Hi Chanwoo Choi
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 type to
specific connector.
For EXTCON_DISP_DP, we can add the two type as following. And
EXTCON_PROP_TYPEC_POLARITY property
should be added to EXTCON_TYPE_USB.
+ [EXTCON_DISP_DP] = {
+ .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
+ .id = EXTCON_DISP_DP,
+ .name = "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_POLARITY, 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 DisplayPort
without Type-C.
Maybe we should add a new cable: EXTCON_DISP_DP_ALT
+ [EXTCON_DISP_DP] = {
+ .type = EXTCON_TYPE_DISP,
+ .id = EXTCON_DISP_DP,
+ .name = "DP",
+ },
+ [EXTCON_DISP_DP_ALT] = {
+ .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
+ .id = EXTCON_DISP_DP,
+ .name = "DP ALT",
+ },
EXTCON_DISP_DP_ALT means EXTCON_DISP_DP connector with
EXTCON_PROP_TYPEC_POLARITY property.
So, we can explain the DP alternative mode without EXTCON_DISP_DP_ALT.
I'm wondering to add the new EXTCON_DISP_DP_ALT connector
because alternative mode was defined as mode instead of new h/w connector type.
Thanks,
Chanwoo Choi
Okay, so I think some comment for EXTCON_DISP_DP is necessary and enough.
