drivers/net/phy/meson-gxl.c

   1 /*
   2  * Amlogic Meson GXL Internal PHY Driver
   3  *
   4  * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
   5  * Copyright (C) 2016 BayLibre, SAS. All rights reserved.
   6  * Author: Neil Armstrong <narmstrong@baylibre.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  */
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/mii.h>
  22 #include <linux/ethtool.h>
  23 #include <linux/phy.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/bitfield.h>
  26
  27 #define TSTCNTL         20
  28 #define  TSTCNTL_READ           BIT(15)
  29 #define  TSTCNTL_WRITE          BIT(14)
  30 #define  TSTCNTL_REG_BANK_SEL   GENMASK(12, 11)
  31 #define  TSTCNTL_TEST_MODE      BIT(10)
  32 #define  TSTCNTL_READ_ADDRESS   GENMASK(9, 5)
  33 #define  TSTCNTL_WRITE_ADDRESS  GENMASK(4, 0)
  34 #define TSTREAD1        21
  35 #define TSTWRITE        23
  36 #define INTSRC_FLAG     29
  37 #define  INTSRC_ANEG_PR         BIT(1)
  38 #define  INTSRC_PARALLEL_FAULT  BIT(2)
  39 #define  INTSRC_ANEG_LP_ACK     BIT(3)
  40 #define  INTSRC_LINK_DOWN       BIT(4)
  41 #define  INTSRC_REMOTE_FAULT    BIT(5)
  42 #define  INTSRC_ANEG_COMPLETE   BIT(6)
  43 #define INTSRC_MASK     30
  44
  45 #define BANK_ANALOG_DSP         0
  46 #define BANK_WOL                1
  47 #define BANK_BIST               3
  48
  49 /* WOL Registers */
  50 #define LPI_STATUS      0xc
  51 #define  LPI_STATUS_RSV12       BIT(12)
  52
  53 /* BIST Registers */
  54 #define FR_PLL_CONTROL  0x1b
  55 #define FR_PLL_DIV0     0x1c
  56 #define FR_PLL_DIV1     0x1d
  57
  58 static int meson_gxl_open_banks(struct phy_device *phydev)
  59 {
  60         int ret;
  61
  62         /* Enable Analog and DSP register Bank access by
  63          * toggling TSTCNTL_TEST_MODE bit in the TSTCNTL register
  64          */
  65         ret = phy_write(phydev, TSTCNTL, 0);
  66         if (ret)
  67                 return ret;
  68         ret = phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
  69         if (ret)
  70                 return ret;
  71         ret = phy_write(phydev, TSTCNTL, 0);
  72         if (ret)
  73                 return ret;
  74         return phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
  75 }
  76
  77 static void meson_gxl_close_banks(struct phy_device *phydev)
  78 {
  79         phy_write(phydev, TSTCNTL, 0);
  80 }
  81
  82 static int meson_gxl_read_reg(struct phy_device *phydev,
  83                               unsigned int bank, unsigned int reg)
  84 {
  85         int ret;
  86
  87         ret = meson_gxl_open_banks(phydev);
  88         if (ret)
  89                 goto out;
  90
  91         ret = phy_write(phydev, TSTCNTL, TSTCNTL_READ |
  92                         FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
  93                         TSTCNTL_TEST_MODE |
  94                         FIELD_PREP(TSTCNTL_READ_ADDRESS, reg));
  95         if (ret)
  96                 goto out;
  97
  98         ret = phy_read(phydev, TSTREAD1);
  99 out:
 100         /* Close the bank access on our way out */
 101         meson_gxl_close_banks(phydev);
 102         return ret;
 103 }
 104
 105 static int meson_gxl_write_reg(struct phy_device *phydev,
 106                                unsigned int bank, unsigned int reg,
 107                                uint16_t value)
 108 {
 109         int ret;
 110
 111         ret = meson_gxl_open_banks(phydev);
 112         if (ret)
 113                 goto out;
 114
 115         ret = phy_write(phydev, TSTWRITE, value);
 116         if (ret)
 117                 goto out;
 118
 119         ret = phy_write(phydev, TSTCNTL, TSTCNTL_WRITE |
 120                         FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
 121                         TSTCNTL_TEST_MODE |
 122                         FIELD_PREP(TSTCNTL_WRITE_ADDRESS, reg));
 123
 124 out:
 125         /* Close the bank access on our way out */
 126         meson_gxl_close_banks(phydev);
 127         return ret;
 128 }
 129
 130 static int meson_gxl_config_init(struct phy_device *phydev)
 131 {
 132         int ret;
 133
 134         /* Enable fractional PLL */
 135         ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_CONTROL, 0x5);
 136         if (ret)
 137                 return ret;
 138
 139         /* Program fraction FR_PLL_DIV1 */
 140         ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV1, 0x029a);
 141         if (ret)
 142                 return ret;
 143
 144         /* Program fraction FR_PLL_DIV1 */
 145         ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV0, 0xaaaa);
 146         if (ret)
 147                 return ret;
 148
 149         return genphy_config_init(phydev);
 150 }
 151
 152 /* This function is provided to cope with the possible failures of this phy
 153  * during aneg process. When aneg fails, the PHY reports that aneg is done
 154  * but the value found in MII_LPA is wrong:
 155  *  - Early failures: MII_LPA is just 0x0001. if MII_EXPANSION reports that
 156  *    the link partner (LP) supports aneg but the LP never acked our base
 157  *    code word, it is likely that we never sent it to begin with.
