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path: root/drivers/rtc/rtc-at91sam9.c
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Diffstat (limited to 'drivers/rtc/rtc-at91sam9.c')
-rw-r--r--drivers/rtc/rtc-at91sam9.c276
1 files changed, 182 insertions, 94 deletions
diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 309b8b342d9c..38991cca5930 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -1,30 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0+
/*
* "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/clk.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
#include <linux/platform_device.h>
-#include <linux/time.h>
+#include <linux/regmap.h>
#include <linux/rtc.h>
-#include <linux/interrupt.h>
-#include <linux/ioctl.h>
#include <linux/slab.h>
-#include <linux/platform_data/atmel.h>
-#include <linux/io.h>
-
-#include <mach/at91_rtt.h>
-#include <mach/cpu.h>
-
+#include <linux/suspend.h>
+#include <linux/time.h>
/*
* This driver uses two configurable hardware resources that live in the
@@ -47,30 +43,59 @@
* registers available, likewise usable for more than "RTC" support.
*/
+#define AT91_RTT_MR 0x00 /* Real-time Mode Register */
+#define AT91_RTT_RTPRES (0xffff << 0) /* Timer Prescaler Value */
+#define AT91_RTT_ALMIEN BIT(16) /* Alarm Interrupt Enable */
+#define AT91_RTT_RTTINCIEN BIT(17) /* Increment Interrupt Enable */
+#define AT91_RTT_RTTRST BIT(18) /* Timer Restart */
+
+#define AT91_RTT_AR 0x04 /* Real-time Alarm Register */
+#define AT91_RTT_ALMV (0xffffffff) /* Alarm Value */
+
+#define AT91_RTT_VR 0x08 /* Real-time Value Register */
+#define AT91_RTT_CRTV (0xffffffff) /* Current Real-time Value */
+
+#define AT91_RTT_SR 0x0c /* Real-time Status Register */
+#define AT91_RTT_ALMS BIT(0) /* Alarm Status */
+#define AT91_RTT_RTTINC BIT(1) /* Timer Increment */
+
/*
* 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;
- void __iomem *gpbr;
- int irq;
+ struct regmap *gpbr;
+ unsigned int gpbr_offset;
+ int irq;
+ struct clk *sclk;
+ bool suspended;
+ unsigned long events;
+ spinlock_t lock;
};
#define rtt_readl(rtc, field) \
- __raw_readl((rtc)->rtt + AT91_RTT_ ## field)
+ readl((rtc)->rtt + AT91_RTT_ ## field)
#define rtt_writel(rtc, field, val) \
- __raw_writel((val), (rtc)->rtt + AT91_RTT_ ## field)
+ writel((val), (rtc)->rtt + AT91_RTT_ ## field)
+
+static inline unsigned int gpbr_readl(struct sam9_rtc *rtc)
+{
+ unsigned int val;
+
+ regmap_read(rtc->gpbr, rtc->gpbr_offset, &val);
-#define gpbr_readl(rtc) \
- __raw_readl((rtc)->gpbr)
-#define gpbr_writel(rtc, val) \
- __raw_writel((val), (rtc)->gpbr)
+ return val;
+}
+
+static inline void gpbr_writel(struct sam9_rtc *rtc, unsigned int val)
+{
+ regmap_write(rtc->gpbr, rtc->gpbr_offset, val);
+}
/*
* Read current time and date in RTC
@@ -92,11 +117,9 @@ static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
if (secs != secs2)
secs = rtt_readl(rtc, VR);
- rtc_time_to_tm(offset + secs, tm);
+ rtc_time64_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);
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
return 0;
}
@@ -107,17 +130,12 @@ static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
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);
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
- err = rtc_tm_to_time(tm, &secs);
- if (err != 0)
- return err;
+ secs = rtc_tm_to_time64(tm);
mr = rtt_readl(rtc, MR);
@@ -166,12 +184,10 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
return -EILSEQ;
memset(alrm, 0, sizeof(*alrm));
- if (alarm != ALARM_DISABLED && offset != 0) {
- rtc_time_to_tm(offset + alarm, tm);
+ if (alarm != ALARM_DISABLED) {
+ rtc_time64_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);
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
if (rtt_readl(rtc, MR) & AT91_RTT_ALMIEN)
alrm->enabled = 1;
@@ -187,11 +203,8 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
unsigned long secs;
u32 offset;
u32 mr;
- int err;
- err = rtc_tm_to_time(tm, &secs);
- if (err != 0)
- return err;
+ secs = rtc_tm_to_time64(tm);
offset = gpbr_readl(rtc);
if (offset == 0) {
@@ -212,9 +225,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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);
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
return 0;
}
@@ -238,21 +249,16 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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);
+ u32 mr = rtt_readl(rtc, MR);
seq_printf(seq, "update_IRQ\t: %s\n",
- (mr & AT91_RTT_RTTINCIEN) ? "yes" : "no");
+ (mr & AT91_RTT_RTTINCIEN) ? "yes" : "no");
return 0;
}
-/*
- * IRQ handler for the RTC
- */
-static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
+static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *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!
