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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>
This commit is contained in:
Marek Szyprowski 2019-01-21 12:09:30 +01:00 committed by Alexandre Belloni
parent f724c6bee1
commit 5a5b614ba6
1 changed files with 32 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
drivers/rtc/rtc-s3c.c
View File

@ -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);
spin_lock_irqsave(&info->alarm_lock, flags);
if (info->alarm_enabled && !enabled)
s3c_rtc_disable_clk(info);
else if (!info->alarm_enabled && enabled)
ret = s3c_rtc_enable_clk(info);
info->alarm_enabled = enabled;
spin_unlock_irqrestore(&info->alarm_lock, flags);
s3c_rtc_disable_clk(info);
if (enabled) {
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
} else {
s3c_rtc_disable_clk(info);
}
return 0;
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: