From: David Rivshin Date: Sat, 30 Jan 2016 04:26:53 +0000 (-0500) Subject: pwm: omap-dmtimer: Round load and match values rather than truncate X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7b0883f33809ff0aeca9848193c31629a752bb77;p=linux-beck.git pwm: omap-dmtimer: Round load and match values rather than truncate When converting period and duty_cycle from nanoseconds to fclk cycles, the error introduced by the integer division can be appreciable, especially in the case of slow fclk or short period. Use DIV_ROUND_CLOSEST_ULL() so that the error is kept to +/- 0.5 clock cycles. Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") Signed-off-by: David Rivshin Acked-by: Neil Armstrong Signed-off-by: Thierry Reding --- diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c index 54641e45f45b..e0679eb399f6 100644 --- a/drivers/pwm/pwm-omap-dmtimer.c +++ b/drivers/pwm/pwm-omap-dmtimer.c @@ -49,11 +49,7 @@ to_pwm_omap_dmtimer_chip(struct pwm_chip *chip) static u32 pwm_omap_dmtimer_get_clock_cycles(unsigned long clk_rate, int ns) { - u64 c = (u64)clk_rate * ns; - - do_div(c, NSEC_PER_SEC); - - return c; + return DIV_ROUND_CLOSEST_ULL((u64)clk_rate * ns, NSEC_PER_SEC); } static void pwm_omap_dmtimer_start(struct pwm_omap_dmtimer_chip *omap)