kernel-ark/drivers/rtc/rtc-at91sam9.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

526 lines
13 KiB
C

/*
* "RTT as Real Time Clock" driver for AT91SAM9 SoC family
*
* (C) 2007 Michel Benoit
*
* Based on rtc-at91rm9200.c by Rick Bronson
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <mach/board.h>
#include <mach/at91_rtt.h>
#include <mach/cpu.h>
/*
* This driver uses two configurable hardware resources that live in the
* AT91SAM9 backup power domain (intended to be powered at all times)
* to implement the Real Time Clock interfaces
*
* - A "Real-time Timer" (RTT) counts up in seconds from a base time.
* We can't assign the counter value (CRTV) ... but we can reset it.
*
* - One of the "General Purpose Backup Registers" (GPBRs) holds the
* base time, normally an offset from the beginning of the POSIX
* epoch (1970-Jan-1 00:00:00 UTC). Some systems also include the
* local timezone's offset.
*
* The RTC's value is the RTT counter plus that offset. The RTC's alarm
* is likewise a base (ALMV) plus that offset.
*
* Not all RTTs will be used as RTCs; some systems have multiple RTTs to
* choose from, or a "real" RTC module. All systems have multiple GPBR
* registers available, likewise usable for more than "RTC" support.
*/
/*
* We store ALARM_DISABLED in ALMV to record that no alarm is set.
* It's also the reset value for that field.
*/
#define ALARM_DISABLED ((u32)~0)
struct sam9_rtc {
void __iomem *rtt;
struct rtc_device *rtcdev;
u32 imr;
};
#define rtt_readl(rtc, field) \
__raw_readl((rtc)->rtt + AT91_RTT_ ## field)
#define rtt_writel(rtc, field, val) \
__raw_writel((val), (rtc)->rtt + AT91_RTT_ ## field)
#define gpbr_readl(rtc) \
at91_sys_read(AT91_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR)
#define gpbr_writel(rtc, val) \
at91_sys_write(AT91_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR, (val))
/*
* Read current time and date in RTC
*/
static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
u32 secs, secs2;
u32 offset;
/* read current time offset */
offset = gpbr_readl(rtc);
if (offset == 0)
return -EILSEQ;
/* reread the counter to help sync the two clock domains */
secs = rtt_readl(rtc, VR);
secs2 = rtt_readl(rtc, VR);
if (secs != secs2)
secs = rtt_readl(rtc, VR);
rtc_time_to_tm(offset + secs, tm);
dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "readtime",
1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
/*
* Set current time and date in RTC
*/
static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
int err;
u32 offset, alarm, mr;
unsigned long secs;
dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "settime",
1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
err = rtc_tm_to_time(tm, &secs);
if (err != 0)
return err;
mr = rtt_readl(rtc, MR);
/* disable interrupts */
rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
/* read current time offset */
offset = gpbr_readl(rtc);
/* store the new base time in a battery backup register */
secs += 1;
gpbr_writel(rtc, secs);
/* adjust the alarm time for the new base */
alarm = rtt_readl(rtc, AR);
if (alarm != ALARM_DISABLED) {
if (offset > secs) {
/* time jumped backwards, increase time until alarm */
alarm += (offset - secs);
} else if ((alarm + offset) > secs) {
/* time jumped forwards, decrease time until alarm */
alarm -= (secs - offset);
} else {
/* time jumped past the alarm, disable alarm */
alarm = ALARM_DISABLED;
mr &= ~AT91_RTT_ALMIEN;
}
rtt_writel(rtc, AR, alarm);
}
/* reset the timer, and re-enable interrupts */
rtt_writel(rtc, MR, mr | AT91_RTT_RTTRST);
return 0;
}
static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
struct rtc_time *tm = &alrm->time;
u32 alarm = rtt_readl(rtc, AR);
u32 offset;
offset = gpbr_readl(rtc);
if (offset == 0)
return -EILSEQ;
memset(alrm, 0, sizeof(*alrm));
if (alarm != ALARM_DISABLED && offset != 0) {
rtc_time_to_tm(offset + alarm, tm);
dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "readalarm",
1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (rtt_readl(rtc, MR) & AT91_RTT_ALMIEN)
