rtc: at91sam9 RTC support (RTT and/or RTC)
AT91sam9 RTC support, primarily in the form of an RTT-as-RTC driver that was
extracted from 2.6.23-at91 patch and updated:
- Relies on now-merged platform updates, which associate the RTT
hardware address with each RTT and use the "at91_rtt" name.
- RTC framework related fixes and cleanups, notably:
* removed now-needless suspend/resume clock offset logic
* alarm read/write now respects the "enabled" flag
* suspend always disables update irqs
* shutdown (and startup) disables all irqs
- Misc cleanup:
* use dev_*() messaging
* add comments
* remove globals,
* ... etc
- Don't force use of RTT0 and GPBR0. Either resource may need
to be used for other purposes (like NO_HZ support).
- Update "AT91RM9200 RTC" Kconfig to allow it on SAM9RL chips
(it has both RTT and RTC).
Driver binding uses bus_find_device() to avoid needing any kind of "timer
library" code when there's more than one RTT module. (This timer can be used
as an RTC, to support NO_HZ operation, or potentially for other stuff. The
choice is a per-system policy.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Michel Benoit <murpme@gmail.com>
Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
David Brownell
Linus Torvalds
parent
f618258ad8
commit
4cdf854f7d
|
|
@ -469,10 +469,47 @@ config RTC_DRV_AT32AP700X
|
|||
AT32AP700x family processors.
|
||||
|
||||
config RTC_DRV_AT91RM9200
|
||||
tristate "AT91RM9200"
|
||||
depends on ARCH_AT91RM9200
|
||||
tristate "AT91RM9200 or AT91SAM9RL"
|
||||
depends on ARCH_AT91RM9200 || ARCH_AT91SAM9RL
|
||||
help
|
||||
Driver for the Atmel AT91RM9200's internal RTC (Realtime Clock).
|
||||
Driver for the internal RTC (Realtime Clock) module found on
|
||||
Atmel AT91RM9200's and AT91SAM9RL chips. On SAM9RL chips
|
||||
this is powered by the backup power supply.
|
||||
|
||||
config RTC_DRV_AT91SAM9
|
||||
tristate "AT91SAM9x"
|
||||
depends on ARCH_AT91 && !(ARCH_AT91RM9200 || ARCH_AT91X40)
|
||||
help
|
||||
RTC driver for the Atmel AT91SAM9x internal RTT (Real Time Timer).
|
||||
These timers are powered by the backup power supply (such as a
|
||||
small coin cell battery), but do not need to be used as RTCs.
|
||||
|
||||
(On AT91SAM9rl chips you probably want to use the dedicated RTC
|
||||
module and leave the RTT available for other uses.)
|
||||
|
||||
config RTC_DRV_AT91SAM9_RTT
|
||||
int
|
||||
range 0 1
|
||||
default 0
|
||||
prompt "RTT module Number" if ARCH_AT91SAM9263
|
||||
depends on RTC_DRV_AT91SAM9
|
||||
help
|
||||
More than one RTT module is available. You can choose which
|
||||
one will be used as an RTC. The default of zero is normally
|
||||
OK to use, though some systems use that for non-RTC purposes.
|
||||
|
||||
config RTC_DRV_AT91SAM9_GPBR
|
||||
int
|
||||
range 0 3 if !ARCH_AT91SAM9263
|
||||
range 0 15 if ARCH_AT91SAM9263
|
||||
default 0
|
||||
prompt "Backup Register Number"
|
||||
depends on RTC_DRV_AT91SAM9
|
||||
help
|
||||
The RTC driver needs to use one of the General Purpose Backup
|
||||
Registers (GPBRs) as well as the RTT. You can choose which one
|
||||
will be used. The default of zero is normally OK to use, but
|
||||
on some systems other software needs to use that register.
|
||||
|
||||
config RTC_DRV_BFIN
|
||||
tristate "Blackfin On-Chip RTC"
|
||||
|
|
|
|||
|
|
@ -19,6 +19,7 @@ rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
|
|||
|
||||
obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
|
||||
obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
|
||||
obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o
|
||||
obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o
|
||||
obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
|
||||
obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,520 @@
|
|||
/*
|
||||
* "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 <asm/mach/time.h>
|
||||
#include <asm/arch/board.h>
|
||||
#include <asm/arch/at91_rtt.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;
|
||||
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", __FUNCTION__,
|
||||
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_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,
|
||||
rtc->rtcdev->dev.bus_id, 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",
|
||||
rtc->rtcdev->dev.bus_id);
|
||||
|
||||
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");
|
||||
Loading…
Reference in New Issue