drivers/rtc/rtc-ep93xx.c

   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);