66 67 rtc_time_to_tm(readl(rtc->base + RTC_DR), tm); 68 69 return 0; 70 } 71 72 /* 73 * Set the RTC time. Unfortunately, we can't accurately set 74 * the point at which the counter updates. 75 * 76 * Also, since RTC_LR is transferred to RTC_CR on next rising 77 * edge of the 1Hz clock, we must write the time one second 78 * in advance. 79 */ 80 static int pl030_set_time(struct device *dev, struct rtc_time *tm) 81 { 82 struct pl030_rtc *rtc = dev_get_drvdata(dev); 83 unsigned long time; 84 int ret; 85 86 ret = rtc_tm_to_time(tm, &time); 87 if (ret == 0) 88 writel(time + 1, rtc->base + RTC_LR); 89 90 return ret; 91 } 92 93 static const struct rtc_class_ops pl030_ops = { 94 .read_time = pl030_read_time, 95 .set_time = pl030_set_time, 96 .read_alarm = pl030_read_alarm, 97 .set_alarm = pl030_set_alarm, 98 }; 99 100 static int pl030_probe(struct amba_device *dev, const struct amba_id *id) 101 { 102 struct pl030_rtc *rtc; 103 int ret; 104 105 ret = amba_request_regions(dev, NULL); 106 if (ret) 107 goto err_req; 108 109 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL); 110 if (!rtc) { 111 ret = -ENOMEM; 112 goto err_rtc; 113 } 114 115 rtc->base = ioremap(dev->res.start, resource_size(&dev->res)); 116 if (!rtc->base) { 117 ret = -ENOMEM; 118 goto err_map; 119 } 120 121 __raw_writel(0, rtc->base + RTC_CR); 122 __raw_writel(0, rtc->base + RTC_EOI); 123 124 amba_set_drvdata(dev, rtc); 125 126 ret = request_irq(dev->irq[0], pl030_interrupt, 0, 127 "rtc-pl030", rtc); 128 if (ret) 129 goto err_irq; 130 131 rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops, 132 THIS_MODULE); 133 if (IS_ERR(rtc->rtc)) { 134 ret = PTR_ERR(rtc->rtc); 135 goto err_reg; 136 } 137 138 return 0; 139 140 err_reg: 141 free_irq(dev->irq[0], rtc); 142 err_irq: 143 iounmap(rtc->base); 144 err_map: 145 kfree(rtc); 146 err_rtc: 147 amba_release_regions(dev); 148 err_req: 149 return ret; 150 } 151 152 static int pl030_remove(struct amba_device *dev) 153 { 154 struct pl030_rtc *rtc = amba_get_drvdata(dev); 155 156 amba_set_drvdata(dev, NULL); 157 158 writel(0, rtc->base + RTC_CR); 159 160 free_irq(dev->irq[0], rtc); 161 rtc_device_unregister(rtc->rtc); 162 iounmap(rtc->base); 163 kfree(rtc); 164 amba_release_regions(dev); 165 166 return 0; 167 } 168 169 static struct amba_id pl030_ids[] = { 170 { 171 .id = 0x00041030, 172 .mask = 0x000fffff, 173 }, 174 { 0, 0 }, 175 }; 176 177 MODULE_DEVICE_TABLE(amba, pl030_ids); 178 179 static struct amba_driver pl030_driver = { 180 .drv = { 181 .name = "rtc-pl030", 182 }, 183 .probe = pl030_probe, 184 .remove = pl030_remove, 185 .id_table = pl030_ids, 186 }; 187 188 module_amba_driver(pl030_driver); 189 190 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 191 MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver"); 192 MODULE_LICENSE("GPL"); 193