[PATCH net-next v7 5/5] net: phy: add Rust Asix PHY driver

FUJITA Tomonori
2023-10-26T00:16:58Z

This is the Rust implementation of drivers/net/phy/ax88796b.c. The
features are equivalent. You can choose C or Rust versionon kernel
configuration.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
---
MAINTAINERS | 8 ++
drivers/net/phy/Kconfig | 8 ++
drivers/net/phy/Makefile | 6 +-
drivers/net/phy/ax88796b_rust.rs | 129 +++++++++++++++++++++++++++++++
rust/uapi/uapi_helper.h | 2 +
5 files changed, 152 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/phy/ax88796b_rust.rs

diff --git a/MAINTAINERS b/MAINTAINERS
index f0f0610defd6..aad0325121e0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3058,6 +3058,14 @@ S: Maintained
F: Documentation/devicetree/bindings/net/asix,ax88796c.yaml
F: drivers/net/ethernet/asix/ax88796c_*

+ASIX PHY DRIVER [RUST]
+M: FUJITA Tomonori <fujita.tomonori@gmail.com>
+R: Trevor Gross <tmgross@umich.edu>
+L: netdev@vger.kernel.org
+L: rust-for-linux@vger.kernel.org
+S: Maintained
+F: drivers/net/phy/ax88796b_rust.rs
+
ASPEED CRYPTO DRIVER
M: Neal Liu <neal_liu@aspeedtech.com>
L: linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 0faebdb184ca..11b18370a05b 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -115,6 +115,14 @@ config AX88796B_PHY
Currently supports the Asix Electronics PHY found in the X-Surf 100
AX88796B package.

