From 392e8802486cb573b916e746010e141a75f507e6 Mon Sep 17 00:00:00 2001 From: Kevin Date: Sat, 15 Nov 2014 09:58:27 +0800 Subject: init android origin source code --- ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c | 249 ++++++++++++++++++++++++++++++++++ 1 file changed, 249 insertions(+) create mode 100644 ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c (limited to 'ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c') diff --git a/ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c b/ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c new file mode 100644 index 00000000..380083ca --- /dev/null +++ b/ANDROID_3.4.5/drivers/rtc/rtc-sysfs.c @@ -0,0 +1,249 @@ +/* + * RTC subsystem, sysfs interface + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include +#include + +#include "rtc-core.h" + + +/* device attributes */ + +/* + * NOTE: RTC times displayed in sysfs use the RTC's timezone. That's + * ideally UTC. However, PCs that also boot to MS-Windows normally use + * the local time and change to match daylight savings time. That affects + * attributes including date, time, since_epoch, and wakealarm. + */ + +static ssize_t +rtc_sysfs_show_name(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%s\n", to_rtc_device(dev)->name); +} + +static ssize_t +rtc_sysfs_show_date(struct device *dev, struct device_attribute *attr, + char *buf) +{ + ssize_t retval; + struct rtc_time tm; + + retval = rtc_read_time(to_rtc_device(dev), &tm); + if (retval == 0) { + retval = sprintf(buf, "%04d-%02d-%02d\n", + tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday); + } + + return retval; +} + +static ssize_t +rtc_sysfs_show_time(struct device *dev, struct device_attribute *attr, + char *buf) +{ + ssize_t retval; + struct rtc_time tm; + + retval = rtc_read_time(to_rtc_device(dev), &tm); + if (retval == 0) { + retval = sprintf(buf, "%02d:%02d:%02d\n", + tm.tm_hour, tm.tm_min, tm.tm_sec); + } + + return retval; +} + +static ssize_t +rtc_sysfs_show_since_epoch(struct device *dev, struct device_attribute *attr, + char *buf) +{ + ssize_t retval; + struct rtc_time tm; + + retval = rtc_read_time(to_rtc_device(dev), &tm); + if (retval == 0) { + unsigned long time; + rtc_tm_to_time(&tm, &time); + retval = sprintf(buf, "%lu\n", time); + } + + return retval; +} + +static ssize_t +rtc_sysfs_show_max_user_freq(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", to_rtc_device(dev)->max_user_freq); +} + +static ssize_t +rtc_sysfs_set_max_user_freq(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + struct rtc_device *rtc = to_rtc_device(dev); + unsigned long val = simple_strtoul(buf, NULL, 0); + + if (val >= 4096 || val == 0) + return -EINVAL; + + rtc->max_user_freq = (int)val; + + return n; +} + +static ssize_t +rtc_sysfs_show_hctosys(struct device *dev, struct device_attribute *attr, + char *buf) +{ +#ifdef CONFIG_RTC_HCTOSYS_DEVICE + if (rtc_hctosys_ret == 0 && + strcmp(dev_name(&to_rtc_device(dev)->dev), + CONFIG_RTC_HCTOSYS_DEVICE) == 0) + return sprintf(buf, "1\n"); + else +#endif + return sprintf(buf, "0\n"); +} + +static struct device_attribute rtc_attrs[] = { + __ATTR(name, S_IRUGO, rtc_sysfs_show_name, NULL), + __ATTR(date, S_IRUGO, rtc_sysfs_show_date, NULL), + __ATTR(time, S_IRUGO, rtc_sysfs_show_time, NULL), + __ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL), + __ATTR(max_user_freq, S_IRUGO | S_IWUSR, rtc_sysfs_show_max_user_freq, + rtc_sysfs_set_max_user_freq), + __ATTR(hctosys, S_IRUGO, rtc_sysfs_show_hctosys, NULL), + { }, +}; + +static ssize_t +rtc_sysfs_show_wakealarm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + ssize_t retval; + unsigned long alarm; + struct rtc_wkalrm alm; + + /* Don't show disabled alarms. For uniformity, RTC alarms are + * conceptually one-shot, even though some common RTCs (on PCs) + * don't actually work that way. + * + * NOTE: RTC implementations where the alarm doesn't match an + * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC + * alarms after they trigger, to ensure one-shot semantics. + */ + retval = rtc_read_alarm(to_rtc_device(dev), &alm); + if (retval == 0 && alm.enabled) { + rtc_tm_to_time(&alm.time, &alarm); + retval = sprintf(buf, "%lu\n", alarm); + } + + return retval; +} + +static ssize_t +rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + ssize_t retval; + unsigned long now, alarm; + struct rtc_wkalrm alm; + struct rtc_device *rtc = to_rtc_device(dev); + char *buf_ptr; + int adjust = 0; + + /* Only request alarms that trigger in the future. Disable them + * by writing another time, e.g. 0 meaning Jan 1 1970 UTC. + */ + retval = rtc_read_time(rtc, &alm.time); + if (retval < 0) + return retval; + rtc_tm_to_time(&alm.time, &now); + + buf_ptr = (char *)buf; + if (*buf_ptr == '+') { + buf_ptr++; + adjust = 1; + } + alarm = simple_strtoul(buf_ptr, NULL, 0); + if (adjust) { + alarm += now; + } + if (alarm > now) { + /* Avoid accidentally clobbering active alarms; we can't + * entirely prevent that here, without even the minimal + * locking from the /dev/rtcN api. + */ + retval = rtc_read_alarm(rtc, &alm); + if (retval < 0) + return retval; + if (alm.enabled) + return -EBUSY; + + alm.enabled = 1; + } else { + alm.enabled = 0; + + /* Provide a valid future alarm time. Linux isn't EFI, + * this time won't be ignored when disabling the alarm. + */ + alarm = now + 300; + } + rtc_time_to_tm(alarm, &alm.time); + + retval = rtc_set_alarm(rtc, &alm); + return (retval < 0) ? retval : n; +} +static DEVICE_ATTR(wakealarm, S_IRUGO | S_IWUSR, + rtc_sysfs_show_wakealarm, rtc_sysfs_set_wakealarm); + + +/* The reason to trigger an alarm with no process watching it (via sysfs) + * is its side effect: waking from a system state like suspend-to-RAM or + * suspend-to-disk. So: no attribute unless that side effect is possible. + * (Userspace may disable that mechanism later.) + */ +static inline int rtc_does_wakealarm(struct rtc_device *rtc) +{ + if (!device_can_wakeup(rtc->dev.parent)) + return 0; + return rtc->ops->set_alarm != NULL; +} + + +void rtc_sysfs_add_device(struct rtc_device *rtc) +{ + int err; + + /* not all RTCs support both alarms and wakeup */ + if (!rtc_does_wakealarm(rtc)) + return; + + err = device_create_file(&rtc->dev, &dev_attr_wakealarm); + if (err) + dev_err(rtc->dev.parent, + "failed to create alarm attribute, %d\n", err); +} + +void rtc_sysfs_del_device(struct rtc_device *rtc) +{ + /* REVISIT did we add it successfully? */ + if (rtc_does_wakealarm(rtc)) + device_remove_file(&rtc->dev, &dev_attr_wakealarm); +} + +void __init rtc_sysfs_init(struct class *rtc_class) +{ + rtc_class->dev_attrs = rtc_attrs; +} -- cgit