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authorMarek Szyprowski <m.szyprowski@samsung.com>2019-01-21 14:09:30 +0300
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-01-22 20:34:42 +0300
commit5a5b614ba61cc2a89ad0dffc63d913a1a6ba1f9f (patch)
treef8be6feae309e045dcda0bb8c8be81ed82a1c07e /drivers/rtc/rtc-s3c.c
parentf724c6bee162be3a9cd3b9168414ca106e0cdfe2 (diff)
downloadlinux-5a5b614ba61cc2a89ad0dffc63d913a1a6ba1f9f.tar.xz
rtc: s3c: Rewrite clock handling
s3c_rtc_enable/disable_clk() functions were designed to be called multiple times without reference counting, because they were initially only used in alarm setting/clearing functions, which can be called both when alarm is already set or not. Later however, calls to those functions have been added to other places in the driver - like time and /proc reading callbacks, what results in broken alarm if any of such events happens after the alarm has been set. Fix this by simplifying s3c_rtc_enable/disable_clk() functions to rely on proper reference counting in clock core and move alarm enable counter to s3c_rtc_setaie() function. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-s3c.c')
-rw-r--r--drivers/rtc/rtc-s3c.c74
1 files changed, 31 insertions, 43 deletions
diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 04c68178c42d..ea82efba6f94 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -39,7 +39,7 @@ struct s3c_rtc {
void __iomem *base;
struct clk *rtc_clk;
struct clk *rtc_src_clk;
- bool clk_disabled;
+ bool alarm_enabled;
const struct s3c_rtc_data *data;
@@ -47,7 +47,7 @@ struct s3c_rtc {
int irq_tick;
spinlock_t pie_lock;
- spinlock_t alarm_clk_lock;
+ spinlock_t alarm_lock;
int ticnt_save;
int ticnt_en_save;
@@ -70,44 +70,27 @@ struct s3c_rtc_data {
static int s3c_rtc_enable_clk(struct s3c_rtc *info)
{
- unsigned long irq_flags;
- int ret = 0;
+ int ret;
- spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
+ ret = clk_enable(info->rtc_clk);
+ if (ret)
+ return ret;
- if (info->clk_disabled) {
- 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;
- }
+ if (info->data->needs_src_clk) {
+ ret = clk_enable(info->rtc_src_clk);
+ if (ret) {
+ clk_disable(info->rtc_clk);
+ return ret;
}
- info->clk_disabled = false;
}
-
-out:
- spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
-
- return ret;
+ return 0;
}
static void s3c_rtc_disable_clk(struct s3c_rtc *info)
{
- unsigned long irq_flags;
-
- spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
- if (!info->clk_disabled) {
- if (info->data->needs_src_clk)
- clk_disable(info->rtc_src_clk);
- clk_disable(info->rtc_clk);
- info->clk_disabled = true;
- }
- spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
+ if (info->data->needs_src_clk)
+ clk_disable(info->rtc_src_clk);
+ clk_disable(info->rtc_clk);
}
/* IRQ Handlers */
@@ -135,6 +118,7 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
+ unsigned long flags;
unsigned int tmp;
int ret;
@@ -151,17 +135,19 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
writeb(tmp, info->base + S3C2410_RTCALM);
- s3c_rtc_disable_clk(info);
+ spin_lock_irqsave(&info->alarm_lock, flags);
- if (enabled) {
- ret = s3c_rtc_enable_clk(info);
- if (ret)
- return ret;
- } else {
+ if (info->alarm_enabled && !enabled)
s3c_rtc_disable_clk(info);
- }
+ else if (!info->alarm_enabled && enabled)
+ ret = s3c_rtc_enable_clk(info);
- return 0;
+ info->alarm_enabled = enabled;
+ spin_unlock_irqrestore(&info->alarm_lock, flags);
+
+ s3c_rtc_disable_clk(info);
+
+ return ret;
}
/* Set RTC frequency */
@@ -357,10 +343,10 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
writeb(alrm_en, info->base + S3C2410_RTCALM);
- s3c_rtc_disable_clk(info);
-
s3c_rtc_setaie(dev, alrm->enabled);
+ s3c_rtc_disable_clk(info);
+
return 0;
}
@@ -491,7 +477,7 @@ static int s3c_rtc_probe(struct platform_device *pdev)
return -EINVAL;
}
spin_lock_init(&info->pie_lock);
- spin_lock_init(&info->alarm_clk_lock);
+ spin_lock_init(&info->alarm_lock);
platform_set_drvdata(pdev, info);
@@ -591,6 +577,8 @@ static int s3c_rtc_probe(struct platform_device *pdev)
s3c_rtc_setfreq(info, 1);
+ s3c_rtc_disable_clk(info);
+
return 0;
err_nortc: