Re: [v3 PATCH 3/5] phy: Add USB Type-C PHY driver for rk3399

From: Chris Zhong
Date: Sun Jun 26 2016 - 22:19:33 EST


Hi Heiko

On 06/25/2016 03:39 AM, Heiko Stuebner wrote:
Am Donnerstag, 23. Juni 2016, 18:27:52 schrieb Kishon Vijay Abraham I:
Hi,

On Thursday 23 June 2016 06:21 PM, Chris Zhong wrote:
Add a PHY provider driver for the rk3399 SoC Type-c PHY. The USB
Type-C PHY is designed to support the USB3 and DP applications. The
PHY basically has two main components: USB3 and DisplyPort. USB3
operates in SuperSpeed mode and the DP can operate at RBR, HBR and
HBR2 data rates.

Signed-off-by: Chris Zhong <zyw@xxxxxxxxxxxxxx>
Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>

---

Changes in v3:
- remove the phy framework(Kishon Vijay Abraham I)
- add parentheses around the macro
- use a single space between type and name
- add spaces after opening and before closing braces.
- use u16 for register value
- remove type-c phy header file
- CodingStyle optimization
- use some cable extcon to get type-c port information
- add a extcon to notify Display Port

Changes in v2:
- select RESET_CONTROLLER
- alphabetic order
- modify some spelling mistakes
- make mode cleaner
- use bool for enable/disable
- check all of the return value
- return a better err number
- use more readx_poll_timeout()
- clk_disable_unprepare(tcphy->clk_ref);
- remove unuse functions, rockchip_typec_phy_power_on/off
- remove unnecessary typecast from void *
- use dts node to distinguish between phys.

Changes in v1:
- update the licence note
- init core clock to 50MHz
- use extcon API
- remove unused global
- add some comments for magic num
- change usleep_range(1000, 2000) tousleep_range(1000, 1050)
- remove __func__ from dev_err
- return err number when get clk failed
- remove ADDR_ADJ define
- use devm_clk_get(&pdev->dev, "tcpdcore")

drivers/phy/Kconfig | 8 +
drivers/phy/Makefile | 1 +
drivers/phy/phy-rockchip-typec.c | 1027
++++++++++++++++++++++++++++++++++++++ 3 files changed, 1036
insertions(+)
create mode 100644 drivers/phy/phy-rockchip-typec.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 26566db..ec87b3a 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -351,6 +351,14 @@ config PHY_ROCKCHIP_DP

help

Enable this to support the Rockchip Display Port PHY.

+config PHY_ROCKCHIP_TYPEC
+ tristate "Rockchip TYPEC PHY Driver"
+ depends on ARCH_ROCKCHIP && OF
+ select GENERIC_PHY
Why? None of the generic PHY API's are used here. Why do you want select
generic PHY?
I'm actually wondering, why there are no phy ops to start and stop the py.
Right now the device seems to be on and handling all the extcon notifies all
the time even if no-one is using the phy.

There are two users of this phy, the dp-controller as well as some usb
component. The phy framework is nicely refcounted, so can handle any number
of phy users and somehow I'd expect the phy to do nothing (and try to not
consume power) if neither the dp-controller nor the usb-part is actually
running.

It may very well be my ignorance, but Chris could you explain, if there is a
reason for this?


Thanks
Heiko


It is good idea, The USB3 and DP controller detect the extcon cable state: USB/USB HOST/DP. If a Type-C device plugged, call phy power on, the phy driver get all the state of extcon: dfp, ufp, dp, flip, pin assignment, and then finish the phy init. So the phy driver need not register extcon notification.
But this mechanism allows phy driver only focus plug/unplug event, if some other things happen, such as data role change, the phy will not be notified. I'm not sure if this situation exists.
Hi Guenter,
Do you have any ohter concerns?