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