drivers/net/ethernet/samsung/sxgbe/sxgbe_mdio.c

   1 /* 10G controller driver for Samsung SoCs
   2  *
   3  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Author: Siva Reddy Kallam <siva.kallam@samsung.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 version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/io.h>
  16 #include <linux/mii.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/phy.h>
  20 #include <linux/slab.h>
  21 #include <linux/sxgbe_platform.h>
  22
  23 #include "sxgbe_common.h"
  24 #include "sxgbe_reg.h"
  25
  26 #define SXGBE_SMA_WRITE_CMD     0x01 /* write command */
  27 #define SXGBE_SMA_PREAD_CMD     0x02 /* post read  increament address */
  28 #define SXGBE_SMA_READ_CMD      0x03 /* read command */
  29 #define SXGBE_SMA_SKIP_ADDRFRM  0x00040000 /* skip the address frame */
  30 #define SXGBE_MII_BUSY          0x00400000 /* mii busy */
  31
  32 static int sxgbe_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_data)
  33 {
  34         unsigned long fin_time = jiffies + 3 * HZ; /* 3 seconds */
  35
  36         while (!time_after(jiffies, fin_time)) {
  37                 if (!(readl(ioaddr + mii_data) & SXGBE_MII_BUSY))
  38                         return 0;
  39                 cpu_relax();
  40         }
  41
  42         return -EBUSY;
  43 }
  44
  45 static void sxgbe_mdio_ctrl_data(struct sxgbe_priv_data *sp, u32 cmd,
  46                                  u16 phydata)
  47 {
  48         u32 reg = phydata;
  49
  50         reg |= (cmd << 16) | SXGBE_SMA_SKIP_ADDRFRM |
  51                ((sp->clk_csr & 0x7) << 19) | SXGBE_MII_BUSY;
  52         writel(reg, sp->ioaddr + sp->hw->mii.data);
  53 }
  54
  55 static void sxgbe_mdio_c45(struct sxgbe_priv_data *sp, u32 cmd, int phyaddr,
  56                            int phyreg, u16 phydata)
  57 {
  58         u32 reg;
  59
  60         /* set mdio address register */
  61         reg = ((phyreg >> 16) & 0x1f) << 21;
  62         reg |= (phyaddr << 16) | (phyreg & 0xffff);
  63         writel(reg, sp->ioaddr + sp->hw->mii.addr);
  64
  65         sxgbe_mdio_ctrl_data(sp, cmd, phydata);
  66 }
  67
  68 static void sxgbe_mdio_c22(struct sxgbe_priv_data *sp, u32 cmd, int phyaddr,
  69                            int phyreg, u16 phydata)
  70 {
  71         u32 reg;
  72
  73         writel(1 << phyaddr, sp->ioaddr + SXGBE_MDIO_CLAUSE22_PORT_REG);
  74
  75         /* set mdio address register */
  76         reg = (phyaddr << 16) | (phyreg & 0x1f);
  77         writel(reg, sp->ioaddr + sp->hw->mii.addr);
  78
  79         sxgbe_mdio_ctrl_data(sp, cmd, phydata);
  80 }
  81
  82 static int sxgbe_mdio_access(struct sxgbe_priv_data *sp, u32 cmd, int phyaddr,
  83                              int phyreg, u16 phydata)
  84 {
  85         const struct mii_regs *mii = &sp->hw->mii;
  86         int rc;
  87
  88         rc = sxgbe_mdio_busy_wait(sp->ioaddr, mii->data);
  89         if (rc < 0)
  90                 return rc;
  91
  92         if (phyreg & MII_ADDR_C45) {
  93                 sxgbe_mdio_c45(sp, cmd, phyaddr, phyreg, phydata);
  94         } else {
  95                  /* Ports 0-3 only support C22. */
  96                 if (phyaddr >= 4)
  97                         return -ENODEV;
  98
  99                 sxgbe_mdio_c22(sp, cmd, phyaddr, phyreg, phydata);
 100         }
 101
 102         return sxgbe_mdio_busy_wait(sp->ioaddr, mii->data);
 103 }
 104
 105 /**
 106  * sxgbe_mdio_read
 107  * @bus: points to the mii_bus structure
 108  * @phyaddr: address of phy port
 109  * @phyreg: address of register with in phy register
 110  * Description: this function used for C45 and C22 MDIO Read
 111  */
 112 static int sxgbe_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 113 {
 114         struct net_device *ndev = bus->priv;
 115         struct sxgbe_priv_data *priv = netdev_priv(ndev);
 116         int rc;
 117
 118         rc = sxgbe_mdio_access(priv, SXGBE_SMA_READ_CMD, phyaddr, phyreg, 0);
 119         if (rc < 0)
 120                 return rc;
 121
 122         return readl(priv->ioaddr + priv->hw->mii.data) & 0xffff;
 123 }
 124
 125 /**
 126  * sxgbe_mdio_write
 127  * @bus: points to the mii_bus structure
 128  * @phyaddr: address of phy port
 129  * @phyreg: address of phy registers
 130  * @phydata: data to be written into phy register
 131  * Description: this function is used for C45 and C22 MDIO write
 132  */
 133 static int sxgbe_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 134                              u16 phydata)
 135 {
 136         struct net_device *ndev = bus->priv;
