pwm: Add relative duty cycle manipulation helpers

	state->duty_cycle = 0;

}

/**

 * pwm_get_relative_duty_cycle() - Get a relative duty cycle value

 * @state: PWM state to extract the duty cycle from

 * @scale: target scale of the relative duty cycle

 *

 * This functions converts the absolute duty cycle stored in @state (expressed

 * in nanosecond) into a value relative to the period.

 *

 * For example if you want to get the duty_cycle expressed in percent, call:

 *

 * pwm_get_state(pwm, &state);

 * duty = pwm_get_relative_duty_cycle(&state, 100);

 */

static inline unsigned int

pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale)

{

	if (!state->period)

		return 0;

	return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale,

				     state->period);

}

/**

 * pwm_set_relative_duty_cycle() - Set a relative duty cycle value

 * @state: PWM state to fill

 * @duty_cycle: relative duty cycle value

 * @scale: scale in which @duty_cycle is expressed

 *

 * This functions converts a relative into an absolute duty cycle (expressed

 * in nanoseconds), and puts the result in state->duty_cycle.

 *

 * For example if you want to configure a 50% duty cycle, call:

 *

 * pwm_init_state(pwm, &state);

 * pwm_set_relative_duty_cycle(&state, 50, 100);

 * pwm_apply_state(pwm, &state);

 *

 * This functions returns -EINVAL if @duty_cycle and/or @scale are

 * inconsistent (@scale == 0 or @duty_cycle > @scale).

 */

static inline int

pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle,

			    unsigned int scale)

{

	if (!scale || duty_cycle > scale)

		return -EINVAL;

	state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *

						  state->period,

						  scale);

	return 0;

}

/**

 * struct pwm_ops - PWM controller operations

 * @request: optional hook for requesting a PWM