dsa: add support for the Marvell 88E6131 switch chip

Add support for the Marvell 88E6131 switch chip.  This chip only
supports the original (ethertype-less) DSA tagging format.

On the 88E6131, there is a PHY Polling Unit (PPU) which has exclusive
access to each of the PHYs's MII management registers.  If we want to
talk to the PHYs from software, we have to disable the PPU and wait
for it to complete its current transaction before we can do so, and we
need to re-enable the PPU afterwards to make sure that the switch will
notice changes in link state and speed on the individual ports as they
occur.

Since disabling the PPU is rather slow, and since MII management
accesses are typically done in bursts, this patch keeps the PPU disabled
for 10ms after a software access completes.  This makes handling the
PPU slightly more complex, but speeds up something like running ethtool
on one of the switch slave interfaces from ~300ms to ~30ms on typical
hardware.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Nicolas Pitre <nico@marvell.com>
Tested-by: Peter van Valderen <linux@ddcrew.com>
Tested-by: Dirk Teurlings <dirk@upexia.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/mv88e6xxx.h b/net/dsa/mv88e6xxx.h
index a004d4d..eb0e0aa 100644
--- a/net/dsa/mv88e6xxx.h
+++ b/net/dsa/mv88e6xxx.h
@@ -23,6 +23,17 @@
 	 */
 	struct mutex	smi_mutex;
 
+#ifdef CONFIG_NET_DSA_MV88E6XXX_NEED_PPU
+	/*
+	 * Handles automatic disabling and re-enabling of the PHY
+	 * polling unit.
+	 */
+	struct mutex		ppu_mutex;
+	int			ppu_disabled;
+	struct work_struct	ppu_work;
+	struct timer_list	ppu_timer;
+#endif
+
 	/*
 	 * This mutex serialises access to the statistics unit.
 	 * Hold this mutex over snapshot + dump sequences.
@@ -42,9 +53,14 @@
                           int reg, u16 val);
 int mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg, u16 val);
 int mv88e6xxx_config_prio(struct dsa_switch *ds);
+int mv88e6xxx_set_addr_direct(struct dsa_switch *ds, u8 *addr);
 int mv88e6xxx_set_addr_indirect(struct dsa_switch *ds, u8 *addr);
 int mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum);
 int mv88e6xxx_phy_write(struct dsa_switch *ds, int addr, int regnum, u16 val);
+void mv88e6xxx_ppu_state_init(struct dsa_switch *ds);
+int mv88e6xxx_phy_read_ppu(struct dsa_switch *ds, int addr, int regnum);
+int mv88e6xxx_phy_write_ppu(struct dsa_switch *ds, int addr,
+			    int regnum, u16 val);
 void mv88e6xxx_poll_link(struct dsa_switch *ds);
 void mv88e6xxx_get_strings(struct dsa_switch *ds,
 			   int nr_stats, struct mv88e6xxx_hw_stat *stats,