drivers/net/ethernet/freescale/xgmac_mdio.c

   1 /*
   2  * QorIQ 10G MDIO Controller
   3  *
   4  * Copyright 2012 Freescale Semiconductor, Inc.
   5  *
   6  * Authors: Andy Fleming <afleming@freescale.com>
   7  *          Timur Tabi <timur@freescale.com>
   8  *
   9  * This file is licensed under the terms of the GNU General Public License
  10  * version 2.  This program is licensed "as is" without any warranty of any
  11  * kind, whether express or implied.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/module.h>
  18 #include <linux/phy.h>
  19 #include <linux/mdio.h>
  20 #include <linux/of_address.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/of_mdio.h>
  23
  24 /* Number of microseconds to wait for a register to respond */
  25 #define TIMEOUT 1000
  26
  27 struct tgec_mdio_controller {
  28         __be32  reserved[12];
  29         __be32  mdio_stat;      /* MDIO configuration and status */
  30         __be32  mdio_ctl;       /* MDIO control */
  31         __be32  mdio_data;      /* MDIO data */
  32         __be32  mdio_addr;      /* MDIO address */
  33 } __packed;
  34
  35 #define MDIO_STAT_ENC           BIT(6)
  36 #define MDIO_STAT_CLKDIV(x)     (((x>>1) & 0xff) << 8)
  37 #define MDIO_STAT_BSY           BIT(0)
  38 #define MDIO_STAT_RD_ER         BIT(1)
  39 #define MDIO_CTL_DEV_ADDR(x)    (x & 0x1f)
  40 #define MDIO_CTL_PORT_ADDR(x)   ((x & 0x1f) << 5)
  41 #define MDIO_CTL_PRE_DIS        BIT(10)
  42 #define MDIO_CTL_SCAN_EN        BIT(11)
  43 #define MDIO_CTL_POST_INC       BIT(14)
  44 #define MDIO_CTL_READ           BIT(15)
  45
  46 #define MDIO_DATA(x)            (x & 0xffff)
  47 #define MDIO_DATA_BSY           BIT(31)
  48
  49 struct mdio_fsl_priv {
  50         struct  tgec_mdio_controller __iomem *mdio_base;
  51         bool    is_little_endian;
  52 };
  53
  54 static u32 xgmac_read32(void __iomem *regs,
  55                         bool is_little_endian)
  56 {
  57         if (is_little_endian)
  58                 return ioread32(regs);
  59         else
  60                 return ioread32be(regs);
  61 }
  62
  63 static void xgmac_write32(u32 value,
  64                           void __iomem *regs,
  65                           bool is_little_endian)
  66 {
  67         if (is_little_endian)
  68                 iowrite32(value, regs);
  69         else
  70                 iowrite32be(value, regs);
  71 }
  72
  73 /*
  74  * Wait until the MDIO bus is free
  75  */
  76 static int xgmac_wait_until_free(struct device *dev,
  77                                  struct tgec_mdio_controller __iomem *regs,
  78                                  bool is_little_endian)
  79 {
  80         unsigned int timeout;
  81
  82         /* Wait till the bus is free */
  83         timeout = TIMEOUT;
  84         while ((xgmac_read32(&regs->mdio_stat, is_little_endian) &
  85                 MDIO_STAT_BSY) && timeout) {
  86                 cpu_relax();
  87                 timeout--;
  88         }
  89
  90         if (!timeout) {
  91                 dev_err(dev, "timeout waiting for bus to be free\n");
  92                 return -ETIMEDOUT;
  93         }
  94
  95         return 0;
  96 }
  97
  98 /*
  99  * Wait till the MDIO read or write operation is complete
 100  */
 101 static int xgmac_wait_until_done(struct device *dev,
 102                                  struct tgec_mdio_controller __iomem *regs,
 103                                  bool is_little_endian)
 104 {
 105         unsigned int timeout;
 106
 107         /* Wait till the MDIO write is complete */
 108         timeout = TIMEOUT;
 109         while ((xgmac_read32(&regs->mdio_stat, is_little_endian) &
 110                 MDIO_STAT_BSY) && timeout) {
 111                 cpu_relax();
 112                 timeout--;
 113         }
 114
 115         if (!timeout) {
 116                 dev_err(dev, "timeout waiting for operation to complete\n");
 117                 return -ETIMEDOUT;
 118         }
 119
 120         return 0;
 121 }
 122
 123 /*
 124  * Write value to the PHY for this device to the register at regnum,waiting
 125  * until the write is done before it returns.  All PHY configuration has to be
 126  * done through the TSEC1 MIIM regs.
