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 #define DRV_VERSION "0.3"
  32
  33 /*
  34  * struct device dev.platform_data is used to store our private data
  35  * because struct rtc_device does not have a variable to hold it.
  36  */
  37 struct ep93xx_rtc {
  38         void __iomem    *mmio_base;
  39         struct rtc_device *rtc;
  40 };
  41
  42 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
  43                                 unsigned short *delete)
  44 {
  45         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  46         unsigned long comp;
  47
  48         comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
  49
  50         if (preload)
  51                 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
  52                                 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
  53
  54         if (delete)
  55                 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
  56                                 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
  57
  58         return 0;
  59 }
  60
  61 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
  62 {
  63         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  64         unsigned long time;
  65
  66          time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
  67
  68         rtc_time_to_tm(time, tm);
  69         return 0;
  70 }
  71
  72 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
  73 {
  74         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
  75
  76         writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
  77         return 0;
  78 }
  79
  80 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
  81 {
  82         unsigned short preload, delete;
  83
  84         ep93xx_rtc_get_swcomp(dev, &preload, &delete);
  85
  86         seq_printf(seq, "preload\t\t: %d\n", preload);
  87         seq_printf(seq, "delete\t\t: %d\n", delete);
  88
  89         return 0;
  90 }
  91
  92 static const struct rtc_class_ops ep93xx_rtc_ops = {
  93         .read_time      = ep93xx_rtc_read_time,
  94         .set_mmss       = ep93xx_rtc_set_mmss,
  95         .proc           = ep93xx_rtc_proc,
  96 };
  97
  98 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
  99                         struct device_attribute *attr, char *buf)
 100 {
 101         unsigned short preload;
 102
 103         ep93xx_rtc_get_swcomp(dev, &preload, NULL);
 104
 105         return sprintf(buf, "%d\n", preload);
 106 }
 107 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
 108
 109 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
 110                         struct device_attribute *attr, char *buf)
 111 {
 112         unsigned short delete;
 113
 114         ep93xx_rtc_get_swcomp(dev, NULL, &delete);
 115
 116         return sprintf(buf, "%d\n", delete);
 117 }
 118 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
 119
 120 static struct attribute *ep93xx_rtc_attrs[] = {
 121         &dev_attr_comp_preload.attr,
 122         &dev_attr_comp_delete.attr,
 123         NULL
 124 };
 125
 126 static const struct attribute_group ep93xx_rtc_sysfs_files = {
 127         .attrs  = ep93xx_rtc_attrs,
 128 };
 129
 130 static int ep93xx_rtc_probe(struct platform_device *pdev)
 131 {
 132         struct ep93xx_rtc *ep93xx_rtc;
 133         struct resource *res;
 134         int err;
 135
 136         ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
 137         if (!ep93xx_rtc)
 138                 return -ENOMEM;
 139
 140         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 141         ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
 142         if (IS_ERR(ep93xx_rtc->mmio_base))
 143                 return PTR_ERR(ep93xx_rtc->mmio_base);
 144
 145         pdev->dev.platform_data = ep93xx_rtc;
 146         platform_set_drvdata(pdev, ep93xx_rtc);
 147
 148         ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev,
 149                                 pdev->name, &ep93xx_rtc_ops, THIS_MODULE);
 150         if (IS_ERR(ep93xx_rtc->rtc)) {
 151                 err = PTR_ERR(ep93xx_rtc->rtc);
 152                 goto exit;
 153         }
 154
 155         err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 156         if (err)
 157                 goto exit;
 158
 159         return 0;
 160
 161 exit:
 162         pdev->dev.platform_data = NULL;
 163         return err;
 164 }
 165
 166 static int ep93xx_rtc_remove(struct platform_device *pdev)
 167 {
 168         sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 169         pdev->dev.platform_data = NULL;
 170
 171         return 0;
 172 }
 173
 174 static struct platform_driver ep93xx_rtc_driver = {
 175         .driver         = {
 176                 .name   = "ep93xx-rtc",
 177         },
 178         .probe          = ep93xx_rtc_probe,
 179         .remove         = ep93xx_rtc_remove,
 180 };
 181
 182 module_platform_driver(ep93xx_rtc_driver);
 183
 184 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 185 MODULE_DESCRIPTION("EP93XX RTC driver");
 186 MODULE_LICENSE("GPL");
 187 MODULE_VERSION(DRV_VERSION);
 188 MODULE_ALIAS("platform:ep93xx-rtc");