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, "24hr\t\t: yes\n"); 71 seq_printf(seq, "preload\t\t: %d\n", preload); 72 seq_printf(seq, "delete\t\t: %d\n", delete); 73 74 return 0; 75 } 76 77 static struct rtc_class_ops ep93xx_rtc_ops = { 78 .read_time = ep93xx_rtc_read_time, 79 .set_time = ep93xx_rtc_set_time, 80 .set_mmss = ep93xx_rtc_set_mmss, 81 .proc = ep93xx_rtc_proc, 82 }; 83 84 static ssize_t ep93xx_sysfs_show_comp_preload(struct device *dev, 85 struct device_attribute *attr, char *buf) 86 { 87 unsigned short preload; 88 89 ep93xx_get_swcomp(dev, &preload, NULL); 90 91 return sprintf(buf, "%d\n", preload); 92 } 93 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_sysfs_show_comp_preload, NULL); 94 95 static ssize_t ep93xx_sysfs_show_comp_delete(struct device *dev, 96 struct device_attribute *attr, char *buf) 97 { 98 unsigned short delete; 99 100 ep93xx_get_swcomp(dev, NULL, &delete); 101 102 return sprintf(buf, "%d\n", delete); 103 } 104 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_sysfs_show_comp_delete, NULL); 105 106 107 static int __devinit ep93xx_rtc_probe(struct platform_device *dev) 108 { 109 struct rtc_device *rtc = rtc_device_register("ep93xx", 110 &dev->dev, &ep93xx_rtc_ops, THIS_MODULE); 111 112 if (IS_ERR(rtc)) { 113 dev_err(&dev->dev, "unable to register\n"); 114 return PTR_ERR(rtc); 115 } 116 117 platform_set_drvdata(dev, rtc); 118 119 device_create_file(&dev->dev, &dev_attr_comp_preload); 120 device_create_file(&dev->dev, &dev_attr_comp_delete); 121 122 return 0; 123 } 124 125 static int __devexit ep93xx_rtc_remove(struct platform_device *dev) 126 { 127 struct rtc_device *rtc = platform_get_drvdata(dev); 128 129 if (rtc) 130 rtc_device_unregister(rtc); 131 132 platform_set_drvdata(dev, NULL); 133 134 return 0; 135 } 136 137 static struct platform_driver ep93xx_rtc_platform_driver = { 138 .driver = { 139 .name = "ep93xx-rtc", 140 .owner = THIS_MODULE, 141 }, 142 .probe = ep93xx_rtc_probe, 143 .remove = __devexit_p(ep93xx_rtc_remove), 144 }; 145 146 static int __init ep93xx_rtc_init(void) 147 { 148 return platform_driver_register(&ep93xx_rtc_platform_driver); 149 } 150 151 static void __exit ep93xx_rtc_exit(void) 152 { 153 platform_driver_unregister(&ep93xx_rtc_platform_driver); 154 } 155 156 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 157 MODULE_DESCRIPTION("EP93XX RTC driver"); 158 MODULE_LICENSE("GPL"); 159 MODULE_VERSION(DRV_VERSION); 160 161 module_init(ep93xx_rtc_init); 162 module_exit(ep93xx_rtc_exit); 163