lkml.org 
[lkml]   [2017]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [GIT PULL] USB/PHY driver changes for 4.15-rc1
On Mon, Nov 13, 2017 at 09:29:36PM -0800, Linus Torvalds wrote:
> On Mon, Nov 13, 2017 at 8:19 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > Other major thing is the typec code that moved out of staging and into
> > the "real" part of the drivers/usb/ tree, which was nice to see happen.
>
> Hmm. So now it asks me about Type-C Port Controller Manager. Fair
> enough. I say "N", because I have none. But then it still asks me
> about that TI TPS6598x driver...
>
> So I do see the _technical_ logic in there - the "TYPEC" config option
> is a hidden internal option, and it's selected by the things that need
> it.
>
> But from a user perspective, this configuration model is really strange.
>
> Why is TYPEC_TCPM something you ask the user, but not "do you want
> Type-C support"? And if you single out the PCM side to ask about, why
> don't you single out the power delivery side?
>
> Wouldn't it make more sense to at least ask whether I want Type-C
> power delivery chips before it then starts asking about individual PD
> drivers, the same way you asked about the port controller before you
> started asking ab out individual port controller drivers?

True. The options were made originally the way they are as the
assumption was that the OS will always handle the USB Type-C and PD
state machines, meaning we would always depend on the Type-C Port
Controller Manager, which of course is not the case any more.

Would the attached patch be sufficient?


Thanks,

--
heikki
From 3bbd624a67df91c23db996db5f2f931fde77fcc1 Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: Tue, 14 Nov 2017 14:45:27 +0300
Subject: [PATCH] usb: add user selectable option for the whole USB Type-C
Support

It is more clear from user perspective to wrap the whole USB
Type-C support under a single option that the user can
select, then it is to always ask the user for every USB
Type-C and USB Power Delivery driver separately.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
drivers/usb/typec/Kconfig | 54 +++++++++++++++++++++++++++++++++++-------
drivers/usb/typec/ucsi/Kconfig | 1 -
2 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/typec/Kconfig b/drivers/usb/typec/Kconfig
index 465d7da849c3..bcb2744c5977 100644
--- a/drivers/usb/typec/Kconfig
+++ b/drivers/usb/typec/Kconfig
@@ -1,13 +1,53 @@

-menu "USB Power Delivery and Type-C drivers"
+menuconfig TYPEC
+ tristate "USB Type-C Support"
+ help
+ USB Type-C Specification defines a cable and connector for USB where
+ only one type of plug is supported on both ends, i.e. there will not
+ be Type-A plug on one end of the cable and Type-B plug on the other.
+ Determination of the host-to-device relationship happens through a
+ specific Configuration Channel (CC) which goes through the USB Type-C
+ cable. The Configuration Channel may also be used to detect optional
+ Accessory Modes - Analog Audio and Debug - and if USB Power Delivery
+ is supported, the Alternate Modes, where the connector is used for
+ something else then USB communication.
+
+ USB Power Delivery Specification defines a protocol that can be used
+ to negotiate the voltage and current levels with the connected
+ partners. USB Power Delivery allows higher voltages then the normal
+ 5V, up to 20V, and current up to 5A over the cable. The USB Power
+ Delivery protocol is also used to negotiate the optional Alternate
+ Modes when they are supported. USB Power Delivery does not depend on
+ USB Type-C connector, however it is mostly used together with USB
+ Type-C connectors.
+
+ USB Type-C and USB Power Delivery Specifications define a set of state
+ machines that need to be implemented in either software or firmware.
+ Simple USB Type-C PHYs, for example USB Type-C Port Controller
+ Interface Specification compliant "Port Controllers" need the state
+ machines to be handled in the OS, but stand-alone USB Type-C and Power
+ Delivery controllers handle the state machines inside their firmware.
+ The USB Type-C and Power Delivery controllers usually function
+ autonomously, and do not necessarily require drivers.
+
+ Enable this configurations option if you have USB Type-C connectors on
+ your system and 1) you know your USB Type-C hardware requires OS
+ control (a driver) to function, or 2) if you need to be able to read
+ the status of the USB Type-C ports in your system, or 3) if you need
+ to be able to swap the power role (decide are you supplying or
+ consuming power over the cable) or data role (host or device) when
+ both roles are supported.
+
+ For more information, see the kernel documentation for USB Type-C
+ Connector Class API (Documentation/driver-api/usb/typec.rst)
+ <https://www.kernel.org/doc/html/latest/driver-api/usb/typec.html>
+ and ABI (Documentation/ABI/testing/sysfs-class-typec).

-config TYPEC
- tristate
+if TYPEC

config TYPEC_TCPM
tristate "USB Type-C Port Controller Manager"
depends on USB
- select TYPEC
help
The Type-C Port Controller Manager provides a USB PD and USB Type-C
state machine for use with Type-C Port Controllers.
@@ -22,7 +62,6 @@ config TYPEC_WCOVE
depends on INTEL_SOC_PMIC
depends on INTEL_PMC_IPC
depends on BXT_WC_PMIC_OPREGION
- select TYPEC
help
This driver adds support for USB Type-C detection on Intel Broxton
platforms that have Intel Whiskey Cove PMIC. The driver can detect the
@@ -31,14 +70,13 @@ config TYPEC_WCOVE
To compile this driver as module, choose M here: the module will be
called typec_wcove

-endif
+endif # TYPEC_TCPM

source "drivers/usb/typec/ucsi/Kconfig"

config TYPEC_TPS6598X
tristate "TI TPS6598x USB Power Delivery controller driver"
depends on I2C
- select TYPEC
help
Say Y or M here if your system has TI TPS65982 or TPS65983 USB Power
Delivery controller.
@@ -46,4 +84,4 @@ config TYPEC_TPS6598X
If you choose to build this driver as a dynamically linked module, the
module will be called tps6598x.ko.

-endmenu
+endif # TYPEC
diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index d0c31cee4720..e36d6c73c4a4 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -1,7 +1,6 @@
config TYPEC_UCSI
tristate "USB Type-C Connector System Software Interface driver"
depends on !CPU_BIG_ENDIAN
- select TYPEC
help
USB Type-C Connector System Software Interface (UCSI) is a
specification for an interface that allows the operating system to
--
2.15.0
\
 
 \ /
  Last update: 2017-11-14 14:24    [W:0.070 / U:6.888 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site