drivers/net/phy/ax88796b.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Driver for Asix PHYs
   3  *
   4  * Author: Michael Schmitz <schmitzmic@gmail.com>
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  *
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/mii.h>
  17 #include <linux/phy.h>
  18
  19 #define PHY_ID_ASIX_AX88796B            0x003b1841
  20
  21 MODULE_DESCRIPTION("Asix PHY driver");
  22 MODULE_AUTHOR("Michael Schmitz <schmitzmic@gmail.com>");
  23 MODULE_LICENSE("GPL");
  24
  25 /**
  26  * asix_soft_reset - software reset the PHY via BMCR_RESET bit
  27  * @phydev: target phy_device struct
  28  *
  29  * Description: Perform a software PHY reset using the standard
  30  * BMCR_RESET bit and poll for the reset bit to be cleared.
  31  * Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
  32  * such as used on the Individual Computers' X-Surf 100 Zorro card.
  33  *
  34  * Returns: 0 on success, < 0 on failure
  35  */
  36 static int asix_soft_reset(struct phy_device *phydev)
  37 {
  38         int ret;
  39
  40         /* Asix PHY won't reset unless reset bit toggles */
  41         ret = phy_write(phydev, MII_BMCR, 0);
  42         if (ret < 0)
  43                 return ret;
  44
  45         return genphy_soft_reset(phydev);
  46 }
  47
  48 static struct phy_driver asix_driver[] = { {
  49         .phy_id         = PHY_ID_ASIX_AX88796B,
  50         .name           = "Asix Electronics AX88796B",
  51         .phy_id_mask    = 0xfffffff0,
  52         .features       = PHY_BASIC_FEATURES,
  53         .soft_reset     = asix_soft_reset,
  54 } };
  55
  56 module_phy_driver(asix_driver);
  57
  58 static struct mdio_device_id __maybe_unused asix_tbl[] = {
  59         { PHY_ID_ASIX_AX88796B, 0xfffffff0 },
  60         { }
  61 };
  62
  63 MODULE_DEVICE_TABLE(mdio, asix_tbl);