1 /*
2 i2c Support for Via Technologies 82C586B South Bridge
3
4 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/pci.h>
24 #include <linux/ioport.h>
25 #include <linux/init.h>
26 #include <linux/i2c.h>
27 #include <linux/i2c-algo-bit.h>
28 #include <linux/io.h>
29
30 /* Power management registers */
31 #define PM_CFG_REVID 0x08 /* silicon revision code */
32 #define PM_CFG_IOBASE0 0x20
33 #define PM_CFG_IOBASE1 0x48
34
35 #define I2C_DIR (pm_io_base+0x40)
36 #define I2C_OUT (pm_io_base+0x42)
37 #define I2C_IN (pm_io_base+0x44)
38 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */
39 #define I2C_SDA 0x04
40
41 /* io-region reservation */
42 #define IOSPACE 0x06
43
44 static struct pci_driver vt586b_driver;
45 static u16 pm_io_base;
46
47 /*
48 It does not appear from the datasheet that the GPIO pins are
49 open drain. So a we set a low value by setting the direction to
50 output and a high value by setting the direction to input and
51 relying on the required I2C pullup. The data value is initialized
52 to 0 in via_init() and never changed.
53 */
bit_via_setscl(void * data,int state)54 static void bit_via_setscl(void *data, int state)
55 {
56 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR);
57 }
58
bit_via_setsda(void * data,int state)59 static void bit_via_setsda(void *data, int state)
60 {
61 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR);
62 }
63
bit_via_getscl(void * data)64 static int bit_via_getscl(void *data)
65 {
66 return (0 != (inb(I2C_IN) & I2C_SCL));
67 }
68
bit_via_getsda(void * data)69 static int bit_via_getsda(void *data)
70 {
71 return (0 != (inb(I2C_IN) & I2C_SDA));
72 }
73
74
75 static struct i2c_algo_bit_data bit_data = {
76 .setsda = bit_via_setsda,
77 .setscl = bit_via_setscl,
78 .getsda = bit_via_getsda,
79 .getscl = bit_via_getscl,
80 .udelay = 5,
81 .timeout = HZ
82 };
83
84 static struct i2c_adapter vt586b_adapter = {
85 .owner = THIS_MODULE,
86 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
87 .name = "VIA i2c",
88 .algo_data = &bit_data,
89 };
90
91
92 static DEFINE_PCI_DEVICE_TABLE(vt586b_ids) = {
93 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
94 { 0, }
95 };
96
97 MODULE_DEVICE_TABLE (pci, vt586b_ids);
98
vt586b_probe(struct pci_dev * dev,const struct pci_device_id * id)99 static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id)
100 {
101 u16 base;
102 u8 rev;
103 int res;
104
105 if (pm_io_base) {
106 dev_err(&dev->dev, "i2c-via: Will only support one host\n");
107 return -ENODEV;
108 }
109
110 pci_read_config_byte(dev, PM_CFG_REVID, &rev);
111
112 switch (rev) {
113 case 0x00:
114 base = PM_CFG_IOBASE0;
115 break;
116 case 0x01:
117 case 0x10:
118 base = PM_CFG_IOBASE1;
119 break;
120
121 default:
122 base = PM_CFG_IOBASE1;
123 /* later revision */
124 }
125
126 pci_read_config_word(dev, base, &pm_io_base);
127 pm_io_base &= (0xff << 8);
128
129 if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) {
130 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE);
131 return -ENODEV;
132 }
133
134 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR);
135 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT);
136
137 /* set up the sysfs linkage to our parent device */
138 vt586b_adapter.dev.parent = &dev->dev;
139
140 res = i2c_bit_add_bus(&vt586b_adapter);
141 if ( res < 0 ) {
142 release_region(I2C_DIR, IOSPACE);
143 pm_io_base = 0;
144 return res;
145 }
146 return 0;
147 }
148
vt586b_remove(struct pci_dev * dev)149 static void __devexit vt586b_remove(struct pci_dev *dev)
150 {
151 i2c_del_adapter(&vt586b_adapter);
152 release_region(I2C_DIR, IOSPACE);
153 pm_io_base = 0;
154 }
155
156
157 static struct pci_driver vt586b_driver = {
158 .name = "vt586b_smbus",
159 .id_table = vt586b_ids,
160 .probe = vt586b_probe,
161 .remove = __devexit_p(vt586b_remove),
162 };
163
i2c_vt586b_init(void)164 static int __init i2c_vt586b_init(void)
165 {
166 return pci_register_driver(&vt586b_driver);
167 }
168
i2c_vt586b_exit(void)169 static void __exit i2c_vt586b_exit(void)
170 {
171 pci_unregister_driver(&vt586b_driver);
172 }
173
174
175 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>");
176 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
177 MODULE_LICENSE("GPL");
178
179 module_init(i2c_vt586b_init);
180 module_exit(i2c_vt586b_exit);
181