From 399cf0f63f6f24d7a837fbfbc801010cb6e77579 Mon Sep 17 00:00:00 2001 From: Keerthy Date: Tue, 18 Aug 2015 15:11:16 +0530 Subject: [PATCH] rtc: omap: Add external clock enabling support Configure the clock source to external clock if available. External clock is preferred as it can be ticking during suspend. Signed-off-by: Keerthy Acked-by: Tony Lindgren Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-omap.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c index f31c0127dae0..ec2e9c5fb993 100644 --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c @@ -108,6 +108,7 @@ /* OMAP_RTC_OSC_REG bit fields: */ #define OMAP_RTC_OSC_32KCLK_EN BIT(6) +#define OMAP_RTC_OSC_SEL_32KCLK_SRC BIT(3) /* OMAP_RTC_IRQWAKEEN bit fields: */ #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1) @@ -138,6 +139,7 @@ struct omap_rtc { int irq_timer; u8 interrupts_reg; bool is_pmic_controller; + bool has_ext_clk; const struct omap_rtc_device_type *type; }; @@ -555,7 +557,11 @@ static int omap_rtc_probe(struct platform_device *pdev) if (rtc->irq_alarm <= 0) return -ENOENT; - rtc->clk = devm_clk_get(&pdev->dev, "int-clk"); + rtc->clk = devm_clk_get(&pdev->dev, "ext-clk"); + if (!IS_ERR(rtc->clk)) + rtc->has_ext_clk = true; + else + rtc->clk = devm_clk_get(&pdev->dev, "int-clk"); if (!IS_ERR(rtc->clk)) clk_prepare_enable(rtc->clk); @@ -634,6 +640,16 @@ static int omap_rtc_probe(struct platform_device *pdev) if (reg != new_ctrl) rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl); + /* + * If we have the external clock then switch to it so we can keep + * ticking across suspend. + */ + if (rtc->has_ext_clk) { + reg = rtc_read(rtc, OMAP_RTC_OSC_REG); + rtc_write(rtc, OMAP_RTC_OSC_REG, + reg | OMAP_RTC_OSC_SEL_32KCLK_SRC); + } + rtc->type->lock(rtc); device_init_wakeup(&pdev->dev, true); @@ -679,6 +695,7 @@ err: static int __exit omap_rtc_remove(struct platform_device *pdev) { struct omap_rtc *rtc = platform_get_drvdata(pdev); + u8 reg; if (pm_power_off == omap_rtc_power_off && omap_rtc_power_off_rtc == rtc) { @@ -695,6 +712,12 @@ static int __exit omap_rtc_remove(struct platform_device *pdev) /* leave rtc running, but disable irqs */ rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0); + if (rtc->has_ext_clk) { + reg = rtc_read(rtc, OMAP_RTC_OSC_REG); + reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC; + rtc_write(rtc, OMAP_RTC_OSC_REG, reg); + } + rtc->type->lock(rtc); /* Disable the clock/module */