From cefe4fbbaab8e20a7581a187db82d33c1e3320c0 Mon Sep 17 00:00:00 2001 From: Donggeun Kim Date: Mon, 25 Jul 2011 17:13:32 -0700 Subject: [PATCH] drivers/rtc/rtc-s3c.c: support clock gating Add support for clock gating. Power consumption can be reduced by setting rtc_clk disabled state except for when RTC related registers are accessed. Signed-off-by: Donggeun Kim Signed-off-by: MyungJoo Ham Signed-off-by: KyungMin Park Cc: Alessandro Zummo Cc: Ben Dooks Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-s3c.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index 16512ecae31a..53c99b1a3c92 100644 --- a/drivers/rtc/rtc-s3c.c +++ b/drivers/rtc/rtc-s3c.c @@ -57,11 +57,13 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) { struct rtc_device *rdev = id; + clk_enable(rtc_clk); rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); if (s3c_rtc_cpu_type == TYPE_S3C64XX) writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP); + clk_disable(rtc_clk); return IRQ_HANDLED; } @@ -69,11 +71,13 @@ static irqreturn_t s3c_rtc_tickirq(int irq, void *id) { struct rtc_device *rdev = id; + clk_enable(rtc_clk); rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF); if (s3c_rtc_cpu_type == TYPE_S3C64XX) writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP); + clk_disable(rtc_clk); return IRQ_HANDLED; } @@ -84,12 +88,14 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) pr_debug("%s: aie=%d\n", __func__, enabled); + clk_enable(rtc_clk); tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; if (enabled) tmp |= S3C2410_RTCALM_ALMEN; writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); + clk_disable(rtc_clk); return 0; } @@ -103,6 +109,7 @@ static int s3c_rtc_setfreq(struct device *dev, int freq) if (!is_power_of_2(freq)) return -EINVAL; + clk_enable(rtc_clk); spin_lock_irq(&s3c_rtc_pie_lock); if (s3c_rtc_cpu_type == TYPE_S3C2410) { @@ -114,6 +121,7 @@ static int s3c_rtc_setfreq(struct device *dev, int freq) writel(tmp, s3c_rtc_base + S3C2410_TICNT); spin_unlock_irq(&s3c_rtc_pie_lock); + clk_disable(rtc_clk); return 0; } @@ -125,6 +133,7 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) unsigned int have_retried = 0; void __iomem *base = s3c_rtc_base; + clk_enable(rtc_clk); retry_get_time: rtc_tm->tm_min = readb(base + S3C2410_RTCMIN); rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR); @@ -157,6 +166,7 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) rtc_tm->tm_year += 100; rtc_tm->tm_mon -= 1; + clk_disable(rtc_clk); return rtc_valid_tm(rtc_tm); } @@ -165,6 +175,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) void __iomem *base = s3c_rtc_base; int year = tm->tm_year - 100; + clk_enable(rtc_clk); pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n", 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); @@ -182,6 +193,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE); writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON); writeb(bin2bcd(year), base + S3C2410_RTCYEAR); + clk_disable(rtc_clk); return 0; } @@ -192,6 +204,7 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) void __iomem *base = s3c_rtc_base; unsigned int alm_en; + clk_enable(rtc_clk); alm_tm->tm_sec = readb(base + S3C2410_ALMSEC); alm_tm->tm_min = readb(base + S3C2410_ALMMIN); alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR); @@ -243,6 +256,7 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) else alm_tm->tm_year = -1; + clk_disable(rtc_clk); return 0; } @@ -252,6 +266,7 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) void __iomem *base = s3c_rtc_base; unsigned int alrm_en; + clk_enable(rtc_clk); pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n", alrm->enabled, 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, @@ -282,6 +297,7 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) s3c_rtc_setaie(dev, alrm->enabled); + clk_disable(rtc_clk); return 0; } @@ -289,6 +305,7 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) { unsigned int ticnt; + clk_enable(rtc_clk); if (s3c_rtc_cpu_type == TYPE_S3C64XX) { ticnt = readw(s3c_rtc_base + S3C2410_RTCCON); ticnt &= S3C64XX_RTCCON_TICEN; @@ -298,6 +315,7 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) } seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no"); + clk_disable(rtc_clk); return 0; } @@ -360,6 +378,7 @@ static void s3c_rtc_enable(struct platform_device *pdev, int en) if (s3c_rtc_base == NULL) return; + clk_enable(rtc_clk); if (!en) { tmp = readw(base + S3C2410_RTCCON); if (s3c_rtc_cpu_type == TYPE_S3C64XX) @@ -399,6 +418,7 @@ static void s3c_rtc_enable(struct platform_device *pdev, int en) base + S3C2410_RTCCON); } } + clk_disable(rtc_clk); } static int __devexit s3c_rtc_remove(struct platform_device *dev) @@ -410,7 +430,6 @@ static int __devexit s3c_rtc_remove(struct platform_device *dev) s3c_rtc_setaie(&dev->dev, 0); - clk_disable(rtc_clk); clk_put(rtc_clk); rtc_clk = NULL; @@ -530,6 +549,8 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev) s3c_rtc_setfreq(&pdev->dev, 1); + clk_disable(rtc_clk); + return 0; err_nortc: @@ -555,6 +576,7 @@ static int ticnt_save, ticnt_en_save; static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) { + clk_enable(rtc_clk); /* save TICNT for anyone using periodic interrupts */ ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); if (s3c_rtc_cpu_type == TYPE_S3C64XX) { @@ -569,6 +591,7 @@ static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) else dev_err(&pdev->dev, "enable_irq_wake failed\n"); } + clk_disable(rtc_clk); return 0; } @@ -577,6 +600,7 @@ static int s3c_rtc_resume(struct platform_device *pdev) { unsigned int tmp; + clk_enable(rtc_clk); s3c_rtc_enable(pdev, 1); writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) { @@ -588,6 +612,7 @@ static int s3c_rtc_resume(struct platform_device *pdev) disable_irq_wake(s3c_rtc_alarmno); wake_en = false; } + clk_disable(rtc_clk); return 0; } -- 2.20.1