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
  17 #define EP93XX_RTC_DATA                 0x000
  18 #define EP93XX_RTC_MATCH                0x004
  19 #define EP93XX_RTC_STATUS               0x008
  20 #define  EP93XX_RTC_STATUS_INTR          (1<<0)
  21 #define EP93XX_RTC_LOAD                 0x00C
  22 #define EP93XX_RTC_CONTROL              0x010
  23 #define  EP93XX_RTC_CONTROL_MIE          (1<<0)
  24 #define EP93XX_RTC_SWCOMP               0x108
  25 #define  EP93XX_RTC_SWCOMP_DEL_MASK      0x001f0000
  26 #define  EP93XX_RTC_SWCOMP_DEL_SHIFT     16
  27 #define  EP93XX_RTC_SWCOMP_INT_MASK      0x0000ffff
  28 #define  EP93XX_RTC_SWCOMP_INT_SHIFT     0
  29
  30 #define DRV_VERSION "0.3"
  31
  32 /*
  33  * struct device dev.platform_data is used to store our private data
  34  * because struct rtc_device does not have a variable to hold it.
  35  */
  36 struct ep93xx_rtc {
  37         void __iomem    *mmio_base;
  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->platform_data;
  44         unsigned long comp;
  45
  46         comp = __raw_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->platform_data;
  62         unsigned long time;
  63
  64          time = __raw_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->platform_data;
  73
  74         __raw_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 __init ep93xx_rtc_probe(struct platform_device *pdev)
 129 {
 130         struct ep93xx_rtc *ep93xx_rtc;
 131         struct resource *res;
 132         struct rtc_device *rtc;
 133         int err;
 134
 135         ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
 136         if (!ep93xx_rtc)
 137                 return -ENOMEM;
 138
 139         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 140         if (!res)
 141                 return -ENXIO;
 142
 143         if (!devm_request_mem_region(&pdev->dev, res->start,
 144                                      resource_size(res), pdev->name))
 145                 return -EBUSY;
 146
 147         ep93xx_rtc->mmio_base = devm_ioremap(&pdev->dev, res->start,
 148                                              resource_size(res));
 149         if (!ep93xx_rtc->mmio_base)
 150                 return -ENXIO;
 151
 152         pdev->dev.platform_data = ep93xx_rtc;
 153
 154         rtc = rtc_device_register(pdev->name,
 155                                 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE);
 156         if (IS_ERR(rtc)) {
 157                 err = PTR_ERR(rtc);
 158                 goto exit;
 159         }
 160
 161         platform_set_drvdata(pdev, rtc);
 162
 163         err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 164         if (err)
 165                 goto fail;
 166
 167         return 0;
 168
 169 fail:
 170         platform_set_drvdata(pdev, NULL);
 171         rtc_device_unregister(rtc);
 172 exit:
 173         pdev->dev.platform_data = NULL;
 174         return err;
 175 }
 176
 177 static int __exit ep93xx_rtc_remove(struct platform_device *pdev)
 178 {
 179         struct rtc_device *rtc = platform_get_drvdata(pdev);
 180
 181         sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 182         platform_set_drvdata(pdev, NULL);
 183         rtc_device_unregister(rtc);
 184         pdev->dev.platform_data = NULL;
 185
 186         return 0;
 187 }
 188
 189 /* work with hotplug and coldplug */
 190 MODULE_ALIAS("platform:ep93xx-rtc");
 191
 192 static struct platform_driver ep93xx_rtc_driver = {
 193         .driver         = {
 194                 .name   = "ep93xx-rtc",
 195                 .owner  = THIS_MODULE,
 196         },
 197         .remove         = __exit_p(ep93xx_rtc_remove),
 198 };
 199
 200 static int __init ep93xx_rtc_init(void)
 201 {
 202         return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe);
 203 }
 204
 205 static void __exit ep93xx_rtc_exit(void)
 206 {
 207         platform_driver_unregister(&ep93xx_rtc_driver);
 208 }
 209
 210 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 211 MODULE_DESCRIPTION("EP93XX RTC driver");
 212 MODULE_LICENSE("GPL");
 213 MODULE_VERSION(DRV_VERSION);
 214
 215 module_init(ep93xx_rtc_init);
 216 module_exit(ep93xx_rtc_exit);