generic: mt7530: backport support for the MT7988 built-in switch

Backport commits adding support for the MT7988 built-in switch to the
mt7530 driver.

This change results in the Kconfig symbol NET_DSA_MT7530 to be extended
by NET_DSA_MT7530_MDIO (everything formally covered by NET_DSA_MT7530)
and NET_DSA_MT7530_MMIO (a new driver for the MMIO-connected built-in
switch of the MT7988 SoC).

Select NET_DSA_MT7530_MDIO for all targets previously selecting
NET_DSA_MT7530, with the exception of mediatek/filogic which also
selects NET_DSA_MT7530_MMIO.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
(cherry picked from commit 958fdf36e35c814eb83faf2c39db4ca379c921b5)

1 files changed, 74 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.15/790-v6.4-0003-net-dsa-mt7530-use-unlocked-regmap-accessors.patch b/target/linux/generic/backport-5.15/790-v6.4-0003-net-dsa-mt7530-use-unlocked-regmap-accessors.patch
new file mode 100644
index 0000000000..1b4a956199
--- /dev/null
+++ b/target/linux/generic/backport-5.15/790-v6.4-0003-net-dsa-mt7530-use-unlocked-regmap-accessors.patch
@@ -0,0 +1,74 @@
+From 1bd099c49f65ed923b9f19b8c4b3cd1ff0024091 Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Mon, 3 Apr 2023 02:17:40 +0100
+Subject: [PATCH 06/16] net: dsa: mt7530: use unlocked regmap accessors
+
+Instead of wrapping the locked register accessor functions, use the
+unlocked variants and add locking wrapper functions to let regmap
+handle the locking.
+
+This is a preparation towards being able to always use regmap to
+access switch registers instead of open-coded accessor functions.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/mt7530.c | 23 ++++++++++++++---------
+ 1 file changed, 14 insertions(+), 9 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -2899,7 +2899,7 @@ static int mt7530_regmap_read(void *cont
+ {
+ 	struct mt7530_priv *priv = context;
+ 
+-	*val = mt7530_read(priv, reg);
++	*val = mt7530_mii_read(priv, reg);
+ 	return 0;
+ };
+ 
+@@ -2907,23 +2907,25 @@ static int mt7530_regmap_write(void *con
+ {
+ 	struct mt7530_priv *priv = context;
+ 
+-	mt7530_write(priv, reg, val);
++	mt7530_mii_write(priv, reg, val);
+ 	return 0;
+ };
+ 
+-static int mt7530_regmap_update_bits(void *context, unsigned int reg,
+-				     unsigned int mask, unsigned int val)
++static void
++mt7530_mdio_regmap_lock(void *mdio_lock)
+ {
+-	struct mt7530_priv *priv = context;
++	mutex_lock_nested(mdio_lock, MDIO_MUTEX_NESTED);
++}
+ 
+-	mt7530_rmw(priv, reg, mask, val);
+-	return 0;
+-};
++static void
++mt7530_mdio_regmap_unlock(void *mdio_lock)
++{
++	mutex_unlock(mdio_lock);
++}
+ 
+ static const struct regmap_bus mt7531_regmap_bus = {
+ 	.reg_write = mt7530_regmap_write,
+ 	.reg_read = mt7530_regmap_read,
+-	.reg_update_bits = mt7530_regmap_update_bits,
+ };
+ 
+ static int
+@@ -2949,6 +2951,9 @@ mt7531_create_sgmii(struct mt7530_priv *
+ 		mt7531_pcs_config[i]->reg_stride = 4;
+ 		mt7531_pcs_config[i]->reg_base = MT7531_SGMII_REG_BASE(5 + i);
+ 		mt7531_pcs_config[i]->max_register = 0x17c;
++		mt7531_pcs_config[i]->lock = mt7530_mdio_regmap_lock;
++		mt7531_pcs_config[i]->unlock = mt7530_mdio_regmap_unlock;
++		mt7531_pcs_config[i]->lock_arg = &priv->bus->mdio_lock;
+ 
+ 		regmap = devm_regmap_init(priv->dev,
+ 					  &mt7531_regmap_bus, priv,