 127  */
 128 static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
 129 {
 130         struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
 131         struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
 132         uint16_t dev_addr;
 133         u32 mdio_ctl, mdio_stat;
 134         int ret;
 135         bool endian = priv->is_little_endian;
 136
 137         mdio_stat = xgmac_read32(&regs->mdio_stat, endian);
 138         if (regnum & MII_ADDR_C45) {
 139                 /* Clause 45 (ie 10G) */
 140                 dev_addr = (regnum >> 16) & 0x1f;
 141                 mdio_stat |= MDIO_STAT_ENC;
 142         } else {
 143                 /* Clause 22 (ie 1G) */
 144                 dev_addr = regnum & 0x1f;
 145                 mdio_stat &= ~MDIO_STAT_ENC;
 146         }
 147
 148         xgmac_write32(mdio_stat, &regs->mdio_stat, endian);
 149
 150         ret = xgmac_wait_until_free(&bus->dev, regs, endian);
 151         if (ret)
 152                 return ret;
 153
 154         /* Set the port and dev addr */
 155         mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
 156         xgmac_write32(mdio_ctl, &regs->mdio_ctl, endian);
 157
 158         /* Set the register address */
 159         if (regnum & MII_ADDR_C45) {
 160                 xgmac_write32(regnum & 0xffff, &regs->mdio_addr, endian);
 161
 162                 ret = xgmac_wait_until_free(&bus->dev, regs, endian);
 163                 if (ret)
 164                         return ret;
 165         }
 166
 167         /* Write the value to the register */
 168         xgmac_write32(MDIO_DATA(value), &regs->mdio_data, endian);
 169
 170         ret = xgmac_wait_until_done(&bus->dev, regs, endian);
 171         if (ret)
 172                 return ret;
 173
 174         return 0;
 175 }
 176
 177 /*
 178  * Reads from register regnum in the PHY for device dev, returning the value.
 179  * Clears miimcom first.  All PHY configuration has to be done through the
 180  * TSEC1 MIIM regs.
 181  */
 182 static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 183 {
 184         struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
 185         struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
 186         uint16_t dev_addr;
 187         uint32_t mdio_stat;
 188         uint32_t mdio_ctl;
 189         uint16_t value;
 190         int ret;
 191         bool endian = priv->is_little_endian;
 192
 193         mdio_stat = xgmac_read32(&regs->mdio_stat, endian);
 194         if (regnum & MII_ADDR_C45) {
 195                 dev_addr = (regnum >> 16) & 0x1f;
 196                 mdio_stat |= MDIO_STAT_ENC;
 197         } else {
 198                 dev_addr = regnum & 0x1f;
 199                 mdio_stat &= ~MDIO_STAT_ENC;
 200         }
 201
 202         xgmac_write32(mdio_stat, &regs->mdio_stat, endian);
 203
 204         ret = xgmac_wait_until_free(&bus->dev, regs, endian);
 205         if (ret)
 206                 return ret;
 207
 208         /* Set the Port and Device Addrs */
 209         mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
 210         xgmac_write32(mdio_ctl, &regs->mdio_ctl, endian);
 211
 212         /* Set the register address */
 213         if (regnum & MII_ADDR_C45) {
 214                 xgmac_write32(regnum & 0xffff, &regs->mdio_addr, endian);
 215
 216                 ret = xgmac_wait_until_free(&bus->dev, regs, endian);
 217                 if (ret)
 218                         return ret;
 219         }
 220
 221         /* Initiate the read */
