TRNG_V1_ISTAT
istat = rk_rng_readl(rk_rng, TRNG_V1_ISTAT);
rk_rng_writel(rk_rng, istat, TRNG_V1_ISTAT);
reg = rk_rng_readl(rk_rng, TRNG_V1_ISTAT);
rk_rng_writel(rk_rng, reg, TRNG_V1_ISTAT);
ret = readl_poll_timeout_atomic(rk_rng->base + TRNG_V1_ISTAT, reg,
rk_rng_writel(rk_rng, reg, TRNG_V1_ISTAT);