drivers/net/phy/amd.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Driver for AMD am79c PHYs
   4  *
   5  * Author: Heiko Schocher <hs@denx.de>
   6  *
   7  * Copyright (c) 2011 DENX Software Engineering GmbH
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/mii.h>
  14 #include <linux/phy.h>
  15
  16 #define PHY_ID_AM79C874         0x0022561b
  17
  18 #define MII_AM79C_IR            17      /* Interrupt Status/Control Register */
  19 #define MII_AM79C_IR_EN_LINK    0x0400  /* IR enable Linkstate */
  20 #define MII_AM79C_IR_EN_ANEG    0x0100  /* IR enable Aneg Complete */
  21 #define MII_AM79C_IR_IMASK_INIT (MII_AM79C_IR_EN_LINK | MII_AM79C_IR_EN_ANEG)
  22
  23 #define MII_AM79C_IR_LINK_DOWN  BIT(2)
  24 #define MII_AM79C_IR_ANEG_DONE  BIT(0)
  25 #define MII_AM79C_IR_IMASK_STAT (MII_AM79C_IR_LINK_DOWN | MII_AM79C_IR_ANEG_DONE)
  26
  27 MODULE_DESCRIPTION("AMD PHY driver");
  28 MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
  29 MODULE_LICENSE("GPL");
  30
  31 static int am79c_ack_interrupt(struct phy_device *phydev)
  32 {
  33         int err;
  34
  35         err = phy_read(phydev, MII_BMSR);
  36         if (err < 0)
  37                 return err;
  38
  39         err = phy_read(phydev, MII_AM79C_IR);
  40         if (err < 0)
  41                 return err;
  42
  43         return 0;
  44 }
  45
  46 static int am79c_config_init(struct phy_device *phydev)
  47 {
  48         return 0;
  49 }
  50
  51 static int am79c_config_intr(struct phy_device *phydev)
  52 {
  53         int err;
  54
  55         if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
  56                 err = am79c_ack_interrupt(phydev);
  57                 if (err)
  58                         return err;
  59
  60                 err = phy_write(phydev, MII_AM79C_IR, MII_AM79C_IR_IMASK_INIT);
  61         } else {
  62                 err = phy_write(phydev, MII_AM79C_IR, 0);
  63                 if (err)
  64                         return err;
  65
  66                 err = am79c_ack_interrupt(phydev);
  67         }
  68
  69         return err;
  70 }
  71
  72 static irqreturn_t am79c_handle_interrupt(struct phy_device *phydev)
  73 {
  74         int irq_status;
  75
  76         irq_status = phy_read(phydev, MII_AM79C_IR);
  77         if (irq_status < 0) {
  78                 phy_error(phydev);
  79                 return IRQ_NONE;
  80         }
  81
  82         if (!(irq_status & MII_AM79C_IR_IMASK_STAT))
  83                 return IRQ_NONE;
  84
  85         phy_trigger_machine(phydev);
  86
  87         return IRQ_HANDLED;
  88 }
  89
  90 static struct phy_driver am79c_driver[] = { {
  91         .phy_id         = PHY_ID_AM79C874,
  92         .name           = "AM79C874",
  93         .phy_id_mask    = 0xfffffff0,
  94         /* PHY_BASIC_FEATURES */
  95         .config_init    = am79c_config_init,
  96         .config_intr    = am79c_config_intr,
  97         .handle_interrupt = am79c_handle_interrupt,
  98 } };
  99
 100 module_phy_driver(am79c_driver);
 101
 102 static struct mdio_device_id __maybe_unused amd_tbl[] = {
 103         { PHY_ID_AM79C874, 0xfffffff0 },
 104         { }
 105 };
 106
 107 MODULE_DEVICE_TABLE(mdio, amd_tbl);