2 i2c-via.c - Part of lm_sensors, Linux kernel modules
3 for hardware monitoring
5 i2c Support for Via Technologies 82C586B South Bridge
7 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
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.
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.
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.
24 #include <linux/config.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/pci.h>
28 #include <linux/ioport.h>
29 #include <linux/init.h>
30 #include <linux/i2c.h>
31 #include <linux/i2c-algo-bit.h>
34 /* Power management registers */
35 #define PM_CFG_REVID 0x08 /* silicon revision code */
36 #define PM_CFG_IOBASE0 0x20
37 #define PM_CFG_IOBASE1 0x48
39 #define I2C_DIR (pm_io_base+0x40)
40 #define I2C_OUT (pm_io_base+0x42)
41 #define I2C_IN (pm_io_base+0x44)
42 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */
45 /* io-region reservation */
47 #define IOTEXT "via-i2c"
49 static u16 pm_io_base = 0;
52 It does not appear from the datasheet that the GPIO pins are
53 open drain. So a we set a low value by setting the direction to
54 output and a high value by setting the direction to input and
55 relying on the required I2C pullup. The data value is initialized
56 to 0 in via_init() and never changed.
58 static void bit_via_setscl(void *data, int state)
60 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR);
63 static void bit_via_setsda(void *data, int state)
65 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR);
68 static int bit_via_getscl(void *data)
70 return (0 != (inb(I2C_IN) & I2C_SCL));
73 static int bit_via_getsda(void *data)
75 return (0 != (inb(I2C_IN) & I2C_SDA));
79 static struct i2c_algo_bit_data bit_data = {
80 .setsda = bit_via_setsda,
81 .setscl = bit_via_setscl,
82 .getsda = bit_via_getsda,
83 .getscl = bit_via_getscl,
89 static struct i2c_adapter vt586b_adapter = {
91 .class = I2C_CLASS_HWMON,
93 .algo_data = &bit_data,
97 static struct pci_device_id vt586b_ids[] __devinitdata = {
98 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
102 MODULE_DEVICE_TABLE (pci, vt586b_ids);
104 static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id)
111 dev_err(&dev->dev, "i2c-via: Will only support one host\n");
115 pci_read_config_byte(dev, PM_CFG_REVID, &rev);
119 base = PM_CFG_IOBASE0;
123 base = PM_CFG_IOBASE1;
127 base = PM_CFG_IOBASE1;
131 pci_read_config_word(dev, base, &pm_io_base);
132 pm_io_base &= (0xff << 8);
134 if (!request_region(I2C_DIR, IOSPACE, IOTEXT)) {
135 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE);
139 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR);
140 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT);
142 /* set up the driverfs linkage to our parent device */
143 vt586b_adapter.dev.parent = &dev->dev;
145 res = i2c_bit_add_bus(&vt586b_adapter);
147 release_region(I2C_DIR, IOSPACE);
154 static void __devexit vt586b_remove(struct pci_dev *dev)
156 i2c_bit_del_bus(&vt586b_adapter);
157 release_region(I2C_DIR, IOSPACE);
162 static struct pci_driver vt586b_driver = {
163 .name = "vt586b_smbus",
164 .id_table = vt586b_ids,
165 .probe = vt586b_probe,
166 .remove = __devexit_p(vt586b_remove),
169 static int __init i2c_vt586b_init(void)
171 return pci_register_driver(&vt586b_driver);
174 static void __exit i2c_vt586b_exit(void)
176 pci_unregister_driver(&vt586b_driver);
180 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>");
181 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
182 MODULE_LICENSE("GPL");
184 module_init(i2c_vt586b_init);
185 module_exit(i2c_vt586b_exit);