net: phylink: add EEE management

Add EEE management to phylink, making use of the phylib implementation.
This will only be used where a MAC driver populates the methods and
capabilities bitfield, otherwise we keep our old behaviour.

Phylink will keep track of the EEE configuration, including the clock
stop abilities at each end of the MAC to PHY link, programming the PHY
appropriately and preserving the LPI configuration should the PHY go
away.

Phylink will call into the MAC driver when LPI needs to be enabled or
disabled, with the requirement that the MAC have LPI disabled prior
to the netdev being brought up (in other words, it will only call
mac_disable_tx_lpi() if it has already called mac_enable_tx_lpi().)

Support for phylink managed EEE is enabled by populating both tx_lpi
MAC operations method pointers, and filling in both LPI interfaces
and capabilities. If the methods are provided but the LPI interfaces
or capabilities remain empty, this indicates to phylink that EEE is
implemented by the driver but the hardware it is driving does not
support EEE, and thus the ethtool set_eee() and get_eee() methods will
return EOPNOTSUPP.

No validation of the LPI timer value is performed by this patch.

For interface modes which do not support LPI, we make no attempt to
manipulate the phylib EEE advertisement, but instead refuse to
activate LPI at the MAC, noting it at debug message level.

We also restrict the advertisement and reported userspace support
linkmode masks according to the lpi_capabilities provided to
phylink by the MAC driver.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/E1tYADq-0014Pn-J1@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index f19b7108c840..898b00451bbf 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -5,6 +5,8 @@
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
+#include <net/eee.h>
+
 struct device_node;
 struct ethtool_cmd;
 struct fwnode_handle;
@@ -143,11 +145,17 @@ enum phylink_op_type {
  *                    possible and avoid stopping it during suspend events.
  * @default_an_inband: if true, defaults to MLO_AN_INBAND rather than
  *		       MLO_AN_PHY. A fixed-link specification will override.
+ * @eee_rx_clk_stop_enable: if true, PHY can stop the receive clock during LPI
  * @get_fixed_state: callback to execute to determine the fixed link state,
  *		     if MAC link is at %MLO_AN_FIXED mode.
  * @supported_interfaces: bitmap describing which PHY_INTERFACE_MODE_xxx
  *                        are supported by the MAC/PCS.
+ * @lpi_interfaces: bitmap describing which PHY interface modes can support
+ *		    LPI signalling.
  * @mac_capabilities: MAC pause/speed/duplex capabilities.
+ * @lpi_capabilities: MAC speeds which can support LPI signalling
+ * @lpi_timer_default: Default EEE LPI timer setting.
+ * @eee_enabled_default: If set, EEE will be enabled by phylink at creation time
  */
 struct phylink_config {
 	struct device *dev;
@@ -156,10 +164,15 @@ struct phylink_config {
 	bool mac_managed_pm;
 	bool mac_requires_rxc;
 	bool default_an_inband;
+	bool eee_rx_clk_stop_enable;
 	void (*get_fixed_state)(struct phylink_config *config,
 				struct phylink_link_state *state);
 	DECLARE_PHY_INTERFACE_MASK(supported_interfaces);
+	DECLARE_PHY_INTERFACE_MASK(lpi_interfaces);
 	unsigned long mac_capabilities;
+	unsigned long lpi_capabilities;
+	u32 lpi_timer_default;
+	bool eee_enabled_default;
 };
 
 void phylink_limit_mac_speed(struct phylink_config *config, u32 max_speed);
@@ -173,6 +186,8 @@ void phylink_limit_mac_speed(struct phylink_config *config, u32 max_speed);
  * @mac_finish: finish a major reconfiguration of the interface.
  * @mac_link_down: take the link down.
  * @mac_link_up: allow the link to come up.
+ * @mac_disable_tx_lpi: disable LPI.
+ * @mac_enable_tx_lpi: enable and configure LPI.
  *
  * The individual methods are described more fully below.
  */
@@ -193,6 +208,9 @@ struct phylink_mac_ops {
 			    struct phy_device *phy, unsigned int mode,
 			    phy_interface_t interface, int speed, int duplex,
 			    bool tx_pause, bool rx_pause);
+	void (*mac_disable_tx_lpi)(struct phylink_config *config);
+	int (*mac_enable_tx_lpi)(struct phylink_config *config, u32 timer,
+				 bool tx_clk_stop);
 };
 
 #if 0 /* For kernel-doc purposes only. */
@@ -387,6 +405,33 @@ void mac_link_down(struct phylink_config *config, unsigned int mode,
 void mac_link_up(struct phylink_config *config, struct phy_device *phy,
 		 unsigned int mode, phy_interface_t interface,
 		 int speed, int duplex, bool tx_pause, bool rx_pause);
+
+/**
+ * mac_disable_tx_lpi() - disable LPI generation at the MAC
+ * @config: a pointer to a &struct phylink_config.
+ *
+ * Disable generation of LPI at the MAC, effectively preventing the MAC
+ * from indicating that it is idle.
+ */
+void mac_disable_tx_lpi(struct phylink_config *config);
+
+/**
+ * mac_enable_tx_lpi() - configure and enable LPI generation at the MAC
+ * @config: a pointer to a &struct phylink_config.
+ * @timer: LPI timeout in microseconds.
+ * @tx_clk_stop: allow xMII transmit clock to be stopped during LPI
+ *
+ * Configure the LPI timeout accordingly. This will only be called when
+ * the link is already up, to cater for situations where the hardware
+ * needs to be programmed according to the link speed.
+ *
+ * Enable LPI generation at the MAC, and configure whether the xMII transmit
+ * clock may be stopped.
+ *
+ * Returns: 0 on success. Please consult with rmk before returning an error.
+ */
+int mac_enable_tx_lpi(struct phylink_config *config, u32 timer,
+		      bool tx_clk_stop);
 #endif
 
 struct phylink_pcs_ops;