Based on latest silicon validation we should allow at least 2 milliseconds after DCVDD enable or hard reset released before trying to communicate with the silicon.
Signed-off-by: Richard Fitzgerald <[email protected]> --- drivers/mfd/madera-core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index 440030cecbbd..3ff9a0615658 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -135,6 +135,15 @@ EXPORT_SYMBOL_GPL(madera_name_from_type); #define MADERA_BOOT_POLL_INTERVAL_USEC 5000 #define MADERA_BOOT_POLL_TIMEOUT_USEC 25000 +static void madera_por_delay(void) +{ + /* + * After DCVDD enable or hard reset released wait for internal + * POR (power-on-reset) before trying to communicate with the silicon + */ + usleep_range(2000, 3000); +} + static int madera_wait_for_boot(struct madera *madera) { ktime_t timeout; @@ -209,7 +218,7 @@ static void madera_disable_hard_reset(struct madera *madera) return; gpiod_set_raw_value_cansleep(madera->pdata.reset, 1); - usleep_range(1000, 2000); + madera_por_delay(); } static int __maybe_unused madera_runtime_resume(struct device *dev) @@ -225,6 +234,7 @@ static int __maybe_unused madera_runtime_resume(struct device *dev) return ret; } + madera_por_delay(); regcache_cache_only(madera->regmap, false); regcache_cache_only(madera->regmap_32bit, false); -- 2.11.0
