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/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/mii.h>
23 #include <linux/platform_device.h>
24 #include <linux/mdio-bitbang.h>
25 #include <linux/of_address.h>
26 #include <linux/of_mdio.h>
27 #include <linux/of_platform.h>
28 
29 #include "fs_enet.h"
30 
31 struct bb_info {
32 	struct mdiobb_ctrl ctrl;
33 	__be32 __iomem *dir;
34 	__be32 __iomem *dat;
35 	u32 mdio_msk;
36 	u32 mdc_msk;
37 };
38 
39 /* FIXME: If any other users of GPIO crop up, then these will have to
40  * have some sort of global synchronization to avoid races with other
41  * pins on the same port.  The ideal solution would probably be to
42  * bind the ports to a GPIO driver, and have this be a client of it.
43  */
44 static inline void bb_set(u32 __iomem *p, u32 m)
45 {
46 	out_be32(p, in_be32(p) | m);
47 }
48 
49 static inline void bb_clr(u32 __iomem *p, u32 m)
50 {
51 	out_be32(p, in_be32(p) & ~m);
52 }
53 
54 static inline int bb_read(u32 __iomem *p, u32 m)
55 {
56 	return (in_be32(p) & m) != 0;
57 }
58 
59 static inline void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
60 {
61 	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
62 
63 	if (dir)
64 		bb_set(bitbang->dir, bitbang->mdio_msk);
65 	else
66 		bb_clr(bitbang->dir, bitbang->mdio_msk);
67 
68 	/* Read back to flush the write. */
69 	in_be32(bitbang->dir);
70 }
71 
72 static inline int mdio_read(struct mdiobb_ctrl *ctrl)
73 {
74 	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
75 	return bb_read(bitbang->dat, bitbang->mdio_msk);
76 }
77 
78 static inline void mdio(struct mdiobb_ctrl *ctrl, int what)
79 {
80 	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
81 
82 	if (what)
83 		bb_set(bitbang->dat, bitbang->mdio_msk);
84 	else
85 		bb_clr(bitbang->dat, bitbang->mdio_msk);
86 
87 	/* Read back to flush the write. */
88 	in_be32(bitbang->dat);
89 }
90 
91 static inline void mdc(struct mdiobb_ctrl *ctrl, int what)
92 {
93 	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
94 
95 	if (what)
96 		bb_set(bitbang->dat, bitbang->mdc_msk);
97 	else
98 		bb_clr(bitbang->dat, bitbang->mdc_msk);
99 
100 	/* Read back to flush the write. */
101 	in_be32(bitbang->dat);
102 }
103 
104 static struct mdiobb_ops bb_ops = {
105 	.owner = THIS_MODULE,
106 	.set_mdc = mdc,
107 	.set_mdio_dir = mdio_dir,
108 	.set_mdio_data = mdio,
109 	.get_mdio_data = mdio_read,
110 };
111 
112 static int fs_mii_bitbang_init(struct mii_bus *bus, struct device_node *np)
113 {
114 	struct resource res;
115 	const u32 *data;
116 	int mdio_pin, mdc_pin, len;
117 	struct bb_info *bitbang = bus->priv;
118 
119 	int ret = of_address_to_resource(np, 0, &res);
120 	if (ret)
121 		return ret;
122 
123 	if (resource_size(&res) <= 13)
124 		return -ENODEV;
125 
126 	/* This should really encode the pin number as well, but all
127 	 * we get is an int, and the odds of multiple bitbang mdio buses
128 	 * is low enough that it's not worth going too crazy.
129 	 */
130 	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
131 
132 	data = of_get_property(np, "fsl,mdio-pin", &len);
133 	if (!data || len != 4)
134 		return -ENODEV;
135 	mdio_pin = *data;
136 
137 	data = of_get_property(np, "fsl,mdc-pin", &len);
138 	if (!data || len != 4)
139 		return -ENODEV;
140 	mdc_pin = *data;
141 
142 	bitbang->dir = ioremap(res.start, resource_size(&res));
143 	if (!bitbang->dir)
144 		return -ENOMEM;
145 
146 	bitbang->dat = bitbang->dir + 4;
147 	bitbang->mdio_msk = 1 << (31 - mdio_pin);
148 	bitbang->mdc_msk = 1 << (31 - mdc_pin);
149 
150 	return 0;
151 }
152 
153 static int fs_enet_mdio_probe(struct platform_device *ofdev)
154 {
155 	struct mii_bus *new_bus;
156 	struct bb_info *bitbang;
157 	int ret = -ENOMEM;
158 
159 	bitbang = kzalloc(sizeof(struct bb_info), GFP_KERNEL);
160 	if (!bitbang)
161 		goto out;
162 
163 	bitbang->ctrl.ops = &bb_ops;
164 
165 	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
166 	if (!new_bus)
167 		goto out_free_priv;
168 
169 	new_bus->name = "CPM2 Bitbanged MII",
170 
171 	ret = fs_mii_bitbang_init(new_bus, ofdev->dev.of_node);
172 	if (ret)
173 		goto out_free_bus;
174 
175 	new_bus->phy_mask = ~0;
176 	new_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
177 	if (!new_bus->irq) {
178 		ret = -ENOMEM;
179 		goto out_unmap_regs;
180 	}
181 
182 	new_bus->parent = &ofdev->dev;
183 	platform_set_drvdata(ofdev, new_bus);
184 
185 	ret = of_mdiobus_register(new_bus, ofdev->dev.of_node);
186 	if (ret)
187 		goto out_free_irqs;
188 
189 	return 0;
190 
191 out_free_irqs:
192 	kfree(new_bus->irq);
193 out_unmap_regs:
194 	iounmap(bitbang->dir);
195 out_free_bus:
196 	free_mdio_bitbang(new_bus);
197 out_free_priv:
198 	kfree(bitbang);
199 out:
200 	return ret;
201 }
202 
203 static int fs_enet_mdio_remove(struct platform_device *ofdev)
204 {
205 	struct mii_bus *bus = platform_get_drvdata(ofdev);
206 	struct bb_info *bitbang = bus->priv;
207 
208 	mdiobus_unregister(bus);
209 	kfree(bus->irq);
210 	free_mdio_bitbang(bus);
211 	iounmap(bitbang->dir);
212 	kfree(bitbang);
213 
214 	return 0;
215 }
216 
217 static struct of_device_id fs_enet_mdio_bb_match[] = {
218 	{
219 		.compatible = "fsl,cpm2-mdio-bitbang",
220 	},
221 	{},
222 };
223 MODULE_DEVICE_TABLE(of, fs_enet_mdio_bb_match);
224 
225 static struct platform_driver fs_enet_bb_mdio_driver = {
226 	.driver = {
227 		.name = "fsl-bb-mdio",
228 		.owner = THIS_MODULE,
229 		.of_match_table = fs_enet_mdio_bb_match,
230 	},
231 	.probe = fs_enet_mdio_probe,
232 	.remove = fs_enet_mdio_remove,
233 };
234 
235 module_platform_driver(fs_enet_bb_mdio_driver);
236