drivers/net/phy/national.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * drivers/net/phy/national.c
   4  *
   5  * Driver for National Semiconductor PHYs
   6  *
   7  * Author: Stuart Menefy <stuart.menefy@st.com>
   8  * Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
   9  *
  10  * Copyright (c) 2008 STMicroelectronics Limited
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/mii.h>
  18 #include <linux/ethtool.h>
  19 #include <linux/phy.h>
  20 #include <linux/netdevice.h>
  21
  22 /* DP83865 phy identifier values */
  23 #define DP83865_PHY_ID  0x20005c7a
  24
  25 #define DP83865_INT_STATUS      0x14
  26 #define DP83865_INT_MASK        0x15
  27 #define DP83865_INT_CLEAR       0x17
  28
  29 #define DP83865_INT_REMOTE_FAULT 0x0008
  30 #define DP83865_INT_ANE_COMPLETED 0x0010
  31 #define DP83865_INT_LINK_CHANGE 0xe000
  32 #define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
  33                                 DP83865_INT_ANE_COMPLETED | \
  34                                 DP83865_INT_LINK_CHANGE)
  35
  36 /* Advanced proprietary configuration */
  37 #define NS_EXP_MEM_CTL  0x16
  38 #define NS_EXP_MEM_DATA 0x1d
  39 #define NS_EXP_MEM_ADD  0x1e
  40
  41 #define LED_CTRL_REG 0x13
  42 #define AN_FALLBACK_AN 0x0001
  43 #define AN_FALLBACK_CRC 0x0002
  44 #define AN_FALLBACK_IE 0x0004
  45 #define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)
  46
  47 enum hdx_loopback {
  48         hdx_loopback_on = 0,
  49         hdx_loopback_off = 1,
  50 };
  51
  52 static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
  53 {
  54         phy_write(phydev, NS_EXP_MEM_ADD, reg);
  55         return phy_read(phydev, NS_EXP_MEM_DATA);
  56 }
  57
  58 static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
  59 {
  60         phy_write(phydev, NS_EXP_MEM_ADD, reg);
  61         phy_write(phydev, NS_EXP_MEM_DATA, data);
  62 }
  63
  64 static int ns_ack_interrupt(struct phy_device *phydev)
  65 {
  66         int ret = phy_read(phydev, DP83865_INT_STATUS);
  67         if (ret < 0)
  68                 return ret;
  69
  70         /* Clear the interrupt status bit by writing a “1”
  71          * to the corresponding bit in INT_CLEAR (2:0 are reserved)
  72          */
  73         ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
  74
  75         return ret;
  76 }
  77
  78 static irqreturn_t ns_handle_interrupt(struct phy_device *phydev)
  79 {
  80         int irq_status;
  81
  82         irq_status = phy_read(phydev, DP83865_INT_STATUS);
  83         if (irq_status < 0) {
  84                 phy_error(phydev);
  85                 return IRQ_NONE;
  86         }
  87
  88         if (!(irq_status & DP83865_INT_MASK_DEFAULT))
  89                 return IRQ_NONE;
  90
  91         /* clear the interrupt */
  92         phy_write(phydev, DP83865_INT_CLEAR, irq_status & ~0x7);
  93
  94         phy_trigger_machine(phydev);
  95
  96         return IRQ_HANDLED;
  97 }
  98
  99 static int ns_config_intr(struct phy_device *phydev)
 100 {
 101         int err;
 102
 103         if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
 104                 err = ns_ack_interrupt(phydev);
 105                 if (err)
 106                         return err;
 107
 108                 err = phy_write(phydev, DP83865_INT_MASK,
 109                                 DP83865_INT_MASK_DEFAULT);
 110         } else {
 111                 err = phy_write(phydev, DP83865_INT_MASK, 0);
 112                 if (err)
 113                         return err;
 114
 115                 err = ns_ack_interrupt(phydev);
 116         }
 117
 118         return err;
 119 }
 120
 121 static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
 122 {
 123         int bmcr = phy_read(phydev, MII_BMCR);
 124
 125         phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
 126
 127         /* Enable 8 bit expended memory read/write (no auto increment) */
 128         phy_write(phydev, NS_EXP_MEM_CTL, 0);
 129         phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
 130         phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
 131         phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
 132         phy_write(phydev, LED_CTRL_REG, mode);
 133 }
 134
 135 static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
 136 {
 137         u16 lb_dis = BIT(1);
 138
 139         if (disable)
 140                 ns_exp_write(phydev, 0x1c0,
 141                              ns_exp_read(phydev, 0x1c0) | lb_dis);
 142         else
 143                 ns_exp_write(phydev, 0x1c0,
 144                              ns_exp_read(phydev, 0x1c0) & ~lb_dis);
 145
 146         pr_debug("10BASE-T HDX loopback %s\n",
 147                  (ns_exp_read(phydev, 0x1c0) & lb_dis) ? "off" : "on");
 148 }
 149
 150 static int ns_config_init(struct phy_device *phydev)
 151 {
 152         ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
 153         /* In the latest MAC or switches design, the 10 Mbps loopback
 154          * is desired to be turned off.
 155          */
 156         ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
 157         return ns_ack_interrupt(phydev);
 158 }
 159
 160 static struct phy_driver dp83865_driver[] = { {
 161         .phy_id = DP83865_PHY_ID,
 162         .phy_id_mask = 0xfffffff0,
 163         .name = "NatSemi DP83865",
 164         /* PHY_GBIT_FEATURES */
 165         .config_init = ns_config_init,
 166         .config_intr = ns_config_intr,
 167         .handle_interrupt = ns_handle_interrupt,
 168 } };
 169
 170 module_phy_driver(dp83865_driver);
 171
 172 MODULE_DESCRIPTION("NatSemi PHY driver");
 173 MODULE_AUTHOR("Stuart Menefy");
 174 MODULE_LICENSE("GPL");
 175
 176 static struct mdio_device_id __maybe_unused ns_tbl[] = {
 177         { DP83865_PHY_ID, 0xfffffff0 },
 178         { }
 179 };
 180
 181 MODULE_DEVICE_TABLE(mdio, ns_tbl);