rtc: bunch of drivers: fix 'no irq' case handing

This patch fixes a bunch of irq checking misuses.  Most drivers were
getting irq via platform_get_irq(), which returns -ENXIO or r->start.

rtc-cmos.c is special.  It is using PNP and platform bindings.  Hopefully
nobody is using PNP IRQ 0 for RTC.  So the changes should be safe.

rtc-sh.c is using platform_get_irq, but was storing a result into an
unsigned type, then was checking for < 0.  This is fixed now.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-at32ap700x.c b/drivers/rtc/rtc-at32ap700x.c
index 90b9a65..e1ec33e 100644
--- a/drivers/rtc/rtc-at32ap700x.c
+++ b/drivers/rtc/rtc-at32ap700x.c
@@ -205,7 +205,7 @@
 {
 	struct resource	*regs;
 	struct rtc_at32ap700x *rtc;
-	int irq = -1;
+	int irq;
 	int ret;
 
 	rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
@@ -222,7 +222,7 @@
 	}
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
+	if (irq <= 0) {
 		dev_dbg(&pdev->dev, "could not get irq\n");
 		ret = -ENXIO;
 		goto out;
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index d37bb86..cf98a5d 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -58,7 +58,7 @@
 };
 
 /* both platform and pnp busses use negative numbers for invalid irqs */
-#define is_valid_irq(n)		((n) >= 0)
+#define is_valid_irq(n)		((n) > 0)
 
 static const char driver_name[] = "rtc_cmos";
 
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
index 25caada..23a07fe 100644
--- a/drivers/rtc/rtc-ds1511.c
+++ b/drivers/rtc/rtc-ds1511.c
@@ -326,9 +326,9 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0) {
+	if (pdata->irq <= 0)
 		return -EINVAL;
-	}
+
 	pdata->alrm_mday = alrm->time.tm_mday;
 	pdata->alrm_hour = alrm->time.tm_hour;
 	pdata->alrm_min = alrm->time.tm_min;
@@ -346,9 +346,9 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0) {
+	if (pdata->irq <= 0)
 		return -EINVAL;
-	}
+
 	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
 	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
 	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
@@ -385,7 +385,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0) {
+	if (pdata->irq <= 0) {
 		return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
 	}
 	switch (cmd) {
@@ -503,7 +503,6 @@
 	if (!pdata) {
 		return -ENOMEM;
 	}
-	pdata->irq = -1;
 	pdata->size = res->end - res->start + 1;
 	if (!request_mem_region(res->start, pdata->size, pdev->name)) {
 		ret = -EBUSY;
@@ -545,13 +544,13 @@
 	 * if the platform has an interrupt in mind for this device,
 	 * then by all means, set it
 	 */
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		rtc_read(RTC_CMD1);
 		if (request_irq(pdata->irq, ds1511_interrupt,
 			IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
 
 			dev_warn(&pdev->dev, "interrupt not available.\n");
-			pdata->irq = -1;
+			pdata->irq = 0;
 		}
 	}
 
@@ -572,7 +571,7 @@
 	if (pdata->rtc) {
 		rtc_device_unregister(pdata->rtc);
 	}
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		free_irq(pdata->irq, pdev);
 	}
 	if (ds1511_base) {
@@ -595,7 +594,7 @@
 	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
 	rtc_device_unregister(pdata->rtc);
 	pdata->rtc = NULL;
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		/*
 		 * disable the alarm interrupt
 		 */
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
index b9475cd..38d472b 100644
--- a/drivers/rtc/rtc-ds1553.c
+++ b/drivers/rtc/rtc-ds1553.c
@@ -162,7 +162,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -EINVAL;
 	pdata->alrm_mday = alrm->time.tm_mday;
 	pdata->alrm_hour = alrm->time.tm_hour;
@@ -179,7 +179,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -EINVAL;
 	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
 	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
@@ -213,7 +213,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
 	switch (cmd) {
 	case RTC_AIE_OFF:
@@ -301,7 +301,6 @@
 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
-	pdata->irq = -1;
 	if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
 		ret = -EBUSY;
 		goto out;
@@ -327,13 +326,13 @@
 	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
 		dev_warn(&pdev->dev, "voltage-low detected.\n");
 
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		writeb(0, ioaddr + RTC_INTERRUPTS);
 		if (request_irq(pdata->irq, ds1553_rtc_interrupt,
 				IRQF_DISABLED | IRQF_SHARED,
 				pdev->name, pdev) < 0) {
 			dev_warn(&pdev->dev, "interrupt not available.\n");
-			pdata->irq = -1;
+			pdata->irq = 0;
 		}
 	}
 
@@ -353,7 +352,7 @@
  out:
 	if (pdata->rtc)
 		rtc_device_unregister(pdata->rtc);
-	if (pdata->irq >= 0)
+	if (pdata->irq > 0)
 		free_irq(pdata->irq, pdev);
 	if (ioaddr)
 		iounmap(ioaddr);
@@ -369,7 +368,7 @@
 
