1/*
2    i2c Support for the Apple `Hydra' Mac I/O
3
4    Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
5
6    Based on i2c Support for Via Technologies 82C586B South Bridge
7    Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
8
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 2 of the License, or
12    (at your option) any later version.
13
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18*/
19
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/pci.h>
23#include <linux/types.h>
24#include <linux/i2c.h>
25#include <linux/i2c-algo-bit.h>
26#include <linux/io.h>
27#include <asm/hydra.h>
28
29
30#define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
31#define HYDRA_CPD_PD1	0x00000002
32#define HYDRA_CPD_PD2	0x00000004
33#define HYDRA_CPD_PD3	0x00000008
34
35#define HYDRA_SCLK	HYDRA_CPD_PD0
36#define HYDRA_SDAT	HYDRA_CPD_PD1
37#define HYDRA_SCLK_OE	0x00000010
38#define HYDRA_SDAT_OE	0x00000020
39
40static inline void pdregw(void *data, u32 val)
41{
42	struct Hydra *hydra = (struct Hydra *)data;
43	writel(val, &hydra->CachePD);
44}
45
46static inline u32 pdregr(void *data)
47{
48	struct Hydra *hydra = (struct Hydra *)data;
49	return readl(&hydra->CachePD);
50}
51
52static void hydra_bit_setscl(void *data, int state)
53{
54	u32 val = pdregr(data);
55	if (state)
56		val &= ~HYDRA_SCLK_OE;
57	else {
58		val &= ~HYDRA_SCLK;
59		val |= HYDRA_SCLK_OE;
60	}
61	pdregw(data, val);
62}
63
64static void hydra_bit_setsda(void *data, int state)
65{
66	u32 val = pdregr(data);
67	if (state)
68		val &= ~HYDRA_SDAT_OE;
69	else {
70		val &= ~HYDRA_SDAT;
71		val |= HYDRA_SDAT_OE;
72	}
73	pdregw(data, val);
74}
75
76static int hydra_bit_getscl(void *data)
77{
78	return (pdregr(data) & HYDRA_SCLK) != 0;
79}
80
81static int hydra_bit_getsda(void *data)
82{
83	return (pdregr(data) & HYDRA_SDAT) != 0;
84}
85
86/* ------------------------------------------------------------------------ */
87
88static struct i2c_algo_bit_data hydra_bit_data = {
89	.setsda		= hydra_bit_setsda,
90	.setscl		= hydra_bit_setscl,
91	.getsda		= hydra_bit_getsda,
92	.getscl		= hydra_bit_getscl,
93	.udelay		= 5,
94	.timeout	= HZ
95};
96
97static struct i2c_adapter hydra_adap = {
98	.owner		= THIS_MODULE,
99	.name		= "Hydra i2c",
100	.algo_data	= &hydra_bit_data,
101};
102
103static const struct pci_device_id hydra_ids[] = {
104	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
105	{ 0, }
106};
107
108MODULE_DEVICE_TABLE (pci, hydra_ids);
109
110static int hydra_probe(struct pci_dev *dev,
111				 const struct pci_device_id *id)
112{
113	unsigned long base = pci_resource_start(dev, 0);
114	int res;
115
116	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
117				hydra_adap.name))
118		return -EBUSY;
119
120	hydra_bit_data.data = pci_ioremap_bar(dev, 0);
121	if (hydra_bit_data.data == NULL) {
122		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
123		return -ENODEV;
124	}
125
126	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
127	hydra_adap.dev.parent = &dev->dev;
128	res = i2c_bit_add_bus(&hydra_adap);
129	if (res < 0) {
130		iounmap(hydra_bit_data.data);
131		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
132		return res;
133	}
134	return 0;
135}
136
137static void hydra_remove(struct pci_dev *dev)
138{
139	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
140	i2c_del_adapter(&hydra_adap);
141	iounmap(hydra_bit_data.data);
142	release_mem_region(pci_resource_start(dev, 0)+
143			   offsetof(struct Hydra, CachePD), 4);
144}
145
146
147static struct pci_driver hydra_driver = {
148	.name		= "hydra_smbus",
149	.id_table	= hydra_ids,
150	.probe		= hydra_probe,
151	.remove		= hydra_remove,
152};
153
154module_pci_driver(hydra_driver);
155
156MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
157MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
158MODULE_LICENSE("GPL");
159