2 sis96x.c - Part of lm_sensors, Linux kernel modules for hardware
5 Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 This module must be considered BETA unless and until
24 the chipset manufacturer releases a datasheet.
25 The register definitions are based on the SiS630.
27 This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c)
28 for just about every machine for which users have reported.
29 If this module isn't detecting your 96x south bridge, have a
32 We assume there can only be one SiS96x with one SMBus interface.
35 #include <linux/module.h>
36 #include <linux/pci.h>
37 #include <linux/kernel.h>
38 #include <linux/delay.h>
39 #include <linux/stddef.h>
40 #include <linux/sched.h>
41 #include <linux/ioport.h>
42 #include <linux/i2c.h>
43 #include <linux/init.h>
46 /* base address register in PCI config space */
47 #define SIS96x_BAR 0x04
49 /* SiS96x SMBus registers */
53 #define SMB_HOST_CNT 0x03
56 #define SMB_PCOUNT 0x06
57 #define SMB_COUNT 0x07
59 #define SMB_DEV_ADDR 0x10
64 /* register count for request_region */
65 #define SMB_IOSIZE 0x20
68 #define MAX_TIMEOUT 500
70 /* SiS96x SMBus constants */
71 #define SIS96x_QUICK 0x00
72 #define SIS96x_BYTE 0x01
73 #define SIS96x_BYTE_DATA 0x02
74 #define SIS96x_WORD_DATA 0x03
75 #define SIS96x_PROC_CALL 0x04
76 #define SIS96x_BLOCK_DATA 0x05
78 static struct pci_driver sis96x_driver;
79 static struct i2c_adapter sis96x_adapter;
80 static u16 sis96x_smbus_base;
82 static inline u8 sis96x_read(u8 reg)
84 return inb(sis96x_smbus_base + reg) ;
87 static inline void sis96x_write(u8 reg, u8 data)
89 outb(data, sis96x_smbus_base + reg) ;
92 /* Execute a SMBus transaction.
93 int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA
95 static int sis96x_transaction(int size)
101 dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
103 /* Make sure the SMBus host is ready to start transmitting */
104 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
106 dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
107 "Resetting...\n", temp);
109 /* kill the transaction */
110 sis96x_write(SMB_HOST_CNT, 0x20);
113 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
114 dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
117 dev_dbg(&sis96x_adapter.dev, "Successful\n");
121 /* Turn off timeout interrupts, set fast host clock */
122 sis96x_write(SMB_CNT, 0x20);
124 /* clear all (sticky) status flags */
125 temp = sis96x_read(SMB_STS);
126 sis96x_write(SMB_STS, temp & 0x1e);
128 /* start the transaction by setting bit 4 and size bits */
129 sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
131 /* We will always wait for a fraction of a second! */
134 temp = sis96x_read(SMB_STS);
135 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
137 /* If the SMBus is still busy, we give up */
138 if (timeout >= MAX_TIMEOUT) {
139 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
143 /* device error - probably missing ACK */
145 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
151 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
155 /* Finish up by resetting the bus */
156 sis96x_write(SMB_STS, temp);
157 if ((temp = sis96x_read(SMB_STS))) {
158 dev_dbg(&sis96x_adapter.dev, "Failed reset at "
159 "end of transaction! (0x%02x)\n", temp);
165 /* Return -1 on error. */
166 static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
167 unsigned short flags, char read_write,
168 u8 command, int size, union i2c_smbus_data * data)
172 case I2C_SMBUS_QUICK:
173 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
178 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
179 if (read_write == I2C_SMBUS_WRITE)
180 sis96x_write(SMB_CMD, command);
184 case I2C_SMBUS_BYTE_DATA:
185 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
186 sis96x_write(SMB_CMD, command);
187 if (read_write == I2C_SMBUS_WRITE)
188 sis96x_write(SMB_BYTE, data->byte);
189 size = SIS96x_BYTE_DATA;
192 case I2C_SMBUS_PROC_CALL:
193 case I2C_SMBUS_WORD_DATA:
194 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
195 sis96x_write(SMB_CMD, command);
196 if (read_write == I2C_SMBUS_WRITE) {
197 sis96x_write(SMB_BYTE, data->word & 0xff);
198 sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
200 size = (size == I2C_SMBUS_PROC_CALL ?
