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_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  */
bb_set(u32 __iomem * p,u32 m)43 static inline void bb_set(u32 __iomem *p, u32 m)
44 {
45 	out_be32(p, in_be32(p) | m);
46 }
47 
bb_clr(u32 __iomem * p,u32 m)48 static inline void bb_clr(u32 __iomem *p, u32 m)
49 {
50 	out_be32(p, in_be32(p) & ~m);
51 }
52 
bb_read(u32 __iomem * p,u32 m)53 static inline int bb_read(u32 __iomem *p, u32 m)
54 {
55 	return (in_be32(p) & m) != 0;
56 }
57 
mdio_dir(struct mdiobb_ctrl * ctrl,int dir)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 
mdio_read(struct mdiobb_ctrl * ctrl)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 
mdio(struct mdiobb_ctrl * ctrl,int what)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 
mdc(struct mdiobb_ctrl * ctrl,int what)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 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 
fs_mii_bitbang_init(struct mii_bus * bus,struct device_node * np)111 static int __devinit fs_mii_bitbang_init(struct mii_bus *bus,
112                                          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 
fs_enet_mdio_probe(struct platform_device * ofdev)153 static int __devinit 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 		goto out_unmap_regs;
179 
180 	new_bus->parent = &ofdev->dev;
181 	dev_set_drvdata(&ofdev->dev, new_bus);
182 
183 	ret = of_mdiobus_register(new_bus, ofdev->dev.of_node);
184 	if (ret)
185 		goto out_free_irqs;
186 
187 	return 0;
188 
189 out_free_irqs:
190 	dev_set_drvdata(&ofdev->dev, NULL);
191 	kfree(new_bus->irq);
192 out_unmap_regs:
193 	iounmap(bitbang->dir);
194 out_free_bus:
195 	free_mdio_bitbang(new_bus);
196 out_free_priv:
197 	kfree(bitbang);
198 out:
199 	return ret;
200 }
201 
fs_enet_mdio_remove(struct platform_device * ofdev)202 static int fs_enet_mdio_remove(struct platform_device *ofdev)
203 {
204 	struct mii_bus *bus = dev_get_drvdata(&ofdev->dev);
205 	struct bb_info *bitbang = bus->priv;
206 
207 	mdiobus_unregister(bus);
208 	dev_set_drvdata(&ofdev->dev, NULL);
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