On 13/08/2015 at 12:37:48 +0530, Keerthy wrote :
> 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 <[email protected]>
> ---
> drivers/rtc/rtc-omap.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index 8b6355f..479f730 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)
> @@ -136,6 +138,7 @@ struct omap_rtc {
> int irq_timer;
> u8 interrupts_reg;
> bool is_pmic_controller;
> + bool has_ext_clk;
> const struct omap_rtc_device_type *type;
> };
>
> @@ -525,6 +528,7 @@ static int omap_rtc_probe(struct platform_device *pdev)
> {
> struct omap_rtc *rtc;
> struct resource *res;
> + struct clk *ext_clk, *int_clk;
> u8 reg, mask, new_ctrl;
> const struct platform_device_id *id_entry;
> const struct of_device_id *of_id;
> @@ -553,6 +557,17 @@ static int omap_rtc_probe(struct platform_device *pdev)
> if (rtc->irq_alarm <= 0)
> return -ENOENT;
>
> + ext_clk = devm_clk_get(&pdev->dev, "ext-clk");
> + if (!IS_ERR(ext_clk)) {
> + rtc->has_ext_clk = true;
> + clk_prepare(ext_clk);
I'd say this has to be prepare_enable because you are not enabling those
clocks anywhere
> + } else {
> + int_clk = devm_clk_get(&pdev->dev, "int-clk");
> +
> + if (!IS_ERR(int_clk))
> + clk_prepare(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 +642,17 @@ 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 external clock 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 +698,8 @@ err:
> static int __exit omap_rtc_remove(struct platform_device *pdev)
> {
> struct omap_rtc *rtc = platform_get_drvdata(pdev);
> + struct clk *ext_clk, *int_clk;
> + u8 reg;
>
> if (pm_power_off == omap_rtc_power_off &&
> omap_rtc_power_off_rtc == rtc) {
> @@ -681,10 +709,26 @@ static int __exit omap_rtc_remove(struct
> platform_device *pdev)
>
> device_init_wakeup(&pdev->dev, 0);
>
> + ext_clk = devm_clk_get(&pdev->dev, "ext-clk");
> + if (!IS_ERR(ext_clk)) {
> + clk_unprepare(ext_clk);
> + } else {
> + int_clk = devm_clk_get(&pdev->dev, "int-clk");
> +
> + if (!IS_ERR(int_clk))
> + clk_unprepare(int_clk);
> + }
> +
You can probably add ext_clk and int_clk to struct omap_rtc and avoid
those devm_clk_get.
> rtc->type->unlock(rtc);
> /* leave rtc running, but disable irqs */
> rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
>
> + if (rtc->has_ext_clk) {
Then you could also avoid has_ext_clk and simply test rtc->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
>
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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