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,
  82                 phy_interface_t *mode)
  83 {
  84         struct zmii_instance *dev = platform_get_drvdata(ofdev);
  85         struct zmii_regs __iomem *p = dev->base;
  86
  87         ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
  88
  89         if (!zmii_valid_mode(*mode)) {
  90                 /* Probably an EMAC connected to RGMII,
  91                  * but it still may need ZMII for MDIO so
  92                  * we don't fail here.
  93                  */
  94                 dev->users++;
  95                 return 0;
  96         }
  97
  98         mutex_lock(&dev->lock);
  99
 100         /* Autodetect ZMII mode if not specified.
 101          * This is only for backward compatibility with the old driver.
 102          * Please, always specify PHY mode in your board port to avoid
 103          * any surprises.
 104          */
 105         if (dev->mode == PHY_INTERFACE_MODE_NA) {
 106                 if (*mode == PHY_INTERFACE_MODE_NA) {
 107                         u32 r = dev->fer_save;
 108
 109                         ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
 110
 111                         if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
 112                                 dev->mode = PHY_INTERFACE_MODE_MII;
 113                         else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
 114                                 dev->mode = PHY_INTERFACE_MODE_RMII;
 115                         else
 116                                 dev->mode = PHY_INTERFACE_MODE_SMII;
 117                 } else {
 118                         dev->mode = *mode;
 119                 }
 120                 printk(KERN_NOTICE "%pOF: bridge in %s mode\n",
 121                        ofdev->dev.of_node,
 122                        zmii_mode_name(dev->mode));
 123         } else {
 124                 /* All inputs must use the same mode */
 125                 if (*mode != PHY_INTERFACE_MODE_NA && *mode != dev->mode) {
 126                         printk(KERN_ERR
 127                                "%pOF: invalid mode %d specified for input %d\n",
 128                                ofdev->dev.of_node, *mode, input);
 129                         mutex_unlock(&dev->lock);
 130                         return -EINVAL;
 131                 }
 132         }
 133
 134         /* Report back correct PHY mode,
 135          * it may be used during PHY initialization.
 136          */
 137         *mode = dev->mode;
 138
 139         /* Enable this input */
 140         out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
 141         ++dev->users;
 142
 143         mutex_unlock(&dev->lock);
 144
 145         return 0;
 146 }
 147
 148 void zmii_get_mdio(struct platform_device *ofdev, int input)
 149 {
 150         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 151         u32 fer;
 152
 153         ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
 154
 155         mutex_lock(&dev->lock);
 156
 157         fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
 158         out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
 159 }
 160
 161 void zmii_put_mdio(struct platform_device *ofdev, int input)
 162 {
 163         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 164
 165         ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
 166         mutex_unlock(&dev->lock);
 167 }
 168
 169
 170 void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
 171 {
 172         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 173         u32 ssr;
 174
 175         mutex_lock(&dev->lock);
 176
 177         ssr = in_be32(&dev->base->ssr);
 178
 179         ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
 180
 181         if (speed == SPEED_100)
 182                 ssr |= ZMII_SSR_SP(input);
 183         else
 184                 ssr &= ~ZMII_SSR_SP(input);
 185
 186         out_be32(&dev->base->ssr, ssr);
 187
 188         mutex_unlock(&dev->lock);
 189 }
 190
 191 void zmii_detach(struct platform_device *ofdev, int input)
 192 {
 193         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 194
 195         BUG_ON(!dev || dev->users == 0);
 196
 197         mutex_lock(&dev->lock);
 198
 199         ZMII_DBG(dev, "detach(%d)" NL, input);
 200
 201         /* Disable this input */
 202         out_be32(&dev->base->fer,
 203                  in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
 204
 205         --dev->users;
 206
 207         mutex_unlock(&dev->lock);
 208 }
 209
 210 int zmii_get_regs_len(struct platform_device *ofdev)
 211 {
 212         return sizeof(struct emac_ethtool_regs_subhdr) +
 213                 sizeof(struct zmii_regs);
 214 }
 215
 216 void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
 217 {
 218         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 219         struct emac_ethtool_regs_subhdr *hdr = buf;
 220         struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
 221
 222         hdr->version = 0;
 223         hdr->index = 0; /* for now, are there chips with more than one
 224                          * zmii ? if yes, then we'll add a cell_index
 225                          * like we do for emac
 226                          */
 227         memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
 228         return regs + 1;
 229 }
 230
 231 static int zmii_probe(struct platform_device *ofdev)
 232 {
 233         struct device_node *np = ofdev->dev.of_node;
 234         struct zmii_instance *dev;
 235         struct resource regs;
 236         int rc;
 237
 238         rc = -ENOMEM;
 239         dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
 240         if (dev == NULL)
 241                 goto err_gone;
 242
 243         mutex_init(&dev->lock);
 244         dev->ofdev = ofdev;
 245         dev->mode = PHY_INTERFACE_MODE_NA;
 246
 247         rc = -ENXIO;
 248         if (of_address_to_resource(np, 0, &regs)) {
 249                 printk(KERN_ERR "%pOF: Can't get registers address\n", np);
 250                 goto err_free;
 251         }
 252
 253         rc = -ENOMEM;
 254         dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
 255                                                 sizeof(struct zmii_regs));
 256         if (dev->base == NULL) {
 257                 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
 258                 goto err_free;
 259         }
 260
 261         /* We may need FER value for autodetection later */
 262         dev->fer_save = in_be32(&dev->base->fer);
 263
 264         /* Disable all inputs by default */
 265         out_be32(&dev->base->fer, 0);
 266
 267         printk(KERN_INFO "ZMII %pOF initialized\n", ofdev->dev.of_node);
 268         wmb();
 269         platform_set_drvdata(ofdev, dev);
 270
 271         return 0;
 272
 273  err_free:
 274         kfree(dev);
 275  err_gone:
 276         return rc;
 277 }
 278
 279 static int zmii_remove(struct platform_device *ofdev)
 280 {
 281         struct zmii_instance *dev = platform_get_drvdata(ofdev);
 282
 283         WARN_ON(dev->users != 0);
 284
 285         iounmap(dev->base);
 286         kfree(dev);
 287
 288         return 0;
 289 }
 290
 291 static const struct of_device_id zmii_match[] =
 292 {
 293         {
 294                 .compatible     = "ibm,zmii",
 295         },
 296         /* For backward compat with old DT */
 297         {
 298                 .type           = "emac-zmii",
 299         },
 300         {},
 301 };
 302
 303 static struct platform_driver zmii_driver = {
 304         .driver = {
 305                 .name = "emac-zmii",
 306                 .of_match_table = zmii_match,
 307         },
 308         .probe = zmii_probe,
 309         .remove = zmii_remove,
 310 };
 311
 312 int __init zmii_init(void)
 313 {
 314         return platform_driver_register(&zmii_driver);
 315 }
 316
 317 void zmii_exit(void)
 318 {
 319         platform_driver_unregister(&zmii_driver);
 320 }