From: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
[ Upstream commit aef1a3799b5cb3ba4841f6034497b179646ccc70 ]
To not trigger the warnings provided by CONFIG_PWM_DEBUG
- use up-rounding in .get_state()
- don't divide by the result of a division
- don't use the rounded counter value for the period length to calculate
the counter value for the duty cycle
Signed-off-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.red...@gmail.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
drivers/pwm/pwm-imx27.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index a6e40d4c485f3..732a6f3701e8e 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -150,13 +150,12 @@ static void pwm_imx27_get_state(struct pwm_chip *chip,
prescaler = MX3_PWMCR_PRESCALER_GET(val);
pwm_clk = clk_get_rate(imx->clk_per);
- pwm_clk = DIV_ROUND_CLOSEST_ULL(pwm_clk, prescaler);
val = readl(imx->mmio_base + MX3_PWMPR);
period = val >= MX3_PWMPR_MAX ? MX3_PWMPR_MAX : val;
/* PWMOUT (Hz) = PWMCLK / (PWMPR + 2) */
- tmp = NSEC_PER_SEC * (u64)(period + 2);
- state->period = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk);
+ tmp = NSEC_PER_SEC * (u64)(period + 2) * prescaler;
+ state->period = DIV_ROUND_UP_ULL(tmp, pwm_clk);
/*
* PWMSAR can be read only if PWM is enabled. If the PWM is disabled,
@@ -167,8 +166,8 @@ static void pwm_imx27_get_state(struct pwm_chip *chip,
else
val = imx->duty_cycle;
- tmp = NSEC_PER_SEC * (u64)(val);
- state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk);
+ tmp = NSEC_PER_SEC * (u64)(val) * prescaler;
+ state->duty_cycle = DIV_ROUND_UP_ULL(tmp, pwm_clk);
pwm_imx27_clk_disable_unprepare(imx);
}
@@ -220,22 +219,23 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct
pwm_device *pwm,
struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
struct pwm_state cstate;
unsigned long long c;
+ unsigned long long clkrate;
int ret;
u32 cr;
pwm_get_state(pwm, &cstate);
- c = clk_get_rate(imx->clk_per);
- c *= state->period;
+ clkrate = clk_get_rate(imx->clk_per);
+ c = clkrate * state->period;
- do_div(c, 1000000000);
+ do_div(c, NSEC_PER_SEC);
period_cycles = c;
prescale = period_cycles / 0x10000 + 1;
period_cycles /= prescale;
- c = (unsigned long long)period_cycles * state->duty_cycle;
- do_div(c, state->period);
+ c = clkrate * state->duty_cycle;
+ do_div(c, NSEC_PER_SEC * prescale);
duty_cycles = c;
/*
--
2.25.1
