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
30struct bb_info {
31	struct mdiobb_ctrl ctrl;
32	u32 __iomem *dir;
33	u32 __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 */
43static inline void bb_set(u32 __iomem *p, u32 m)
44{
45	out_be32(p, in_be32(p) | m);
46}
47
48static inline void bb_clr(u32 __iomem *p, u32 m)
49{
50	out_be32(p, in_be32(p) & ~m);
51}
52
53static inline int bb_read(u32 __iomem *p, u32 m)
54{
55	return (in_be32(p) & m) != 0;
56}
57
58static 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
71static 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
77static 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
90static 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
103static 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
111static 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
152static 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
185out_unmap_regs:
186	iounmap(bitbang->dir);
187out_free_bus:
188	free_mdio_bitbang(new_bus);
189out_free_priv:
190	kfree(bitbang);
191out:
192	return ret;
193}
194
195static void 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
206static const struct of_device_id fs_enet_mdio_bb_match[] = {
207	{
208		.compatible = "fsl,cpm2-mdio-bitbang",
209	},
210	{},
211};
212MODULE_DEVICE_TABLE(of, fs_enet_mdio_bb_match);
213
214static struct platform_driver fs_enet_bb_mdio_driver = {
215	.driver = {
216		.name = "fsl-bb-mdio",
217		.of_match_table = fs_enet_mdio_bb_match,
218	},
219	.probe = fs_enet_mdio_probe,
220	.remove_new = fs_enet_mdio_remove,
221};
222
223module_platform_driver(fs_enet_bb_mdio_driver);
224MODULE_LICENSE("GPL");
225