[PATCH v2 00/12] usb: Handle different sublink speeds

[PATCH v2 00/12] usb: Handle different sublink speeds

[Thinh Nguyen]

A USB super-speed-plus device may operate at different sublink speed and lane
count (e.g. gen2x2, gen1x2, or gen2x1). The usb gadget stack needs to be able
to handle a couple things:

1) Report the sublink speed attributes the device support
2) Select the sublink speed attribute

This series introduces sublink speed attribute structure to ch9.h to capture
the device capability of the gadget. It also introduces a new gadget ops
udc_set_num_lanes_and_speed to select a specific sublink speed.

DWC3 needs this support for DWC_usb32 IP. Implement the new changes for DWC3.

Changes in v2:
 - Move usb_sublink_speed attribute struct and enum to include/linux/usb/ch9.h
 - Use "num-lanes" and "lane-speed-mantissa-gbps" as common properties instead
 - Add common functions to get num-lanes and lsm properties
 - Fix missing gen1x2 sublink speed attribute check report in dwc3


Thinh Nguyen (12):
  usb: ch9: Add sublink speed struct
  usb: gadget: composite: Avoid using magic numbers
  usb: gadget: Expose sublink speed attributes
  usb: gadget: Set max speed for SSP devices
  usb: composite: Properly report sublink speed
  usb: devicetree: Introduce num-lanes and lsm
  usb: common: Add functions to get lanes and lsm
  usb: dwc3: Initialize lane count and sublink speed
  usb: dwc3: gadget: Report sublink speed capability
  usb: dwc3: gadget: Implement setting of sublink speed
  usb: dwc3: gadget: Track connected lane and sublink speed
  usb: dwc3: gadget: Set speed only up to the max supported

 Documentation/devicetree/bindings/usb/generic.txt |  11 ++
 drivers/usb/common/common.c                       |  26 ++++
 drivers/usb/dwc3/core.c                           |  62 ++++++++++
 drivers/usb/dwc3/core.h                           |  18 +++
 drivers/usb/dwc3/gadget.c                         | 143 +++++++++++++++++++++-
 drivers/usb/gadget/composite.c                    |  81 ++++++++----
 drivers/usb/gadget/udc/core.c                     |  24 +++-
 include/linux/usb/ch9.h                           |  62 ++++++++++
 include/linux/usb/gadget.h                        |  23 ++++
 9 files changed, 414 insertions(+), 36 deletions(-)


base-commit: 5db5ea26a2469d8899f995e82e8b718dc9e9d168
-- 
2.11.0

[PATCH v2 06/12] usb: devicetree: Introduce num-lanes and lsm

[Thinh Nguyen]

According to USB 3.2 spec, a super-speed-plus device can operate at
gen2x2, gen2x1, or gen1x2. Introduce "num-lanes" and
"lane-speed-mantissa-gbps" properties for devices operating in
super-speed-plus. If the USB controller device supports multiple lanes
at different transfer rate, the user can specify the HW capability via
these properties.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
Changes in v2:
- Make "num-lanes" and "lane-speed-mantissa-gbps" common USB properties

 Documentation/devicetree/bindings/usb/generic.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
index ba472e7aefc9..a8253da684af 100644
--- a/Documentation/devicetree/bindings/usb/generic.txt
+++ b/Documentation/devicetree/bindings/usb/generic.txt
@@ -7,6 +7,17 @@ Optional properties:
 			"low-speed". In case this isn't passed via DT, USB
 			controllers should default to their maximum HW
 			capability.
+ - num-lanes: tells USB controllers that we want to work up to a certain number
+			of lanes. Valid arguments are 1 or 2. Apply if the
+			maximum-speed is super-speed-plus. In case this isn't
+			passed via DT, the USB controllers should default to
+			their maximum HW capability.
+ - lane-speed-mantissa-gbps: tells USB controllers that we want the symmetric
+			lanes to operate up to a certain rate in Gbps. Valid
+			inputs are 5 or 10 (i.e. Gen 1/Gen 2 transfer rate).
+			Apply if the maximum-speed is super-speed-plus. In case
+			this isn't passed via DT, the USB controllers should
+			default to their maximum HW capability.
  - dr_mode: tells Dual-Role USB controllers that we want to work on a
 			particular mode. Valid arguments are "host",
 			"peripheral" and "otg". In case this attribute isn't
-- 
2.11.0

Re: [PATCH v2 06/12] usb: devicetree: Introduce num-lanes and lsm

[Rob Herring]

