Merge branch 'timers/posix-cpu-timers-for-tglx' of

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core

Frederic sayed: "Most of these patches have been hanging around for
several month now, in -mmotm for a significant chunk. They already
missed a few releases."

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 111 insertions, 20 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index 0eab77b22340..f296f3f7db9b 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -25,6 +25,7 @@
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/interrupt.h>
+#include <linux/spinlock.h>
 #include <linux/ioctl.h>
 #include <linux/completion.h>
 #include <linux/io.h>
@@ -42,10 +43,65 @@
 
 #define AT91_RTC_EPOCH		1900UL	/* just like arch/arm/common/rtctime.c */
 
+struct at91_rtc_config {
+	bool use_shadow_imr;
+};
+
+static const struct at91_rtc_config *at91_rtc_config;
 static DECLARE_COMPLETION(at91_rtc_updated);
 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
 static void __iomem *at91_rtc_regs;
 static int irq;
+static DEFINE_SPINLOCK(at91_rtc_lock);
+static u32 at91_rtc_shadow_imr;
+
+static void at91_rtc_write_ier(u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&at91_rtc_lock, flags);
+	at91_rtc_shadow_imr |= mask;
+	at91_rtc_write(AT91_RTC_IER, mask);
+	spin_unlock_irqrestore(&at91_rtc_lock, flags);
+}
+
+static void at91_rtc_write_idr(u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&at91_rtc_lock, flags);
+	at91_rtc_write(AT91_RTC_IDR, mask);
+	/*
+	 * Register read back (of any RTC-register) needed to make sure
+	 * IDR-register write has reached the peripheral before updating
+	 * shadow mask.
+	 *
+	 * Note that there is still a possibility that the mask is updated
+	 * before interrupts have actually been disabled in hardware. The only
+	 * way to be certain would be to poll the IMR-register, which is is
+	 * the very register we are trying to emulate. The register read back
+	 * is a reasonable heuristic.
+	 */
+	at91_rtc_read(AT91_RTC_SR);
+	at91_rtc_shadow_imr &= ~mask;
+	spin_unlock_irqrestore(&at91_rtc_lock, flags);
+}
+
+static u32 at91_rtc_read_imr(void)
+{
+	unsigned long flags;
+	u32 mask;
+
+	if (at91_rtc_config->use_shadow_imr) {
+		spin_lock_irqsave(&at91_rtc_lock, flags);
+		mask = at91_rtc_shadow_imr;
+		spin_unlock_irqrestore(&at91_rtc_lock, flags);
+	} else {
+		mask = at91_rtc_read(AT91_RTC_IMR);
+	}
+
+	return mask;
+}
 
 /*
  * Decode time/date into rtc_time structure
@@ -110,9 +166,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
 	cr = at91_rtc_read(AT91_RTC_CR);
 	at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 
-	at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
+	at91_rtc_write_ier(AT91_RTC_ACKUPD);
 	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */
-	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
+	at91_rtc_write_idr(AT91_RTC_ACKUPD);
 
 	at91_rtc_write(AT91_RTC_TIMR,
 			  bin2bcd(tm->tm_sec) << 0
@@ -144,7 +200,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 	tm->tm_year = at91_alarm_year - 1900;
 
-	alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
+	alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
 			? 1 : 0;
 
 	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
@@ -169,7 +225,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	tm.tm_min = alrm->time.tm_min;
 	tm.tm_sec = alrm->time.tm_sec;
 
-	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
+	at91_rtc_write_idr(AT91_RTC_ALARM);
 	at91_rtc_write(AT91_RTC_TIMALR,
 		  bin2bcd(tm.tm_sec) << 0
 		| bin2bcd(tm.tm_min) << 8
@@ -182,7 +238,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	if (alrm->enabled) {
 		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
-		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
+		at91_rtc_write_ier(AT91_RTC_ALARM);
 	}
 
