Re: [PATCH 2/2] pwm: add this series patch to support for rk-pwm and vop-pwm.

[caesar]

Hi Thierry,

ä 2014å07æ18æ 18:03, Thierry Reding åé:
> On Fri, Jul 18, 2014 at 01:05:56PM +0800, caesar wrote:
> > ä 2014å07æ18æ 03:24, Beniamino Galvani åé:
> > > On Thu, Jul 17, 2014 at 02:08:14PM +0800, caesar wrote:
> [...]
> > > > @@ -119,9 +185,12 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
> > > >   		return -ENOMEM;
> > > >   	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > > -	pc->base = devm_ioremap_resource(&pdev->dev, r);
> > > > -	if (IS_ERR(pc->base))
> > > > -		return PTR_ERR(pc->base);
> > > > +	pc->base = of_iomap(np, 0);
> > > > +	if (!pc->base) {
> > > > +		dev_err(&pdev->dev, "failed to map controller\n");
> > > > +		ret = -ENOMEM;
> > > > +		goto fail_map;
> > > > +	}
> > > I think that this change is not needed. devm_ioremap_resource()
> > > guarantees an automatic unmapping when the device is destroyed.
> > >
> > > Moreover, when of_iomap() fails you don't need to call iounmap().
> > >
> > > Beniamino
> > VOP-PWM base has be requested for lcdc.
> Why?
VOP is  a seperate controllers for rk3288 and genenation SoCs.
The VOP contains lcdc,pwm......

For example :Rk3288 SOC address mapping

lcdc0: lcdc@ff930000                     vop0pwm: pwm@ff9301a0
reg = <0xff930000 0x10000>       reg = <0xff9301a0 0x10>;
offset = 0x10000                            offset = 0x10

lcdc1: lcdc@ff940000                    vop1pwm: pwm@ff9401a0
reg = <0xff940000 0x10000>      reg = <0xff9401a0 0x10>;
offset = 0x10000                           offset = 0x10

In a word, lcdc and vop-pwm has shared the map address.
> > When I use devm_ioremap_resource(), the vop-pwm will request region fail.
> >
> > Example:.931020] rockchip-pwm ff9401a0.pwm: can't request region for
> > resource [mem 0xff9401a0-0xff9401af] /pwm@ff9401a0.
> > So ,I have to charge it.
> >
> > I will be simplyfied by having:
> > - pc->base = devm_ioremap_resource(&pdev->dev, r);
> > + if (!strcmp(of_id->compatible, "rockchip,vop-pwm"))
> > + pc->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
> > + else
> > + pc->base = devm_ioremap_resource(&pdev->dev, r);
> >
> > Maybe, Could you give me better suggestions for it?
> The right thing to do is not have two drivers access the same device.
> Why does lcdc request the PWM register region?
>
> Thierry
Ditto,
Maybe,Could you give me a better suggestion to do it?


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