diff options
| -rw-r--r-- | chip/npcx/clock.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/chip/npcx/clock.c b/chip/npcx/clock.c index 6bb5d4962e..287583232a 100644 --- a/chip/npcx/clock.c +++ b/chip/npcx/clock.c @@ -96,19 +96,26 @@ void clock_init(void) #endif /* - * Configure frequency multiplier M/N values according to - * the requested OSC_CLK (Unit:Hz). + * Resting the OSC_CLK (even to the same value) will make the clock + * unstable for a little which can affect peripheral communication like + * eSPI. Skip this if not needed (e.g. RW jump) */ - NPCX_HFCGN = HFCGN; - NPCX_HFCGML = HFCGML; - NPCX_HFCGMH = HFCGMH; - - /* Load M and N values into the frequency multiplier */ - SET_BIT(NPCX_HFCGCTRL, NPCX_HFCGCTRL_LOAD); - - /* Wait for stable */ - while (IS_BIT_SET(NPCX_HFCGCTRL, NPCX_HFCGCTRL_CLK_CHNG)) - ; + if (NPCX_HFCGN != HFCGN || NPCX_HFCGML != HFCGML + || NPCX_HFCGMH != HFCGMH) { + /* + * Configure frequency multiplier M/N values according to + * the requested OSC_CLK (Unit:Hz). + */ + NPCX_HFCGN = HFCGN; + NPCX_HFCGML = HFCGML; + NPCX_HFCGMH = HFCGMH; + + /* Load M and N values into the frequency multiplier */ + SET_BIT(NPCX_HFCGCTRL, NPCX_HFCGCTRL_LOAD); + /* Wait for stable */ + while (IS_BIT_SET(NPCX_HFCGCTRL, NPCX_HFCGCTRL_CLK_CHNG)) + ; + } /* Set all clock prescalers of core and peripherals. */ #if defined(CHIP_FAMILY_NPCX5) |