@@ -264,18 +270,54 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
/* alarm status */
if (sr & AT91_RTT_ALMS)
- events |= (RTC_AF | RTC_IRQF);
+ rtc->events |= (RTC_AF | RTC_IRQF);
/* timer update/increment */
if (sr & AT91_RTT_RTTINC)
- events |= (RTC_UF | RTC_IRQF);
+ rtc->events |= (RTC_UF | RTC_IRQF);
- rtc_update_irq(rtc->rtcdev, 1, events);
+ return IRQ_HANDLED;
+}
+
+static void at91_rtc_flush_events(struct sam9_rtc *rtc)
+{
+ if (!rtc->events)
+ return;
+
+ rtc_update_irq(rtc->rtcdev, 1, rtc->events);
+ rtc->events = 0;
pr_debug("%s: num=%ld, events=0x%02lx\n", __func__,
- events >> 8, events & 0x000000FF);
+ rtc->events >> 8, rtc->events & 0x000000FF);
+}
- return IRQ_HANDLED;
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
+{
+ struct sam9_rtc *rtc = _rtc;
+ int ret;
+
+ spin_lock(&rtc->lock);
+
+ ret = at91_rtc_cache_events(rtc);
+
+ /* We're called in suspended state */
+ if (rtc->suspended) {
+ /* Mask irqs coming from this peripheral */
+ rtt_writel(rtc, MR,
+ rtt_readl(rtc, MR) &
+ ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
+ /* Trigger a system wakeup */
+ pm_system_wakeup();
+ } else {
+ at91_rtc_flush_events(rtc);
+ }
+
+ spin_unlock(&rtc->lock);
+
+ return ret;
}
static const struct rtc_class_ops at91_rtc_ops = {
@@ -292,53 +334,69 @@ static const struct rtc_class_ops at91_rtc_ops = {
*/
static int at91_rtc_probe(struct platform_device *pdev)
{
- struct resource *r, *r_gpbr;
struct sam9_rtc *rtc;
int ret, irq;
u32 mr;
-
- r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- r_gpbr = platform_get_resource(pdev, IORESOURCE_MEM, 1);
- if (!r || !r_gpbr) {
- dev_err(&pdev->dev, "need 2 ressources\n");
- return -ENODEV;
- }
+ unsigned int sclk_rate;
+ struct of_phandle_args args;
irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "failed to get interrupt resource\n");
+ if (irq < 0)
return irq;
- }
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
+ spin_lock_init(&rtc->lock);
rtc->irq = irq;
/* platform setup code should have handled this; sigh */
if (!device_can_wakeup(&pdev->dev))
- device_init_wakeup(&pdev->dev, 1);
+ device_init_wakeup(&pdev->dev, true);
platform_set_drvdata(pdev, rtc);
- rtc->rtt = devm_ioremap(&pdev->dev, r->start, resource_size(r));
- if (!rtc->rtt) {
- dev_err(&pdev->dev, "failed to map registers, aborting.\n");
+
+ rtc->rtt = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(rtc->rtt))
+ return PTR_ERR(rtc->rtt);
+
+ ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
+ "atmel,rtt-rtc-time-reg", 1, 0,
+ &args);
+ if (ret)
+ return ret;
+
+ rtc->gpbr = syscon_node_to_regmap(args.np);
+ of_node_put(args.np);
+ rtc->gpbr_offset = args.args[0];
+ if (IS_ERR(rtc->gpbr)) {
+ dev_err(&pdev->dev, "failed to retrieve gpbr regmap, aborting.\n");
return -ENOMEM;
}
- rtc->gpbr = devm_ioremap(&pdev->dev, r_gpbr->start,
- resource_size(r_gpbr));
- if (!rtc->gpbr) {
- dev_err(&pdev->dev, "failed to map gpbr registers, aborting.\n");
- return -ENOMEM;
+ rtc->sclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(rtc->sclk))
+ return PTR_ERR(rtc->sclk);
+
+ ret = clk_prepare_enable(rtc->sclk);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not enable slow clock\n");
+ return ret;
+ }
+
+ sclk_rate = clk_get_rate(rtc->sclk);
+ if (!sclk_rate || sclk_rate > AT91_RTT_RTPRES) {
+ dev_err(&pdev->dev, "Invalid slow clock rate\n");
+ ret = -EINVAL;
+ goto err_clk;
}
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);
