| From f8f38c77ad8cfa0eb3c81d038c6052296922147d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 8 Apr 2022 17:22:38 +0200 |
| Subject: pwm: lp3943: Fix duty calculation in case period was clamped |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
| |
| [ Upstream commit 5e3b07ca5cc78cd4a987e78446849e41288d87cb ] |
| |
| The hardware only supports periods <= 1.6 ms and if a bigger period is |
| requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger |
| than 1.6 ms and then the duty cycle register is written with a value |
| bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly. |
| |
| Fixes: af66b3c0934e ("pwm: Add LP3943 PWM driver") |
| Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
| Signed-off-by: Thierry Reding <thierry.reding@gmail.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/pwm/pwm-lp3943.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| diff --git a/drivers/pwm/pwm-lp3943.c b/drivers/pwm/pwm-lp3943.c |
| index 872ea76a4f19..4612315687cd 100644 |
| --- a/drivers/pwm/pwm-lp3943.c |
| +++ b/drivers/pwm/pwm-lp3943.c |
| @@ -128,6 +128,7 @@ static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
| if (err) |
| return err; |
| |
| + duty_ns = min(duty_ns, period_ns); |
| val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns); |
| |
| return lp3943_write_byte(lp3943, reg_duty, val); |
| -- |
| 2.35.1 |
| |
