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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | i2c Support for Via Technologies 82C586B South Bridge |
4 | ||
96de0e25 | 5 | Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi> |
1da177e4 | 6 | |
1da177e4 LT |
7 | */ |
8 | ||
1da177e4 LT |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/pci.h> | |
12 | #include <linux/ioport.h> | |
1da177e4 LT |
13 | #include <linux/i2c.h> |
14 | #include <linux/i2c-algo-bit.h> | |
21782180 | 15 | #include <linux/io.h> |
1da177e4 LT |
16 | |
17 | /* Power management registers */ | |
18 | #define PM_CFG_REVID 0x08 /* silicon revision code */ | |
19 | #define PM_CFG_IOBASE0 0x20 | |
20 | #define PM_CFG_IOBASE1 0x48 | |
21 | ||
22 | #define I2C_DIR (pm_io_base+0x40) | |
23 | #define I2C_OUT (pm_io_base+0x42) | |
24 | #define I2C_IN (pm_io_base+0x44) | |
25 | #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ | |
26 | #define I2C_SDA 0x04 | |
27 | ||
28 | /* io-region reservation */ | |
29 | #define IOSPACE 0x06 | |
1da177e4 | 30 | |
d6072f84 | 31 | static struct pci_driver vt586b_driver; |
60507095 | 32 | static u16 pm_io_base; |
1da177e4 LT |
33 | |
34 | /* | |
35 | It does not appear from the datasheet that the GPIO pins are | |
36 | open drain. So a we set a low value by setting the direction to | |
37 | output and a high value by setting the direction to input and | |
38 | relying on the required I2C pullup. The data value is initialized | |
39 | to 0 in via_init() and never changed. | |
40 | */ | |
41 | static void bit_via_setscl(void *data, int state) | |
42 | { | |
43 | outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); | |
44 | } | |
45 | ||
46 | static void bit_via_setsda(void *data, int state) | |
47 | { | |
48 | outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); | |
49 | } | |
50 | ||
51 | static int bit_via_getscl(void *data) | |
52 | { | |
53 | return (0 != (inb(I2C_IN) & I2C_SCL)); | |
54 | } | |
55 | ||
56 | static int bit_via_getsda(void *data) | |
57 | { | |
58 | return (0 != (inb(I2C_IN) & I2C_SDA)); | |
59 | } | |
60 | ||
61 | ||
62 | static struct i2c_algo_bit_data bit_data = { | |
63 | .setsda = bit_via_setsda, | |
64 | .setscl = bit_via_setscl, | |
65 | .getsda = bit_via_getsda, | |
66 | .getscl = bit_via_getscl, | |
67 | .udelay = 5, | |
1da177e4 LT |
68 | .timeout = HZ |
69 | }; | |
70 | ||
71 | static struct i2c_adapter vt586b_adapter = { | |
72 | .owner = THIS_MODULE, | |
3401b2ff | 73 | .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, |
1da177e4 LT |
74 | .name = "VIA i2c", |
75 | .algo_data = &bit_data, | |
76 | }; | |
77 | ||
78 | ||
392debf1 | 79 | static const struct pci_device_id vt586b_ids[] = { |
1da177e4 LT |
80 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, |
81 | { 0, } | |
82 | }; | |
83 | ||
84 | MODULE_DEVICE_TABLE (pci, vt586b_ids); | |
85 | ||
0b255e92 | 86 | static int vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) |
1da177e4 LT |
87 | { |
88 | u16 base; | |
89 | u8 rev; | |
90 | int res; | |
91 | ||
92 | if (pm_io_base) { | |
93 | dev_err(&dev->dev, "i2c-via: Will only support one host\n"); | |
94 | return -ENODEV; | |
95 | } | |
96 | ||
97 | pci_read_config_byte(dev, PM_CFG_REVID, &rev); | |
98 | ||
99 | switch (rev) { | |
100 | case 0x00: | |
101 | base = PM_CFG_IOBASE0; | |
102 | break; | |
103 | case 0x01: | |
104 | case 0x10: | |
105 | base = PM_CFG_IOBASE1; | |
106 | break; | |
107 | ||
108 | default: | |
109 | base = PM_CFG_IOBASE1; | |
110 | /* later revision */ | |
111 | } | |
112 | ||
113 | pci_read_config_word(dev, base, &pm_io_base); | |
114 | pm_io_base &= (0xff << 8); | |
115 | ||
d6072f84 | 116 | if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) { |
1da177e4 LT |
117 | dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); |
118 | return -ENODEV; | |
119 | } | |
120 | ||
121 | outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); | |
122 | outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); | |
123 | ||
405ae7d3 | 124 | /* set up the sysfs linkage to our parent device */ |
1da177e4 LT |
125 | vt586b_adapter.dev.parent = &dev->dev; |
126 | ||
127 | res = i2c_bit_add_bus(&vt586b_adapter); | |
128 | if ( res < 0 ) { | |
129 | release_region(I2C_DIR, IOSPACE); | |
130 | pm_io_base = 0; | |
131 | return res; | |
132 | } | |
133 | return 0; | |
134 | } | |
135 | ||
0b255e92 | 136 | static void vt586b_remove(struct pci_dev *dev) |
1da177e4 | 137 | { |
3269711b | 138 | i2c_del_adapter(&vt586b_adapter); |
1da177e4 LT |
139 | release_region(I2C_DIR, IOSPACE); |
140 | pm_io_base = 0; | |
141 | } | |
142 | ||
143 | ||
144 | static struct pci_driver vt586b_driver = { | |
145 | .name = "vt586b_smbus", | |
146 | .id_table = vt586b_ids, | |
147 | .probe = vt586b_probe, | |
0b255e92 | 148 | .remove = vt586b_remove, |
1da177e4 LT |
149 | }; |
150 | ||
56f21788 | 151 | module_pci_driver(vt586b_driver); |
1da177e4 | 152 | |
96de0e25 | 153 | MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>"); |
1da177e4 LT |
154 | MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); |
155 | MODULE_LICENSE("GPL"); |