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Commit 82dbbc61 authored by Fenglin Wu's avatar Fenglin Wu
Browse files

pwm: qti-lpg: change to use u64 data type for calculation 



Change to use the u64 data type for multiplication and division so that
there is no need to check the overflow.

Change-Id: I4aca3afac1056fb304728cc9fb04d97056919223
Signed-off-by: default avatarFenglin Wu <fenglinw@codeaurora.org>
parent cdeb7902

drivers/pwm/pwm-qti-lpg.c

+12 −14
Original line number Diff line number Diff line
@@ -816,11 +816,11 @@ static void __qpnp_lpg_calc_pwm_duty(int period_ns, int duty_ns, 
			struct lpg_pwm_config *pwm_config)

{

	u16 pwm_value, max_pwm_value;

	u64 tmp;



	if ((1 << pwm_config->pwm_size) > (INT_MAX / duty_ns))

		pwm_value = duty_ns / (period_ns >> pwm_config->pwm_size);

	else

		pwm_value = (duty_ns << pwm_config->pwm_size) / period_ns;

	tmp = (u64)duty_ns << pwm_config->pwm_size;

	do_div(tmp, period_ns);

	pwm_value = (u16)tmp;



	max_pwm_value = (1 << pwm_config->pwm_size) - 1;

	if (pwm_value > max_pwm_value)
@@ -1067,6 +1067,7 @@ static int qpnp_lpg_pwm_set_output_pattern(struct pwm_chip *pwm_chip, 
	struct qpnp_lpg_channel *lpg;

	int rc = 0, i, period_ns, duty_ns;

	u32 *percentages;

	u64 tmp;



	lpg = pwm_dev_to_qpnp_lpg(pwm_chip, pwm);

	if (lpg == NULL) {
@@ -1095,10 +1096,9 @@ static int qpnp_lpg_pwm_set_output_pattern(struct pwm_chip *pwm_chip, 
			goto err;

		}

		/* Translate the pattern in duty_ns to percentage */

		if ((INT_MAX / duty_ns) < 100)

			percentages[i] = duty_ns / (period_ns / 100);

		else

			percentages[i] = (duty_ns * 100) / period_ns;

		tmp = (u64)duty_ns * 100;

		do_div(tmp, period_ns);

		percentages[i] = (u32)tmp;

	}



	rc = qpnp_lpg_set_lut_pattern(lpg, percentages,
@@ -1114,12 +1114,10 @@ static int qpnp_lpg_pwm_set_output_pattern(struct pwm_chip *pwm_chip, 
			output_pattern->num_entries);

	lpg->ramp_config.hi_idx = lpg->ramp_config.lo_idx +

				output_pattern->num_entries - 1;

	if ((INT_MAX / period_ns) > output_pattern->cycles_per_duty)

		lpg->ramp_config.step_ms = output_pattern->cycles_per_duty *

			period_ns / NSEC_PER_MSEC;

	else

		lpg->ramp_config.step_ms = (period_ns / NSEC_PER_MSEC) *

			output_pattern->cycles_per_duty;



	tmp = (u64)output_pattern->cycles_per_duty * period_ns;

	do_div(tmp, NSEC_PER_MSEC);

	lpg->ramp_config.step_ms = (u16)tmp;



	rc = qpnp_lpg_set_ramp_config(lpg);

	if (rc < 0)