rtc: s3c: Handle clock enable failures

clk_enable() can fail so handle such case.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 0cb2f27..a8992c2 100644 (file)
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -68,18 +68,32 @@ struct s3c_rtc_data {
        void (*disable) (struct s3c_rtc *info);
 };
 
-static void s3c_rtc_enable_clk(struct s3c_rtc *info)
+static int s3c_rtc_enable_clk(struct s3c_rtc *info)
 {
        unsigned long irq_flags;
+       int ret = 0;
 
        spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
+
        if (info->clk_disabled) {
-               clk_enable(info->rtc_clk);
-               if (info->data->needs_src_clk)
-                       clk_enable(info->rtc_src_clk);
+               ret = clk_enable(info->rtc_clk);
+               if (ret)
+                       goto out;
+
+               if (info->data->needs_src_clk) {
+                       ret = clk_enable(info->rtc_src_clk);
+                       if (ret) {
+                               clk_disable(info->rtc_clk);
+                               goto out;
+                       }
+               }
                info->clk_disabled = false;
        }
+
+out:
        spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
+
+       return ret;
 }
 
 static void s3c_rtc_disable_clk(struct s3c_rtc *info)
@@ -122,10 +136,13 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
        unsigned int tmp;
+       int ret;
 
        dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
 
@@ -136,10 +153,13 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
 
        s3c_rtc_disable_clk(info);
 
-       if (enabled)
-               s3c_rtc_enable_clk(info);
-       else
+       if (enabled) {
+               ret = s3c_rtc_enable_clk(info);
+               if (ret)
+                       return ret;
+       } else {
                s3c_rtc_disable_clk(info);
+       }
 
        return 0;
 }
@@ -147,10 +167,14 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
 /* Set RTC frequency */
 static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
 {
+       int ret;
+
        if (!is_power_of_2(freq))
                return -EINVAL;
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
        spin_lock_irq(&info->pie_lock);
 
        if (info->data->set_freq)
@@ -167,8 +191,11 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
        unsigned int have_retried = 0;
+       int ret;
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
 retry_get_time:
        rtc_tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
@@ -212,6 +239,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
        int year = tm->tm_year - 100;
+       int ret;
 
        dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
@@ -224,7 +252,9 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
                return -EINVAL;
        }
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        writeb(bin2bcd(tm->tm_sec),  info->base + S3C2410_RTCSEC);
        writeb(bin2bcd(tm->tm_min),  info->base + S3C2410_RTCMIN);
@@ -243,8 +273,11 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
        struct s3c_rtc *info = dev_get_drvdata(dev);
        struct rtc_time *alm_tm = &alrm->time;
        unsigned int alm_en;
+       int ret;
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        alm_tm->tm_sec  = readb(info->base + S3C2410_ALMSEC);
        alm_tm->tm_min  = readb(info->base + S3C2410_ALMMIN);
@@ -293,6 +326,7 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
        struct s3c_rtc *info = dev_get_drvdata(dev);
        struct rtc_time *tm = &alrm->time;
        unsigned int alrm_en;
+       int ret;
        int year = tm->tm_year - 100;
 
        dev_dbg(dev, "s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
@@ -300,7 +334,9 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
                1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
                tm->tm_hour, tm->tm_min, tm->tm_sec);
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
        writeb(0x00, info->base + S3C2410_RTCALM);
@@ -349,8 +385,11 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
+       int ret;
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        if (info->data->enable_tick)
                info->data->enable_tick(info, seq);
@@ -589,8 +628,11 @@ err_src_clk:
 static int s3c_rtc_suspend(struct device *dev)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
+       int ret;
 
-       s3c_rtc_enable_clk(info);
+       ret = s3c_rtc_enable_clk(info);
+       if (ret)
+               return ret;
 
        /* save TICNT for anyone using periodic interrupts */
        if (info->data->save_tick_cnt)