Re: [PATCH v8 2/5] pwm: Add Apple PWM controller

From: Uwe Kleine-König
Date: Fri Mar 10 2023 - 16:54:17 EST


Hello Sascha,

On Fri, Mar 10, 2023 at 07:44:08PM +0100, Sasha Finkelstein via B4 Relay wrote:
> +static int apple_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> + const struct pwm_state *state)
> +{
> + struct apple_pwm *fpwm;
> +
> + if (state->polarity == PWM_POLARITY_INVERSED)
> + return -EINVAL;
> +
> + fpwm = to_apple_pwm(chip);
> + if (state->enabled) {
> + u64 on_cycles, off_cycles;
> +
> + on_cycles = mul_u64_u64_div_u64(fpwm->clkrate,
> + state->duty_cycle, NSEC_PER_SEC);
> + if (on_cycles > 0xFFFFFFFF)
> + on_cycles = 0xFFFFFFFF;
> +
> + off_cycles = mul_u64_u64_div_u64(fpwm->clkrate,
> + state->period, NSEC_PER_SEC) - on_cycles;
> + if (off_cycles > 0xFFFFFFFF)
> + return -ERANGE;

This is still wrong and needs clamping, too.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
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