diff options
Diffstat (limited to 'arch/arm/mach-k3/am625_init.c')
| -rw-r--r-- | arch/arm/mach-k3/am625_init.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/arm/mach-k3/am625_init.c b/arch/arm/mach-k3/am625_init.c index 026c4f9c02..787fe92295 100644 --- a/arch/arm/mach-k3/am625_init.c +++ b/arch/arm/mach-k3/am625_init.c @@ -15,6 +15,15 @@ #include <dm/uclass-internal.h> #include <dm/pinctrl.h> +#define RTC_BASE_ADDRESS 0x2b1f0000 +#define REG_K3RTC_S_CNT_LSW (RTC_BASE_ADDRESS + 0x18) +#define REG_K3RTC_KICK0 (RTC_BASE_ADDRESS + 0x70) +#define REG_K3RTC_KICK1 (RTC_BASE_ADDRESS + 0x74) + +/* Magic values for lock/unlock */ +#define K3RTC_KICK0_UNLOCK_VALUE 0x83e70b13 +#define K3RTC_KICK1_UNLOCK_VALUE 0x95a4f1e0 + /* * This uninitialized global variable would normal end up in the .bss section, * but the .bss is cleared between writing and reading this variable, so move @@ -71,6 +80,42 @@ static __maybe_unused void enable_mcu_esm_reset(void) writel(stat, CTRLMMR_MCU_RST_CTRL); } +#if defined(CONFIG_CPU_V7R) + +/* + * RTC Erratum i2327 Workaround for Silicon Revision 1 + * + * Due to a bug in initial synchronization out of cold power on, + * IRQ status can get locked infinitely if we do not unlock RTC + * + * This workaround *must* be applied within 1 second of power on, + * So, this is closest point to be able to guarantee the max + * timing. + * + * https://www.ti.com/lit/er/sprz487c/sprz487c.pdf + */ +void rtc_erratumi2327_init(void) +{ + u32 counter; + + /* + * If counter has gone past 1, nothing we can do, leave + * system locked! This is the only way we know if RTC + * can be used for all practical purposes. + */ + counter = readl(REG_K3RTC_S_CNT_LSW); + if (counter > 1) + return; + /* + * Need to set this up at the very start + * MUST BE DONE under 1 second of boot. + */ + writel(K3RTC_KICK0_UNLOCK_VALUE, REG_K3RTC_KICK0); + writel(K3RTC_KICK1_UNLOCK_VALUE, REG_K3RTC_KICK1); + return; +} +#endif + void board_init_f(ulong dummy) { struct udevice *dev; @@ -78,6 +123,7 @@ void board_init_f(ulong dummy) #if defined(CONFIG_CPU_V7R) setup_k3_mpu_regions(); + rtc_erratumi2327_init(); #endif /* |