From mboxrd@z Thu Jan 1 00:00:00 1970 From: caesar Subject: Re: [PATCH 2/2] pwm: add this series patch to support for rk-pwm and vop-pwm. Date: Fri, 18 Jul 2014 19:04:24 +0800 Message-ID: <53C8FF38.8010506@rock-chips.com> References: <1405577294-19336-1-git-send-email-caesar.wang@rock-chips.com> <1405577294-19336-3-git-send-email-caesar.wang@rock-chips.com> <20140717192459.GA4617@gmail.com> <53C8AB34.3050102@rock-chips.com> <20140718100341.GA30497@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140718100341.GA30497@ulmo> Sender: linux-doc-owner@vger.kernel.org To: Thierry Reding Cc: Beniamino Galvani , robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, rdunlap@infradead.org, linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, cf@rock-chips.com, addy.ke@rock-chips.com, xjq@rock-chips.com, huangtao@rock-chips.com, hj@rock-chips.com List-Id: linux-pwm@vger.kernel.org Hi Thierry, =E4=BA=8E 2014=E5=B9=B407=E6=9C=8818=E6=97=A5 18:03, Thierry Reding =E5= =86=99=E9=81=93: > On Fri, Jul 18, 2014 at 01:05:56PM +0800, caesar wrote: >> =E4=BA=8E 2014=E5=B9=B407=E6=9C=8818=E6=97=A5 03:24, Beniamino Galva= ni =E5=86=99=E9=81=93: >>> 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 =3D platform_get_resource(pdev, IORESOURCE_MEM, 0); >>>> - pc->base =3D devm_ioremap_resource(&pdev->dev, r); >>>> - if (IS_ERR(pc->base)) >>>> - return PTR_ERR(pc->base); >>>> + pc->base =3D of_iomap(np, 0); >>>> + if (!pc->base) { >>>> + dev_err(&pdev->dev, "failed to map controller\n"); >>>> + ret =3D -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...... =46or example :Rk3288 SOC address mapping lcdc0: lcdc@ff930000 vop0pwm: pwm@ff9301a0 reg =3D <0xff930000 0x10000> reg =3D <0xff9301a0 0x10>; offset =3D 0x10000 offset =3D 0x10 lcdc1: lcdc@ff940000 vop1pwm: pwm@ff9401a0 reg =3D <0xff940000 0x10000> reg =3D <0xff9401a0 0x10>; offset =3D 0x10000 offset =3D 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 =3D devm_ioremap_resource(&pdev->dev, r); >> + if (!strcmp(of_id->compatible, "rockchip,vop-pwm")) >> + pc->base =3D devm_ioremap(&pdev->dev, r->start, resource_size(r)); >> + else >> + pc->base =3D 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?