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/slab.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_mdio.h>
20 #include <linux/platform_device.h>
21 #include <asm/io.h>
22 #include <asm/mpc52xx.h>
23 #include "fec_mpc52xx.h"
24 
25 struct mpc52xx_fec_mdio_priv {
26 	struct mpc52xx_fec __iomem *regs;
27 };
28 
29 static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
30 		int reg, u32 value)
31 {
32 	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
33 	struct mpc52xx_fec __iomem *fec = priv->regs;
34 	int tries = 3;
35 
36 	value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
37 	value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
38 
39 	out_be32(&fec->ievent, FEC_IEVENT_MII);
40 	out_be32(&fec->mii_data, value);
41 
42 	/* wait for it to finish, this takes about 23 us on lite5200b */
43 	while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
44 		msleep(1);
45 
46 	if (!tries)
47 		return -ETIMEDOUT;
48 
49 	return value & FEC_MII_DATA_OP_RD ?
50 		in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
51 }
52 
53 static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
54 {
55 	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
56 }
57 
58 static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
59 		u16 data)
60 {
61 	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
62 		data | FEC_MII_WRITE_FRAME);
63 }
64 
65 static int mpc52xx_fec_mdio_probe(struct platform_device *of)
66 {
67 	struct device *dev = &of->dev;
68 	struct device_node *np = of->dev.of_node;
69 	struct mii_bus *bus;
70 	struct mpc52xx_fec_mdio_priv *priv;
71 	struct resource res;
72 	int err;
73 
74 	bus = mdiobus_alloc();
75 	if (bus == NULL)
76 		return -ENOMEM;
77 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
78 	if (priv == NULL) {
79 		err = -ENOMEM;
80 		goto out_free;
81 	}
82 
83 	bus->name = "mpc52xx MII bus";
84 	bus->read = mpc52xx_fec_mdio_read;
85 	bus->write = mpc52xx_fec_mdio_write;
86 
87 	/* setup registers */
88 	err = of_address_to_resource(np, 0, &res);
89 	if (err)
90 		goto out_free;
91 	priv->regs = ioremap(res.start, resource_size(&res));
92 	if (priv->regs == NULL) {
93 		err = -ENOMEM;
94 		goto out_free;
95 	}
96 
97 	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
98 	bus->priv = priv;
99 
100 	bus->parent = dev;
101 	dev_set_drvdata(dev, bus);
102 
103 	/* set MII speed */
104 	out_be32(&priv->regs->mii_speed, ((mpc5xxx_get_bus_frequency(dev) >> 20) / 5) << 1);
105 
106 	err = of_mdiobus_register(bus, np);
107 	if (err)
108 		goto out_unmap;
109 
110 	return 0;
111 
112  out_unmap:
113 	iounmap(priv->regs);
114  out_free:
115 	kfree(priv);
116 	mdiobus_free(bus);
117 
118 	return err;
119 }
120 
121 static void mpc52xx_fec_mdio_remove(struct platform_device *of)
122 {
123 	struct mii_bus *bus = platform_get_drvdata(of);
124 	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
125 
126 	mdiobus_unregister(bus);
127 	iounmap(priv->regs);
128 	kfree(priv);
129 	mdiobus_free(bus);
130 }
131 
132 static const struct of_device_id mpc52xx_fec_mdio_match[] = {
133 	{ .compatible = "fsl,mpc5200b-mdio", },
134 	{ .compatible = "fsl,mpc5200-mdio", },
135 	{ .compatible = "mpc5200b-fec-phy", },
136 	{}
137 };
138 MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);
139 
140 struct platform_driver mpc52xx_fec_mdio_driver = {
141 	.driver = {
142 		.name = "mpc5200b-fec-phy",
143 		.owner = THIS_MODULE,
144 		.of_match_table = mpc52xx_fec_mdio_match,
145 	},
146 	.probe = mpc52xx_fec_mdio_probe,
147 	.remove_new = mpc52xx_fec_mdio_remove,
148 };
149 
150 /* let fec driver call it, since this has to be registered before it */
151 EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);
152 
153 MODULE_LICENSE("Dual BSD/GPL");
154