net-next: phy: new Asix Electronics PHY driver

The Asix Electronics PHY found on the X-Surf 100 Amiga Zorro network
card by Individual Computers is buggy, and needs the reset bit toggled
as workaround to make a PHY soft reset succeed.

Add workaround driver just for this special case.

Suggested in xsurf100 patch series review by Andrew Lunn <andrew@lunn.ch>

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index bdfbabb..edb8b9a 100644 (file)
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -218,6 +218,12 @@ config AQUANTIA_PHY
        ---help---
          Currently supports the Aquantia AQ1202, AQ2104, AQR105, AQR405
 
+config ASIX_PHY
+       tristate "Asix PHYs"
+       help
+         Currently supports the Asix Electronics PHY found in the X-Surf 100
+         AX88796B package.
+
 config AT803X_PHY
        tristate "AT803X PHYs"
        ---help---

diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 01acbcb..701ca0b 100644 (file)
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -45,6 +45,7 @@ obj-y                         += $(sfp-obj-y) $(sfp-obj-m)
 
 obj-$(CONFIG_AMD_PHY)          += amd.o
 obj-$(CONFIG_AQUANTIA_PHY)     += aquantia.o
+obj-$(CONFIG_ASIX_PHY)         += asix.o
 obj-$(CONFIG_AT803X_PHY)       += at803x.o
 obj-$(CONFIG_BCM63XX_PHY)      += bcm63xx.o
 obj-$(CONFIG_BCM7XXX_PHY)      += bcm7xxx.o

diff --git a/drivers/net/phy/asix.c b/drivers/net/phy/asix.c
new file mode 100644 (file)
index 0000000..8ebe7f5
--- /dev/null
+++ b/drivers/net/phy/asix.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Driver for Asix PHYs
+ *
+ * Author: Michael Schmitz <schmitzmic@gmail.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+
+#define PHY_ID_ASIX_AX88796B           0x003b1841
+
+MODULE_DESCRIPTION("Asix PHY driver");
+MODULE_AUTHOR("Michael Schmitz <schmitzmic@gmail.com>");
+MODULE_LICENSE("GPL");
+
+/**
+ * asix_soft_reset - software reset the PHY via BMCR_RESET bit
+ * @phydev: target phy_device struct
+ *
+ * Description: Perform a software PHY reset using the standard
+ * BMCR_RESET bit and poll for the reset bit to be cleared.
+ * Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
+ * such as used on the Individual Computers' X-Surf 100 Zorro card.
+ *
+ * Returns: 0 on success, < 0 on failure
+ */
+static int asix_soft_reset(struct phy_device *phydev)
+{
+       int ret;
+
+       /* Asix PHY won't reset unless reset bit toggles */
+       ret = phy_write(phydev, MII_BMCR, 0);
+       if (ret < 0)
+               return ret;
+
+       return genphy_soft_reset(phydev);
+}
+
+static struct phy_driver asix_driver[] = { {
+       .phy_id         = PHY_ID_ASIX_AX88796B,
+       .name           = "Asix Electronics AX88796B",
+       .phy_id_mask    = 0xfffffff0,
+       .features       = PHY_BASIC_FEATURES,
+       .soft_reset     = asix_soft_reset,
+} };
+
+module_phy_driver(asix_driver);
+
+static struct mdio_device_id __maybe_unused asix_tbl[] = {
+       { PHY_ID_ASIX_AX88796B, 0xfffffff0 },
+       { }
+};
+
+MODULE_DEVICE_TABLE(mdio, asix_tbl);