[PATCH] thunderbolt: Add 'generation' attribute for devices

[PATCH] thunderbolt: Add 'generation' attribute for devices

[Christian Kellner]

From: Christian Kellner <christian@kellner.me>

The Thunderbolt standard went through several major iterations, here
called generation. USB4, which will be based on Thunderbolt, will be
generation 4. Let userspace know the generation of the controller in
the devices in order to distinguish between Thunderbolt and USB4, so
it can be shown in various user interfaces.

Signed-off-by: Christian Kellner <christian@kellner.me>
---
 Documentation/ABI/testing/sysfs-bus-thunderbolt |  8 ++++++++
 drivers/thunderbolt/switch.c                    | 10 ++++++++++
 2 files changed, 18 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
index b21fba14689b..630e51344f1c 100644
--- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
+++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
@@ -80,6 +80,14 @@ Contact:	thunderbolt-software@lists.01.org
 Description:	This attribute contains 1 if Thunderbolt device was already
 		authorized on boot and 0 otherwise.
 
+What: /sys/bus/thunderbolt/devices/.../generation
+Date:		Aug 2019
+KernelVersion:	5.5
+Contact:	Christian Kellner <christian@kellner.me>
+Description:	This attribute contains the generation of the Thunderbolt
+		controller associated with the device. It will contain 4
+		for USB4.
+
 What: /sys/bus/thunderbolt/devices/.../key
 Date:		Sep 2017
 KernelVersion:	4.13
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 410bf1bceeee..ac9fa2740800 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1120,6 +1120,15 @@ device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
 }
 static DEVICE_ATTR_RO(device_name);
 
+static ssize_t
+generation_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sprintf(buf, "%u\n", sw->generation);
+}
+static DEVICE_ATTR_RO(generation);
+
 static ssize_t key_show(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
@@ -1325,6 +1334,7 @@ static struct attribute *switch_attrs[] = {
 	&dev_attr_boot.attr,
 	&dev_attr_device.attr,
 	&dev_attr_device_name.attr,
+	&dev_attr_generation.attr,
 	&dev_attr_key.attr,
 	&dev_attr_nvm_authenticate.attr,
 	&dev_attr_nvm_version.attr,
-- 
2.23.0

Re: [PATCH] thunderbolt: Add 'generation' attribute for devices

[Mika Westerberg]

On Thu, Oct 03, 2019 at 07:32:40PM +0200, Christian Kellner wrote:
> From: Christian Kellner <christian@kellner.me>
> 
> The Thunderbolt standard went through several major iterations, here
> called generation. USB4, which will be based on Thunderbolt, will be
> generation 4. Let userspace know the generation of the controller in
> the devices in order to distinguish between Thunderbolt and USB4, so
> it can be shown in various user interfaces.
> 
> Signed-off-by: Christian Kellner <christian@kellner.me>
> ---
>  Documentation/ABI/testing/sysfs-bus-thunderbolt |  8 ++++++++
>  drivers/thunderbolt/switch.c                    | 10 ++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
> index b21fba14689b..630e51344f1c 100644
> --- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
> +++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
> @@ -80,6 +80,14 @@ Contact:	thunderbolt-software@lists.01.org
>  Description:	This attribute contains 1 if Thunderbolt device was already
>  		authorized on boot and 0 otherwise.
>  
> +What: /sys/bus/thunderbolt/devices/.../generation
> +Date:		Aug 2019

I updated this to be Jan 2020, which is estimated release date of v5.5
according to http://phb-crystal-ball.org/, and queued it for v5.5.

Thanks!