1 /* 2 * A driver for the RTC embedded in the Cirrus Logic EP93XX processors 3 * Copyright (c) 2006 Tower Technologies 4 * 5 * Author: Alessandro Zummo <a.zummo@towertech.it> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/rtc.h> 14 #include <linux/platform_device.h> 15 #include <asm/hardware.h> 16 17 #define EP93XX_RTC_REG(x) (EP93XX_RTC_BASE + (x)) 18 #define EP93XX_RTC_DATA EP93XX_RTC_REG(0x0000) 19 #define EP93XX_RTC_LOAD EP93XX_RTC_REG(0x000C) 20 #define EP93XX_RTC_SWCOMP EP93XX_RTC_REG(0x0108) 21 22 #define DRV_VERSION "0.2" 23 24 static int ep93xx_get_swcomp(struct device *dev, unsigned short *preload, 25 unsigned short *delete) 26 { 27 unsigned short comp = __raw_readl(EP93XX_RTC_SWCOMP); 28 29 if (preload) 30 *preload = comp & 0xffff; 31 32 if (delete) 33 *delete = (comp >> 16) & 0x1f; 34 35 return 0; 36 } 37 38 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 39 { 40 unsigned long time = __raw_readl(EP93XX_RTC_DATA); 41 42 rtc_time_to_tm(time, tm); 43 return 0; 44 } 45 46 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs) 47 { 48 __raw_writel(secs + 1, EP93XX_RTC_LOAD); 49 return 0; 50 } 51 52 static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm) 53 { 54 int err; 55 unsigned long secs; 56 57 err = rtc_tm_to_time(tm, &secs); 58 if (err != 0) 59 return err; 60 61 return ep93xx_rtc_set_mmss(dev, secs); 62 } 63 64 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 65 { 66 unsigned short preload, delete; 67 68 ep93xx_get_swcomp(dev, &preload, &delete); 69 70 seq_printf(seq, "preload\t\t: %d\n", preload); 71 seq_printf(seq, "delete\t\t: %d\n", delete); 72 73 return 0; 74 } 75 76 static const struct rtc_class_ops ep93xx_rtc_ops = { 77 .read_time = ep93xx_rtc_read_time, 78 .set_time = ep93xx_rtc_set_time, 79 .set_mmss = ep93xx_rtc_set_mmss, 80 .proc = ep93xx_rtc_proc, 81 }; 82 83 static ssize_t ep93xx_sysfs_show_comp_preload(struct device *dev, 84 struct device_attribute *attr, char *buf) 85 { 86 unsigned short preload; 87 88 ep93xx_get_swcomp(dev, &preload, NULL); 89 90 return sprintf(buf, "%d\n", preload); 91 } 92 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_sysfs_show_comp_preload, NULL); 93 94 static ssize_t ep93xx_sysfs_show_comp_delete(struct device *dev, 95 struct device_attribute *attr, char *buf) 96 { 97 unsigned short delete; 98 99 ep93xx_get_swcomp(dev, NULL, &delete); 100 101 return sprintf(buf, "%d\n", delete); 102 } 103 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_sysfs_show_comp_delete, NULL); 104 105 106 static int __devinit ep93xx_rtc_probe(struct platform_device *dev) 107 { 108 struct rtc_device *rtc = rtc_device_register("ep93xx", 109 &dev->dev, &ep93xx_rtc_ops, THIS_MODULE); 110 111 if (IS_ERR(rtc)) { 112 return PTR_ERR(rtc); 113 } 114 115 platform_set_drvdata(dev, rtc); 116 117 device_create_file(&dev->dev, &dev_attr_comp_preload); 118 device_create_file(&dev->dev, &dev_attr_comp_delete); 119 120 return 0; 121 } 122 123 static int __devexit ep93xx_rtc_remove(struct platform_device *dev) 124 { 125 struct rtc_device *rtc = platform_get_drvdata(dev); 126 127 if (rtc) 128 rtc_device_unregister(rtc); 129 130 platform_set_drvdata(dev, NULL); 131 132 return 0; 133 } 134 135 /* work with hotplug and coldplug */ 136 MODULE_ALIAS("platform:ep93xx-rtc"); 137 138 static struct platform_driver ep93xx_rtc_platform_driver = { 139 .driver = { 140 .name = "ep93xx-rtc", 141 .owner = THIS_MODULE, 142 }, 143 .probe = ep93xx_rtc_probe, 144 .remove = __devexit_p(ep93xx_rtc_remove), 145 }; 146 147 static int __init ep93xx_rtc_init(void) 148 { 149 return platform_driver_register(&ep93xx_rtc_platform_driver); 150 } 151 152 static void __exit ep93xx_rtc_exit(void) 153 { 154 platform_driver_unregister(&ep93xx_rtc_platform_driver); 155 } 156 157 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 158 MODULE_DESCRIPTION("EP93XX RTC driver"); 159 MODULE_LICENSE("GPL"); 160 MODULE_VERSION(DRV_VERSION); 161 162 module_init(ep93xx_rtc_init); 163 module_exit(ep93xx_rtc_exit); 164