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 };
  40
  41 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
  42                                 unsigned short *delete)
  43 {
  44         struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
  45         unsigned long comp;
  46
  47         comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
  48
  49         if (preload)
  50                 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
  51                                 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
  52
  53         if (delete)
  54                 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
  55                                 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
  56
  57         return 0;
  58 }
  59
  60 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
  61 {
  62         struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
  63         unsigned long time;
  64
  65          time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
  66
  67         rtc_time_to_tm(time, tm);
  68         return 0;
  69 }
  70
  71 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
  72 {
  73         struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
  74
  75         __raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
  76         return 0;
  77 }
  78
  79 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
  80 {
  81         unsigned short preload, delete;
  82
  83         ep93xx_rtc_get_swcomp(dev, &preload, &delete);
  84
  85         seq_printf(seq, "preload\t\t: %d\n", preload);
  86         seq_printf(seq, "delete\t\t: %d\n", delete);
  87
  88         return 0;
  89 }
  90
  91 static const struct rtc_class_ops ep93xx_rtc_ops = {
  92         .read_time      = ep93xx_rtc_read_time,
  93         .set_mmss       = ep93xx_rtc_set_mmss,
  94         .proc           = ep93xx_rtc_proc,
  95 };
  96
  97 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
  98                         struct device_attribute *attr, char *buf)
  99 {
 100         unsigned short preload;
 101
 102         ep93xx_rtc_get_swcomp(dev, &preload, NULL);
 103
 104         return sprintf(buf, "%d\n", preload);
 105 }
 106 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
 107
 108 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
 109                         struct device_attribute *attr, char *buf)
 110 {
 111         unsigned short delete;
 112
 113         ep93xx_rtc_get_swcomp(dev, NULL, &delete);
 114
 115         return sprintf(buf, "%d\n", delete);
 116 }
 117 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
 118
 119 static struct attribute *ep93xx_rtc_attrs[] = {
 120         &dev_attr_comp_preload.attr,
 121         &dev_attr_comp_delete.attr,
 122         NULL
 123 };
 124
 125 static const struct attribute_group ep93xx_rtc_sysfs_files = {
 126         .attrs  = ep93xx_rtc_attrs,
 127 };
 128
 129 static int __init ep93xx_rtc_probe(struct platform_device *pdev)
 130 {
 131         struct ep93xx_rtc *ep93xx_rtc;
 132         struct resource *res;
 133         struct rtc_device *rtc;
 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         if (!res)
 142                 return -ENXIO;
 143
 144         if (!devm_request_mem_region(&pdev->dev, res->start,
 145                                      resource_size(res), pdev->name))
 146                 return -EBUSY;
 147
 148         ep93xx_rtc->mmio_base = devm_ioremap(&pdev->dev, res->start,
 149                                              resource_size(res));
 150         if (!ep93xx_rtc->mmio_base)
 151                 return -ENXIO;
 152
 153         pdev->dev.platform_data = ep93xx_rtc;
 154
 155         rtc = rtc_device_register(pdev->name,
 156                                 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE);
 157         if (IS_ERR(rtc)) {
 158                 err = PTR_ERR(rtc);
 159                 goto exit;
 160         }
 161
 162         platform_set_drvdata(pdev, rtc);
 163
 164         err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 165         if (err)
 166                 goto fail;
 167
 168         return 0;
 169
 170 fail:
 171         platform_set_drvdata(pdev, NULL);
 172         rtc_device_unregister(rtc);
 173 exit:
 174         pdev->dev.platform_data = NULL;
 175         return err;
 176 }
 177
 178 static int __exit ep93xx_rtc_remove(struct platform_device *pdev)
 179 {
 180         struct rtc_device *rtc = platform_get_drvdata(pdev);
 181
 182         sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
 183         platform_set_drvdata(pdev, NULL);
 184         rtc_device_unregister(rtc);
 185         pdev->dev.platform_data = NULL;
 186
 187         return 0;
 188 }
 189
 190 /* work with hotplug and coldplug */
 191 MODULE_ALIAS("platform:ep93xx-rtc");
 192
 193 static struct platform_driver ep93xx_rtc_driver = {
 194         .driver         = {
 195                 .name   = "ep93xx-rtc",
 196                 .owner  = THIS_MODULE,
 197         },
 198         .remove         = __exit_p(ep93xx_rtc_remove),
 199 };
 200
 201 static int __init ep93xx_rtc_init(void)
 202 {
 203         return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe);
 204 }
 205
 206 static void __exit ep93xx_rtc_exit(void)
 207 {
 208         platform_driver_unregister(&ep93xx_rtc_driver);
 209 }
 210
 211 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 212 MODULE_DESCRIPTION("EP93XX RTC driver");
 213 MODULE_LICENSE("GPL");
 214 MODULE_VERSION(DRV_VERSION);
 215
 216 module_init(ep93xx_rtc_init);
 217 module_exit(ep93xx_rtc_exit);