1/*
2    i2c-via.c - Part of lm_sensors,  Linux kernel modules
3                for hardware monitoring
4
5    i2c Support for Via Technologies 82C586B South Bridge
6
7    Copyright (c) 1998, 1999 Ky�sti M�lkki <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    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22*/
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/pci.h>
27#include <linux/ioport.h>
28#include <linux/init.h>
29#include <linux/i2c.h>
30#include <linux/i2c-algo-bit.h>
31#include <asm/io.h>
32
33/* Power management registers */
34#define PM_CFG_REVID	0x08	/* silicon revision code */
35#define PM_CFG_IOBASE0	0x20
36#define PM_CFG_IOBASE1	0x48
37
38#define I2C_DIR		(pm_io_base+0x40)
39#define I2C_OUT		(pm_io_base+0x42)
40#define I2C_IN		(pm_io_base+0x44)
41#define I2C_SCL		0x02	/* clock bit in DIR/OUT/IN register */
42#define I2C_SDA		0x04
43
44/* io-region reservation */
45#define IOSPACE		0x06
46
47static struct pci_driver vt586b_driver;
48static u16 pm_io_base;
49
50/*
51   It does not appear from the datasheet that the GPIO pins are
52   open drain. So a we set a low value by setting the direction to
53   output and a high value by setting the direction to input and
54   relying on the required I2C pullup. The data value is initialized
55   to 0 in via_init() and never changed.
56*/
57static void bit_via_setscl(void *data, int state)
58{
59	outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR);
60}
61
62static void bit_via_setsda(void *data, int state)
63{
64	outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR);
65}
66
67static int bit_via_getscl(void *data)
68{
69	return (0 != (inb(I2C_IN) & I2C_SCL));
70}
71
72static int bit_via_getsda(void *data)
73{
74	return (0 != (inb(I2C_IN) & I2C_SDA));
75}
76
77
78static struct i2c_algo_bit_data bit_data = {
79	.setsda		= bit_via_setsda,
80	.setscl		= bit_via_setscl,
81	.getsda		= bit_via_getsda,
82	.getscl		= bit_via_getscl,
83	.udelay		= 5,
84	.timeout	= HZ
85};
86
87static struct i2c_adapter vt586b_adapter = {
88	.owner		= THIS_MODULE,
89	.id		= I2C_HW_B_VIA,
90	.class          = I2C_CLASS_HWMON,
91	.name		= "VIA i2c",
92	.algo_data	= &bit_data,
93};
94
95
96static struct pci_device_id vt586b_ids[] __devinitdata = {
97	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
98	{ 0, }
99};
100
101MODULE_DEVICE_TABLE (pci, vt586b_ids);
102
103static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id)
104{
105	u16 base;
106	u8 rev;
107	int res;
108
109	if (pm_io_base) {
110		dev_err(&dev->dev, "i2c-via: Will only support one host\n");
111		return -ENODEV;
112	}
113
114	pci_read_config_byte(dev, PM_CFG_REVID, &rev);
115
116	switch (rev) {
117	case 0x00:
118		base = PM_CFG_IOBASE0;
119		break;
120	case 0x01:
121	case 0x10:
122		base = PM_CFG_IOBASE1;
123		break;
124
125	default:
126		base = PM_CFG_IOBASE1;
127		/* later revision */
128	}
129
130	pci_read_config_word(dev, base, &pm_io_base);
131	pm_io_base &= (0xff << 8);
132
133	if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) {
134		dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE);
135		return -ENODEV;
136	}
137
138	outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR);
139	outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT);
140
141	/* set up the sysfs linkage to our parent device */
142	vt586b_adapter.dev.parent = &dev->dev;
143
144	res = i2c_bit_add_bus(&vt586b_adapter);
145	if ( res < 0 ) {
146		release_region(I2C_DIR, IOSPACE);
147		pm_io_base = 0;
148		return res;
149	}
150	return 0;
151}
152
153static void __devexit vt586b_remove(struct pci_dev *dev)
154{
155	i2c_del_adapter(&vt586b_adapter);
156	release_region(I2C_DIR, IOSPACE);
157	pm_io_base = 0;
158}
159
160
161static struct pci_driver vt586b_driver = {
162	.name		= "vt586b_smbus",
163	.id_table	= vt586b_ids,
164	.probe		= vt586b_probe,
165	.remove		= __devexit_p(vt586b_remove),
166};
167
168static int __init i2c_vt586b_init(void)
169{
170	return pci_register_driver(&vt586b_driver);
171}
172
173static void __exit i2c_vt586b_exit(void)
174{
175	pci_unregister_driver(&vt586b_driver);
176}
177
178
179MODULE_AUTHOR("Ky�sti M�lkki <kmalkki@cc.hut.fi>");
180MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
181MODULE_LICENSE("GPL");
182
183module_init(i2c_vt586b_init);
184module_exit(i2c_vt586b_exit);
185