1 /*
2 * Driver for the MPC5200 Fast Ethernet Controller - MDIO bus driver
3 *
4 * Copyright (C) 2007 Domen Puncer, Telargo, Inc.
5 * Copyright (C) 2008 Wolfram Sang, Pengutronix
6 *
7 * This file is licensed under the terms of the GNU General Public License
8 * version 2. This program is licensed "as is" without any warranty of any
9 * kind, whether express or implied.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/phy.h>
16 #include <linux/of_platform.h>
17 #include <linux/slab.h>
18 #include <linux/of_mdio.h>
19 #include <asm/io.h>
20 #include <asm/mpc52xx.h>
21 #include "fec_mpc52xx.h"
22
23 struct mpc52xx_fec_mdio_priv {
24 struct mpc52xx_fec __iomem *regs;
25 };
26
mpc52xx_fec_mdio_transfer(struct mii_bus * bus,int phy_id,int reg,u32 value)27 static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
28 int reg, u32 value)
29 {
30 struct mpc52xx_fec_mdio_priv *priv = bus->priv;
31 struct mpc52xx_fec __iomem *fec = priv->regs;
32 int tries = 3;
33
34 value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
35 value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
36
37 out_be32(&fec->ievent, FEC_IEVENT_MII);
38 out_be32(&fec->mii_data, value);
39
40 /* wait for it to finish, this takes about 23 us on lite5200b */
41 while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
42 msleep(1);
43
44 if (!tries)
45 return -ETIMEDOUT;
46
47 return value & FEC_MII_DATA_OP_RD ?
48 in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
49 }
50
mpc52xx_fec_mdio_read(struct mii_bus * bus,int phy_id,int reg)51 static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
52 {
53 return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
54 }
55
mpc52xx_fec_mdio_write(struct mii_bus * bus,int phy_id,int reg,u16 data)56 static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
57 u16 data)
58 {
59 return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
60 data | FEC_MII_WRITE_FRAME);
61 }
62
mpc52xx_fec_mdio_probe(struct platform_device * of)63 static int mpc52xx_fec_mdio_probe(struct platform_device *of)
64 {
65 struct device *dev = &of->dev;
66 struct device_node *np = of->dev.of_node;
67 struct mii_bus *bus;
68 struct mpc52xx_fec_mdio_priv *priv;
69 struct resource res;
70 int err;
71
72 bus = mdiobus_alloc();
73 if (bus == NULL)
74 return -ENOMEM;
75 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
76 if (priv == NULL) {
77 err = -ENOMEM;
78 goto out_free;
79 }
80
81 bus->name = "mpc52xx MII bus";
82 bus->read = mpc52xx_fec_mdio_read;
83 bus->write = mpc52xx_fec_mdio_write;
84
85 /* setup registers */
86 err = of_address_to_resource(np, 0, &res);
87 if (err)
88 goto out_free;
89 priv->regs = ioremap(res.start, resource_size(&res));
90 if (priv->regs == NULL) {
91 err = -ENOMEM;
92 goto out_free;
93 }
94
95 snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
96 bus->priv = priv;
97
98 bus->parent = dev;
99 dev_set_drvdata(dev, bus);
100
101 /* set MII speed */
102 out_be32(&priv->regs->mii_speed,
103 ((mpc5xxx_get_bus_frequency(of->dev.of_node) >> 20) / 5) << 1);
104
105 err = of_mdiobus_register(bus, np);
106 if (err)
107 goto out_unmap;
108
109 return 0;
110
111 out_unmap:
112 iounmap(priv->regs);
113 out_free:
114 kfree(priv);
115 mdiobus_free(bus);
116
117 return err;
118 }
119
mpc52xx_fec_mdio_remove(struct platform_device * of)120 static int mpc52xx_fec_mdio_remove(struct platform_device *of)
121 {
122 struct mii_bus *bus = platform_get_drvdata(of);
123 struct mpc52xx_fec_mdio_priv *priv = bus->priv;
124
125 mdiobus_unregister(bus);
126 iounmap(priv->regs);
127 kfree(priv);
128 mdiobus_free(bus);
129
130 return 0;
131 }
132
133 static const struct of_device_id mpc52xx_fec_mdio_match[] = {
134 { .compatible = "fsl,mpc5200b-mdio", },
135 { .compatible = "fsl,mpc5200-mdio", },
136 { .compatible = "mpc5200b-fec-phy", },
137 {}
138 };
139 MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);
140
141 struct platform_driver mpc52xx_fec_mdio_driver = {
142 .driver = {
143 .name = "mpc5200b-fec-phy",
144 .owner = THIS_MODULE,
145 .of_match_table = mpc52xx_fec_mdio_match,
146 },
147 .probe = mpc52xx_fec_mdio_probe,
148 .remove = mpc52xx_fec_mdio_remove,
149 };
150
151 /* let fec driver call it, since this has to be registered before it */
152 EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);
153
154 MODULE_LICENSE("Dual BSD/GPL");
155