Messages in this thread | | | Date | Mon, 22 Oct 2012 19:25:45 +0530 | Subject | Re: [PATCH V4] PWM: Add SPEAr PWM chip driver support | From | Viresh Kumar <> |
| |
On 22 October 2012 16:36, Shiraz Hashim <shiraz.hashim@st.com> wrote: > Add support for PWM chips present on SPEAr platforms. These PWM > chips support 4 channel output with programmable duty cycle and > frequency. > > More details on these PWM chips can be obtained from relevant > chapter of reference manual, present at following[1] location. > > 1. http://www.st.com/internet/mcu/product/251211.jsp > > Cc: Thierry Reding <thierry.reding@avionic-design.de> > Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > Reviewed-by: Vipin Kumar <vipin.kumar@st.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> diff --git a/drivers/pwm/pwm-spear.c b/drivers/pwm/pwm-spear.c > +static int spear_pwm_probe(struct platform_device *pdev) > +{
> + ret = pwmchip_add(&pc->chip); > + if (ret < 0) { > + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); > + return ret; > + }
Sorry couldn't think of this complex situation earlier :(
Can it happen that we get a request for a pwm here and its config or enable gets called...?
If yes, then we must call clk_prepare() before doing pwmchip_add?? Otherwise you will see a crash :)
@Thierry: Can this happen?
> + ret = clk_prepare_enable(pc->clk); > + if (ret < 0) > + return pwmchip_remove(&pc->chip);
-- viresh
| |