Configure the clock source to either internal clock
or external clock based on the availability of the clocks.
External clock is preferred as it can be ticking during suspend.
Signed-off-by: Keerthy <j-keer...@ti.com>
---
Changes in V2:
* Changed clk_prepare calls to clk_prepare_enable.
* Changed clk_unprepare calls to clk_disable_unprepare.
* Added clk pointers for external and internal clock to omap_rtc structure.
drivers/rtc/rtc-omap.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 8b6355f..46b3944 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -25,6 +25,7 @@
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/io.h>
+#include <linux/clk.h>
/*
* The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
@@ -107,6 +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)
@@ -132,10 +134,13 @@ struct omap_rtc_device_type {
struct omap_rtc {
struct rtc_device *rtc;
void __iomem *base;
+ struct clk *ext_clk;
+ struct clk *int_clk;
int irq_alarm;
int irq_timer;
u8 interrupts_reg;
bool is_pmic_controller;
+ bool has_ext_clk;
const struct omap_rtc_device_type *type;
};
@@ -553,6 +558,17 @@ static int omap_rtc_probe(struct platform_device *pdev)
if (rtc->irq_alarm <= 0)
return -ENOENT;
+ rtc->ext_clk = devm_clk_get(&pdev->dev, "ext-clk");
+ if (!IS_ERR(rtc->ext_clk)) {
+ rtc->has_ext_clk = true;
+ clk_prepare_enable(rtc->ext_clk);
+ } else {
+ rtc->int_clk = devm_clk_get(&pdev->dev, "int-clk");
+
+ if (!IS_ERR(rtc->int_clk))
+ clk_prepare_enable(rtc->int_clk);
+ }
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rtc->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rtc->base))
@@ -627,6 +643,16 @@ 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 acorss 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);
@@ -672,6 +698,7 @@ 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) {
@@ -681,10 +708,23 @@ static int __exit omap_rtc_remove(struct platform_device
*pdev)
device_init_wakeup(&pdev->dev, 0);
+ if (!IS_ERR(rtc->ext_clk)) {
+ clk_disable_unprepare(rtc->ext_clk);
+ } else {
+ if (!IS_ERR(rtc->int_clk))
+ clk_disable_unprepare(rtc->int_clk);
+ }
+
rtc->type->unlock(rtc);
/* 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 */
--
1.9.1
--
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