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);
226