Hello,

On Mon, Nov 26, 2018 at 10:31:58PM +0100, Uwe Kleine-König wrote:

quoted

+static int sun8i_pwm_config(struct sun8i_pwm_chip *sun8i_pwm, u8 ch,
+			    struct pwm_state *state)
+{
+[...]
+		clk_rate = clk_get_rate(clk);
+		val = state->period * clk_rate;
+		do_div(val, NSEC_PER_SEC);
+		if (val <= 1) {
+			dev_err(sun8i_pwm->chip.dev,
+				"Period expects a larger value\n");
+			return -EINVAL;
+		}
+
+		/* change clock source to "mux-1" */
+		clk_disable_unprepare(sun8i_pwm->clk);
+		devm_clk_put(sun8i_pwm->chip.dev, sun8i_pwm->clk);
+		sun8i_pwm->clk = clk;

sun8i_pwm is shared for all 8 PWMs, right? So if you assign mux-1 here
for the second mux, how does this influence the first PWM?

To clearify my question:

after the first pwm is used and enabled (maybe using mux-0) changing
sun8i_pwm->clk for the second pwm is broken because then when the first
pwm is disabled the wrong clock is stopped.

Best regards
Uwe

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