2 atxp1.c - kernel module for setting CPU VID and general purpose
3 I/Os using the Attansic ATXP1 chip.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/jiffies.h>
25 #include <linux/i2c.h>
26 #include <linux/hwmon.h>
27 #include <linux/hwmon-vid.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
30 #include <linux/sysfs.h>
32 MODULE_LICENSE("GPL");
33 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
34 MODULE_VERSION("0.6.3");
35 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
37 #define ATXP1_VID 0x00
38 #define ATXP1_CVID 0x01
39 #define ATXP1_GPIO1 0x06
40 #define ATXP1_GPIO2 0x0a
41 #define ATXP1_VIDENA 0x20
42 #define ATXP1_VIDMASK 0x1f
43 #define ATXP1_GPIO1MASK 0x0f
45 static const unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
47 I2C_CLIENT_INSMOD_1(atxp1);
49 static int atxp1_probe(struct i2c_client *client,
50 const struct i2c_device_id *id);
51 static int atxp1_remove(struct i2c_client *client);
52 static struct atxp1_data * atxp1_update_device(struct device *dev);
53 static int atxp1_detect(struct i2c_client *client, struct i2c_board_info *info);
55 static const struct i2c_device_id atxp1_id[] = {
59 MODULE_DEVICE_TABLE(i2c, atxp1_id);
61 static struct i2c_driver atxp1_driver = {
62 .class = I2C_CLASS_HWMON,
67 .remove = atxp1_remove,
69 .detect = atxp1_detect,
70 .address_list = normal_i2c,
74 struct device *hwmon_dev;
75 struct mutex update_lock;
76 unsigned long last_updated;
79 u8 vid; /* VID output register */
80 u8 cpu_vid; /* VID input from CPU */
81 u8 gpio1; /* General purpose I/O register 1 */
82 u8 gpio2; /* General purpose I/O register 2 */
84 u8 vrm; /* Detected CPU VRM */
87 static struct atxp1_data * atxp1_update_device(struct device *dev)
89 struct i2c_client *client;
90 struct atxp1_data *data;
92 client = to_i2c_client(dev);
93 data = i2c_get_clientdata(client);
95 mutex_lock(&data->update_lock);
97 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
99 /* Update local register data */
100 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
101 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID);
102 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
103 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
108 mutex_unlock(&data->update_lock);
113 /* sys file functions for cpu0_vid */
114 static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf)
117 struct atxp1_data *data;
119 data = atxp1_update_device(dev);
121 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm));
126 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
128 struct atxp1_data *data;
129 struct i2c_client *client;
133 client = to_i2c_client(dev);
134 data = atxp1_update_device(dev);
136 vcore = simple_strtoul(buf, NULL, 10);
141 vid = vid_to_reg(vcore, data->vrm);
144 dev_err(dev, "VID calculation failed.\n");
148 /* If output enabled, use control register value. Otherwise original CPU VID */
149 if (data->reg.vid & ATXP1_VIDENA)
150 cvid = data->reg.vid & ATXP1_VIDMASK;
152 cvid = data->reg.cpu_vid;
154 /* Nothing changed, aborting */
158 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
160 /* Write every 25 mV step to increase stability */
162 for (; cvid >= vid; cvid--) {
163 i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
167 for (; cvid <= vid; cvid++) {
168 i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
177 /* CPU core reference voltage
180 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
182 /* sys file functions for GPIO1 */
183 static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf)
186 struct atxp1_data *data;
188 data = atxp1_update_device(dev);
190 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
195 static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count)
197 struct atxp1_data *data;
198 struct i2c_client *client;
201 client = to_i2c_client(dev);
202 data = atxp1_update_device(dev);
204 value = simple_strtoul(buf, NULL, 16);
206 value &= ATXP1_GPIO1MASK;
208 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
209 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
211 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
219 /* GPIO1 data register
220 unit: Four bit as hex (e.g. 0x0f)
222 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
224 /* sys file functions for GPIO2 */
225 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
228 struct atxp1_data *data;
230 data = atxp1_update_device(dev);
232 size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
237 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
239 struct atxp1_data *data;
240 struct i2c_client *client;
243 client = to_i2c_client(dev);
244 data = atxp1_update_device(dev);
246 value = simple_strtoul(buf, NULL, 16) & 0xff;
248 if (value != data->reg.gpio2) {
249 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
251 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
259 /* GPIO2 data register
260 unit: Eight bit as hex (e.g. 0xff)
262 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
264 static struct attribute *atxp1_attributes[] = {
265 &dev_attr_gpio1.attr,
266 &dev_attr_gpio2.attr,
267 &dev_attr_cpu0_vid.attr,
271 static const struct attribute_group atxp1_group = {
272 .attrs = atxp1_attributes,
276 /* Return 0 if detection is successful, -ENODEV otherwise */
277 static int atxp1_detect(struct i2c_client *new_client,
278 struct i2c_board_info *info)
280 struct i2c_adapter *adapter = new_client->adapter;
284 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
287 /* Detect ATXP1, checking if vendor ID registers are all zero */
288 if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
289 (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
290 (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
291 (i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
294 /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
295 * showing the same as register 0x00 */
296 temp = i2c_smbus_read_byte_data(new_client, 0x00);
298 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
299 (i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
303 temp = vid_which_vrm();
305 if ((temp != 90) && (temp != 91)) {
306 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
307 temp / 10, temp % 10);
311 strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
316 static int atxp1_probe(struct i2c_client *new_client,
317 const struct i2c_device_id *id)
319 struct atxp1_data *data;
322 data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL);
329 data->vrm = vid_which_vrm();
331 i2c_set_clientdata(new_client, data);
334 mutex_init(&data->update_lock);
336 /* Register sysfs hooks */
337 if ((err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group)))
340 data->hwmon_dev = hwmon_device_register(&new_client->dev);
341 if (IS_ERR(data->hwmon_dev)) {
342 err = PTR_ERR(data->hwmon_dev);
343 goto exit_remove_files;
346 dev_info(&new_client->dev, "Using VRM: %d.%d\n",
347 data->vrm / 10, data->vrm % 10);
352 sysfs_remove_group(&new_client->dev.kobj, &atxp1_group);
359 static int atxp1_remove(struct i2c_client *client)
361 struct atxp1_data * data = i2c_get_clientdata(client);
363 hwmon_device_unregister(data->hwmon_dev);
364 sysfs_remove_group(&client->dev.kobj, &atxp1_group);
371 static int __init atxp1_init(void)
373 return i2c_add_driver(&atxp1_driver);
376 static void __exit atxp1_exit(void)
378 i2c_del_driver(&atxp1_driver);
381 module_init(atxp1_init);
382 module_exit(atxp1_exit);