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 <linux/io.h>
  16 #include <linux/gfp.h>
  17
  18 #define EP93XX_RTC_DATA                 0x000
  19 #define EP93XX_RTC_MATCH                0x004
  20 #define EP93XX_RTC_STATUS               0x008
  21 #define  EP93XX_RTC_STATUS_INTR          (1<<0)
  22 #define EP93XX_RTC_LOAD                 0x00C
  23 #define EP93XX_RTC_CONTROL              0x010
  24 #define  EP93XX_RTC_CONTROL_MIE          (1<<0)
  25 #define EP93XX_RTC_SWCOMP               0x108
  26 #define  EP93XX_RTC_SWCOMP_DEL_MASK      0x001f0000
  27 #define  EP93XX_RTC_SWCOMP_DEL_SHIFT     16
  28 #define  EP93XX_RTC_SWCOMP_INT_MASK      0x0000ffff
  29 #define  EP93XX_RTC_SWCOMP_INT_SHIFT     0
  30
  31 /*
  32  * struct device dev.platform_data is used to store our private data
  33  * because struct rtc_device does not have a variable to hold it.
  34  */
  35 struct ep93xx_rtc {
  36         void __iomem    *mmio_base;
  37         struct rtc_device *rtc;
  38 };
  39
  40 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
  41                                 unsigned short *delete)
  42 {
  43         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  44         unsigned long comp;
  45
  46         comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
  47
  48         if (preload)
  49                 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
  50                                 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
  51
  52         if (delete)
  53                 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
  54                                 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
  55
  56         return 0;
  57 }
  58
  59 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
  60 {
  61         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  62         unsigned long time;
  63
  64          time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
  65
  66         rtc_time_to_tm(time, tm);
  67         return 0;
  68 }
  69
  70 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
  71 {
  72         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  73
  74         writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
  75         return 0;
  76 }
  77
  78 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
  79 {
  80         unsigned short preload, delete;
  81
  82         ep93xx_rtc_get_swcomp(dev, &preload, &delete);
  83
  84         seq_printf(seq, "preload\t\t: %d\n", preload);
  85         seq_printf(seq, "delete\t\t: %d\n", delete);
  86
  87         return 0;
  88 }
  89
  90 static const struct rtc_class_ops ep93xx_rtc_ops = {
  91         .read_time      = ep93xx_rtc_read_time,
  92         .set_mmss       = ep93xx_rtc_set_mmss,
  93         .proc           = ep93xx_rtc_proc,
  94 };
  95
  96 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
  97                         struct device_attribute *attr, char *buf)
  98 {
  99         unsigned short preload;
 100
 101         ep93xx_rtc_get_swcomp(dev, &preload, NULL);
 102
 103         return sprintf(buf, "%d\n", preload);
 104 }
 105 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
 106
 107 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
 108                         struct device_attribute *attr, char *buf)
 109 {
 110         unsigned short delete;
 111
 112         ep93xx_rtc_get_swcomp(dev, NULL, &delete);
 113
 114         return sprintf(buf, "%d\n", delete);
 115 }
 116 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
 117
 118 static struct attribute *ep93xx_rtc_attrs[] = {
 119         &dev_attr_comp_preload.attr,
 120         &dev_attr_comp_delete.attr,
 121         NULL
 122 };
 123
 124 static const struct attribute_group ep93xx_rtc_sysfs_files = {
 125         .attrs  = ep93xx_rtc_attrs,
 126 };
 127
 128 static int ep93xx_rtc_probe(struct platform_device *pdev)
 129 {
 130         struct ep93xx_rtc *ep93xx_rtc;
 131         struct resource *res;
 132         int err;
 133
 134         ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
 135         if (!ep93xx_rtc)
 136                 return -ENOMEM;
 137
 138         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 139         ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
 140         if (IS_ERR(ep93xx_rtc->mmio_base))
 141                 return PTR_ERR(ep93xx_rtc->mmio_base);
 142
 143         pdev->dev.platform_data = ep93xx_rtc;
 144         platform_set_drvdata(pdev, ep93xx_rtc);
 145
 146         ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev,
 147                                 pdev->name, &ep93xx_rtc_ops, THIS_MODULE);
 148         if (IS_ERR(ep93xx_rtc->rtc)) {
 149                 err = PTR_ERR(ep93xx_rtc->rtc);
 150                 goto exit;
 151         }
 152
 153         err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 154         if (err)
 155                 goto exit;
 156
 157         return 0;
 158
 159 exit:
 160         pdev->dev.platform_data = NULL;
 161         return err;
 162 }
 163
 164 static int ep93xx_rtc_remove(struct platform_device *pdev)
 165 {
 166         sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 167         pdev->dev.platform_data = NULL;
 168
 169         return 0;
 170 }
 171
 172 static struct platform_driver ep93xx_rtc_driver = {
 173         .driver         = {
 174                 .name   = "ep93xx-rtc",
 175         },
 176         .probe          = ep93xx_rtc_probe,
 177         .remove         = ep93xx_rtc_remove,
 178 };
 179
 180 module_platform_driver(ep93xx_rtc_driver);
 181
 182 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 183 MODULE_DESCRIPTION("EP93XX RTC driver");
 184 MODULE_LICENSE("GPL");
 185 MODULE_ALIAS("platform:ep93xx-rtc");