alrm->enabled = 1;
}
return 0;
}
static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
struct rtc_time *tm = &alrm->time;
unsigned long secs;
u32 offset;
u32 mr;
int err;
err = rtc_tm_to_time(tm, &secs);
if (err != 0)
return err;
offset = gpbr_readl(rtc);
if (offset == 0) {
/* time is not set */
return -EILSEQ;
}
mr = rtt_readl(rtc, MR);
rtt_writel(rtc, MR, mr & ~AT91_RTT_ALMIEN);
/* alarm in the past? finish and leave disabled */
if (secs <= offset) {
rtt_writel(rtc, AR, ALARM_DISABLED);
return 0;
}
/* else set alarm and maybe enable it */
rtt_writel(rtc, AR, secs - offset);
if (alrm->enabled)
rtt_writel(rtc, MR, mr | AT91_RTT_ALMIEN);
dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "setalarm",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour,
tm->tm_min, tm->tm_sec);
return 0;
}
/*
* Handle commands from user-space
*/
static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
unsigned long arg)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
int ret = 0;
u32 mr = rtt_readl(rtc, MR);
dev_dbg(dev, "ioctl: cmd=%08x, arg=%08lx, mr %08x\n", cmd, arg, mr);
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
rtt_writel(rtc, MR, mr & ~AT91_RTT_ALMIEN);
break;
case RTC_AIE_ON: /* alarm on */
rtt_writel(rtc, MR, mr | AT91_RTT_ALMIEN);
break;
case RTC_UIE_OFF: /* update off */
rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
break;
case RTC_UIE_ON: /* update on */
rtt_writel(rtc, MR, mr | AT91_RTT_RTTINCIEN);
break;
default:
ret = -ENOIOCTLCMD;
break;
}
return ret;
}
/*
* Provide additional RTC information in /proc/driver/rtc
*/
static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
{
struct sam9_rtc *rtc = dev_get_drvdata(dev);
u32 mr = mr = rtt_readl(rtc, MR);
seq_printf(seq, "update_IRQ\t: %s\n",
(mr & AT91_RTT_RTTINCIEN) ? "yes" : "no");
return 0;
}
/*
* IRQ handler for the RTC
*/
static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
{
struct sam9_rtc *rtc = _rtc;
u32 sr, mr;
unsigned long events = 0;
/* Shared interrupt may be for another device. Note: reading
* SR clears it, so we must only read it in this irq handler!
*/
mr = rtt_readl(rtc, MR) & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
sr = rtt_readl(rtc, SR) & (mr >> 16);
if (!sr)
return IRQ_NONE;
/* alarm status */
if (sr & AT91_RTT_ALMS)
events |= (RTC_AF | RTC_IRQF);
/* timer update/increment */
if (sr & AT91_RTT_RTTINC)
events |= (RTC_UF | RTC_IRQF);
rtc_update_irq(rtc->rtcdev, 1, events);
pr_debug("%s: num=%ld, events=0x%02lx\n", __func__,
events >> 8, events & 0x000000FF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops at91_rtc_ops = {
.ioctl = at91_rtc_ioctl,
.read_time = at91_rtc_readtime,
.set_time = at91_rtc_settime,
.read_alarm = at91_rtc_readalarm,
.set_alarm = at91_rtc_setalarm,
.proc = at91_rtc_proc,
};
/*
* Initialize and install RTC driver
*/
static int __init at91_rtc_probe(struct platform_device *pdev)
{
struct resource *r;
struct sam9_rtc *rtc;
int ret;
u32 mr;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r)
return -ENODEV;
rtc = kzalloc(sizeof *rtc, GFP_KERNEL);
if (!rtc)
return -ENOMEM;
/* platform setup code should have handled this; sigh */
if (!device_can_wakeup(&pdev->dev))
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, rtc);
rtc->rtt = (void __force __iomem *) (AT91_VA_BASE_SYS - AT91_BASE_SYS);
rtc->rtt += r->start;
mr = rtt_readl(rtc, MR);
/* unless RTT is counting at 1 Hz, re-initialize it */
if ((mr & AT91_RTT_RTPRES) != AT91_SLOW_CLOCK) {
mr = AT91_RTT_RTTRST | (AT91_SLOW_CLOCK & AT91_RTT_RTPRES);
gpbr_writel(rtc, 0);
}
/* disable all interrupts (same as on shutdown path) */
mr &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
rtt_writel(rtc, MR, mr);
rtc->rtcdev = rtc_device_register(pdev->name, &pdev->dev,
&at91_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtcdev)) {
ret = PTR_ERR(rtc->rtcdev);
goto fail;
}
/* register irq handler after we know what name we'll use */
ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
IRQF_DISABLED | IRQF_SHARED,
