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 <mach/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_proc(struct device *dev, struct seq_file *seq) 53 { 54 unsigned short preload, delete; 55 56 ep93xx_get_swcomp(dev, &preload, &delete); 57 58 seq_printf(seq, "preload\t\t: %d\n", preload); 59 seq_printf(seq, "delete\t\t: %d\n", delete); 60 61 return 0; 62 } 63 64 static const struct rtc_class_ops ep93xx_rtc_ops = { 65 .read_time = ep93xx_rtc_read_time, 66 .set_mmss = ep93xx_rtc_set_mmss, 67 .proc = ep93xx_rtc_proc, 68 }; 69 70 static ssize_t ep93xx_sysfs_show_comp_preload(struct device *dev, 71 struct device_attribute *attr, char *buf) 72 { 73 unsigned short preload; 74 75 ep93xx_get_swcomp(dev, &preload, NULL); 76 77 return sprintf(buf, "%d\n", preload); 78 } 79 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_sysfs_show_comp_preload, NULL); 80 81 static ssize_t ep93xx_sysfs_show_comp_delete(struct device *dev, 82 struct device_attribute *attr, char *buf) 83 { 84 unsigned short delete; 85 86 ep93xx_get_swcomp(dev, NULL, &delete); 87 88 return sprintf(buf, "%d\n", delete); 89 } 90 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_sysfs_show_comp_delete, NULL); 91 92 93 static int __devinit ep93xx_rtc_probe(struct platform_device *dev) 94 { 95 struct rtc_device *rtc = rtc_device_register("ep93xx", 96 &dev->dev, &ep93xx_rtc_ops, THIS_MODULE); 97 98 if (IS_ERR(rtc)) { 99 return PTR_ERR(rtc); 100 } 101 102 platform_set_drvdata(dev, rtc); 103 104 device_create_file(&dev->dev, &dev_attr_comp_preload); 105 device_create_file(&dev->dev, &dev_attr_comp_delete); 106 107 return 0; 108 } 109 110 static int __devexit ep93xx_rtc_remove(struct platform_device *dev) 111 { 112 struct rtc_device *rtc = platform_get_drvdata(dev); 113 114 if (rtc) 115 rtc_device_unregister(rtc); 116 117 platform_set_drvdata(dev, NULL); 118 119 return 0; 120 } 121 122 /* work with hotplug and coldplug */ 123 MODULE_ALIAS("platform:ep93xx-rtc"); 124 125 static struct platform_driver ep93xx_rtc_platform_driver = { 126 .driver = { 127 .name = "ep93xx-rtc", 128 .owner = THIS_MODULE, 129 }, 130 .probe = ep93xx_rtc_probe, 131 .remove = __devexit_p(ep93xx_rtc_remove), 132 }; 133 134 static int __init ep93xx_rtc_init(void) 135 { 136 return platform_driver_register(&ep93xx_rtc_platform_driver); 137 } 138 139 static void __exit ep93xx_rtc_exit(void) 140 { 141 platform_driver_unregister(&ep93xx_rtc_platform_driver); 142 } 143 144 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 145 MODULE_DESCRIPTION("EP93XX RTC driver"); 146 MODULE_LICENSE("GPL"); 147 MODULE_VERSION(DRV_VERSION); 148 149 module_init(ep93xx_rtc_init); 150 module_exit(ep93xx_rtc_exit); 151