 222         xgmac_write32(mdio_ctl | MDIO_CTL_READ, &regs->mdio_ctl, endian);
 223
 224         ret = xgmac_wait_until_done(&bus->dev, regs, endian);
 225         if (ret)
 226                 return ret;
 227
 228         /* Return all Fs if nothing was there */
 229         if (xgmac_read32(&regs->mdio_stat, endian) & MDIO_STAT_RD_ER) {
 230                 dev_err(&bus->dev,
 231                         "Error while reading PHY%d reg at %d.%hhu\n",
 232                         phy_id, dev_addr, regnum);
 233                 return 0xffff;
 234         }
 235
 236         value = xgmac_read32(&regs->mdio_data, endian) & 0xffff;
 237         dev_dbg(&bus->dev, "read %04x\n", value);
 238
 239         return value;
 240 }
 241
 242 static int xgmac_mdio_probe(struct platform_device *pdev)
 243 {
 244         struct device_node *np = pdev->dev.of_node;
 245         struct mii_bus *bus;
 246         struct resource res;
 247         struct mdio_fsl_priv *priv;
 248         int ret;
 249
 250         ret = of_address_to_resource(np, 0, &res);
 251         if (ret) {
 252                 dev_err(&pdev->dev, "could not obtain address\n");
 253                 return ret;
 254         }
 255
 256         bus = mdiobus_alloc_size(sizeof(struct mdio_fsl_priv));
 257         if (!bus)
 258                 return -ENOMEM;
 259
 260         bus->name = "Freescale XGMAC MDIO Bus";
 261         bus->read = xgmac_mdio_read;
 262         bus->write = xgmac_mdio_write;
 263         bus->parent = &pdev->dev;
 264         snprintf(bus->id, MII_BUS_ID_SIZE, "%llx", (unsigned long long)res.start);
 265
 266         /* Set the PHY base address */
 267         priv = bus->priv;
 268         priv->mdio_base = of_iomap(np, 0);
 269         if (!priv->mdio_base) {
 270                 ret = -ENOMEM;
 271                 goto err_ioremap;
 272         }
 273
 274         priv->is_little_endian = of_property_read_bool(pdev->dev.of_node,
 275                                                        "little-endian");
 276
 277         ret = of_mdiobus_register(bus, np);
 278         if (ret) {
 279                 dev_err(&pdev->dev, "cannot register MDIO bus\n");
 280                 goto err_registration;
 281         }
 282
 283         platform_set_drvdata(pdev, bus);
 284
 285         return 0;
 286
 287 err_registration:
 288         iounmap(priv->mdio_base);
 289
 290 err_ioremap:
 291         mdiobus_free(bus);
 292
 293         return ret;
 294 }
 295
 296 static int xgmac_mdio_remove(struct platform_device *pdev)
 297 {
 298         struct mii_bus *bus = platform_get_drvdata(pdev);
 299
 300         mdiobus_unregister(bus);
 301         iounmap(bus->priv);
 302         mdiobus_free(bus);
 303
 304         return 0;
 305 }
 306
 307 static const struct of_device_id xgmac_mdio_match[] = {
 308         {
 309                 .compatible = "fsl,fman-xmdio",
 310         },
 311         {
 312                 .compatible = "fsl,fman-memac-mdio",
 313         },
 314         {},
 315 };
 316 MODULE_DEVICE_TABLE(of, xgmac_mdio_match);
 317
 318 static struct platform_driver xgmac_mdio_driver = {
 319         .driver = {
 320                 .name = "fsl-fman_xmdio",
 321                 .of_match_table = xgmac_mdio_match,
 322         },
 323         .probe = xgmac_mdio_probe,
 324         .remove = xgmac_mdio_remove,
 325 };
 326
 327 module_platform_driver(xgmac_mdio_driver);
 328
 329 MODULE_DESCRIPTION("Freescale QorIQ 10G MDIO Controller");
 330 MODULE_LICENSE("GPL v2");