 	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
 	rtc_device_unregister(pdata->rtc);
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
 		free_irq(pdata->irq, pdev);
 	}
diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
index 43afb7a..33921a6 100644
--- a/drivers/rtc/rtc-m48t59.c
+++ b/drivers/rtc/rtc-m48t59.c
@@ -450,7 +450,7 @@
 	 * the mode without IRQ.
 	 */
 	m48t59->irq = platform_get_irq(pdev, 0);
-	if (m48t59->irq < 0)
+	if (m48t59->irq <= 0)
 		m48t59->irq = NO_IRQ;
 
 	if (m48t59->irq != NO_IRQ) {
diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c
index aaf9d6a..5ed66ac 100644
--- a/drivers/rtc/rtc-sh.c
+++ b/drivers/rtc/rtc-sh.c
@@ -89,7 +89,9 @@
 	void __iomem *regbase;
 	unsigned long regsize;
 	struct resource *res;
-	unsigned int alarm_irq, periodic_irq, carry_irq;
+	int alarm_irq;
+	int periodic_irq;
+	int carry_irq;
 	struct rtc_device *rtc_dev;
 	spinlock_t lock;
 	unsigned long capabilities;	/* See asm-sh/rtc.h for cap bits */
@@ -578,7 +580,7 @@
 
 	/* get periodic/carry/alarm irqs */
 	ret = platform_get_irq(pdev, 0);
-	if (unlikely(ret < 0)) {
+	if (unlikely(ret <= 0)) {
 		ret = -ENOENT;
 		dev_err(&pdev->dev, "No IRQ for period\n");
 		goto err_badres;
@@ -586,7 +588,7 @@
 	rtc->periodic_irq = ret;
 
 	ret = platform_get_irq(pdev, 1);
-	if (unlikely(ret < 0)) {
+	if (unlikely(ret <= 0)) {
 		ret = -ENOENT;
 		dev_err(&pdev->dev, "No IRQ for carry\n");
 		goto err_badres;
@@ -594,7 +596,7 @@
 	rtc->carry_irq = ret;
 
 	ret = platform_get_irq(pdev, 2);
-	if (unlikely(ret < 0)) {
+	if (unlikely(ret <= 0)) {
 		ret = -ENOENT;
 		dev_err(&pdev->dev, "No IRQ for alarm\n");
 		goto err_badres;
diff --git a/drivers/rtc/rtc-stk17ta8.c b/drivers/rtc/rtc-stk17ta8.c
index f4cd46e..dc0b622 100644
--- a/drivers/rtc/rtc-stk17ta8.c
+++ b/drivers/rtc/rtc-stk17ta8.c
@@ -170,7 +170,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -EINVAL;
 	pdata->alrm_mday = alrm->time.tm_mday;
 	pdata->alrm_hour = alrm->time.tm_hour;
@@ -187,7 +187,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -EINVAL;
 	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
 	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
@@ -221,7 +221,7 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	if (pdata->irq < 0)
+	if (pdata->irq <= 0)
 		return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
 	switch (cmd) {
 	case RTC_AIE_OFF:
@@ -303,7 +303,6 @@
 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
-	pdata->irq = -1;
 	if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
 		ret = -EBUSY;
 		goto out;
@@ -329,13 +328,13 @@
 	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
 		dev_warn(&pdev->dev, "voltage-low detected.\n");
 
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		writeb(0, ioaddr + RTC_INTERRUPTS);
 		if (request_irq(pdata->irq, stk17ta8_rtc_interrupt,
 				IRQF_DISABLED | IRQF_SHARED,
 				pdev->name, pdev) < 0) {
 			dev_warn(&pdev->dev, "interrupt not available.\n");
-			pdata->irq = -1;
+			pdata->irq = 0;
 		}
 	}
 
@@ -355,7 +354,7 @@
  out:
 	if (pdata->rtc)
 		rtc_device_unregister(pdata->rtc);
-	if (pdata->irq >= 0)
+	if (pdata->irq > 0)
 		free_irq(pdata->irq, pdev);
 	if (ioaddr)
 		iounmap(ioaddr);
@@ -371,7 +370,7 @@
 
 	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
 	rtc_device_unregister(pdata->rtc);
-	if (pdata->irq >= 0) {
+	if (pdata->irq > 0) {
 		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
 		free_irq(pdata->irq, pdev);
 	}
diff --git a/drivers/rtc/rtc-twl4030.c b/drivers/rtc/rtc-twl4030.c
index 01d8da9..8ce5f74 100644
--- a/drivers/rtc/rtc-twl4030.c
+++ b/drivers/rtc/rtc-twl4030.c
@@ -19,6 +19,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/types.h>
@@ -415,8 +416,8 @@
 	int irq = platform_get_irq(pdev, 0);
 	u8 rd_reg;
 
-	if (irq < 0)
-		return irq;
+	if (irq <= 0)
+		return -EINVAL;
 
 	rtc = rtc_device_register(pdev->name,
 				  &pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c
index 834dcc6..57b7aac 100644
--- a/drivers/rtc/rtc-vr41xx.c
+++ b/drivers/rtc/rtc-vr41xx.c
@@ -84,8 +84,8 @@
 static char rtc_name[] = "RTC";
 static unsigned long periodic_count;
 static unsigned int alarm_enabled;
-static int aie_irq = -1;
-static int pie_irq = -1;
+static int aie_irq;
+static int pie_irq;
 
 static inline unsigned long read_elapsed_second(void)
 {
@@ -360,7 +360,7 @@
 	spin_unlock_irq(&rtc_lock);
 
 	aie_irq = platform_get_irq(pdev, 0);
-	if (aie_irq < 0 || aie_irq >= nr_irqs) {
+	if (aie_irq <= 0) {
 		retval = -EBUSY;
 		goto err_device_unregister;
 	}
@@ -371,7 +371,7 @@
 		goto err_device_unregister;
 
 	pie_irq = platform_get_irq(pdev, 1);
-	if (pie_irq < 0 || pie_irq >= nr_irqs)
+	if (pie_irq <= 0)
 		goto err_free_irq;
 
 	retval = request_irq(pie_irq, rtclong1_interrupt, IRQF_DISABLED,