1/* 2 atxp1.c - kernel module for setting CPU VID and general purpose 3 I/Os using the Attansic ATXP1 chip. 4 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. 9 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. 14 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. 18 19*/ 20 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> 31#include <linux/slab.h> 32 33MODULE_LICENSE("GPL"); 34MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); 35MODULE_VERSION("0.6.3"); 36MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>"); 37 38#define ATXP1_VID 0x00 39#define ATXP1_CVID 0x01 40#define ATXP1_GPIO1 0x06 41#define ATXP1_GPIO2 0x0a 42#define ATXP1_VIDENA 0x20 43#define ATXP1_VIDMASK 0x1f 44#define ATXP1_GPIO1MASK 0x0f 45 46static const unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END }; 47 48static int atxp1_probe(struct i2c_client *client, 49 const struct i2c_device_id *id); 50static int atxp1_remove(struct i2c_client *client); 51static struct atxp1_data * atxp1_update_device(struct device *dev); 52static int atxp1_detect(struct i2c_client *client, struct i2c_board_info *info); 53 54static const struct i2c_device_id atxp1_id[] = { 55 { "atxp1", 0 }, 56 { } 57}; 58MODULE_DEVICE_TABLE(i2c, atxp1_id); 59 60static struct i2c_driver atxp1_driver = { 61 .class = I2C_CLASS_HWMON, 62 .driver = { 63 .name = "atxp1", 64 }, 65 .probe = atxp1_probe, 66 .remove = atxp1_remove, 67 .id_table = atxp1_id, 68 .detect = atxp1_detect, 69 .address_list = normal_i2c, 70}; 71 72struct atxp1_data { 73 struct device *hwmon_dev; 74 struct mutex update_lock; 75 unsigned long last_updated; 76 u8 valid; 77 struct { 78 u8 vid; /* VID output register */ 79 u8 cpu_vid; /* VID input from CPU */ 80 u8 gpio1; /* General purpose I/O register 1 */ 81 u8 gpio2; /* General purpose I/O register 2 */ 82 } reg; 83 u8 vrm; /* Detected CPU VRM */ 84}; 85 86static struct atxp1_data * atxp1_update_device(struct device *dev) 87{ 88 struct i2c_client *client; 89 struct atxp1_data *data; 90 91 client = to_i2c_client(dev); 92 data = i2c_get_clientdata(client); 93 94 mutex_lock(&data->update_lock); 95 96 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 97 98 /* Update local register data */ 99 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); 100 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID); 101 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); 102 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); 103 104 data->valid = 1; 105 } 106 107 mutex_unlock(&data->update_lock); 108 109 return(data); 110} 111 112/* sys file functions for cpu0_vid */ 113static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf) 114{ 115 int size; 116 struct atxp1_data *data; 117 118 data = atxp1_update_device(dev); 119 120 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm)); 121 122 return size; 123} 124 125static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 126{ 127 struct atxp1_data *data; 128 struct i2c_client *client; 129 int vid, cvid; 130 unsigned int vcore; 131 132 client = to_i2c_client(dev); 133 data = atxp1_update_device(dev); 134 135 vcore = simple_strtoul(buf, NULL, 10); 136 vcore /= 25; 137 vcore *= 25; 138 139 /* Calculate VID */ 140 vid = vid_to_reg(vcore, data->vrm); 141 142 if (vid < 0) { 143 dev_err(dev, "VID calculation failed.\n"); 144 return -1; 145 } 146 147 /* If output enabled, use control register value. Otherwise original CPU VID */ 148 if (data->reg.vid & ATXP1_VIDENA) 149 cvid = data->reg.vid & ATXP1_VIDMASK; 150 else 151 cvid = data->reg.cpu_vid; 152 153 /* Nothing changed, aborting */ 154 if (vid == cvid) 155 return count; 156 157 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid); 158 159 /* Write every 25 mV step to increase stability */ 160 if (cvid > vid) { 161 for (; cvid >= vid; cvid--) { 162 i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA); 163 } 164 } 165 else { 166 for (; cvid <= vid; cvid++) { 167 i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA); 168 } 169 } 170 171 data->valid = 0; 172 173 return count; 174} 175 176/* CPU core reference voltage 177 unit: millivolt 178*/ 179static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore); 180 181/* sys file functions for GPIO1 */ 182static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf) 183{ 184 int size; 185 struct atxp1_data *data; 186 187 data = atxp1_update_device(dev); 188 189 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 190 191 return size; 192} 193 194static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count) 195{ 196 struct atxp1_data *data; 197 struct i2c_client *client; 198 unsigned int value; 199 200 client = to_i2c_client(dev); 201 data = atxp1_update_device(dev); 202 203 value = simple_strtoul(buf, NULL, 16); 204 205 value &= ATXP1_GPIO1MASK; 206 207 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 208 dev_info(dev, "Writing 0x%x to GPIO1.