drivers/net/ethernet/ibm/emac/zmii.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/net/ethernet/ibm/emac/zmii.c
   4  *
   5  * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
   6  *
   7  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
   8  *                <benh@kernel.crashing.org>
   9  *
  10  * Based on the arch/ppc version of the driver:
  11  *
  12  * Copyright (c) 2004, 2005 Zultys Technologies.
  13  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
  14  *
  15  * Based on original work by
  16  *      Armin Kuster <akuster@mvista.com>
  17  *      Copyright 2001 MontaVista Softare Inc.
  18  */
  19 #include <linux/slab.h>
  20 #include <linux/kernel.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/of_address.h>
  23 #include <asm/io.h>
  24
  25 #include "emac.h"
  26 #include "core.h"
  27
  28 /* ZMIIx_FER */
  29 #define ZMII_FER_MDI(idx)       (0x80000000 >> ((idx) * 4))
  30 #define ZMII_FER_MDI_ALL        (ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
  31                                  ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
  32
  33 #define ZMII_FER_SMII(idx)      (0x40000000 >> ((idx) * 4))
  34 #define ZMII_FER_RMII(idx)      (0x20000000 >> ((idx) * 4))
  35 #define ZMII_FER_MII(idx)       (0x10000000 >> ((idx) * 4))
  36
  37 /* ZMIIx_SSR */
  38 #define ZMII_SSR_SCI(idx)       (0x40000000 >> ((idx) * 4))
  39 #define ZMII_SSR_FSS(idx)       (0x20000000 >> ((idx) * 4))
  40 #define ZMII_SSR_SP(idx)        (0x10000000 >> ((idx) * 4))
  41
  42 /* ZMII only supports MII, RMII and SMII
  43  * we also support autodetection for backward compatibility
  44  */
  45 static inline int zmii_valid_mode(int mode)
  46 {
  47         return  mode == PHY_INTERFACE_MODE_MII ||
  48                 mode == PHY_INTERFACE_MODE_RMII ||
  49                 mode == PHY_INTERFACE_MODE_SMII ||
  50                 mode == PHY_INTERFACE_MODE_NA;
  51 }
  52
  53 static inline const char *zmii_mode_name(int mode)
  54 {
  55         switch (mode) {
  56         case PHY_INTERFACE_MODE_MII:
  57                 return "MII";
  58         case PHY_INTERFACE_MODE_RMII:
  59                 return "RMII";
  60         case PHY_INTERFACE_MODE_SMII:
  61                 return "SMII";
  62         default:
  63                 BUG();
  64         }
  65 }
  66
  67 static inline u32 zmii_mode_mask(int mode, int input)
  68 {
  69         switch (mode) {
  70         case PHY_INTERFACE_MODE_MII:
  71                 return ZMII_FER_MII(input);
  72         case PHY_INTERFACE_MODE_RMII:
  73                 return ZMII_FER_RMII(input);
  74         case PHY_INTERFACE_MODE_SMII:
  75                 return ZMII_FER_SMII(input);
  76         default:
  77                 return 0;
  78         }
  79 }
  80
  81 int zmii_attach(struct platform_device *ofdev, int input, int *mode)
  82 {
  83         struct zmii_instance *dev = platform_get_drvdata(ofdev);
  84         struct zmii_regs __iomem *p = dev->base;
  85
  86         ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
  87
  88         if (!zmii_valid_mode(*mode)) {
  89                 /* Probably an EMAC connected to RGMII,
  90                  * but it still may need ZMII for MDIO so
  91                  * we don't fail here.
  92                  */
  93                 dev->users++;
  94                 return 0;
  95         }
  96
  97         mutex_lock(&dev->lock);
  98
  99         /* Autodetect ZMII mode if not specified.
 100          * This is only for backward compatibility with the old driver.
 101          * Please, always specify PHY mode in your board port to avoid
 102          * any surprises.
 103          */
 104         if (dev->mode == PHY_INTERFACE_MODE_NA) {
 105                 if (*mode == PHY_INTERFACE_MODE_NA) {
 106                         u32 r = dev->fer_save;
 107
 108                         ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
 109
 110                         if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
 111                                 dev->mode = PHY_INTERFACE_MODE_MII;
 112                         else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
 113                                 dev->mode = PHY_INTERFACE_MODE_RMII;
 114                         else
 115                                 dev->mode = PHY_INTERFACE_MODE_SMII;
 116                 } else {
 117                         dev->mode = *mode;
 118                 }
 119                 printk(KERN_NOTICE "%pOF: bridge in %s mode\n",
 120                        ofdev->dev.of_node,
 121                        zmii_mode_name(dev->mode));
 122         } else {
 123                 /* All inputs must use the same mode */
 124                 if (*mode != PHY_INTERFACE_MODE_NA && *mode != dev->mode) {
 125                         printk(KERN_ERR
 126                                "%pOF: invalid mode %d specified for input %d\n",
 127                                ofdev->dev.of_node, *mode, input);
 128                         mutex_unlock(&dev->lock);
 129                         return -EINVAL;
 130                 }
 131         }
 132
 133         /* Report back correct PHY mode,
 134          * it may be used during PHY initialization.
