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 <j-keerthy@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index f31c012..ec2e9c5 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 @@
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 @@
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 @@
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 @@
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 @@
/* 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 */