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 33 MODULE_LICENSE("GPL"); 34 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); 35 MODULE_VERSION("0.6.3"); 36 MODULE_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 46 static const unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END }; 47 48 static int atxp1_probe(struct i2c_client *client, 49 const struct i2c_device_id *id); 50 static int atxp1_remove(struct i2c_client *client); 51 static struct atxp1_data *atxp1_update_device(struct device *dev); 52 static int atxp1_detect(struct i2c_client *client, struct i2c_board_info *info); 53 54 static const struct i2c_device_id atxp1_id[] = { 55 { "atxp1", 0 }, 56 { } 57 }; 58 MODULE_DEVICE_TABLE(i2c, atxp1_id); 59 60 static 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 72 struct 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 86 static 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, 101 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); 104 105 data->valid = 1; 106 } 107 108 mutex_unlock(&data->update_lock); 109 110 return data; 111 } 112 113 /* sys file functions for cpu0_vid */ 114 static ssize_t atxp1_showvcore(struct device *dev, 115 struct device_attribute *attr, char *buf) 116 { 117 int size; 118 struct atxp1_data *data; 119 120 data = atxp1_update_device(dev); 121 122 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, 123 data->vrm)); 124 125 return size; 126 } 127 128 static ssize_t atxp1_storevcore(struct device *dev, 129 struct device_attribute *attr, 130 const char *buf, size_t count) 131 { 132 struct atxp1_data *data; 133 struct i2c_client *client; 134 int vid, cvid; 135 unsigned long vcore; 136 int err; 137 138 client = to_i2c_client(dev); 139 data = atxp1_update_device(dev); 140 141 err = kstrtoul(buf, 10, &vcore); 142 if (err) 143 return err; 144 145 vcore /= 25; 146 vcore *= 25; 147 148 /* Calculate VID */ 149 vid = vid_to_reg(vcore, data->vrm); 150 151 if (vid < 0) { 152 dev_err(dev, "VID calculation failed.\n"); 153 return -1; 154 } 155 156 /* 157 * If output enabled, use control register value. 158 * Otherwise original CPU VID 159 */ 160 if (data->reg.vid & ATXP1_VIDENA) 161 cvid = data->reg.vid & ATXP1_VIDMASK; 162 else 163 cvid = data->reg.cpu_vid; 164 165 /* Nothing changed, aborting */ 166 if (vid == cvid) 167 return count; 168 169 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); 170 171 /* Write every 25 mV step to increase stability */ 172 if (cvid > vid) { 173 for (; cvid >= vid; cvid--) 174 i2c_smbus_write_byte_data(client, 175 ATXP1_VID, cvid | ATXP1_VIDENA); 176 } else { 177 for (; cvid <= vid; cvid++) 178 i2c_smbus_write_byte_data(client, 179 ATXP1_VID, cvid | ATXP1_VIDENA); 180 } 181 182 data->valid = 0; 183 184 return count; 185 } 186 187 /* 188 * CPU core reference voltage 189 * unit: millivolt 190 */ 191 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, 192 atxp1_storevcore); 193 194 /* sys file functions for GPIO1 */ 195 static ssize_t atxp1_showgpio1(struct device *dev, 196 struct device_attribute *attr, char *buf) 197 { 198 int size; 199 struct atxp1_data *data; 200 201 data = atxp1_update_device(dev); 202 203 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 204 205 return size; 206 } 207 208 static ssize_t atxp1_storegpio1(struct device *dev, 209 struct device_attribute *attr, const char *buf, 210 size_t count) 211 { 212 struct atxp1_data *data; 213 struct i2c_client *client; 214 unsigned long value; 215 int err; 216 217 client = to_i2c_client(dev); 218 data = atxp1_update_device(dev); 219 220 err = kstrtoul(buf, 16, &value); 221 if (err) 222 return err; 223 224 value &= ATXP1_GPIO1MASK; 225 226 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 227 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 228 229 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 230 231 data->valid = 0; 232 } 233 234 return count; 235 } 236 237 /* 238 * GPIO1 data register 239 * unit: