xref: /linux/drivers/net/ethernet/freescale/fs_enet/mii-fec.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Combined Ethernet driver for Motorola MPC8xx and MPC82xx.
4  *
5  * Copyright (c) 2003 Intracom S.A.
6  *  by Pantelis Antoniou <panto@intracom.gr>
7  *
8  * 2005 (c) MontaVista Software, Inc.
9  * Vitaly Bordug <vbordug@ru.mvista.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/ptrace.h>
17 #include <linux/errno.h>
18 #include <linux/ioport.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/delay.h>
22 #include <linux/netdevice.h>
23 #include <linux/etherdevice.h>
24 #include <linux/skbuff.h>
25 #include <linux/spinlock.h>
26 #include <linux/mii.h>
27 #include <linux/ethtool.h>
28 #include <linux/bitops.h>
29 #include <linux/platform_device.h>
30 #include <linux/property.h>
31 #include <linux/of.h>
32 #include <linux/of_address.h>
33 #include <linux/of_mdio.h>
34 #include <linux/pgtable.h>
35 
36 #include <asm/irq.h>
37 #include <linux/uaccess.h>
38 #include <asm/mpc5xxx.h>
39 
40 #include "fs_enet.h"
41 #include "fec.h"
42 
43 /* Make MII read/write commands for the FEC.
44 */
45 #define mk_mii_read(REG)	(0x60020000 | ((REG & 0x1f) << 18))
46 #define mk_mii_write(REG, VAL)	(0x50020000 | ((REG & 0x1f) << 18) | (VAL & 0xffff))
47 #define mk_mii_end		0
48 
49 #define FEC_MII_LOOPS	10000
50 
51 static int fs_enet_fec_mii_read(struct mii_bus *bus , int phy_id, int location)
52 {
53 	struct fec_info* fec = bus->priv;
54 	struct fec __iomem *fecp = fec->fecp;
55 	int i, ret = -1;
56 
57 	BUG_ON((in_be32(&fecp->fec_r_cntrl) & FEC_RCNTRL_MII_MODE) == 0);
58 
59 	/* Add PHY address to register command.  */
60 	out_be32(&fecp->fec_mii_data, (phy_id << 23) | mk_mii_read(location));
61 
62 	for (i = 0; i < FEC_MII_LOOPS; i++)
63 		if ((in_be32(&fecp->fec_ievent) & FEC_ENET_MII) != 0)
64 			break;
65 
66 	if (i < FEC_MII_LOOPS) {
67 		out_be32(&fecp->fec_ievent, FEC_ENET_MII);
68 		ret = in_be32(&fecp->fec_mii_data) & 0xffff;
69 	}
70 
71 	return ret;
72 }
73 
74 static int fs_enet_fec_mii_write(struct mii_bus *bus, int phy_id, int location, u16 val)
75 {
76 	struct fec_info* fec = bus->priv;
77 	struct fec __iomem *fecp = fec->fecp;
78 	int i;
79 
80 	/* this must never happen */
81 	BUG_ON((in_be32(&fecp->fec_r_cntrl) & FEC_RCNTRL_MII_MODE) == 0);
82 
83 	/* Add PHY address to register command.  */
84 	out_be32(&fecp->fec_mii_data, (phy_id << 23) | mk_mii_write(location, val));
85 
86 	for (i = 0; i < FEC_MII_LOOPS; i++)
87 		if ((in_be32(&fecp->fec_ievent) & FEC_ENET_MII) != 0)
88 			break;
89 
90 	if (i < FEC_MII_LOOPS)
91 		out_be32(&fecp->fec_ievent, FEC_ENET_MII);
92 
93 	return 0;
94 
95 }
96 
97 static int fs_enet_mdio_probe(struct platform_device *ofdev)
98 {
99 	struct resource res;
100 	struct mii_bus *new_bus;
101 	struct fec_info *fec;
102 	int (*get_bus_freq)(struct device *);
103 	int ret = -ENOMEM, clock, speed;
104 
105 	get_bus_freq = device_get_match_data(&ofdev->dev);
106 