+ if ((mr & AT91_RTT_RTPRES) != sclk_rate) {
+ mr = AT91_RTT_RTTRST | (sclk_rate & AT91_RTT_RTPRES);
gpbr_writel(rtc, 0);
}
@@ -346,17 +404,22 @@ static int at91_rtc_probe(struct platform_device *pdev)
mr &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
rtt_writel(rtc, MR, mr);
- rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
- &at91_rtc_ops, THIS_MODULE);
- if (IS_ERR(rtc->rtcdev))
- return PTR_ERR(rtc->rtcdev);
+ rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc->rtcdev)) {
+ ret = PTR_ERR(rtc->rtcdev);
+ goto err_clk;
+ }
+
+ rtc->rtcdev->ops = &at91_rtc_ops;
+ rtc->rtcdev->range_max = U32_MAX;
/* register irq handler after we know what name we'll use */
ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt,
- IRQF_SHARED, dev_name(&rtc->rtcdev->dev), rtc);
+ IRQF_SHARED | IRQF_COND_SUSPEND,
+ dev_name(&rtc->rtcdev->dev), rtc);
if (ret) {
dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
- return ret;
+ goto err_clk;
}
/* NOTE: sam9260 rev A silicon has a ROM bug which resets the
@@ -367,15 +430,20 @@ static int at91_rtc_probe(struct platform_device *pdev)
if (gpbr_readl(rtc) == 0)
dev_warn(&pdev->dev, "%s: SET TIME!\n",
- dev_name(&rtc->rtcdev->dev));
+ dev_name(&rtc->rtcdev->dev));
- return 0;
+ return devm_rtc_register_device(rtc->rtcdev);
+
+err_clk:
+ clk_disable_unprepare(rtc->sclk);
+
+ return ret;
}
/*
* Disable and remove the RTC driver
*/
-static int at91_rtc_remove(struct platform_device *pdev)
+static void at91_rtc_remove(struct platform_device *pdev)
{
struct sam9_rtc *rtc = platform_get_drvdata(pdev);
u32 mr = rtt_readl(rtc, MR);
@@ -383,7 +451,7 @@ static int at91_rtc_remove(struct platform_device *pdev)
/* disable all interrupts */
rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
- return 0;
+ clk_disable_unprepare(rtc->sclk);
}
static void at91_rtc_shutdown(struct platform_device *pdev)
@@ -411,12 +479,18 @@ static int at91_rtc_suspend(struct device *dev)
rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
if (rtc->imr) {
if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) {
+ unsigned long flags;
+
enable_irq_wake(rtc->irq);
+ spin_lock_irqsave(&rtc->lock, flags);
+ rtc->suspended = true;
+ spin_unlock_irqrestore(&rtc->lock, flags);
/* don't let RTTINC cause wakeups */
if (mr & AT91_RTT_RTTINCIEN)
rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
- } else
+ } else {
rtt_writel(rtc, MR, mr & ~rtc->imr);
+ }
}
return 0;
@@ -428,10 +502,18 @@ static int at91_rtc_resume(struct device *dev)
u32 mr;
if (rtc->imr) {
+ unsigned long flags;
+
if (device_may_wakeup(dev))
disable_irq_wake(rtc->irq);
mr = rtt_readl(rtc, MR);
rtt_writel(rtc, MR, mr | rtc->imr);
+
+ spin_lock_irqsave(&rtc->lock, flags);
+ rtc->suspended = false;
+ at91_rtc_cache_events(rtc);
+ at91_rtc_flush_events(rtc);
+ spin_unlock_irqrestore(&rtc->lock, flags);
}
return 0;
@@ -440,14 +522,20 @@ static int at91_rtc_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
+static const struct of_device_id at91_rtc_dt_ids[] = {
+ { .compatible = "atmel,at91sam9260-rtt" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+
static struct platform_driver at91_rtc_driver = {
.probe = at91_rtc_probe,
.remove = at91_rtc_remove,
.shutdown = at91_rtc_shutdown,
.driver = {
.name = "rtc-at91sam9",
- .owner = THIS_MODULE,
.pm = &at91_rtc_pm_ops,
+ .of_match_table = at91_rtc_dt_ids,
},
};
generated by cgit (git 2.34.1) at 2025-12-22 00:37:59 +0000