dev_name(&rtc->rtcdev->dev), rtc);
if (ret) {
dev_dbg(&pdev->dev, "can't share IRQ %d?\n", AT91_ID_SYS);
rtc_device_unregister(rtc->rtcdev);
goto fail;
}
/* NOTE: sam9260 rev A silicon has a ROM bug which resets the
* RTT on at least some reboots. If you have that chip, you must
* initialize the time from some external source like a GPS, wall
* clock, discrete RTC, etc
*/
if (gpbr_readl(rtc) == 0)
dev_warn(&pdev->dev, "%s: SET TIME!\n",
dev_name(&rtc->rtcdev->dev));
return 0;
fail:
platform_set_drvdata(pdev, NULL);
kfree(rtc);
return ret;
}
/*
* Disable and remove the RTC driver
*/
static int __exit at91_rtc_remove(struct platform_device *pdev)
{
struct sam9_rtc *rtc = platform_get_drvdata(pdev);
u32 mr = rtt_readl(rtc, MR);
/* disable all interrupts */
rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
free_irq(AT91_ID_SYS, rtc);
rtc_device_unregister(rtc->rtcdev);
platform_set_drvdata(pdev, NULL);
kfree(rtc);
return 0;
}
static void at91_rtc_shutdown(struct platform_device *pdev)
{
struct sam9_rtc *rtc = platform_get_drvdata(pdev);
u32 mr = rtt_readl(rtc, MR);
rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
rtt_writel(rtc, MR, mr & ~rtc->imr);
}
#ifdef CONFIG_PM
/* AT91SAM9 RTC Power management control */
static int at91_rtc_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct sam9_rtc *rtc = platform_get_drvdata(pdev);
u32 mr = rtt_readl(rtc, MR);
/*
* This IRQ is shared with DBGU and other hardware which isn't
* necessarily a wakeup event source.
*/
rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
if (rtc->imr) {
if (device_may_wakeup(&pdev->dev) && (mr & AT91_RTT_ALMIEN)) {
enable_irq_wake(AT91_ID_SYS);
/* don't let RTTINC cause wakeups */
if (mr & AT91_RTT_RTTINCIEN)
rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
} else
rtt_writel(rtc, MR, mr & ~rtc->imr);
}
return 0;
}
static int at91_rtc_resume(struct platform_device *pdev)
{
struct sam9_rtc *rtc = platform_get_drvdata(pdev);
u32 mr;
if (rtc->imr) {
if (device_may_wakeup(&pdev->dev))
disable_irq_wake(AT91_ID_SYS);
mr = rtt_readl(rtc, MR);
rtt_writel(rtc, MR, mr | rtc->imr);
}
return 0;
}
#else
#define at91_rtc_suspend NULL
#define at91_rtc_resume NULL
#endif
static struct platform_driver at91_rtc_driver = {
.driver.name = "rtc-at91sam9",
.driver.owner = THIS_MODULE,
.remove = __exit_p(at91_rtc_remove),
.shutdown = at91_rtc_shutdown,
.suspend = at91_rtc_suspend,
.resume = at91_rtc_resume,
};
/* Chips can have more than one RTT module, and they can be used for more
* than just RTCs. So we can't just register as "the" RTT driver.
*
* A normal approach in such cases is to create a library to allocate and
* free the modules. Here we just use bus_find_device() as like such a
* library, binding directly ... no runtime "library" footprint is needed.
*/
static int __init at91_rtc_match(struct device *dev, void *v)
{
struct platform_device *pdev = to_platform_device(dev);
int ret;
/* continue searching if this isn't the RTT we need */
if (strcmp("at91_rtt", pdev->name) != 0
|| pdev->id != CONFIG_RTC_DRV_AT91SAM9_RTT)
goto fail;
/* else we found it ... but fail unless we can bind to the RTC driver */
if (dev->driver) {
dev_dbg(dev, "busy, can't use as RTC!\n");
goto fail;
}
dev->driver = &at91_rtc_driver.driver;
if (device_attach(dev) == 0) {
dev_dbg(dev, "can't attach RTC!\n");
goto fail;
}
ret = at91_rtc_probe(pdev);
if (ret == 0)
return true;
dev_dbg(dev, "RTC probe err %d!\n", ret);
fail:
return false;
}
static int __init at91_rtc_init(void)
{
int status;
struct device *rtc;
status = platform_driver_register(&at91_rtc_driver);
if (status)
return status;
rtc = bus_find_device(&platform_bus_type, NULL,
NULL, at91_rtc_match);
if (!rtc)
platform_driver_unregister(&at91_rtc_driver);
return rtc ? 0 : -ENODEV;
}
module_init(at91_rtc_init);
static void __exit at91_rtc_exit(void)
{
platform_driver_unregister(&at91_rtc_driver);
}
module_exit(at91_rtc_exit);
MODULE_AUTHOR("Michel Benoit");
MODULE_DESCRIPTION("RTC driver for Atmel AT91SAM9x");
MODULE_LICENSE("GPL");