2 i2c Support for Via Technologies 82C586B South Bridge
4 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
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.
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.
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.
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>
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
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 */
41 /* io-region reservation */
44 static struct pci_driver vt586b_driver
;
45 static u16 pm_io_base
;
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.
54 static void bit_via_setscl(void *data
, int state
)
56 outb(state
? inb(I2C_DIR
) & ~I2C_SCL
: inb(I2C_DIR
) | I2C_SCL
, I2C_DIR
);
59 static void bit_via_setsda(void *data
, int state
)
61 outb(state
? inb(I2C_DIR
) & ~I2C_SDA
: inb(I2C_DIR
) | I2C_SDA
, I2C_DIR
);
64 static int bit_via_getscl(void *data
)
66 return (0 != (inb(I2C_IN
) & I2C_SCL
));
69 static int bit_via_getsda(void *data
)
71 return (0 != (inb(I2C_IN
) & I2C_SDA
));
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
,
84 static struct i2c_adapter vt586b_adapter
= {
86 .class = I2C_CLASS_HWMON
| I2C_CLASS_SPD
,
88 .algo_data
= &bit_data
,
92 static DEFINE_PCI_DEVICE_TABLE(vt586b_ids
) = {
93 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_82C586_3
) },
97 MODULE_DEVICE_TABLE (pci
, vt586b_ids
);
99 static int vt586b_probe(struct pci_dev
*dev
, const struct pci_device_id
*id
)
106 dev_err(&dev
->dev
, "i2c-via: Will only support one host\n");
110 pci_read_config_byte(dev
, PM_CFG_REVID
, &rev
);
114 base
= PM_CFG_IOBASE0
;
118 base
= PM_CFG_IOBASE1
;
122 base
= PM_CFG_IOBASE1
;
126 pci_read_config_word(dev
, base
, &pm_io_base
);
127 pm_io_base
&= (0xff << 8);
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
);
134 outb(inb(I2C_DIR
) & ~(I2C_SDA
| I2C_SCL
), I2C_DIR
);
135 outb(inb(I2C_OUT
) & ~(I2C_SDA
| I2C_SCL
), I2C_OUT
);
137 /* set up the sysfs linkage to our parent device */
138 vt586b_adapter
.dev
.parent
= &dev
->dev
;
140 res
= i2c_bit_add_bus(&vt586b_adapter
);
142 release_region(I2C_DIR
, IOSPACE
);
149 static void vt586b_remove(struct pci_dev
*dev
)
151 i2c_del_adapter(&vt586b_adapter
);
152 release_region(I2C_DIR
, IOSPACE
);
157 static struct pci_driver vt586b_driver
= {
158 .name
= "vt586b_smbus",
159 .id_table
= vt586b_ids
,
160 .probe
= vt586b_probe
,
161 .remove
= vt586b_remove
,
164 module_pci_driver(vt586b_driver
);
166 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>");
167 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
168 MODULE_LICENSE("GPL");