generic: mxl-gpy: allow configuring LED registers

Add a patch to allow modification of the PHY LED configuration. This is
required for boards, where the reset configuration of LED functions is
incompatibe with the usage of the device LEDs.

This is the case for the ASUS TUF-AX4200 Wireless router. It requires
modification of the LED configuration because as the WAN LED on the
front of the device is driven by the PHY. Without patching, it would
only illuminate in case the Link speed is 100 Mbit/s.

Signed-off-by: David Bauer <mail@david-bauer.net>

diff --git a/target/linux/generic/hack-5.15/765-mxl-gpy-control-LED-reg-from-DT.patch b/target/linux/generic/hack-5.15/765-mxl-gpy-control-LED-reg-from-DT.patch
new file mode 100644 (file)
index 0000000..75014c0
--- /dev/null
+++ b/target/linux/generic/hack-5.15/765-mxl-gpy-control-LED-reg-from-DT.patch
@@ -0,0 +1,106 @@
+From 94b90966095f3fa625897e8f53d215882f6e19b3 Mon Sep 17 00:00:00 2001
+From: David Bauer <mail@david-bauer.net>
+Date: Sat, 11 Mar 2023 17:00:01 +0100
+Subject: [PATCH] mxl-gpy: control LED reg from DT
+
+Add dynamic configuration for the LED control registers on MXL PHYs.
+
+This patch has been tested with MaxLinear GPY211C. It is unlikely to be
+accepted upstream, as upstream plans on integrating their own framework
+for handling these LEDs.
+
+For the time being, use this hack to configure PHY driven device-LEDs to
+show the correct state.
+
+A possible alternative might be to expose the LEDs using the kernel LED
+framework and bind it to the netdevice. This might also be upstreamable,
+although it is a considerable extra amount of work.
+
+Signed-off-by: David Bauer <mail@david-bauer.net>
+---
+ drivers/net/phy/mxl-gpy.c | 37 ++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 36 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
+index 5ce1bf03bbd7..ec10ad5ccad6 100644
+--- a/drivers/net/phy/mxl-gpy.c
++++ b/drivers/net/phy/mxl-gpy.c
+@@ -8,6 +8,7 @@
+ 
+ #include <linux/module.h>
+ #include <linux/bitfield.h>
++#include <linux/of.h>
+ #include <linux/phy.h>
+ #include <linux/netdevice.h>
+ 
+@@ -30,6 +31,7 @@
+ #define PHY_MIISTAT           0x18    /* MII state */
+ #define PHY_IMASK             0x19    /* interrupt mask */
+ #define PHY_ISTAT             0x1A    /* interrupt status */
++#define PHY_LED                       0x1B    /* LED control */
+ #define PHY_FWV                       0x1E    /* firmware version */
+ 
+ #define PHY_MIISTAT_SPD_MASK  GENMASK(2, 0)
+@@ -53,10 +55,15 @@
+                                PHY_IMASK_ADSC | \
+                                PHY_IMASK_ANC)
+ 
++#define PHY_LED_NUM_LEDS      4
++
+ #define PHY_FWV_REL_MASK      BIT(15)
+ #define PHY_FWV_TYPE_MASK     GENMASK(11, 8)
+ #define PHY_FWV_MINOR_MASK    GENMASK(7, 0)
+ 
++/* LED */
++#define VSPEC1_LED(x)         (0x1 + x)
++
+ /* SGMII */
+ #define VSPEC1_SGMII_CTRL     0x08
+ #define VSPEC1_SGMII_CTRL_ANEN        BIT(12)         /* Aneg enable */
+@@ -80,6 +87,31 @@ static const struct {
+       {9, 0x73},
+ };
+ 
++static int gpy_led_write(struct phy_device *phydev)
++{
++      struct device_node *node = phydev->mdio.dev.of_node;
++      u32 led_regs[PHY_LED_NUM_LEDS];
++      int i, ret;
++
++      if (!IS_ENABLED(CONFIG_OF_MDIO))
++              return 0;
++
++      if (of_property_read_u32_array(node, "mxl,led-config", led_regs, PHY_LED_NUM_LEDS))
++              return 0;
++
++      /* Enable LED function handling on all ports*/
++      phy_write(phydev, PHY_LED, 0xFF00);
++
++      /* Write LED register values */
++      for (i = 0; i < PHY_LED_NUM_LEDS; i++) {
++              ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, VSPEC1_LED(i), (u16)led_regs[i]);
++              if (ret < 0)
++                      return ret;
++      }
++
++      return 0;
++}
++
+ static int gpy_config_init(struct phy_device *phydev)
+ {
+       int ret;
+@@ -91,7 +123,10 @@ static int gpy_config_init(struct phy_device *phydev)
+ 
+       /* Clear all pending interrupts */
+       ret = phy_read(phydev, PHY_ISTAT);
+-      return ret < 0 ? ret : 0;
++      if (ret < 0)
++              return ret;
++
++      return gpy_led_write(phydev);
+ }
+ 
+ static int gpy_probe(struct phy_device *phydev)
+-- 
+2.39.2
+