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 #include <linux/kernel.h>
   7 #include <linux/errno.h>
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/mii.h>
  11 #include <linux/phy.h>
  12
  13 #define PHY_ID_ASIX_AX88796B            0x003b1841
  14
  15 MODULE_DESCRIPTION("Asix PHY driver");
  16 MODULE_AUTHOR("Michael Schmitz <schmitzmic@gmail.com>");
  17 MODULE_LICENSE("GPL");
  18
  19 /**
  20  * asix_soft_reset - software reset the PHY via BMCR_RESET bit
  21  * @phydev: target phy_device struct
  22  *
  23  * Description: Perform a software PHY reset using the standard
  24  * BMCR_RESET bit and poll for the reset bit to be cleared.
  25  * Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
  26  * such as used on the Individual Computers' X-Surf 100 Zorro card.
  27  *
  28  * Returns: 0 on success, < 0 on failure
  29  */
  30 static int asix_soft_reset(struct phy_device *phydev)
  31 {
  32         int ret;
  33
  34         /* Asix PHY won't reset unless reset bit toggles */
  35         ret = phy_write(phydev, MII_BMCR, 0);
  36         if (ret < 0)
  37                 return ret;
  38
  39         return genphy_soft_reset(phydev);
  40 }
  41
  42 static struct phy_driver asix_driver[] = { {
  43         .phy_id         = PHY_ID_ASIX_AX88796B,
  44         .name           = "Asix Electronics AX88796B",
  45         .phy_id_mask    = 0xfffffff0,
  46         /* PHY_BASIC_FEATURES */
  47         .soft_reset     = asix_soft_reset,
  48 } };
  49
  50 module_phy_driver(asix_driver);
  51
  52 static struct mdio_device_id __maybe_unused asix_tbl[] = {
  53         { PHY_ID_ASIX_AX88796B, 0xfffffff0 },
  54         { }
  55 };
  56
  57 MODULE_DEVICE_TABLE(mdio, asix_tbl);