Messages in this thread | | | Date | Fri, 18 Jul 2014 19:04:24 +0800 | From | caesar <> | Subject | Re: [PATCH 2/2] pwm: add this series patch to support for rk-pwm and vop-pwm. |
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Hi Thierry,
于 2014年07月18日 18:03, Thierry Reding 写道: > On Fri, Jul 18, 2014 at 01:05:56PM +0800, caesar wrote: >> 于 2014年07月18日 03:24, Beniamino Galvani 写道: >>> 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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