107 	new_bus = mdiobus_alloc();
108 	if (!new_bus)
109 		goto out;
110 
111 	fec = kzalloc(sizeof(struct fec_info), GFP_KERNEL);
112 	if (!fec)
113 		goto out_mii;
114 
115 	new_bus->priv = fec;
116 	new_bus->name = "FEC MII Bus";
117 	new_bus->read = &fs_enet_fec_mii_read;
118 	new_bus->write = &fs_enet_fec_mii_write;
119 
120 	ret = of_address_to_resource(ofdev->dev.of_node, 0, &res);
121 	if (ret)
122 		goto out_res;
123 
124 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%pap", &res.start);
125 
126 	fec->fecp = ioremap(res.start, resource_size(&res));
127 	if (!fec->fecp) {
128 		ret = -ENOMEM;
129 		goto out_fec;
130 	}
131 
132 	if (get_bus_freq) {
133 		clock = get_bus_freq(&ofdev->dev);
134 		if (!clock) {
135 			/* Use maximum divider if clock is unknown */
136 			dev_warn(&ofdev->dev, "could not determine IPS clock\n");
137 			clock = 0x3F * 5000000;
138 		}
139 	} else
140 		clock = ppc_proc_freq;
141 
142 	/*
143 	 * Scale for a MII clock <= 2.5 MHz
144 	 * Note that only 6 bits (25:30) are available for MII speed.
145 	 */
146 	speed = (clock + 4999999) / 5000000;
147 	if (speed > 0x3F) {
148 		speed = 0x3F;
149 		dev_err(&ofdev->dev,
150 			"MII clock (%d Hz) exceeds max (2.5 MHz)\n",
151 			clock / speed);
152 	}
153 
154 	fec->mii_speed = speed << 1;
155 
156 	setbits32(&fec->fecp->fec_r_cntrl, FEC_RCNTRL_MII_MODE);
157 	setbits32(&fec->fecp->fec_ecntrl, FEC_ECNTRL_PINMUX |
158 	                                  FEC_ECNTRL_ETHER_EN);
159 	out_be32(&fec->fecp->fec_ievent, FEC_ENET_MII);
160 	clrsetbits_be32(&fec->fecp->fec_mii_speed, 0x7E, fec->mii_speed);
161 
162 	new_bus->phy_mask = ~0;
163 
164 	new_bus->parent = &ofdev->dev;
165 	platform_set_drvdata(ofdev, new_bus);
166 
167 	ret = of_mdiobus_register(new_bus, ofdev->dev.of_node);
168 	if (ret)
169 		goto out_unmap_regs;
170 
171 	return 0;
172 
173 out_unmap_regs:
174 	iounmap(fec->fecp);
175 out_res:
176 out_fec:
177 	kfree(fec);
178 out_mii:
179 	mdiobus_free(new_bus);
180 out:
181 	return ret;
182 }
183 
184 static void fs_enet_mdio_remove(struct platform_device *ofdev)
185 {
186 	struct mii_bus *bus = platform_get_drvdata(ofdev);
187 	struct fec_info *fec = bus->priv;
188 
189 	mdiobus_unregister(bus);
190 	iounmap(fec->fecp);
191 	kfree(fec);
192 	mdiobus_free(bus);
193 }
194 
195 static const struct of_device_id fs_enet_mdio_fec_match[] = {
196 	{
197 		.compatible = "fsl,pq1-fec-mdio",
198 	},
199 #if defined(CONFIG_PPC_MPC512x)
200 	{
201 		.compatible = "fsl,mpc5121-fec-mdio",
202 		.data = mpc5xxx_get_bus_frequency,
203 	},
204 #endif
205 	{},
206 };
207 MODULE_DEVICE_TABLE(of, fs_enet_mdio_fec_match);
208 
209 static struct platform_driver fs_enet_fec_mdio_driver = {
210 	.driver = {
211 		.name = "fsl-fec-mdio",
212 		.of_match_table = fs_enet_mdio_fec_match,
213 	},
214 	.probe = fs_enet_mdio_probe,
215 	.remove = fs_enet_mdio_remove,
216 };
217 
218 module_platform_driver(fs_enet_fec_mdio_driver);
219 MODULE_LICENSE("GPL");
220