[PATCH 1/3] ARM i.MX: Move i.MX pwm driver to pwm framework

[Shawn Guo]

On Fri, Mar 16, 2012 at 09:08:32AM +0100, Thierry Reding wrote:
> * Shawn Guo wrote:
> > On Thu, Mar 15, 2012 at 10:04:35AM +0100, Sascha Hauer wrote:
> > > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> > > index e859c51..fc7571e 100644
> > > --- a/drivers/pwm/Makefile
> > > +++ b/drivers/pwm/Makefile
> > > @@ -1,4 +1,5 @@
> > >  obj-$(CONFIG_PWM)		+= core.o
> > >  obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
> > > +obj-$(CONFIG_PWM_IMX)		+= imx-pwm.o
> > 
> > s/imx-pwm.o/pwm-imx.o
> 
> Yes, I'll make that change when I integrate the patch in my series.
> 
Thanks for taking this on.

> > > @@ -98,7 +98,7 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
> > >  		else
> > >  			cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
> > >  
> > > -		writel(cr, pwm->mmio_base + MX3_PWMCR);
> > > +		writel(cr, imxpwm->mmio_base + MX3_PWMCR);
> > >  	} else if (cpu_is_mx1() || cpu_is_mx21()) {
> > 
> > Since we are here, can we move one step further to get rid of these
> > cpu_is_xxx()?  Then, we can remove <mach/hardware.h> inclusion from
> > the driver.
> 
> I guess this could be handled by using several names for the driver and
> handling the differences using a table of platform_device_id:s. Perhaps
> you had something different in mind?
> 
Same thing on my mind.

> > >  static int __devinit mxc_pwm_probe(struct platform_device *pdev)
> > 
> > Should we take this opportunity to rename the driver from mxc_pwm to
> > imx_pwm?
> 
> If we decide to rename maybe it should be done in two steps. First it can be
> renamed internally and in the second step the name could be changed along
> with all users. I just want to avoid too much churn in this series, which is
> already growing way larger than I had hoped.
> 
It seems I'm asking too much.  Okay, we can do that after it gets moved.

> > Also, does mxc_pwm_init need necessarily to be an arch_initcall?
> > Otherwise, we can have the following change.
> > 
> > -static int __init mxc_pwm_init(void)
> > -{
> > -       return platform_driver_register(&mxc_pwm_driver);
> > -}
> > -arch_initcall(mxc_pwm_init);
> > -
> > -static void __exit mxc_pwm_exit(void)
> > -{
> > -       platform_driver_unregister(&mxc_pwm_driver);
> > -}
> > -module_exit(mxc_pwm_exit);
> > +module_platform_driver(imx_pwm_driver);
> 
> I assume that some platforms may require it to be initialized early because
> other drivers may depend on the PWMs being present. However this can probably
> be solved in a much better way by using deferred driver probing, which should
> be available in 3.4.
> 
Ditto.

-- 
Regards,
Shawn