Messages in this thread | | | Subject | Re: [PATCH] pwm: bcm-iproc: handle clk_get_rate() return | From | Ray Jui <> | Date | Fri, 17 Jul 2020 10:22:13 -0700 |
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On 7/17/2020 10:07 AM, Scott Branden wrote: > From: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com> > > Handle clk_get_rate() returning <= 0 condition to avoid > possible division by zero. > > Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller") > Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com> > Signed-off-by: Scott Branden <scott.branden@broadcom.com> > --- > drivers/pwm/pwm-bcm-iproc.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c > index 1f829edd8ee7..72a8607b6c8d 100644 > --- a/drivers/pwm/pwm-bcm-iproc.c > +++ b/drivers/pwm/pwm-bcm-iproc.c > @@ -86,6 +86,11 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm, > u32 value, prescale; > > rate = clk_get_rate(ip->clk); > + if (rate == 0) { > + state->period = 0; > + state->duty_cycle = 0; > + return; > + }
Based on the pwm core code, 'get_state' expects the following fields to be populated: 'polarity', 'enabled', 'period', and 'duty cycle'.
The above logic will leave 'polarity' and 'enabled' completely unpopulated when clock rate is zero.
> > value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); > >
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