kernel: add SFP support for Methode DM7052 NBASE-T module

Add support for Methode DM7052 NBASE-T module to OpenWRT. These
patches are taken from my "phy" branch, and will be sent for the
next kernel merge window.

Signed-off-by: Russell King <linux@armlinux.org.uk>
[jonas.gorski: move patches to pending, refresh patches]
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

1 files changed, 131 insertions, 0 deletions

diff --git a/target/linux/generic/pending-4.19/743-net-sfp-add-module-start-stop-upstream-notifications.patch b/target/linux/generic/pending-4.19/743-net-sfp-add-module-start-stop-upstream-notifications.patch
new file mode 100644
index 0000000000..e0eea5e605
--- /dev/null
+++ b/target/linux/generic/pending-4.19/743-net-sfp-add-module-start-stop-upstream-notifications.patch
@@ -0,0 +1,131 @@
+From f9a5a54b59cb904b37bf7409a43635ab195d0214 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Tue, 19 Nov 2019 10:13:25 +0000
+Subject: [PATCH 646/660] net: sfp: add module start/stop upstream
+ notifications
+
+When dealing with some copper modules, we can't positively know the
+module capabilities are until we have probed the PHY. Without the full
+capabilities, we may end up failing a module that we could otherwise
+drive with a restricted set of capabilities.
+
+An example of this would be a module with a NBASE-T PHY plugged into
+a host that supports phy interface modes 2500BASE-X and SGMII. The
+PHY supports 10GBASE-R, 5000BASE-X, 2500BASE-X, SGMII interface modes,
+which means a subset of the capabilities are compatible with the host.
+
+However, reading the module EEPROM leads us to believe that the module
+only supports ethtool link mode 10GBASE-T, which is incompatible with
+the host - and thus results in the module being rejected.
+
+This patch adds an extra notification which are triggered after the
+SFP module's PHY probe, and a corresponding notification just before
+the PHY is removed.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+---
+ drivers/net/phy/sfp-bus.c | 21 +++++++++++++++++++++
+ drivers/net/phy/sfp.c     |  8 ++++++++
+ drivers/net/phy/sfp.h     |  2 ++
+ include/linux/sfp.h       |  4 ++++
+ 4 files changed, 35 insertions(+)
+
+--- a/drivers/net/phy/sfp-bus.c
++++ b/drivers/net/phy/sfp-bus.c
+@@ -711,6 +711,27 @@ void sfp_module_remove(struct sfp_bus *b
+ }
+ EXPORT_SYMBOL_GPL(sfp_module_remove);
+ 
++int sfp_module_start(struct sfp_bus *bus)
++{
++	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
++	int ret = 0;
++
++	if (ops && ops->module_start)
++		ret = ops->module_start(bus->upstream);
++
++	return ret;
++}
++EXPORT_SYMBOL_GPL(sfp_module_start);
++
++void sfp_module_stop(struct sfp_bus *bus)
++{
++	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
++
++	if (ops && ops->module_stop)
++		ops->module_stop(bus->upstream);
++}
++EXPORT_SYMBOL_GPL(sfp_module_stop);
++
+ static void sfp_socket_clear(struct sfp_bus *bus)
+ {
+ 	bus->sfp_dev = NULL;
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -57,6 +57,7 @@ enum {
+ 	SFP_DEV_UP,
+ 
+ 	SFP_S_DOWN = 0,
++	SFP_S_FAIL,
+ 	SFP_S_WAIT,
+ 	SFP_S_INIT,
+ 	SFP_S_INIT_TX_FAULT,
+@@ -120,6 +121,7 @@ static const char *event_to_str(unsigned
+ 
+ static const char * const sm_state_strings[] = {
+ 	[SFP_S_DOWN] = "down",
++	[SFP_S_FAIL] = "fail",
+ 	[SFP_S_WAIT] = "wait",
+ 	[SFP_S_INIT] = "init",
+ 	[SFP_S_INIT_TX_FAULT] = "init_tx_fault",
+@@ -1749,6 +1751,8 @@ static void sfp_sm_main(struct sfp *sfp,
+ 		if (sfp->sm_state == SFP_S_LINK_UP &&
+ 		    sfp->sm_dev_state == SFP_DEV_UP)
+ 			sfp_sm_link_down(sfp);
++		if (sfp->sm_state > SFP_S_INIT)
++			sfp_module_stop(sfp->sfp_bus);
+ 		if (sfp->mod_phy)
+ 			sfp_sm_phy_detach(sfp);
+ 		sfp_module_tx_disable(sfp);
+@@ -1815,6 +1819,10 @@ static void sfp_sm_main(struct sfp *sfp,
+ 			 * clear.  Probe for the PHY and check the LOS state.
+ 			 */
+ 			sfp_sm_probe_for_phy(sfp);
++			if (sfp_module_start(sfp->sfp_bus)) {
++				sfp_sm_next(sfp, SFP_S_FAIL, 0);
++				break;
++			}
+ 			sfp_sm_link_check_los(sfp);
+ 
+ 			/* Reset the fault retry count */
+--- a/drivers/net/phy/sfp.h
++++ b/drivers/net/phy/sfp.h
+@@ -22,6 +22,8 @@ void sfp_link_up(struct sfp_bus *bus);
+ void sfp_link_down(struct sfp_bus *bus);
+ int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id);
+ void sfp_module_remove(struct sfp_bus *bus);
++int sfp_module_start(struct sfp_bus *bus);
++void sfp_module_stop(struct sfp_bus *bus);
+ int sfp_link_configure(struct sfp_bus *bus, const struct sfp_eeprom_id *id);
+ struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
+ 				    const struct sfp_socket_ops *ops);
+--- a/include/linux/sfp.h
++++ b/include/linux/sfp.h
+@@ -507,6 +507,8 @@ struct sfp_bus;
+  * @module_insert: called after a module has been detected to determine
+  *   whether the module is supported for the upstream device.
+  * @module_remove: called after the module has been removed.
++ * @module_start: called after the PHY probe step
++ * @module_stop: called before the PHY is removed
+  * @link_down: called when the link is non-operational for whatever
+  *   reason.
+  * @link_up: called when the link is operational.
+@@ -520,6 +522,8 @@ struct sfp_upstream_ops {
+ 	void (*detach)(void *priv, struct sfp_bus *bus);
+ 	int (*module_insert)(void *priv, const struct sfp_eeprom_id *id);
+ 	void (*module_remove)(void *priv);
++	int (*module_start)(void *priv);
++	void (*module_stop)(void *priv);
+ 	void (*link_down)(void *priv);
+ 	void (*link_up)(void *priv);
+ 	int (*connect_phy)(void *priv, struct phy_device *);