Messages in this thread Patch in this message | | | From | Guru Das Srinagesh <> | Subject | [PATCH v7 05/13] pwm: clps711x: Use 64-bit division macros for period and duty cycle | Date | Mon, 9 Mar 2020 12:35:08 -0700 |
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Because period and duty cycle are defined in the PWM framework structs as ints with units of nanoseconds, the maximum time duration that can be set is limited to ~2.147 seconds. Redefining them as u64 values will enable larger time durations to be set.
As a first step, prepare drivers to handle the switch to u64 period and duty_cycle by replacing division operations involving pwm period and duty cycle with their 64-bit equivalents as appropriate. The actual switch to u64 period and duty_cycle follows as a separate patch.
Where the dividend is 64-bit but the divisor is 32-bit, use *_ULL macros: - DIV_ROUND_UP_ULL - DIV_ROUND_CLOSEST_ULL - div_u64
Where the divisor is 64-bit (dividend may be 32-bit or 64-bit), use DIV64_* macros: - DIV64_U64_ROUND_CLOSEST - div64_u64
Cc: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org> --- drivers/pwm/pwm-clps711x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c index 924d39a..ba9500a 100644 --- a/drivers/pwm/pwm-clps711x.c +++ b/drivers/pwm/pwm-clps711x.c @@ -43,7 +43,7 @@ static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v) static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v) { /* Duty cycle 0..15 max */ - return DIV_ROUND_CLOSEST(v * 0xf, pwm->args.period); + return DIV64_U64_ROUND_CLOSEST(v * 0xf, pwm->args.period); } static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
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