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_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 39 { 40 return -ENOIOCTLCMD; 41 } 42 43 static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 44 { 45 struct pl030_rtc *rtc = dev_get_drvdata(dev); 46 47 rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time); 48 return 0; 49 } 50 51 static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 52 { 53 struct pl030_rtc *rtc = dev_get_drvdata(dev); 54 unsigned long time; 55 int ret; 56 57 /* 58 * At the moment, we can only deal with non-wildcarded alarm times. 59 */ 60 ret = rtc_valid_tm(&alrm->time); 61 if (ret == 0) 62 ret = rtc_tm_to_time(&alrm->time, &time); 63 if (ret == 0) 64 writel(time, rtc->base + RTC_MR); 65 return ret; 66 } 67 68 static int pl030_read_time(struct device *dev, struct rtc_time *tm) 69 { 70 struct pl030_rtc *rtc = dev_get_drvdata(dev); 71 72 rtc_time_to_tm(readl(rtc->base + RTC_DR), tm); 73 74 return 0; 75 } 76 77 /* 78 * Set the RTC time. Unfortunately, we can't accurately set 79 * the point at which the counter updates. 80 * 81 * Also, since RTC_LR is transferred to RTC_CR on next rising 82 * edge of the 1Hz clock, we must write the time one second 83 * in advance. 84 */ 85 static int pl030_set_time(struct device *dev, struct rtc_time *tm) 86 { 87 struct pl030_rtc *rtc = dev_get_drvdata(dev); 88 unsigned long time; 89 int ret; 90 91 ret = rtc_tm_to_time(tm, &time); 92 if (ret == 0) 93 writel(time + 1, rtc->base + RTC_LR); 94 95 return ret; 96 } 97 98 static const struct rtc_class_ops pl030_ops = { 99 .ioctl = pl030_ioctl, 100 .read_time = pl030_read_time, 101 .set_time = pl030_set_time, 102 .read_alarm = pl030_read_alarm, 103 .set_alarm = pl030_set_alarm, 104 }; 105 106 static int pl030_probe(struct amba_device *dev, struct amba_id *id) 107 { 108 struct pl030_rtc *rtc; 109 int ret; 110 111 ret = amba_request_regions(dev, NULL); 112 if (ret) 113 goto err_req; 114 115 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL); 116 if (!rtc) { 117 ret = -ENOMEM; 118 goto err_rtc; 119 } 120 121 rtc->base = ioremap(dev->res.start, resource_size(&dev->res)); 122 if (!rtc->base) { 123 ret = -ENOMEM; 124 goto err_map; 125 } 126 127 __raw_writel(0, rtc->base + RTC_CR); 128 __raw_writel(0, rtc->base + RTC_EOI); 129 130 amba_set_drvdata(dev, rtc); 131 132 ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED, 133 "rtc-pl030", rtc); 134 if (ret) 135 goto err_irq; 136 137 rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops, 138 THIS_MODULE); 139 if (IS_ERR(rtc->rtc)) { 140 ret = PTR_ERR(rtc->rtc); 141 goto err_reg; 142 } 143 144 return 0; 145 146 err_reg: 147 free_irq(dev->irq[0], rtc); 148 err_irq: 149 iounmap(rtc->base); 150 err_map: 151 kfree(rtc); 152 err_rtc: 153 amba_release_regions(dev); 154 err_req: 155 return ret; 156 } 157 158 static int pl030_remove(struct amba_device *dev) 159 { 160 struct pl030_rtc *rtc = amba_get_drvdata(dev); 161 162 amba_set_drvdata(dev, NULL); 163 164 writel(0, rtc->base + RTC_CR); 165 166 free_irq(dev->irq[0], rtc); 167 rtc_device_unregister(rtc->rtc); 168 iounmap(rtc->base); 169 kfree(rtc); 170 amba_release_regions(dev); 171 172 return 0; 173 } 174 175 static struct amba_id pl030_ids[] = { 176 { 177 .id = 0x00041030, 178 .mask = 0x000fffff, 179 }, 180 { 0, 0 }, 181 }; 182 183 static struct amba_driver pl030_driver = { 184 .drv = { 185 .name = "rtc-pl030", 186 }, 187 .probe = pl030_probe, 188 .remove = pl030_remove, 189 .id_table = pl030_ids, 190 }; 191 192 static int __init pl030_init(void) 193 { 194 return amba_driver_register(&pl030_driver); 195 } 196 197 static void __exit pl030_exit(void) 198 { 199 amba_driver_unregister(&pl030_driver); 200 } 201 202 module_init(pl030_init); 203 module_exit(pl030_exit); 204 205 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 206 MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver"); 207 MODULE_LICENSE("GPL"); 208