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