am335x: Enable RTC 32K OSC clock
In order to support low power state, you must source kernel system
timers to persistent clock, available across suspend/resume. In case of
AM335x device, the only source we have is, RTC32K, available in
wakeup/always-on domain. Having said that, during validation it has
been observed that, RTC clock need couple of seconds delay to stabilize
the RTC OSC clock; and such a huge delay is not acceptable in kernel
especially during early init and also it will impact quick/fast boot
use-cases.
So, RTC32k OSC enable dependency has been shifted to
SPL/first-bootloader.
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/arch/arm/cpu/armv7/am33xx/clock.c b/arch/arm/cpu/armv7/am33xx/clock.c
index 2b19506..f870859 100644
--- a/arch/arm/cpu/armv7/am33xx/clock.c
+++ b/arch/arm/cpu/armv7/am33xx/clock.c
@@ -44,6 +44,7 @@
const struct cm_perpll *cmper = (struct cm_perpll *)CM_PER;
const struct cm_wkuppll *cmwkup = (struct cm_wkuppll *)CM_WKUP;
const struct cm_dpll *cmdpll = (struct cm_dpll *)CM_DPLL;
+const struct cm_rtc *cmrtc = (struct cm_rtc *)CM_RTC;
static void enable_interface_clocks(void)
{
@@ -153,6 +154,11 @@
writel(PRCM_MOD_EN, &cmper->spi0clkctrl);
while (readl(&cmper->spi0clkctrl) != PRCM_MOD_EN)
;
+
+ /* RTC */
+ writel(PRCM_MOD_EN, &cmrtc->rtcclkctrl);
+ while (readl(&cmrtc->rtcclkctrl) != PRCM_MOD_EN)
+ ;
}
static void mpu_pll_config(void)