 135          */
 136         *mode = dev->mode;
 137
 138         /* Enable this input */
 139         out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
 140         ++dev->users;
 141
 142         mutex_unlock(&dev->lock);
 143
 144         return 0;
 145 }
 146
 147 void zmii_get_mdio(struct platform_device *ofdev, int input)
 148 {
 149         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 150         u32 fer;
 151
 152         ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
 153
 154         mutex_lock(&dev->lock);
 155
 156         fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
 157         out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
 158 }
 159
 160 void zmii_put_mdio(struct platform_device *ofdev, int input)
 161 {
 162         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 163
 164         ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
 165         mutex_unlock(&dev->lock);
 166 }
 167
 168
 169 void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
 170 {
 171         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 172         u32 ssr;
 173
 174         mutex_lock(&dev->lock);
 175
 176         ssr = in_be32(&dev->base->ssr);
 177
 178         ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
 179
 180         if (speed == SPEED_100)
 181                 ssr |= ZMII_SSR_SP(input);
 182         else
 183                 ssr &= ~ZMII_SSR_SP(input);
 184
 185         out_be32(&dev->base->ssr, ssr);
 186
 187         mutex_unlock(&dev->lock);
 188 }
 189
 190 void zmii_detach(struct platform_device *ofdev, int input)
 191 {
 192         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 193
 194         BUG_ON(!dev || dev->users == 0);
 195
 196         mutex_lock(&dev->lock);
 197
 198         ZMII_DBG(dev, "detach(%d)" NL, input);
 199
 200         /* Disable this input */
 201         out_be32(&dev->base->fer,
 202                  in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
 203
 204         --dev->users;
 205
 206         mutex_unlock(&dev->lock);
 207 }
 208
 209 int zmii_get_regs_len(struct platform_device *ofdev)
 210 {
 211         return sizeof(struct emac_ethtool_regs_subhdr) +
 212                 sizeof(struct zmii_regs);
 213 }
 214
 215 void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
 216 {
 217         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 218         struct emac_ethtool_regs_subhdr *hdr = buf;
 219         struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
 220
 221         hdr->version = 0;
 222         hdr->index = 0; /* for now, are there chips with more than one
 223                          * zmii ? if yes, then we'll add a cell_index
 224                          * like we do for emac
 225                          */
 226         memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
 227         return regs + 1;
 228 }
 229
 230 static int zmii_probe(struct platform_device *ofdev)
 231 {
 232         struct device_node *np = ofdev->dev.of_node;
 233         struct zmii_instance *dev;
 234         struct resource regs;
 235         int rc;
 236
 237         rc = -ENOMEM;
 238         dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
 239         if (dev == NULL)
 240                 goto err_gone;
 241
 242         mutex_init(&dev->lock);
 243         dev->ofdev = ofdev;
 244         dev->mode = PHY_INTERFACE_MODE_NA;
 245
 246         rc = -ENXIO;
 247         if (of_address_to_resource(np, 0, &regs)) {
 248                 printk(KERN_ERR "%pOF: Can't get registers address\n", np);
 249                 goto err_free;
 250         }
 251
 252         rc = -ENOMEM;
 253         dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
 254                                                 sizeof(struct zmii_regs));
 255         if (dev->base == NULL) {
 256                 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
 257                 goto err_free;
 258         }
 259
 260         /* We may need FER value for autodetection later */
 261         dev->fer_save = in_be32(&dev->base->fer);
 262
 263         /* Disable all inputs by default */
 264         out_be32(&dev->base->fer, 0);
 265
 266         printk(KERN_INFO "ZMII %pOF initialized\n", ofdev->dev.of_node);
 267         wmb();
 268         platform_set_drvdata(ofdev, dev);
 269
 270         return 0;
 271
 272  err_free:
 273         kfree(dev);
 274  err_gone:
 275         return rc;
 276 }
 277
 278 static int zmii_remove(struct platform_device *ofdev)
 279 {
 280         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 281
 282         WARN_ON(dev->users != 0);
 283
 284         iounmap(dev->base);
 285         kfree(dev);
 286
 287         return 0;
 288 }
 289
 290 static const struct of_device_id zmii_match[] =
 291 {
 292         {
 293                 .compatible     = "ibm,zmii",
 294         },
 295         /* For backward compat with old DT */
 296         {
 297                 .type           = "emac-zmii",
 298         },
 299         {},
 300 };
 301
 302 static struct platform_driver zmii_driver = {
 303         .driver = {
 304                 .name = "emac-zmii",
 305                 .of_match_table = zmii_match,
 306         },
 307         .probe = zmii_probe,
 308         .remove = zmii_remove,
 309 };
 310
 311 int __init zmii_init(void)
 312 {
 313         return platform_driver_register(&zmii_driver);
 314 }
 315
 316 void zmii_exit(void)
 317 {
 318         platform_driver_unregister(&zmii_driver);
 319 }