diff mbox

[v3,3/3] rtc: omap: Add external clock enabling support

Message ID 1439878724-5828-4-git-send-email-j-keerthy@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

J, KEERTHY Aug. 18, 2015, 6:18 a.m. UTC 
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>
---
 drivers/rtc/rtc-omap.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

Comments

Johan Hovold Aug. 18, 2015, 7:14 a.m. UTC | #1 
On Tue, Aug 18, 2015 at 11:48:44AM +0530, Keerthy wrote:
> 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>
> ---
>  drivers/rtc/rtc-omap.c | 33 ++++++++++++++++++++++++++++++---
>  1 file changed, 30 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index f31c012..255f7b7 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
 
> @@ -555,11 +557,19 @@ 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");
> -
> -	if (!IS_ERR(rtc->clk))
> +	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
> +	if (!IS_ERR(rtc->clk)) {
> +		rtc->has_ext_clk = true;
>  		clk_prepare_enable(rtc->clk);
> +	} else {
> +		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
> +		if (IS_ERR(rtc->clk))
> +			goto no_clk;
> +	}
>
> +	clk_prepare_enable(rtc->clk);

Just always check for errors before enabling here, and get rid of the
double enable and goto above.

> +
> +no_clk:

Johan
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diff mbox

Patch

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index f31c012..255f7b7 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;
 };
 
@@ -555,11 +557,19 @@  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");
-
-	if (!IS_ERR(rtc->clk))
+	rtc->clk = devm_clk_get(&pdev->dev, "ext-clk");
+	if (!IS_ERR(rtc->clk)) {
+		rtc->has_ext_clk = true;
 		clk_prepare_enable(rtc->clk);
+	} else {
+		rtc->clk = devm_clk_get(&pdev->dev, "int-clk");
+		if (IS_ERR(rtc->clk))
+			goto no_clk;
+	}
 
+	clk_prepare_enable(rtc->clk);
+
+no_clk:
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	rtc->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(rtc->base))
@@ -634,6 +644,16 @@  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 +699,7 @@  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 +716,12 @@  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 */