[Letux-kernel] [PATCH] [stable v5.4.x] pwm: jz4740: Fix build failure

Uwe Kleine-König u.kleine-koenig at pengutronix.de
Fri Jul 10 12:27:58 CEST 2020

When commit 9017dc4fbd59 ("pwm: jz4740: Enhance precision in calculation
of duty cycle") from v5.8-rc1 was backported to v5.4.x its dependency on
commit ce1f9cece057 ("pwm: jz4740: Use clocks from TCU driver") was not
noticed which made the pwm-jz4740 driver fail to build.

As ce1f9cece057 depends on still more rework, just backport a small part
of this commit to make the driver build again. (There is no dependency
on the functionality introduced in ce1f9cece057, just the rate variable
is needed.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>

@Paul: Can you please check this is correct? I only build-tested this

Best regards

 drivers/pwm/pwm-jz4740.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index d0f5c69930d0..77c28313e95f 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -92,11 +92,12 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
 	unsigned long long tmp;
-	unsigned long period, duty;
+	unsigned long rate, period, duty;
 	unsigned int prescaler = 0;
 	uint16_t ctrl;
-	tmp = (unsigned long long)clk_get_rate(jz4740->clk) * state->period;
+	rate = clk_get_rate(jz4740->clk);
+	tmp = rate * state->period;
 	do_div(tmp, 1000000000);
 	period = tmp;

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