kernel/drivers/rtc/rtc-tile.c

   1 /*
   2  * Copyright 2011 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  *
  14  * Tilera-specific RTC driver.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/device.h>
  19 #include <linux/rtc.h>
  20 #include <linux/platform_device.h>
  21
  22 /* Platform device pointer. */
  23 static struct platform_device *tile_rtc_platform_device;
  24
  25 /*
  26  * RTC read routine.  Gets time info from RTC chip via hypervisor syscall.
  27  */
  28 static int read_rtc_time(struct device *dev, struct rtc_time *tm)
  29 {
  30         HV_RTCTime hvtm = hv_get_rtc();
  31
  32         tm->tm_sec = hvtm.tm_sec;
  33         tm->tm_min = hvtm.tm_min;
  34         tm->tm_hour = hvtm.tm_hour;
  35         tm->tm_mday = hvtm.tm_mday;
  36         tm->tm_mon = hvtm.tm_mon;
  37         tm->tm_year = hvtm.tm_year;
  38         tm->tm_wday = 0;
  39         tm->tm_yday = 0;
  40         tm->tm_isdst = 0;
  41
  42         if (rtc_valid_tm(tm) < 0)
  43                 dev_warn(dev, "Read invalid date/time from RTC\n");
  44
  45         return 0;
  46 }
  47
  48 /*
  49  * RTC write routine.  Sends time info to hypervisor via syscall, to be
  50  * written to RTC chip.
  51  */
  52 static int set_rtc_time(struct device *dev, struct rtc_time *tm)
  53 {
  54         HV_RTCTime hvtm;
  55
  56         hvtm.tm_sec = tm->tm_sec;
  57         hvtm.tm_min = tm->tm_min;
  58         hvtm.tm_hour = tm->tm_hour;
  59         hvtm.tm_mday = tm->tm_mday;
  60         hvtm.tm_mon = tm->tm_mon;
  61         hvtm.tm_year = tm->tm_year;
  62
  63         hv_set_rtc(hvtm);
  64
  65         return 0;
  66 }
  67
  68 /*
  69  * RTC read/write ops.
  70  */
  71 static const struct rtc_class_ops tile_rtc_ops = {
  72         .read_time      = read_rtc_time,
  73         .set_time       = set_rtc_time,
  74 };
  75
  76 /*
  77  * Device probe routine.
  78  */
  79 static int tile_rtc_probe(struct platform_device *dev)
  80 {
  81         struct rtc_device *rtc;
  82
  83         rtc = devm_rtc_device_register(&dev->dev, "tile",
  84                                 &tile_rtc_ops, THIS_MODULE);
  85
  86         if (IS_ERR(rtc))
  87                 return PTR_ERR(rtc);
  88
  89         platform_set_drvdata(dev, rtc);
  90
  91         return 0;
  92 }
  93
  94 static struct platform_driver tile_rtc_platform_driver = {
  95         .driver         = {
  96                 .name   = "rtc-tile",
  97         },
  98         .probe          = tile_rtc_probe,
  99 };
 100
 101 /*
 102  * Driver init routine.
 103  */
 104 static int __init tile_rtc_driver_init(void)
 105 {
 106         int err;
 107
 108         err = platform_driver_register(&tile_rtc_platform_driver);
 109         if (err)
 110                 return err;
 111
 112         tile_rtc_platform_device = platform_device_alloc("rtc-tile", 0);
 113         if (tile_rtc_platform_device == NULL) {
 114                 err = -ENOMEM;
 115                 goto exit_driver_unregister;
 116         }
 117
 118         err = platform_device_add(tile_rtc_platform_device);
 119         if (err)
 120                 goto exit_device_put;
 121
 122         return 0;
 123
 124 exit_device_put:
 125         platform_device_put(tile_rtc_platform_device);
 126
 127 exit_driver_unregister:
 128         platform_driver_unregister(&tile_rtc_platform_driver);
 129         return err;
 130 }
 131
 132 /*
 133  * Driver cleanup routine.
 134  */
 135 static void __exit tile_rtc_driver_exit(void)
 136 {
 137         platform_device_unregister(tile_rtc_platform_device);
 138         platform_driver_unregister(&tile_rtc_platform_driver);
 139 }
 140
 141 module_init(tile_rtc_driver_init);
 142 module_exit(tile_rtc_driver_exit);
 143
 144 MODULE_DESCRIPTION("Tilera-specific Real Time Clock Driver");
 145 MODULE_LICENSE("GPL");
 146 MODULE_ALIAS("platform:rtc-tile");