\n", value); 209 210 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 211 212 data->valid = 0; 213 } 214 215 return count; 216} 217 218/* GPIO1 data register 219 unit: Four bit as hex (e.g. 0x0f) 220*/ 221static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1); 222 223/* sys file functions for GPIO2 */ 224static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf) 225{ 226 int size; 227 struct atxp1_data *data; 228 229 data = atxp1_update_device(dev); 230 231 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 232 233 return size; 234} 235 236static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 237{ 238 struct atxp1_data *data; 239 struct i2c_client *client; 240 unsigned int value; 241 242 client = to_i2c_client(dev); 243 data = atxp1_update_device(dev); 244 245 value = simple_strtoul(buf, NULL, 16) & 0xff; 246 247 if (value != data->reg.gpio2) { 248 dev_info(dev, "Writing 0x%x to GPIO1.\n", value); 249 250 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 251 252 data->valid = 0; 253 } 254 255 return count; 256} 257 258/* GPIO2 data register 259 unit: Eight bit as hex (e.g. 0xff) 260*/ 261static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2); 262 263static struct attribute *atxp1_attributes[] = { 264 &dev_attr_gpio1.attr, 265 &dev_attr_gpio2.attr, 266 &dev_attr_cpu0_vid.attr, 267 NULL 268}; 269 270static const struct attribute_group atxp1_group = { 271 .attrs = atxp1_attributes, 272}; 273 274 275/* Return 0 if detection is successful, -ENODEV otherwise */ 276static int atxp1_detect(struct i2c_client *new_client, 277 struct i2c_board_info *info) 278{ 279 struct i2c_adapter *adapter = new_client->adapter; 280 281 u8 temp; 282 283 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 284 return -ENODEV; 285 286 /* Detect ATXP1, checking if vendor ID registers are all zero */ 287 if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) && 288 (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) && 289 (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) && 290 (i2c_smbus_read_byte_data(new_client, 0xff) == 0))) 291 return -ENODEV; 292 293 /* No vendor ID, now checking if registers 0x10,0x11 (non-existent) 294 * showing the same as register 0x00 */ 295 temp = i2c_smbus_read_byte_data(new_client, 0x00); 296 297 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) && 298 (i2c_smbus_read_byte_data(new_client, 0x11) == temp))) 299 return -ENODEV; 300 301 /* Get VRM */ 302 temp = vid_which_vrm(); 303 304 if ((temp != 90) && (temp != 91)) { 305 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n", 306 temp / 10, temp % 10); 307 return -ENODEV; 308 } 309 310 strlcpy(info->type, "atxp1", I2C_NAME_SIZE); 311 312 return 0; 313} 314 315static int atxp1_probe(struct i2c_client *new_client, 316 const struct i2c_device_id *id) 317{ 318 struct atxp1_data *data; 319 int err; 320 321 data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL); 322 if (!data) { 323 err = -ENOMEM; 324 goto exit; 325 } 326 327 /* Get VRM */ 328 data->vrm = vid_which_vrm(); 329 330 i2c_set_clientdata(new_client, data); 331 data->valid = 0; 332 333 mutex_init(&data->update_lock); 334 335 /* Register sysfs hooks */ 336 if ((err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group))) 337 goto exit_free; 338 339 data->hwmon_dev = hwmon_device_register(&new_client->dev); 340 if (IS_ERR(data->hwmon_dev)) { 341 err = PTR_ERR(data->hwmon_dev); 342 goto exit_remove_files; 343 } 344 345 dev_info(&new_client->dev, "Using VRM: %d.%d\n", 346 data->vrm / 10, data->vrm % 10); 347 348 return 0; 349 350exit_remove_files: 351 sysfs_remove_group(&new_client->dev.kobj, &atxp1_group); 352exit_free: 353 kfree(data); 354exit: 355 return err; 356}; 357 358static int atxp1_remove(struct i2c_client *client) 359{ 360 struct atxp1_data * data = i2c_get_clientdata(client); 361 362 hwmon_device_unregister(data->hwmon_dev); 363 sysfs_remove_group(&client->dev.kobj, &atxp1_group); 364 365 kfree(data); 366 367 return 0; 368}; 369 370static int __init atxp1_init(void) 371{ 372 return i2c_add_driver(&atxp1_driver); 373}; 374 375static void __exit atxp1_exit(void) 376{ 377 i2c_del_driver(&atxp1_driver); 378}; 379 380module_init(atxp1_init); 381module_exit(atxp1_exit); 382