drivers/net/ethernet/freescale/fs_enet/mii-bitbang.c

   1 /*
   2  * Combined Ethernet driver for Motorola MPC8xx and MPC82xx.
   3  *
   4  * Copyright (c) 2003 Intracom S.A.
   5  *  by Pantelis Antoniou <panto@intracom.gr>
   6  *
   7  * 2005 (c) MontaVista Software, Inc.
   8  * Vitaly Bordug <vbordug@ru.mvista.com>
   9  *
  10  * This file is licensed under the terms of the GNU General Public License
  11  * version 2. This program is licensed "as is" without any warranty of any
  12  * kind, whether express or implied.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/ioport.h>
  17 #include <linux/slab.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/mii.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/mdio-bitbang.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_mdio.h>
  26 #include <linux/of_platform.h>
  27
  28 #include "fs_enet.h"
  29
  30 struct bb_info {
  31         struct mdiobb_ctrl ctrl;
  32         __be32 __iomem *dir;
  33         __be32 __iomem *dat;
  34         u32 mdio_msk;
  35         u32 mdc_msk;
  36 };
  37
  38 /* FIXME: If any other users of GPIO crop up, then these will have to
  39  * have some sort of global synchronization to avoid races with other
  40  * pins on the same port.  The ideal solution would probably be to
  41  * bind the ports to a GPIO driver, and have this be a client of it.
  42  */
  43 static inline void bb_set(u32 __iomem *p, u32 m)
  44 {
  45         out_be32(p, in_be32(p) | m);
  46 }
  47
  48 static inline void bb_clr(u32 __iomem *p, u32 m)
  49 {
  50         out_be32(p, in_be32(p) & ~m);
  51 }
  52
  53 static inline int bb_read(u32 __iomem *p, u32 m)
  54 {
  55         return (in_be32(p) & m) != 0;
  56 }
  57
  58 static inline void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
  59 {
  60         struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  61
  62         if (dir)
  63                 bb_set(bitbang->dir, bitbang->mdio_msk);
  64         else
  65                 bb_clr(bitbang->dir, bitbang->mdio_msk);
  66
  67         /* Read back to flush the write. */
  68         in_be32(bitbang->dir);
  69 }
  70
  71 static inline int mdio_read(struct mdiobb_ctrl *ctrl)
  72 {
  73         struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  74         return bb_read(bitbang->dat, bitbang->mdio_msk);
  75 }
  76
  77 static inline void mdio(struct mdiobb_ctrl *ctrl, int what)
  78 {
  79         struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  80
  81         if (what)
  82                 bb_set(bitbang->dat, bitbang->mdio_msk);
  83         else
  84                 bb_clr(bitbang->dat, bitbang->mdio_msk);
  85
  86         /* Read back to flush the write. */
  87         in_be32(bitbang->dat);
  88 }
  89
  90 static inline void mdc(struct mdiobb_ctrl *ctrl, int what)
  91 {
  92         struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  93
  94         if (what)
  95                 bb_set(bitbang->dat, bitbang->mdc_msk);
  96         else
  97                 bb_clr(bitbang->dat, bitbang->mdc_msk);
  98
  99         /* Read back to flush the write. */
 100         in_be32(bitbang->dat);
 101 }
 102
 103 static const struct mdiobb_ops bb_ops = {
 104         .owner = THIS_MODULE,
 105         .set_mdc = mdc,
 106         .set_mdio_dir = mdio_dir,
 107         .set_mdio_data = mdio,
 108         .get_mdio_data = mdio_read,
 109 };
 110
 111 static int fs_mii_bitbang_init(struct mii_bus *bus, struct device_node *np)
 112 {
 113         struct resource res;
 114         const u32 *data;
 115         int mdio_pin, mdc_pin, len;
 116         struct bb_info *bitbang = bus->priv;
 117
 118         int ret = of_address_to_resource(np, 0, &res);
 119         if (ret)
 120                 return ret;
 121
 122         if (resource_size(&res) <= 13)
 123                 return -ENODEV;
 124
 125         /* This should really encode the pin number as well, but all
 126          * we get is an int, and the odds of multiple bitbang mdio buses
 127          * is low enough that it's not worth going too crazy.
 128          */
 129         snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
 130
 131         data = of_get_property(np, "fsl,mdio-pin", &len);
 132         if (!data || len != 4)
 133                 return -ENODEV;
 134         mdio_pin = *data;
 135
 136         data = of_get_property(np, "fsl,mdc-pin", &len);
 137         if (!data || len != 4)
 138                 return -ENODEV;
 139         mdc_pin = *data;
 140
 141         bitbang->dir = ioremap(res.start, resource_size(&res));
 142         if (!bitbang->dir)
 143                 return -ENOMEM;
 144
 145         bitbang->dat = bitbang->dir + 4;
 146         bitbang->mdio_msk = 1 << (31 - mdio_pin);
 147         bitbang->mdc_msk = 1 << (31 - mdc_pin);
 148
 149         return 0;
 150 }
 151
 152 static int fs_enet_mdio_probe(struct platform_device *ofdev)
 153 {
 154         struct mii_bus *new_bus;
 155         struct bb_info *bitbang;
 156         int ret = -ENOMEM;
 157
 158         bitbang = kzalloc(sizeof(struct bb_info), GFP_KERNEL);
 159         if (!bitbang)
 160                 goto out;
 161
 162         bitbang->ctrl.ops = &bb_ops;
 163
 164         new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
 165         if (!new_bus)
 166                 goto out_free_priv;
 167
 168         new_bus->name = "CPM2 Bitbanged MII",
 169
 170         ret = fs_mii_bitbang_init(new_bus, ofdev->dev.of_node);
 171         if (ret)
 172                 goto out_free_bus;
 173
 174         new_bus->phy_mask = ~0;
 175
 176         new_bus->parent = &ofdev->dev;
 177         platform_set_drvdata(ofdev, new_bus);
 178
 179         ret = of_mdiobus_register(new_bus, ofdev->dev.of_node);
 180         if (ret)
 181                 goto out_unmap_regs;
 182
 183         return 0;
 184
 185 out_unmap_regs:
 186         iounmap(bitbang->dir);
 187 out_free_bus:
 188         free_mdio_bitbang(new_bus);
 189 out_free_priv:
 190         kfree(bitbang);
 191 out:
 192         return ret;
 193 }
 194
 195 static int fs_enet_mdio_remove(struct platform_device *ofdev)
 196 {
 197         struct mii_bus *bus = platform_get_drvdata(ofdev);
 198         struct bb_info *bitbang = bus->priv;
 199
 200         mdiobus_unregister(bus);
 201         free_mdio_bitbang(bus);
 202         iounmap(bitbang->dir);
 203         kfree(bitbang);
 204
 205         return 0;
 206 }
 207
 208 static const struct of_device_id fs_enet_mdio_bb_match[] = {
 209         {
 210                 .compatible = "fsl,cpm2-mdio-bitbang",
 211         },
 212         {},
 213 };
 214 MODULE_DEVICE_TABLE(of, fs_enet_mdio_bb_match);
 215
 216 static struct platform_driver fs_enet_bb_mdio_driver = {
 217         .driver = {
 218                 .name = "fsl-bb-mdio",
 219                 .of_match_table = fs_enet_mdio_bb_match,
 220         },
 221         .probe = fs_enet_mdio_probe,
 222         .remove = fs_enet_mdio_remove,
 223 };
 224
 225 module_platform_driver(fs_enet_bb_mdio_driver);