Hello Roy,

On Sat, Feb 29, 2020 at 12:59:20AM +0000, Roy Im wrote:

Okay, thanks. I have tried to update that as below.
Could I get your comment if you still see anything on this?

	/* Maximum gain is 0x7fff for PWM mode */
	#define MAX_MAGNITUDE_SHIFT		15
       [...]
	period_mag_multi >>= MAX_MAGNITUDE_SHIFT;

	/* The interpretation of duty cycle depends on the acc_en,
	* it should be from 50% to 100% for acc_en = 0.
	* See datasheet 'PWM mode' section for more details.
	*/
	if (!haptics->acc_en) {
		period_mag_multi += state.period;
		period_mag_multi /= 2;
	}

Much better. Extra points if you add a link to the datasheet at the
top of the driver. I didn't look at the datasheet and assume that the
reasoning is obvious then.

Best regards
Uwe

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