On Wed, Jul 22, 2020 at 07:12:39PM -0700, Thinh Nguyen wrote:
> According to USB 3.2 spec, a super-speed-plus device can operate at
> gen2x2, gen2x1, or gen1x2. Introduce "num-lanes" and
> "lane-speed-mantissa-gbps" properties for devices operating in
> super-speed-plus. If the USB controller device supports multiple lanes
> at different transfer rate, the user can specify the HW capability via
> these properties.
> 
> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> ---
> Changes in v2:
> - Make "num-lanes" and "lane-speed-mantissa-gbps" common USB properties
> 
>  Documentation/devicetree/bindings/usb/generic.txt | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
> index ba472e7aefc9..a8253da684af 100644
> --- a/Documentation/devicetree/bindings/usb/generic.txt
> +++ b/Documentation/devicetree/bindings/usb/generic.txt
> @@ -7,6 +7,17 @@ Optional properties:
>  			"low-speed". In case this isn't passed via DT, USB
>  			controllers should default to their maximum HW
>  			capability.
> + - num-lanes: tells USB controllers that we want to work up to a certain number
> +			of lanes. Valid arguments are 1 or 2. Apply if the
> +			maximum-speed is super-speed-plus. In case this isn't
> +			passed via DT, the USB controllers should default to
> +			their maximum HW capability.
> + - lane-speed-mantissa-gbps: tells USB controllers that we want the symmetric
> +			lanes to operate up to a certain rate in Gbps. Valid
> +			inputs are 5 or 10 (i.e. Gen 1/Gen 2 transfer rate).
> +			Apply if the maximum-speed is super-speed-plus. In case
> +			this isn't passed via DT, the USB controllers should
> +			default to their maximum HW capability.

This still leaves 'maximum-speed = "super-speed-plus"' ambiguous. Fix 
that please.

To put it another way, we already have one way to define USB speeds. 
Don't define a new and different way that only covers a fraction of the 
possibilities.

Rob

Re: [PATCH v2 06/12] usb: devicetree: Introduce num-lanes and lsm

[Thinh Nguyen]

Rob Herring wrote:
> On Wed, Jul 22, 2020 at 07:12:39PM -0700, Thinh Nguyen wrote:
>> According to USB 3.2 spec, a super-speed-plus device can operate at
>> gen2x2, gen2x1, or gen1x2. Introduce "num-lanes" and
>> "lane-speed-mantissa-gbps" properties for devices operating in
>> super-speed-plus. If the USB controller device supports multiple lanes
>> at different transfer rate, the user can specify the HW capability via
>> these properties.
>>
>> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
>> ---
>> Changes in v2:
>> - Make "num-lanes" and "lane-speed-mantissa-gbps" common USB properties
>>
>>   Documentation/devicetree/bindings/usb/generic.txt | 11 +++++++++++
>>   1 file changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
>> index ba472e7aefc9..a8253da684af 100644
>> --- a/Documentation/devicetree/bindings/usb/generic.txt
>> +++ b/Documentation/devicetree/bindings/usb/generic.txt
>> @@ -7,6 +7,17 @@ Optional properties:
>>   			"low-speed". In case this isn't passed via DT, USB
>>   			controllers should default to their maximum HW
>>   			capability.
>> + - num-lanes: tells USB controllers that we want to work up to a certain number
>> +			of lanes. Valid arguments are 1 or 2. Apply if the
>> +			maximum-speed is super-speed-plus. In case this isn't
>> +			passed via DT, the USB controllers should default to
>> +			their maximum HW capability.
>> + - lane-speed-mantissa-gbps: tells USB controllers that we want the symmetric
>> +			lanes to operate up to a certain rate in Gbps. Valid
>> +			inputs are 5 or 10 (i.e. Gen 1/Gen 2 transfer rate).
>> +			Apply if the maximum-speed is super-speed-plus. In case
>> +			this isn't passed via DT, the USB controllers should
>> +			default to their maximum HW capability.
> This still leaves 'maximum-speed = "super-speed-plus"' ambiguous. Fix
> that please.
>
> To put it another way, we already have one way to define USB speeds.
> Don't define a new and different way that only covers a fraction of the
> possibilities.
>

Then, we can just do away with the "num-lanes" property, and change it 
to something like this as you suggested?

diff --git a/Documentation/devicetree/bindings/usb/generic.txt 
b/Documentation/devicetree/bindings/usb/generic.txt
index ba472e7aefc9..8541b9571f2f 100644
--- a/Documentation/devicetree/bindings/usb/generic.txt
+++ b/Documentation/devicetree/bindings/usb/generic.txt
@@ -3,10 +3,13 @@ Generic USB Properties
  Optional properties:
   - maximum-speed: tells USB controllers we want to work up to a certain
                         speed. Valid arguments are "super-speed-plus",
-                       "super-speed", "high-speed", "full-speed" and
-                       "low-speed". In case this isn't passed via DT, USB
-                       controllers should default to their maximum HW
-                       capability.
+                       "super-speed-plus-gen2x2", 
"super-speed-plus-gen2x1",
+                       "super-speed-plus-gen1x2", "super-speed", 
"high-speed",
+                       "full-speed" and "low-speed". In case this isn't 
passed
+                       via DT, USB controllers should default to their 
maximum
+                       HW capability. Similarly, if the argument is
+                       "super-speed-plus", USB controllers should 
default to
+                       their maximum transfer rate and number of lanes.
   - dr_mode: tells Dual-Role USB controllers that we want to work on a
                         particular mode. Valid arguments are "host",
                         "peripheral" and "otg". In case this attribute 
isn't


Is that ok?

BR,
Thinh