| | 1 | /* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems. |
| | 2 | * |
| | 3 | * Copyright (C) 2008 David S. Miller <davem@davemloft.net> |
| | 4 | */ |
| | 5 | |
| | 6 | #include <linux/kernel.h> |
| | 7 | #include <linux/module.h> |
| | 8 | #include <linux/delay.h> |
| | 9 | #include <linux/init.h> |
| | 10 | #include <linux/rtc.h> |
| | 11 | #include <linux/platform_device.h> |
| | 12 | |
| | 13 | #include <asm/hypervisor.h> |
| | 14 | |
| | 15 | static unsigned long hypervisor_get_time(void) |
| | 16 | { |
| | 17 | unsigned long ret, time; |
| | 18 | int retries = 10000; |
| | 19 | |
| | 20 | retry: |
| | 21 | ret = sun4v_tod_get(&time); |
| | 22 | if (ret == HV_EOK) |
| | 23 | return time; |
| | 24 | if (ret == HV_EWOULDBLOCK) { |
| | 25 | if (--retries > 0) { |
| | 26 | udelay(100); |
| | 27 | goto retry; |
| | 28 | } |
| | 29 | printk(KERN_WARNING "SUN4V: tod_get() timed out.\n"); |
| | 30 | return 0; |
| | 31 | } |
| | 32 | printk(KERN_WARNING "SUN4V: tod_get() not supported.\n"); |
| | 33 | return 0; |
| | 34 | } |
| | 35 | |
| | 36 | static int sun4v_read_time(struct device *dev, struct rtc_time *tm) |
| | 37 | { |
| | 38 | rtc_time_to_tm(hypervisor_get_time(), tm); |
| | 39 | return 0; |
| | 40 | } |
| | 41 | |
| | 42 | static int hypervisor_set_time(unsigned long secs) |
| | 43 | { |
| | 44 | unsigned long ret; |
| | 45 | int retries = 10000; |
| | 46 | |
| | 47 | retry: |
| | 48 | ret = sun4v_tod_set(secs); |
| | 49 | if (ret == HV_EOK) |
| | 50 | return 0; |
| | 51 | if (ret == HV_EWOULDBLOCK) { |
| | 52 | if (--retries > 0) { |
| | 53 | udelay(100); |
| | 54 | goto retry; |
| | 55 | } |
| | 56 | printk(KERN_WARNING "SUN4V: tod_set() timed out.\n"); |
| | 57 | return -EAGAIN; |
| | 58 | } |
| | 59 | printk(KERN_WARNING "SUN4V: tod_set() not supported.\n"); |
| | 60 | return -EOPNOTSUPP; |
| | 61 | } |
| | 62 | |
| | 63 | static int sun4v_set_time(struct device *dev, struct rtc_time *tm) |
| | 64 | { |
| | 65 | unsigned long secs; |
| | 66 | int err; |
| | 67 | |
| | 68 | err = rtc_tm_to_time(tm, &secs); |
| | 69 | if (err) |
| | 70 | return err; |
| | 71 | |
| | 72 | return hypervisor_set_time(secs); |
| | 73 | } |
| | 74 | |
| | 75 | static const struct rtc_class_ops sun4v_rtc_ops = { |
| | 76 | .read_time = sun4v_read_time, |
| | 77 | .set_time = sun4v_set_time, |
| | 78 | }; |
| | 79 | |
| | 80 | static int __init sun4v_rtc_probe(struct platform_device *pdev) |
| | 81 | { |
| | 82 | struct rtc_device *rtc = rtc_device_register("sun4v", &pdev->dev, |
| | 83 | &sun4v_rtc_ops, THIS_MODULE); |
| | 84 | if (IS_ERR(rtc)) |
| | 85 | return PTR_ERR(rtc); |
| | 86 | |
| | 87 | platform_set_drvdata(pdev, rtc); |
| | 88 | return 0; |
| | 89 | } |
| | 90 | |
| | 91 | static int __exit sun4v_rtc_remove(struct platform_device *pdev) |
| | 92 | { |
| | 93 | struct rtc_device *rtc = platform_get_drvdata(pdev); |
| | 94 | |
| | 95 | rtc_device_unregister(rtc); |
| | 96 | return 0; |
| | 97 | } |
| | 98 | |
| | 99 | static struct platform_driver sun4v_rtc_driver = { |
| | 100 | .driver = { |
| | 101 | .name = "rtc-sun4v", |
| | 102 | .owner = THIS_MODULE, |
| | 103 | }, |
| | 104 | .remove = __exit_p(sun4v_rtc_remove), |
| | 105 | }; |
| | 106 | |
| | 107 | static int __init sun4v_rtc_init(void) |
| | 108 | { |
| | 109 | return platform_driver_probe(&sun4v_rtc_driver, sun4v_rtc_probe); |
| | 110 | } |
| | 111 | |
| | 112 | static void __exit sun4v_rtc_exit(void) |
| | 113 | { |
| | 114 | platform_driver_unregister(&sun4v_rtc_driver); |
| | 115 | } |
| | 116 | |
| | 117 | module_init(sun4v_rtc_init); |
| | 118 | module_exit(sun4v_rtc_exit); |
| | 119 | |
| | 120 | MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); |
| | 121 | MODULE_DESCRIPTION("SUN4V RTC driver"); |
| | 122 | MODULE_LICENSE("GPL"); |
projects / linux-2.6-block.git / blame_incremental