Merge branch 'net-add-phylink-managed-eee-support'

Russell King says:

====================
net: add phylink managed EEE support

Adding managed EEE support to phylink has been on the cards ever since
the idea in phylib was mooted. This overly large series attempts to do
so. I've included all the patches as it's important to get the driver
patches out there.

Patch 1 adds a definition for the clock stop capable bit in the PCS
MMD status register.

Patch 2 adds a phylib API to query whether the PHY allows the transmit
xMII clock to be stopped while in LPI mode. This capability is for MAC
drivers to save power when LPI is active, to allow them to stop their
transmit clock.

Patch 3 extracts a phylink internal helper for determining whether the
link is up.

Patch 4 adds basic phylink managed EEE support. Two new MAC APIs are
added, to enable and disable LPI. The enable method is passed the LPI
timer setting which it is expected to program into the hardware, and
also a flag ehther the transmit clock should be stopped.

I have taken the decision to make enable_tx_lpi() to return an error
code, but not do much with it other than report it - the intention
being that we can later use it to extend functionality if needed
without reworking loads of drivers.

I have also dropped the validation/limitation of the LPI timer, and
left that in the driver code prior to calling phylink_ethtool_set_eee().

The remainder of the patches convert mvneta, lan743x and stmmac, and
add support for mvneta.
====================

Link: https://patch.msgid.link/Z4gdtOaGsBhQCZXn@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 47 insertions, 0 deletions

diff --git a/include/linux/phy.h b/include/linux/phy.h
index afaae74d0949..244f747b3cd9 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -2146,6 +2146,7 @@ int phy_unregister_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask);
 int phy_unregister_fixup_for_id(const char *bus_id);
 int phy_unregister_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask);
 
+int phy_eee_tx_clock_stop_capable(struct phy_device *phydev);
 int phy_eee_rx_clock_stop(struct phy_device *phydev, bool clk_stop_enable);
 int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable);
 int phy_get_eee_err(struct phy_device *phydev);
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;
diff --git a/include/uapi/linux/mdio.h b/include/uapi/linux/mdio.h
index f0d3f268240d..6975f182b22c 100644
--- a/include/uapi/linux/mdio.h
+++ b/include/uapi/linux/mdio.h
@@ -125,6 +125,7 @@
 #define MDIO_STAT1_LPOWERABLE		0x0002	/* Low-power ability */
 #define MDIO_STAT1_LSTATUS		BMSR_LSTATUS
 #define MDIO_STAT1_FAULT		0x0080	/* Fault */
+#define MDIO_PCS_STAT1_CLKSTOP_CAP	0x0040
 #define MDIO_AN_STAT1_LPABLE		0x0001	/* Link partner AN ability */
 #define MDIO_AN_STAT1_ABLE		BMSR_ANEGCAPABLE
 #define MDIO_AN_STAT1_RFAULT		BMSR_RFAULT