Four bit as hex (e.g. 0x0f) 240 */ 241 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1); 242 243 /* sys file functions for GPIO2 */ 244 static ssize_t atxp1_showgpio2(struct device *dev, 245 struct device_attribute *attr, char *buf) 246 { 247 int size; 248 struct atxp1_data *data; 249 250 data = atxp1_update_device(dev); 251 252 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 253 254 return size; 255 } 256 257 static ssize_t atxp1_storegpio2(struct device *dev, 258 struct device_attribute *attr, 259 const char *buf, size_t count) 260 { 261 struct atxp1_data *data = atxp1_update_device(dev); 262 struct i2c_client *client = to_i2c_client(dev); 263 unsigned long value; 264 int err; 265 266 err = kstrtoul(buf, 16, &value); 267 if (err) 268 return err; 269 value &= 0xff; 270 271 if (value != data->reg.gpio2) { 272 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 273 274 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 275 276 data->valid = 0; 277 } 278 279 return count; 280 } 281 282 /* 283 * GPIO2 data register 284 * unit: Eight bit as hex (e.g. 0xff) 285 */ 286 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2); 287 288 static struct attribute *atxp1_attributes[] = { 289 &dev_attr_gpio1.attr, 290 &dev_attr_gpio2.attr, 291 &dev_attr_cpu0_vid.attr, 292 NULL 293 }; 294 295 static const struct attribute_group atxp1_group = { 296 .attrs = atxp1_attributes, 297 }; 298 299 300 /* Return 0 if detection is successful, -ENODEV otherwise */ 301 static int atxp1_detect(struct i2c_client *new_client, 302 struct i2c_board_info *info) 303 { 304 struct i2c_adapter *adapter = new_client->adapter; 305 306 u8 temp; 307 308 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 309 return -ENODEV; 310 311 /* Detect ATXP1, checking if vendor ID registers are all zero */ 312 if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) && 313 (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) && 314 (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) && 315 (i2c_smbus_read_byte_data(new_client, 0xff) == 0))) 316 return -ENODEV; 317 318 /* 319 * No vendor ID, now checking if registers 0x10,0x11 (non-existent) 320 * showing the same as register 0x00 321 */ 322 temp = i2c_smbus_read_byte_data(new_client, 0x00); 323 324 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) && 325 (i2c_smbus_read_byte_data(new_client, 0x11) == temp))) 326 return -ENODEV; 327 328 /* Get VRM */ 329 temp = vid_which_vrm(); 330 331 if ((temp != 90) && (temp != 91)) { 332 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n", 333 temp / 10, temp % 10); 334 return -ENODEV; 335 } 336 337 strlcpy(info->type, "atxp1", I2C_NAME_SIZE); 338 339 return 0; 340 } 341 342 static int atxp1_probe(struct i2c_client *new_client, 343 const struct i2c_device_id *id) 344 { 345 struct atxp1_data *data; 346 int err; 347 348 data = devm_kzalloc(&new_client->dev, sizeof(struct atxp1_data), 349 GFP_KERNEL); 350 if (!data) 351 return -ENOMEM; 352 353 /* Get VRM */ 354 data->vrm = vid_which_vrm(); 355 356 i2c_set_clientdata(new_client, data); 357 data->valid = 0; 358 359 mutex_init(&data->update_lock); 360 361 /* Register sysfs hooks */ 362 err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group); 363 if (err) 364 return err; 365 366 data->hwmon_dev = hwmon_device_register(&new_client->dev); 367 if (IS_ERR(data->hwmon_dev)) { 368 err = PTR_ERR(data->hwmon_dev); 369 goto exit_remove_files; 370 } 371 372 dev_info(&new_client->dev, "Using VRM: %d.%d\n", 373 data->vrm / 10, data->vrm % 10); 374 375 return 0; 376 377 exit_remove_files: 378 sysfs_remove_group(&new_client->dev.kobj, &atxp1_group); 379 return err; 380 }; 381 382 static int atxp1_remove(struct i2c_client *client) 383 { 384 struct atxp1_data *data = i2c_get_clientdata(client); 385 386 hwmon_device_unregister(data->hwmon_dev); 387 sysfs_remove_group(&client->dev.kobj, &atxp1_group); 388 389 return 0; 390 }; 391 392 module_i2c_driver(atxp1_driver); 393