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> + unsigned long period_cycles, duty_cycles, prescale, period_us; > struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip); > unsigned long long c; > unsigned long long clkrate; > @@ -208,6 +208,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, > int val; > int ret; > u32 cr; > + u64 tmp; > > clkrate = clk_get_rate(imx->clks[PWM_IMX27_PER].clk); > c = clkrate * state->period; > @@ -249,6 +250,11 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, > val = readl(imx->mmio_base + MX3_PWMPR); > val = val >= MX3_PWMPR_MAX ? MX3_PWMPR_MAX : val; > cr = readl(imx->mmio_base + MX3_PWMCR); > + > + /* > + * tmp stores period in nanoseconds. Result fits in u64 since > + * val <= 0xfffe and prescaler in [1, 0x1000]. > + */ > tmp = NSEC_PER_SEC * (u64)(val + 2) * MX3_PWMCR_PRESCALER_GET(cr); > tmp = DIV_ROUND_UP_ULL(tmp, clkrate); > period_us = DIV_ROUND_UP_ULL(tmp, 1000); > -- > 2.53.0 >