 137         struct sxgbe_priv_data *priv = netdev_priv(ndev);
 138
 139         return sxgbe_mdio_access(priv, SXGBE_SMA_WRITE_CMD, phyaddr, phyreg,
 140                                  phydata);
 141 }
 142
 143 int sxgbe_mdio_register(struct net_device *ndev)
 144 {
 145         struct mii_bus *mdio_bus;
 146         struct sxgbe_priv_data *priv = netdev_priv(ndev);
 147         struct sxgbe_mdio_bus_data *mdio_data = priv->plat->mdio_bus_data;
 148         int err, phy_addr;
 149         int *irqlist;
 150         bool phy_found = false;
 151         bool act;
 152
 153         /* allocate the new mdio bus */
 154         mdio_bus = mdiobus_alloc();
 155         if (!mdio_bus) {
 156                 netdev_err(ndev, "%s: mii bus allocation failed\n", __func__);
 157                 return -ENOMEM;
 158         }
 159
 160         if (mdio_data->irqs)
 161                 irqlist = mdio_data->irqs;
 162         else
 163                 irqlist = priv->mii_irq;
 164
 165         /* assign mii bus fields */
 166         mdio_bus->name = "sxgbe";
 167         mdio_bus->read = &sxgbe_mdio_read;
 168         mdio_bus->write = &sxgbe_mdio_write;
 169         snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 170                  mdio_bus->name, priv->plat->bus_id);
 171         mdio_bus->priv = ndev;
 172         mdio_bus->phy_mask = mdio_data->phy_mask;
 173         mdio_bus->parent = priv->device;
 174
 175         /* register with kernel subsystem */
 176         err = mdiobus_register(mdio_bus);
 177         if (err != 0) {
 178                 netdev_err(ndev, "mdiobus register failed\n");
 179                 goto mdiobus_err;
 180         }
 181
 182         for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
 183                 struct phy_device *phy = mdiobus_get_phy(mdio_bus, phy_addr);
 184
 185                 if (phy) {
 186                         char irq_num[4];
 187                         char *irq_str;
 188                         /* If an IRQ was provided to be assigned after
 189                          * the bus probe, do it here.
 190                          */
 191                         if ((mdio_data->irqs == NULL) &&
 192                             (mdio_data->probed_phy_irq > 0)) {
 193                                 irqlist[phy_addr] = mdio_data->probed_phy_irq;
 194                                 phy->irq = mdio_data->probed_phy_irq;
 195                         }
 196
 197                         /* If we're  going to bind the MAC to this PHY bus,
 198                          * and no PHY number was provided to the MAC,
 199                          * use the one probed here.
 200                          */
 201                         if (priv->plat->phy_addr == -1)
 202                                 priv->plat->phy_addr = phy_addr;
 203
 204                         act = (priv->plat->phy_addr == phy_addr);
 205                         switch (phy->irq) {
 206                         case PHY_POLL:
 207                                 irq_str = "POLL";
 208                                 break;
 209                         case PHY_IGNORE_INTERRUPT:
 210                                 irq_str = "IGNORE";
 211                                 break;
 212                         default:
 213                                 sprintf(irq_num, "%d", phy->irq);
 214                                 irq_str = irq_num;
 215                                 break;
 216                         }
 217                         netdev_info(ndev, "PHY ID %08x at %d IRQ %s (%s)%s\n",
 218                                     phy->phy_id, phy_addr, irq_str,
 219                                     phydev_name(phy), act ? " active" : "");
 220                         phy_found = true;
 221                 }
 222         }
 223
 224         if (!phy_found) {
 225                 netdev_err(ndev, "PHY not found\n");
 226                 goto phyfound_err;
 227         }
 228
 229         priv->mii = mdio_bus;
 230
 231         return 0;
 232
 233 phyfound_err:
 234         err = -ENODEV;
 235         mdiobus_unregister(mdio_bus);
 236 mdiobus_err:
 237         mdiobus_free(mdio_bus);
 238         return err;
 239 }
 240
 241 int sxgbe_mdio_unregister(struct net_device *ndev)
 242 {
 243         struct sxgbe_priv_data *priv = netdev_priv(ndev);
 244
 245         if (!priv->mii)
 246                 return 0;
 247
 248         mdiobus_unregister(priv->mii);
 249         priv->mii->priv = NULL;
 250         mdiobus_free(priv->mii);
 251         priv->mii = NULL;
 252
 253         return 0;
 254 }