 158  *  - Late failures: MII_LPA is filled with a value which seems to make sense
 159  *    but it actually is not what the LP is advertising. It seems that we
 160  *    can detect this using a magic bit in the WOL bank (reg 12 - bit 12).
 161  *    If this particular bit is not set when aneg is reported being done,
 162  *    it means MII_LPA is likely to be wrong.
 163  *
 164  * In both case, forcing a restart of the aneg process solve the problem.
 165  * When this failure happens, the first retry is usually successful but,
 166  * in some cases, it may take up to 6 retries to get a decent result
 167  */
 168 static int meson_gxl_read_status(struct phy_device *phydev)
 169 {
 170         int ret, wol, lpa, exp;
 171
 172         if (phydev->autoneg == AUTONEG_ENABLE) {
 173                 ret = genphy_aneg_done(phydev);
 174                 if (ret < 0)
 175                         return ret;
 176                 else if (!ret)
 177                         goto read_status_continue;
 178
 179                 /* Aneg is done, let's check everything is fine */
 180                 wol = meson_gxl_read_reg(phydev, BANK_WOL, LPI_STATUS);
 181                 if (wol < 0)
 182                         return wol;
 183
 184                 lpa = phy_read(phydev, MII_LPA);
 185                 if (lpa < 0)
 186                         return lpa;
 187
 188                 exp = phy_read(phydev, MII_EXPANSION);
 189                 if (exp < 0)
 190                         return exp;
 191
 192                 if (!(wol & LPI_STATUS_RSV12) ||
 193                     ((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
 194                         /* Looks like aneg failed after all */
 195                         phydev_dbg(phydev, "LPA corruption - aneg restart\n");
 196                         return genphy_restart_aneg(phydev);
 197                 }
 198         }
 199
 200 read_status_continue:
 201         return genphy_read_status(phydev);
 202 }
 203
 204 static int meson_gxl_ack_interrupt(struct phy_device *phydev)
 205 {
 206         int ret = phy_read(phydev, INTSRC_FLAG);
 207
 208         return ret < 0 ? ret : 0;
 209 }
 210
 211 static int meson_gxl_config_intr(struct phy_device *phydev)
 212 {
 213         u16 val;
 214
 215         if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
 216                 val = INTSRC_ANEG_PR
 217                         | INTSRC_PARALLEL_FAULT
 218                         | INTSRC_ANEG_LP_ACK
 219                         | INTSRC_LINK_DOWN
 220                         | INTSRC_REMOTE_FAULT
 221                         | INTSRC_ANEG_COMPLETE;
 222         } else {
 223                 val = 0;
 224         }
 225
 226         return phy_write(phydev, INTSRC_MASK, val);
 227 }
 228
 229 static struct phy_driver meson_gxl_phy[] = {
 230         {
 231                 .phy_id         = 0x01814400,
 232                 .phy_id_mask    = 0xfffffff0,
 233                 .name           = "Meson GXL Internal PHY",
 234                 .features       = PHY_BASIC_FEATURES,
 235                 .flags          = PHY_IS_INTERNAL | PHY_HAS_INTERRUPT,
 236                 .config_init    = meson_gxl_config_init,
 237                 .aneg_done      = genphy_aneg_done,
 238                 .read_status    = meson_gxl_read_status,
 239                 .ack_interrupt  = meson_gxl_ack_interrupt,
 240                 .config_intr    = meson_gxl_config_intr,
 241                 .suspend        = genphy_suspend,
 242                 .resume         = genphy_resume,
 243         },
 244 };
 245
 246 static struct mdio_device_id __maybe_unused meson_gxl_tbl[] = {
 247         { 0x01814400, 0xfffffff0 },
 248         { }
 249 };
 250
 251 module_phy_driver(meson_gxl_phy);
 252
 253 MODULE_DEVICE_TABLE(mdio, meson_gxl_tbl);
 254
 255 MODULE_DESCRIPTION("Amlogic Meson GXL Internal PHY driver");
 256 MODULE_AUTHOR("Baoqi wang");
 257 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 258 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
 259 MODULE_LICENSE("GPL");