 	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
@@ -198,9 +254,9 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 
 	if (enabled) {
 		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
-		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
+		at91_rtc_write_ier(AT91_RTC_ALARM);
 	} else
-		at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
+		at91_rtc_write_idr(AT91_RTC_ALARM);
 
 	return 0;
 }
@@ -209,7 +265,7 @@ 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)
 {
-	unsigned long imr = at91_rtc_read(AT91_RTC_IMR);
+	unsigned long imr = at91_rtc_read_imr();
 
 	seq_printf(seq, "update_IRQ\t: %s\n",
 			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
@@ -229,7 +285,7 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 	unsigned int rtsr;
 	unsigned long events = 0;
 
-	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
+	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
 	if (rtsr) {		/* this interrupt is shared!  Is it ours? */
 		if (rtsr & AT91_RTC_ALARM)
 			events |= (RTC_AF | RTC_IRQF);
@@ -250,6 +306,43 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 	return IRQ_NONE;		/* not handled */
 }
 
+static const struct at91_rtc_config at91rm9200_config = {
+};
+
+static const struct at91_rtc_config at91sam9x5_config = {
+	.use_shadow_imr	= true,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id at91_rtc_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-rtc",
+		.data = &at91rm9200_config,
+	}, {
+		.compatible = "atmel,at91sam9x5-rtc",
+		.data = &at91sam9x5_config,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+#endif
+
+static const struct at91_rtc_config *
+at91_rtc_get_config(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	if (pdev->dev.of_node) {
+		match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
+		if (!match)
+			return NULL;
+		return (const struct at91_rtc_config *)match->data;
+	}
+
+	return &at91rm9200_config;
+}
+
 static const struct rtc_class_ops at91_rtc_ops = {
 	.read_time	= at91_rtc_readtime,
 	.set_time	= at91_rtc_settime,
@@ -268,6 +361,10 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
 	struct resource *regs;
 	int ret = 0;
 
+	at91_rtc_config = at91_rtc_get_config(pdev);
+	if (!at91_rtc_config)
+		return -ENODEV;
+
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!regs) {
 		dev_err(&pdev->dev, "no mmio resource defined\n");
@@ -290,7 +387,7 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
 	at91_rtc_write(AT91_RTC_MR, 0);		/* 24 hour mode */
 
 	/* Disable all interrupts */
-	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+	at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 					AT91_RTC_SECEV | AT91_RTC_TIMEV |
 					AT91_RTC_CALEV);
 
@@ -335,7 +432,7 @@ static int __exit at91_rtc_remove(struct platform_device *pdev)
 	struct rtc_device *rtc = platform_get_drvdata(pdev);
 
 	/* Disable all interrupts */
-	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+	at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 					AT91_RTC_SECEV | AT91_RTC_TIMEV |
 					AT91_RTC_CALEV);
 	free_irq(irq, pdev);
@@ -358,13 +455,13 @@ static int at91_rtc_suspend(struct device *dev)
 	/* this IRQ is shared with DBGU and other hardware which isn't
 	 * necessarily doing PM like we are...
 	 */
-	at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
+	at91_rtc_imr = at91_rtc_read_imr()
 			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
 	if (at91_rtc_imr) {
 		if (device_may_wakeup(dev))
 			enable_irq_wake(irq);
 		else
-			at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
+			at91_rtc_write_idr(at91_rtc_imr);
 	}
 	return 0;
 }
@@ -375,7 +472,7 @@ static int at91_rtc_resume(struct device *dev)
 		if (device_may_wakeup(dev))
 			disable_irq_wake(irq);
 		else
-			at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
+			at91_rtc_write_ier(at91_rtc_imr);
 	}
 	return 0;
 }
@@ -383,12 +480,6 @@ 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,at91rm9200-rtc" },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
-
 static struct platform_driver at91_rtc_driver = {
 	.remove		= __exit_p(at91_rtc_remove),
 	.driver		= {