From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [v5 PATCH 1/5] extcon: Add Type-C and DP support Date: Thu, 14 Jul 2016 11:10:35 +0900 Message-ID: <5786F49B.20107@samsung.com> References: <1468336188-565-1-git-send-email-zyw@rock-chips.com> <1468336188-565-2-git-send-email-zyw@rock-chips.com> <57859532.1010002@samsung.com> <57859BDA.7080309@rock-chips.com> <5785A1F3.1020703@samsung.com> <5785AD61.3070307@rock-chips.com> <5786E1B6.2000805@samsung.com> <5786E4E7.30505@rock-chips.com> <5786E795.6040504@samsung.com> <5786F3FB.5010608@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-reply-to: <5786F3FB.5010608@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org To: Chris Zhong , dianders@chromium.org, tfiga@chromium.org, heiko@sntech.de, yzq@rock-chips.com, groeck@chromium.org, myungjoo.ham@samsung.com, wulf@rock-chips.com, marcheu@chromium.org Cc: linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-rockchip.vger.kernel.org Hi Chris, On 2016=EB=85=84 07=EC=9B=94 14=EC=9D=BC 11:07, Chris Zhong wrote: > Hi Chanwoo Choi >=20 > On 07/14/2016 09:15 AM, Chanwoo Choi wrote: >> Hi Chris, >> >> [snip] >> >>>>>> Thanks, >>>>>> Chanwoo Choi >>>>> There are 4 modes for Type-C DP alt mode: >>>>> 1) USB host only : >>>>> >>>>> extcon_set_cable_state(edev, EXTCON_USB_HOST, 1); >>>>> extcon_set_cable_state(edev, EXTCON_USB, 0); >>>>> extcon_set_cable_state(edev, EXTCON_DISP_DP, 0); >>>>> >>>>> 2) USB device only >>>>> >>>>> extcon_set_cable_state(edev, EXTCON_USB_HOST, 0); >>>>> extcon_set_cable_state(edev, EXTCON_USB, 1); >>>>> extcon_set_cable_state(edev, EXTCON_DISP_DP, 0); >>>>> >>>>> 3) DP only >>>>> >>>>> extcon_set_cable_state(edev, EXTCON_USB_HOST, 0); >>>>> extcon_set_cable_state(edev, EXTCON_USB, 0); >>>>> extcon_set_cable_state(edev, EXTCON_DISP_DP, 1); >>>>> >>>>> 4) USB + DP >>>>> >>>>> extcon_set_cable_state(edev, EXTCON_USB_HOST, 1); >>>>> extcon_set_cable_state(edev, EXTCON_USB, 0); >>>>> extcon_set_cable_state(edev, EXTCON_DISP_DP, 1); >>>>> >>>>> >>>>> for 3rd mode: DP only, there is only EXTCON_DISP_DP is attached, = the EXTCON_USB_HOST >>>>> and EXTCON_USB are detached, Can I set the property into these 2 = detached cable? >>>>> or just call extcon_set_cable_state(edev, EXTCON_DISP_DP, EXTCON_= PROP_TYPEC_POLARITY, 0 or 1); >>>> I'm thinking to solve this issue. In result, we can add one more t= ype to specific connector. >>>> For EXTCON_DISP_DP, we can add the two type as following. And EXTC= ON_PROP_TYPEC_POLARITY property >>>> should be added to EXTCON_TYPE_USB. >>>> >>>> + [EXTCON_DISP_DP] =3D { >>>> + .type =3D EXTCON_TYPE_DISP | EXTCON_TYPE_USB, >>>> + .id =3D EXTCON_DISP_DP, >>>> + .name =3D "DP", >>>> + }, >>>> >>>> So, as you mentioned, EXTCON_DISP_DP can set the EXTCON_PROP_TYPEC= _POLARITY property as following: >>>> - extcon_set_cable_state(edev, EXTCON_DISP_DP, EXTCON_PROP_TYPEC_P= OLARITY, 0 or 1); >>>> >>>> I'll again developing the extcon property. >>>> >>>> Thanks, >>>> Chanwoo Choi >>>> >>> Nice idea, But I am thinking about is it compatible with real Displ= ayPort without Type-C. >>> Maybe we should add a new cable: EXTCON_DISP_DP_ALT >>> >>> + [EXTCON_DISP_DP] =3D { >>> + .type =3D EXTCON_TYPE_DISP, >>> + .id =3D EXTCON_DISP_DP, >>> + .name =3D "DP", >>> + }, >>> >>> + [EXTCON_DISP_DP_ALT] =3D { >>> + .type =3D EXTCON_TYPE_DISP | EXTCON_TYPE_USB, >>> + .id =3D EXTCON_DISP_DP, >>> + .name =3D "DP ALT", >>> + }, >> EXTCON_DISP_DP_ALT means EXTCON_DISP_DP connector with EXTCON_PROP_T= YPEC_POLARITY property. >> So, we can explain the DP alternative mode without EXTCON_DISP_DP_AL= T. >> >> I'm wondering to add the new EXTCON_DISP_DP_ALT connector >> because alternative mode was defined as mode instead of new h/w conn= ector type. >> >> Thanks, >> Chanwoo Choi >> >> > Okay, so I think some comment for EXTCON_DISP_DP is necessary and eno= ugh. Okay. I'll do that Thanks, Chanwoo Choi