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
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/pci.h>
20 #include <linux/ioport.h>
21 #include <linux/i2c.h>
22 #include <linux/i2c-algo-bit.h>
23 #include <linux/io.h>
24
25 /* Power management registers */
26 #define PM_CFG_REVID 0x08 /* silicon revision code */
27 #define PM_CFG_IOBASE0 0x20
28 #define PM_CFG_IOBASE1 0x48
29
30 #define I2C_DIR (pm_io_base+0x40)
31 #define I2C_OUT (pm_io_base+0x42)
32 #define I2C_IN (pm_io_base+0x44)
33 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */
34 #define I2C_SDA 0x04
35
36 /* io-region reservation */
37 #define IOSPACE 0x06
38
39 static struct pci_driver vt586b_driver;
40 static u16 pm_io_base;
41
42 /*
43 It does not appear from the datasheet that the GPIO pins are
44 open drain. So a we set a low value by setting the direction to
45 output and a high value by setting the direction to input and
46 relying on the required I2C pullup. The data value is initialized
47 to 0 in via_init() and never changed.
48 */
bit_via_setscl(void * data,int state)49 static void bit_via_setscl(void *data, int state)
50 {
51 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR);
52 }
53
bit_via_setsda(void * data,int state)54 static void bit_via_setsda(void *data, int state)
55 {
56 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR);
57 }
58
bit_via_getscl(void * data)59 static int bit_via_getscl(void *data)
60 {
61 return (0 != (inb(I2C_IN) & I2C_SCL));
62 }
63
bit_via_getsda(void * data)64 static int bit_via_getsda(void *data)
65 {
66 return (0 != (inb(I2C_IN) & I2C_SDA));
67 }
68
69
70 static struct i2c_algo_bit_data bit_data = {
71 .setsda = bit_via_setsda,
72 .setscl = bit_via_setscl,
73 .getsda = bit_via_getsda,
74 .getscl = bit_via_getscl,
75 .udelay = 5,
76 .timeout = HZ
77 };
78
79 static struct i2c_adapter vt586b_adapter = {
80 .owner = THIS_MODULE,
81 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
82 .name = "VIA i2c",
83 .algo_data = &bit_data,
84 };
85
86
87 static const struct pci_device_id vt586b_ids[] = {
88 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
89 { 0, }
90 };
91
92 MODULE_DEVICE_TABLE (pci, vt586b_ids);
93
vt586b_probe(struct pci_dev * dev,const struct pci_device_id * id)94 static int vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id)
95 {
96 u16 base;
97 u8 rev;
98 int res;
99
100 if (pm_io_base) {
101 dev_err(&dev->dev, "i2c-via: Will only support one host\n");
102 return -ENODEV;
103 }
104
105 pci_read_config_byte(dev, PM_CFG_REVID, &rev);
106
107 switch (rev) {
108 case 0x00:
109 base = PM_CFG_IOBASE0;
110 break;
111 case 0x01:
112 case 0x10:
113 base = PM_CFG_IOBASE1;
114 break;
115
116 default:
117 base = PM_CFG_IOBASE1;
118 /* later revision */
119 }
120
121 pci_read_config_word(dev, base, &pm_io_base);
122 pm_io_base &= (0xff << 8);
123
124 if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) {
125 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE);
126 return -ENODEV;
127 }
128
129 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR);
130 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT);
131
132 /* set up the sysfs linkage to our parent device */
133 vt586b_adapter.dev.parent = &dev->dev;
134
135 res = i2c_bit_add_bus(&vt586b_adapter);
136 if ( res < 0 ) {
137 release_region(I2C_DIR, IOSPACE);
138 pm_io_base = 0;
139 return res;
140 }
141 return 0;
142 }
143
vt586b_remove(struct pci_dev * dev)144 static void vt586b_remove(struct pci_dev *dev)
145 {
146 i2c_del_adapter(&vt586b_adapter);
147 release_region(I2C_DIR, IOSPACE);
148 pm_io_base = 0;
149 }
150
151
152 static struct pci_driver vt586b_driver = {
153 .name = "vt586b_smbus",
154 .id_table = vt586b_ids,
155 .probe = vt586b_probe,
156 .remove = vt586b_remove,
157 };
158
159 module_pci_driver(vt586b_driver);
160
161 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>");
162 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
163 MODULE_LICENSE("GPL");
164
