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