aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-i810.c
blob: 0ff7016e0629b6bf5622c8f0d9fb5c10b022f97e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
    i2c-i810.c - Part of lm_sensors, Linux kernel modules for hardware
              monitoring
    Copyright (c) 1998, 1999, 2000  Frodo Looijaard <frodol@dds.nl>,
    Philip Edelbrock <phil@netroedge.com>,
    Ralph Metzler <rjkm@thp.uni-koeln.de>, and
    Mark D. Studebaker <mdsxyz123@yahoo.com>
    
    Based on code written by Ralph Metzler <rjkm@thp.uni-koeln.de> and
    Simon Vogl

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
   This interfaces to the I810/I815 to provide access to
   the DDC Bus and the I2C Bus.

   SUPPORTED DEVICES	PCI ID
   i810AA		7121           
   i810AB		7123           
   i810E		7125           
   i815			1132           
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>

/* GPIO register locations */
#define I810_IOCONTROL_OFFSET	0x5000
#define I810_HVSYNC		0x00	/* not used */
#define I810_GPIOA		0x10
#define I810_GPIOB		0x14

/* bit locations in the registers */
#define SCL_DIR_MASK		0x0001
#define SCL_DIR			0x0002
#define SCL_VAL_MASK		0x0004
#define SCL_VAL_OUT		0x0008
#define SCL_VAL_IN		0x0010
#define SDA_DIR_MASK		0x0100
#define SDA_DIR			0x0200
#define SDA_VAL_MASK		0x0400
#define SDA_VAL_OUT		0x0800
#define SDA_VAL_IN		0x1000

/* initialization states */
#define INIT1			0x1
#define INIT2			0x2
#define INIT3			0x4

/* delays */
#define CYCLE_DELAY		10
#define TIMEOUT			(HZ / 2)

static void __iomem *ioaddr;

/* The i810 GPIO registers have individual masks for each bit
   so we never have to read before writing. Nice. */

static void bit_i810i2c_setscl(void *data, int val)
{
	writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,
	     ioaddr + I810_GPIOB);
	readl(ioaddr + I810_GPIOB);	/* flush posted write */
}

static void bit_i810i2c_setsda(void *data, int val)
{
 	writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,
	     ioaddr + I810_GPIOB);
	readl(ioaddr + I810_GPIOB);	/* flush posted write */
}

/* The GPIO pins are open drain, so the pins could always remain outputs.
   However, some chip versions don't latch the inputs unless they
   are set as inputs.
   We rely on the i2c-algo-bit routines to set the pins high before
   reading the input from other chips. Following guidance in the 815
   prog. ref. guide, we do a "dummy write" of 0 to the register before
   reading which forces the input value to be latched. We presume this
   applies to the 810 as well; shouldn't hurt anyway. This is necessary to get
   i2c_algo_bit bit_test=1 to pass. */

static int bit_i810i2c_getscl(void *data)
{
	writel(SCL_DIR_MASK, ioaddr + I810_GPIOB);
	writel(0, ioaddr + I810_GPIOB);
	return (0 != (readl(ioaddr + I810_GPIOB) & SCL_VAL_IN));
}

static int bit_i810i2c_getsda(void *data)
{
	writel(SDA_DIR_MASK, ioaddr + I810_GPIOB);
	writel(0, ioaddr + I810_GPIOB);
	return (0 != (readl(ioaddr + I810_GPIOB) & SDA_VAL_IN));
}

static void bit_i810ddc_setscl(void *data, int val)
{
	writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,
	     ioaddr + I810_GPIOA);
	readl(ioaddr + I810_GPIOA);	/* flush posted write */
}

static void bit_i810ddc_setsda(void *data, int val)
{
 	writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,
	     ioaddr + I810_GPIOA);
	readl(ioaddr + I810_GPIOA);	/* flush posted write */
}

static int bit_i810ddc_getscl(void *data)
{
	writel(SCL_DIR_MASK, ioaddr + I810_GPIOA);
	writel(0, ioaddr + I810_GPIOA);
	return (0 != (readl(ioaddr + I810_GPIOA) & SCL_VAL_IN));
}

static int bit_i810ddc_getsda(void *data)
{
	writel(SDA_DIR_MASK, ioaddr + I810_GPIOA);
	writel(0, ioaddr + I810_GPIOA);
	return (0 != (readl(ioaddr + I810_GPIOA) & SDA_VAL_IN));
}

static int config_i810(struct pci_dev *dev)
{
	unsigned long cadr;

	/* map I810 memory */
	cadr = dev->resource[1].start;
	cadr += I810_IOCONTROL_OFFSET;
	cadr &= PCI_BASE_ADDRESS_MEM_MASK;
	ioaddr = ioremap_nocache(cadr, 0x1000);
	if (ioaddr) {
		bit_i810i2c_setscl(NULL, 1);
		bit_i810i2c_setsda(NULL, 1);
		bit_i810ddc_setscl(NULL, 1);
		bit_i810ddc_setsda(NULL, 1);
		return 0;
	}
	return -ENODEV;
}

static struct i2c_algo_bit_data i810_i2c_bit_data = {
	.setsda		= bit_i810i2c_setsda,
	.setscl		= bit_i810i2c_setscl,
	.getsda		= bit_i810i2c_getsda,
	.getscl		= bit_i810i2c_getscl,
	.udelay		= CYCLE_DELAY,
	.mdelay		= CYCLE_DELAY,
	.timeout	= TIMEOUT,
};

static struct i2c_adapter i810_i2c_adapter = {
	.owner		= THIS_MODULE,
	.name		= "I810/I815 I2C Adapter",
	.algo_data	= &i810_i2c_bit_data,
};

static struct i2c_algo_bit_data i810_ddc_bit_data = {
	.setsda		= bit_i810ddc_setsda,
	.setscl		= bit_i810ddc_setscl,
	.getsda		= bit_i810ddc_getsda,
	.getscl		= bit_i810ddc_getscl,
	.udelay		= CYCLE_DELAY,
	.mdelay		= CYCLE_DELAY,
	.timeout	= TIMEOUT,
};

static struct i2c_adapter i810_ddc_adapter = {
	.owner		= THIS_MODULE,
	.name		= "I810/I815 DDC Adapter",
	.algo_data	= &i810_ddc_bit_data,
};

static struct pci_device_id i810_ids[] __devinitdata = {
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG1) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810E_IG) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82815_CGC) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82845G_IG) },
	{ 0, },
};

MODULE_DEVICE_TABLE (pci, i810_ids);

static int __devinit i810_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
	int retval;

	retval = config_i810(dev);
	if (retval)
		return retval;
	dev_info(&dev->dev, "i810/i815 i2c device found.\n");

	/* set up the sysfs linkage to our parent device */
	i810_i2c_adapter.dev.parent = &dev->dev;
	i810_ddc_adapter.dev.parent = &dev->dev;

	retval = i2c_bit_add_bus(&i810_i2c_adapter);
	if (retval)
		return retval;
	retval = i2c_bit_add_bus(&i810_ddc_adapter);
	if (retval)
		i2c_bit_del_bus(&i810_i2c_adapter);
	return retval;
}

static void __devexit i810_remove(struct pci_dev *dev)
{
	i2c_bit_del_bus(&i810_ddc_adapter);
	i2c_bit_del_bus(&i810_i2c_adapter);
	iounmap(ioaddr);
}

static struct pci_driver i810_driver = {
	.name		= "i810_smbus",
	.id_table	= i810_ids,
	.probe		= i810_probe,
	.remove		= __devexit_p(i810_remove),
};

static int __init i2c_i810_init(void)
{
	return pci_register_driver(&i810_driver);
}

static void __exit i2c_i810_exit(void)
{
	pci_unregister_driver(&i810_driver);
}

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
		"Philip Edelbrock <phil@netroedge.com>, "
		"Ralph Metzler <rjkm@thp.uni-koeln.de>, "
		"and Mark D. Studebaker <mdsxyz123@yahoo.com>");
MODULE_DESCRIPTION("I810/I815 I2C/DDC driver");
MODULE_LICENSE("GPL");

module_init(i2c_i810_init);
module_exit(i2c_i810_exit);