| Message ID | 1477547846-5335-1-git-send-email-j-keerthy@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 27/10/2016 at 11:27:25 +0530, Keerthy wrote : > From: Lokesh Vutla <lokeshvutla@ti.com> > > RTC can be clocked from an external 32KHz oscillator, or from the > Peripheral PLL. The RTC has an internal oscillator buffer to support > direct operation with a crystal. > > ---------------------------------------- > | Device --------- | > | | | | > | | RTCSS | | > | --------- | | | > OSC |<------| RTC | | | | > |------>| OSC |--- | | | > | -------- | | | | > | ----|clk | | > | -------- | | | | > | | PRCM |--- | | | > | -------- -------- | > ---------------------------------------- > > The RTC functional clock is sourced by default from the clock derived > from the Peripheral PLL. In order to select source as external osc clk > the following changes needs to be done: > - Enable the RTC OSC (RTC_OSC_REG[4]OSC32K_GZ = 0) > - Enable the clock mux(RTC_OSC_REG[6]K32CLK_EN = 1) > - Select the external clock source (RTC_OSC_REG[3]32KCLK_SEL = 1) > > Fixes: 399cf0f63f6f2 ("rtc: omap: Add external clock enabling support") > Signed-off-by: Keerthy <j-keerthy@ti.com> > Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> > Signed-off-by: Dave Gerlach <d-gerlach@ti.com> > --- > > Boot tested and checked for rtc ticking on am335x-boneblack, am335x-bone > am437x-gp-evm, dra7-evm, dra72-evm. > > drivers/rtc/rtc-omap.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > Both applied, thanks.
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c index b04ea9b..dddaa60 100644 --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c @@ -113,6 +113,7 @@ /* OMAP_RTC_OSC_REG bit fields: */ #define OMAP_RTC_OSC_32KCLK_EN BIT(6) #define OMAP_RTC_OSC_SEL_32KCLK_SRC BIT(3) +#define OMAP_RTC_OSC_OSC32K_GZ_DISABLE BIT(4) /* OMAP_RTC_IRQWAKEEN bit fields: */ #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1) @@ -786,8 +787,9 @@ static int omap_rtc_probe(struct platform_device *pdev) */ 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); + reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE; + reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC; + rtc_writel(rtc, OMAP_RTC_OSC_REG, reg); } rtc->type->lock(rtc);