201 SIS96x_PROC_CALL : SIS96x_WORD_DATA);
204 case I2C_SMBUS_BLOCK_DATA:
206 dev_info(&adap->dev, "SMBus block not implemented!\n");
211 dev_info(&adap->dev, "Unsupported I2C size\n");
216 if (sis96x_transaction(size))
219 if ((size != SIS96x_PROC_CALL) &&
220 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))
225 case SIS96x_BYTE_DATA:
226 data->byte = sis96x_read(SMB_BYTE);
229 case SIS96x_WORD_DATA:
230 case SIS96x_PROC_CALL:
231 data->word = sis96x_read(SMB_BYTE) +
232 (sis96x_read(SMB_BYTE + 1) << 8);
238 static u32 sis96x_func(struct i2c_adapter *adapter)
240 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
241 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
242 I2C_FUNC_SMBUS_PROC_CALL;
245 static const struct i2c_algorithm smbus_algorithm = {
246 .smbus_xfer = sis96x_access,
247 .functionality = sis96x_func,
250 static struct i2c_adapter sis96x_adapter = {
251 .owner = THIS_MODULE,
252 .id = I2C_HW_SMBUS_SIS96X,
253 .class = I2C_CLASS_HWMON,
254 .algo = &smbus_algorithm,
257 static struct pci_device_id sis96x_ids[] = {
258 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
262 MODULE_DEVICE_TABLE (pci, sis96x_ids);
264 static int __devinit sis96x_probe(struct pci_dev *dev,
265 const struct pci_device_id *id)
270 if (sis96x_smbus_base) {
271 dev_err(&dev->dev, "Only one device supported.\n");
275 pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww);
276 if (PCI_CLASS_SERIAL_SMBUS != ww) {
277 dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww);
281 sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR);
282 if (!sis96x_smbus_base) {
283 dev_err(&dev->dev, "SiS96x SMBus base address "
284 "not initialized!\n");
287 dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n",
290 /* Everything is happy, let's grab the memory and set things up. */
291 if (!request_region(sis96x_smbus_base, SMB_IOSIZE,
292 sis96x_driver.name)) {
293 dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x "
294 "already in use!\n", sis96x_smbus_base,
295 sis96x_smbus_base + SMB_IOSIZE - 1);
297 sis96x_smbus_base = 0;
301 /* set up the driverfs linkage to our parent device */
302 sis96x_adapter.dev.parent = &dev->dev;
304 snprintf(sis96x_adapter.name, I2C_NAME_SIZE,
305 "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base);
307 if ((retval = i2c_add_adapter(&sis96x_adapter))) {
308 dev_err(&dev->dev, "Couldn't register adapter!\n");
309 release_region(sis96x_smbus_base, SMB_IOSIZE);
310 sis96x_smbus_base = 0;
316 static void __devexit sis96x_remove(struct pci_dev *dev)
318 if (sis96x_smbus_base) {
319 i2c_del_adapter(&sis96x_adapter);
320 release_region(sis96x_smbus_base, SMB_IOSIZE);
321 sis96x_smbus_base = 0;
325 static struct pci_driver sis96x_driver = {
326 .name = "sis96x_smbus",
327 .id_table = sis96x_ids,
328 .probe = sis96x_probe,
329 .remove = __devexit_p(sis96x_remove),
332 static int __init i2c_sis96x_init(void)
334 return pci_register_driver(&sis96x_driver);
337 static void __exit i2c_sis96x_exit(void)
339 pci_unregister_driver(&sis96x_driver);
342 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
343 MODULE_DESCRIPTION("SiS96x SMBus driver");
344 MODULE_LICENSE("GPL");
346 /* Register initialization functions using helper macros */
347 module_init(i2c_sis96x_init);
348 module_exit(i2c_sis96x_exit);