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
 30struct 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 */
 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 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 __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
153static 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
189out_free_irqs:
190	dev_set_drvdata(&ofdev->dev, NULL);
191	kfree(new_bus->irq);
192out_unmap_regs:
193	iounmap(bitbang->dir);
194out_free_bus:
195	free_mdio_bitbang(new_bus);
196out_free_priv:
197	kfree(bitbang);
198out:
199	return ret;
200}
201
202static 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
217static struct of_device_id fs_enet_mdio_bb_match[] = {
218	{
219		.compatible = "fsl,cpm2-mdio-bitbang",
220	},
221	{},
222};
223MODULE_DEVICE_TABLE(of, fs_enet_mdio_bb_match);
224
225static 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
235static int fs_enet_mdio_bb_init(void)
236{
237	return platform_driver_register(&fs_enet_bb_mdio_driver);
238}
239
240static void fs_enet_mdio_bb_exit(void)
241{
242	platform_driver_unregister(&fs_enet_bb_mdio_driver);
243}
244
245module_init(fs_enet_mdio_bb_init);
246module_exit(fs_enet_mdio_bb_exit);