[PATCH net] net: wwan: Add WWAN port type attribute

The port type is by default part of the WWAN port device name.
However device name can not be considered as a 'stable' API and
may be subject to change in the future. This change adds a proper
device attribute that can be used to determine the WWAN protocol/
type.

Signed-off-by: Loic Poulain <redacted>
---
 drivers/net/wwan/wwan_core.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index cff04e5..92a8a6f 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c

@@ -169,6 +169,30 @@ static void wwan_remove_dev(struct wwan_device *wwandev)
 
 /* ------- WWAN port management ------- */
 
+/* Keep aligned with wwan_port_type enum */
+static const char * const wwan_port_type_str[] = {
+	"AT",
+	"MBIM",
+	"QMI",
+	"QCDM",
+	"FIREHOSE"
+};
+
+static ssize_t type_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct wwan_port *port = to_wwan_port(dev);
+
+	return sprintf(buf, "%s\n", wwan_port_type_str[port->type]);
+}
+static DEVICE_ATTR_RO(type);
+
+static struct attribute *wwan_port_attrs[] = {
+	&dev_attr_type.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(wwan_port);
+
 static void wwan_port_destroy(struct device *dev)
 {
 	struct wwan_port *port = to_wwan_port(dev);

@@ -182,6 +206,7 @@ static void wwan_port_destroy(struct device *dev)
 static const struct device_type wwan_port_dev_type = {
 	.name = "wwan_port",
 	.release = wwan_port_destroy,
+	.groups = wwan_port_groups,
 };
 
 static int wwan_port_minor_match(struct device *dev, const void *minor)

@@ -201,15 +226,6 @@ static struct wwan_port *wwan_port_get_by_minor(unsigned int minor)
 	return to_wwan_port(dev);
 }
 
-/* Keep aligned with wwan_port_type enum */
-static const char * const wwan_port_type_str[] = {
-	"AT",
-	"MBIM",
-	"QMI",
-	"QCDM",
-	"FIREHOSE"
-};
-
 struct wwan_port *wwan_create_port(struct device *parent,
 				   enum wwan_port_type type,
 				   const struct wwan_port_ops *ops,

-- 
2.7.4

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 17 May 2021 11:53:34 +0200 you wrote:

The port type is by default part of the WWAN port device name.
However device name can not be considered as a 'stable' API and
may be subject to change in the future. This change adds a proper
device attribute that can be used to determine the WWAN protocol/
type.

Signed-off-by: Loic Poulain <redacted>

[...]

Here is the summary with links:
  - [net] net: wwan: Add WWAN port type attribute
    https://git.kernel.org/netdev/net-next/c/b3e22e10fdda

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Hello Loic,

On Mon, May 17, 2021 at 12:48 PM Loic Poulain [off-list ref] wrote:

A small nitpick, maybe this array should be defined in a such way:

static const char * const wwan_port_type_str[WWAN_PORT_MAX] = {
    [WWAN_PORT_AT] = "AT",
    [WWAN_PORT_MBIM] = "MBIM",
    [WWAN_PORT_QMI] = "QMI",
    [WWAN_PORT_QCDM] = "QCDM",
    [WWAN_PORT_FIREHOSE] = "FIREHOSE",
};

So the array index will be clear without additional notes.

-- 
Sergey

Hi Sergey,

On Tue, 18 May 2021 at 01:44, Sergey Ryazanov [off-list ref] wrote:

Hello Loic,

On Mon, May 17, 2021 at 12:48 PM Loic Poulain [off-list ref] wrote:

quoted

The port type is by default part of the WWAN port device name.
However device name can not be considered as a 'stable' API and
may be subject to change in the future. This change adds a proper
device attribute that can be used to determine the WWAN protocol/
type.

Signed-off-by: Loic Poulain <redacted>
---
 drivers/net/wwan/wwan_core.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index cff04e5..92a8a6f 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c

@@ -169,6 +169,30 @@ static void wwan_remove_dev(struct wwan_device *wwandev)

 /* ------- WWAN port management ------- */

+/* Keep aligned with wwan_port_type enum */
+static const char * const wwan_port_type_str[] = {
+       "AT",
+       "MBIM",
+       "QMI",
+       "QCDM",
+       "FIREHOSE"
+};

A small nitpick, maybe this array should be defined in a such way:

static const char * const wwan_port_type_str[WWAN_PORT_MAX] = {
    [WWAN_PORT_AT] = "AT",
    [WWAN_PORT_MBIM] = "MBIM",
    [WWAN_PORT_QMI] = "QMI",
    [WWAN_PORT_QCDM] = "QCDM",
    [WWAN_PORT_FIREHOSE] = "FIREHOSE",
};

So the array index will be clear without additional notes.

You're right, it would indeed be more robust.
I'll submit that change in a subsequent patch.

Thanks,
Loic

--
Sergey