Hello Billy,

just two minor thing left to criticise:

On Mon, Nov 29, 2021 at 02:43:29PM +0800, Billy Tsai wrote:

+	if (clk_en && duty_pt) {
+		dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt
+				 << div_h;
+		state->duty_cycle = DIV_ROUND_UP_ULL(dividend, rate);
+	} else
+		state->duty_cycle = clk_en ? state->period : 0;

I wonder about checkpatch not criticising this construct. See
Documentation/process/coding-style.rst:

	Do not unnecessarily use braces where a single statement will
	do. [...] This does not apply if only one branch of a
	conditional statement is a single statement; in the latter case
	use braces in both branches

[...]
+static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct device *dev = chip->dev;
+	struct aspeed_pwm_data *priv = aspeed_pwm_chip_to_data(chip);
+	u32 hwpwm = pwm->hwpwm, duty_pt;
+	unsigned long rate;
+	u64 div_h, div_l, divisor, expect_period;
+	bool clk_en;
+
+	expect_period = state->period;
+	dev_dbg(dev, "expect period: %lldns, duty_cycle: %lldns", expect_period,
+		state->duty_cycle);
+
+	rate = clk_get_rate(priv->clk);
+	if (expect_period > div64_u64(ULLONG_MAX, (u64)rate))
+		expect_period = div64_u64(ULLONG_MAX, (u64)rate);

If you write that as

	expect_period = min(div64_u64(ULLONG_MAX, (u64)rate), expect_period);

you make sure that the division is only calculated once.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |