[PATCH] i2c-iop3xx: Avoid addressing self
[linux-2.6] / drivers / i2c / busses / i2c-voodoo3.c
1 /*
2     voodoo3.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>,
5     Philip Edelbrock <phil@netroedge.com>,
6     Ralph Metzler <rjkm@thp.uni-koeln.de>, and
7     Mark D. Studebaker <mdsxyz123@yahoo.com>
8     
9     Based on code written by Ralph Metzler <rjkm@thp.uni-koeln.de> and
10     Simon Vogl
11
12     This program is free software; you can redistribute it and/or modify
13     it under the terms of the GNU General Public License as published by
14     the Free Software Foundation; either version 2 of the License, or
15     (at your option) any later version.
16
17     This program is distributed in the hope that it will be useful,
18     but WITHOUT ANY WARRANTY; without even the implied warranty of
19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20     GNU General Public License for more details.
21
22     You should have received a copy of the GNU General Public License
23     along with this program; if not, write to the Free Software
24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27 /* This interfaces to the I2C bus of the Voodoo3 to gain access to
28     the BT869 and possibly other I2C devices. */
29
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/pci.h>
34 #include <linux/i2c.h>
35 #include <linux/i2c-algo-bit.h>
36 #include <asm/io.h>
37
38 /* the only registers we use */
39 #define REG             0x78
40 #define REG2            0x70
41
42 /* bit locations in the register */
43 #define DDC_ENAB        0x00040000
44 #define DDC_SCL_OUT     0x00080000
45 #define DDC_SDA_OUT     0x00100000
46 #define DDC_SCL_IN      0x00200000
47 #define DDC_SDA_IN      0x00400000
48 #define I2C_ENAB        0x00800000
49 #define I2C_SCL_OUT     0x01000000
50 #define I2C_SDA_OUT     0x02000000
51 #define I2C_SCL_IN      0x04000000
52 #define I2C_SDA_IN      0x08000000
53
54 /* initialization states */
55 #define INIT2           0x2
56 #define INIT3           0x4
57
58 /* delays */
59 #define CYCLE_DELAY     10
60 #define TIMEOUT         (HZ / 2)
61
62
63 static void __iomem *ioaddr;
64
65 /* The voo GPIO registers don't have individual masks for each bit
66    so we always have to read before writing. */
67
68 static void bit_vooi2c_setscl(void *data, int val)
69 {
70         unsigned int r;
71         r = readl(ioaddr + REG);
72         if (val)
73                 r |= I2C_SCL_OUT;
74         else
75                 r &= ~I2C_SCL_OUT;
76         writel(r, ioaddr + REG);
77         readl(ioaddr + REG);    /* flush posted write */
78 }
79
80 static void bit_vooi2c_setsda(void *data, int val)
81 {
82         unsigned int r;
83         r = readl(ioaddr + REG);
84         if (val)
85                 r |= I2C_SDA_OUT;
86         else
87                 r &= ~I2C_SDA_OUT;
88         writel(r, ioaddr + REG);
89         readl(ioaddr + REG);    /* flush posted write */
90 }
91
92 /* The GPIO pins are open drain, so the pins always remain outputs.
93    We rely on the i2c-algo-bit routines to set the pins high before
94    reading the input from other chips. */
95
96 static int bit_vooi2c_getscl(void *data)
97 {
98         return (0 != (readl(ioaddr + REG) & I2C_SCL_IN));
99 }
100
101 static int bit_vooi2c_getsda(void *data)
102 {
103         return (0 != (readl(ioaddr + REG) & I2C_SDA_IN));
104 }
105
106 static void bit_vooddc_setscl(void *data, int val)
107 {
108         unsigned int r;
109         r = readl(ioaddr + REG);
110         if (val)
111                 r |= DDC_SCL_OUT;
112         else
113                 r &= ~DDC_SCL_OUT;
114         writel(r, ioaddr + REG);
115         readl(ioaddr + REG);    /* flush posted write */
116 }
117
118 static void bit_vooddc_setsda(void *data, int val)
119 {
120         unsigned int r;
121         r = readl(ioaddr + REG);
122         if (val)
123                 r |= DDC_SDA_OUT;
124         else
125                 r &= ~DDC_SDA_OUT;
126         writel(r, ioaddr + REG);
127         readl(ioaddr + REG);    /* flush posted write */
128 }
129
130 static int bit_vooddc_getscl(void *data)
131 {
