[PATCH v3 1/2] can: c_can: add ethtool support

[Dario Binacchi]

With commit 132f2d45fb23 ("can: c_can: add support to 64 message objects")
the number of message objects used for reception / transmission depends
on FIFO size.
The ethtools API support allows you to retrieve this info. Driver info
has been added too.

Signed-off-by: Dario Binacchi <dariobin@xxxxxxxxx>

---

Changes in v3:
- Remove the version info so that ethtool will return the version of the
  kernel the driver is actually being used in.

Changes in v2:
- Use get_ringparam instead of get_channels.

 drivers/net/can/c_can/Makefile                |  3 ++
 drivers/net/can/c_can/c_can.h                 |  2 +
 drivers/net/can/c_can/c_can_ethtool.c         | 43 +++++++++++++++++++
 .../net/can/c_can/{c_can.c => c_can_main.c}   |  1 +
 4 files changed, 49 insertions(+)
 create mode 100644 drivers/net/can/c_can/c_can_ethtool.c
 rename drivers/net/can/c_can/{c_can.c => c_can_main.c} (99%)

diff --git a/drivers/net/can/c_can/Makefile b/drivers/net/can/c_can/Makefile
index e6a94c948531..ac2bca39d6ff 100644
--- a/drivers/net/can/c_can/Makefile
+++ b/drivers/net/can/c_can/Makefile
@@ -4,5 +4,8 @@
 #
 
 obj-$(CONFIG_CAN_C_CAN) += c_can.o
+
+c_can-objs := c_can_main.o c_can_ethtool.o
+
 obj-$(CONFIG_CAN_C_CAN_PLATFORM) += c_can_platform.o
 obj-$(CONFIG_CAN_C_CAN_PCI) += c_can_pci.o
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 06045f610f0e..f9001072514a 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -219,4 +219,6 @@ int c_can_power_up(struct net_device *dev);
 int c_can_power_down(struct net_device *dev);
 #endif
 
+void c_can_set_ethtool_ops(struct net_device *dev);
+
 #endif /* C_CAN_H */
diff --git a/drivers/net/can/c_can/c_can_ethtool.c b/drivers/net/can/c_can/c_can_ethtool.c
new file mode 100644
index 000000000000..6e50308c3aac
--- /dev/null
+++ b/drivers/net/can/c_can/c_can_ethtool.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021, Dario Binacchi <dariobin@xxxxxxxxx>
+ */
+
+#include <linux/ethtool.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/netdevice.h>
+#include <linux/can/dev.h>
+
+#include "c_can.h"
+
+static void c_can_get_drvinfo(struct net_device *netdev,
+			      struct ethtool_drvinfo *info)
+{
+	struct c_can_priv *priv = netdev_priv(netdev);
+	struct platform_device	*pdev = to_platform_device(priv->device);
+
+	strscpy(info->driver, "c_can", sizeof(info->driver));
+	strscpy(info->bus_info, pdev->name, sizeof(info->bus_info));
+}
+
+static void c_can_get_ringparam(struct net_device *netdev,
+				struct ethtool_ringparam *ring)
+{
+	struct c_can_priv *priv = netdev_priv(netdev);
+
+	ring->rx_max_pending = priv->msg_obj_num;
+	ring->tx_max_pending = priv->msg_obj_num;
+	ring->rx_pending = priv->msg_obj_rx_num;
+	ring->tx_pending = priv->msg_obj_tx_num;
+}
+
+static const struct ethtool_ops c_can_ethtool_ops = {
+	.get_drvinfo = c_can_get_drvinfo,
+	.get_ringparam = c_can_get_ringparam,
+};
+
+void c_can_set_ethtool_ops(struct net_device *netdev)
+{
+	netdev->ethtool_ops = &c_can_ethtool_ops;
+}
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can_main.c
similarity index 99%
rename from drivers/net/can/c_can/c_can.c
rename to drivers/net/can/c_can/c_can_main.c
index 313793f6922d..1903b87d5384 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can_main.c
@@ -1335,6 +1335,7 @@ int register_c_can_dev(struct net_device *dev)
 
 	dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &c_can_netdev_ops;
+	c_can_set_ethtool_ops(dev);
 
 	err = register_candev(dev);
 	if (!err)
-- 
2.17.1