+config AX88796B_RUST_PHY
+ bool "Rust reference driver for Asix PHYs"
+ depends on RUST_PHYLIB_ABSTRACTIONS && AX88796B_PHY
+ help
+ Uses the Rust reference driver for Asix PHYs (ax88796b_rust.ko).
+ The features are equivalent. It supports the Asix Electronics PHY
+ found in the X-Surf 100 AX88796B package.
+
config BROADCOM_PHY
tristate "Broadcom 54XX PHYs"
select BCM_NET_PHYLIB
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index c945ed9bd14b..58d7dfb095ab 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -41,7 +41,11 @@ aquantia-objs += aquantia_hwmon.o
endif
obj-$(CONFIG_AQUANTIA_PHY) += aquantia.o
obj-$(CONFIG_AT803X_PHY) += at803x.o
-obj-$(CONFIG_AX88796B_PHY) += ax88796b.o
+ifdef CONFIG_AX88796B_RUST_PHY
+ obj-$(CONFIG_AX88796B_PHY) += ax88796b_rust.o
+else
+ obj-$(CONFIG_AX88796B_PHY) += ax88796b.o
+endif
obj-$(CONFIG_BCM54140_PHY) += bcm54140.o
obj-$(CONFIG_BCM63XX_PHY) += bcm63xx.o
obj-$(CONFIG_BCM7XXX_PHY) += bcm7xxx.o
diff --git a/drivers/net/phy/ax88796b_rust.rs b/drivers/net/phy/ax88796b_rust.rs
new file mode 100644
index 000000000000..6c24c94ab2db
--- /dev/null
+++ b/drivers/net/phy/ax88796b_rust.rs
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2023 FUJITA Tomonori <fujita.tomonori@gmail.com>
+
+//! Rust Asix PHYs driver
+//!
+//! C version of this driver: [`drivers/net/phy/ax88796b.c`](./ax88796b.c)
+use kernel::c_str;
+use kernel::net::phy::{self, DeviceId, Driver};
+use kernel::prelude::*;
+use kernel::uapi;
+
+kernel::module_phy_driver! {
+ drivers: [PhyAX88772A, PhyAX88772C, PhyAX88796B],
+ device_table: [
+ DeviceId::new_with_driver::<PhyAX88772A>(),
+ DeviceId::new_with_driver::<PhyAX88772C>(),
+ DeviceId::new_with_driver::<PhyAX88796B>()
+ ],
+ name: "rust_asix_phy",
+ author: "FUJITA Tomonori <fujita.tomonori@gmail.com>",
+ description: "Rust Asix PHYs driver",
+ license: "GPL",
+}
+
+// Performs a software PHY reset using the standard
+// BMCR_RESET bit and poll for the reset bit to be cleared.
+// Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
+// such as used on the Individual Computers' X-Surf 100 Zorro card.
+fn asix_soft_reset(dev: &mut phy::Device) -> Result {
+ dev.write(uapi::MII_BMCR as u16, 0)?;
+ dev.genphy_soft_reset()
+}
+
+struct PhyAX88772A;
+
+#[vtable]
+impl phy::Driver for PhyAX88772A {
+ const FLAGS: u32 = phy::flags::IS_INTERNAL;
+ const NAME: &'static CStr = c_str!("Asix Electronics AX88772A");
+ const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x003b1861);
+
+ // AX88772A is not working properly with some old switches (NETGEAR EN 108TP):
+ // after autoneg is done and the link status is reported as active, the MII_LPA
+ // register is 0. This issue is not reproducible on AX88772C.
+ fn read_status(dev: &mut phy::Device) -> Result<u16> {
+ dev.genphy_update_link()?;
+ if !dev.is_link_up() {
+ return Ok(0);
+ }
+ // If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve
+ // linkmode so use MII_BMCR as default values.
+ let ret = dev.read(uapi::MII_BMCR as u16)?;
+
+ if ret as u32 & uapi::BMCR_SPEED100 != 0 {
+ dev.set_speed(uapi::SPEED_100);
+ } else {
+ dev.set_speed(uapi::SPEED_10);
+ }
+
+ let duplex = if ret as u32 & uapi::BMCR_FULLDPLX != 0 {
+ phy::DuplexMode::Full
+ } else {
+ phy::DuplexMode::Half
+ };
+ dev.set_duplex(duplex);
+
+ dev.genphy_read_lpa()?;
+
+ if dev.is_autoneg_enabled() && dev.is_autoneg_completed() {
+ dev.resolve_aneg_linkmode();
+ }
+
+ Ok(0)
+ }
+
+ fn suspend(dev: &mut phy::Device) -> Result {
+ dev.genphy_suspend()
+ }
+
+ fn resume(dev: &mut phy::Device) -> Result {
+ dev.genphy_resume()
+ }
+
+ fn soft_reset(dev: &mut phy::Device) -> Result {
+ asix_soft_reset(dev)
+ }
+
+ fn link_change_notify(dev: &mut phy::Device) {
+ // Reset PHY, otherwise MII_LPA will provide outdated information.
+ // This issue is reproducible only with some link partner PHYs.
+ if dev.state() == phy::DeviceState::NoLink {
+ let _ = dev.init_hw();
+ let _ = dev.start_aneg();
+ }
+ }
+}
+
+struct PhyAX88772C;
+
+#[vtable]
+impl Driver for PhyAX88772C {
+ const FLAGS: u32 = phy::flags::IS_INTERNAL;
+ const NAME: &'static CStr = c_str!("Asix Electronics AX88772C");
+ const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x003b1881);
+
+ fn suspend(dev: &mut phy::Device) -> Result {
+ dev.genphy_suspend()
+ }
+
+ fn resume(dev: &mut phy::Device) -> Result {
+ dev.genphy_resume()
+ }
+
+ fn soft_reset(dev: &mut phy::Device) -> Result {
+ asix_soft_reset(dev)
+ }
+}
+
+struct PhyAX88796B;
+
+#[vtable]
+impl Driver for PhyAX88796B {
+ const NAME: &'static CStr = c_str!("Asix Electronics AX88796B");
+ const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_model_mask(0x003b1841);
+
+ fn soft_reset(dev: &mut phy::Device) -> Result {
+ asix_soft_reset(dev)
+ }
+}
diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
index 301f5207f023..08f5e9334c9e 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -7,3 +7,5 @@
*/

#include <uapi/asm-generic/ioctl.h>
+#include <uapi/linux/mii.h>
+#include <uapi/linux/ethtool.h>
--
2.34.1