132         return (0 != (readl(ioaddr + REG) & DDC_SCL_IN));
133 }
134
135 static int bit_vooddc_getsda(void *data)
136 {
137         return (0 != (readl(ioaddr + REG) & DDC_SDA_IN));
138 }
139
140 static int config_v3(struct pci_dev *dev)
141 {
142         unsigned long cadr;
143
144         /* map Voodoo3 memory */
145         cadr = dev->resource[0].start;
146         cadr &= PCI_BASE_ADDRESS_MEM_MASK;
147         ioaddr = ioremap_nocache(cadr, 0x1000);
148         if (ioaddr) {
149                 writel(0x8160, ioaddr + REG2);
150                 writel(0xcffc0020, ioaddr + REG);
151                 dev_info(&dev->dev, "Using Banshee/Voodoo3 I2C device at %p\n", ioaddr);
152                 return 0;
153         }
154         return -ENODEV;
155 }
156
157 static struct i2c_algo_bit_data voo_i2c_bit_data = {
158         .setsda         = bit_vooi2c_setsda,
159         .setscl         = bit_vooi2c_setscl,
160         .getsda         = bit_vooi2c_getsda,
161         .getscl         = bit_vooi2c_getscl,
162         .udelay         = CYCLE_DELAY,
163         .mdelay         = CYCLE_DELAY,
164         .timeout        = TIMEOUT
165 };
166
167 static struct i2c_adapter voodoo3_i2c_adapter = {
168         .owner          = THIS_MODULE,
169         .class          = I2C_CLASS_TV_ANALOG, 
170         .name           = "I2C Voodoo3/Banshee adapter",
171         .algo_data      = &voo_i2c_bit_data,
172 };
173
174 static struct i2c_algo_bit_data voo_ddc_bit_data = {
175         .setsda         = bit_vooddc_setsda,
176         .setscl         = bit_vooddc_setscl,
177         .getsda         = bit_vooddc_getsda,
178         .getscl         = bit_vooddc_getscl,
179         .udelay         = CYCLE_DELAY,
180         .mdelay         = CYCLE_DELAY,
181         .timeout        = TIMEOUT
182 };
183
184 static struct i2c_adapter voodoo3_ddc_adapter = {
185         .owner          = THIS_MODULE,
186         .class          = I2C_CLASS_DDC, 
187         .name           = "DDC Voodoo3/Banshee adapter",
188         .algo_data      = &voo_ddc_bit_data,
189 };
190
191 static struct pci_device_id voodoo3_ids[] __devinitdata = {
192         { PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO3) },
193         { PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_BANSHEE) },
194         { 0, }
195 };
196
197 MODULE_DEVICE_TABLE (pci, voodoo3_ids);
198
199 static int __devinit voodoo3_probe(struct pci_dev *dev, const struct pci_device_id *id)
200 {
201         int retval;
202
203         retval = config_v3(dev);
204         if (retval)
205                 return retval;
206
207         /* set up the sysfs linkage to our parent device */
208         voodoo3_i2c_adapter.dev.parent = &dev->dev;
209         voodoo3_ddc_adapter.dev.parent = &dev->dev;
210
211         retval = i2c_bit_add_bus(&voodoo3_i2c_adapter);
212         if (retval)
213                 return retval;
214         retval = i2c_bit_add_bus(&voodoo3_ddc_adapter);
215         if (retval)
216                 i2c_bit_del_bus(&voodoo3_i2c_adapter);
217         return retval;
218 }
219
220 static void __devexit voodoo3_remove(struct pci_dev *dev)
221 {
222         i2c_bit_del_bus(&voodoo3_i2c_adapter);
223         i2c_bit_del_bus(&voodoo3_ddc_adapter);
224         iounmap(ioaddr);
225 }
226
227 static struct pci_driver voodoo3_driver = {
228         .name           = "voodoo3_smbus",
229         .id_table       = voodoo3_ids,
230         .probe          = voodoo3_probe,
231         .remove         = __devexit_p(voodoo3_remove),
232 };
233
234 static int __init i2c_voodoo3_init(void)
235 {
236         return pci_register_driver(&voodoo3_driver);
237 }
238
239 static void __exit i2c_voodoo3_exit(void)
240 {
241         pci_unregister_driver(&voodoo3_driver);
242 }
243
244
245 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
246                 "Philip Edelbrock <phil@netroedge.com>, "
247                 "Ralph Metzler <rjkm@thp.uni-koeln.de>, "
248                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
249 MODULE_DESCRIPTION("Voodoo3 I2C/SMBus driver");
250 MODULE_LICENSE("GPL");
251
252 module_init(i2c_voodoo3_init);
253 module_exit(i2c_voodoo3_exit);