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 struct atxp1_data { 49 struct device *hwmon_dev; 50 struct mutex update_lock; 51 unsigned long last_updated; 52 u8 valid; 53 struct { 54 u8 vid; /* VID output register */ 55 u8 cpu_vid; /* VID input from CPU */ 56 u8 gpio1; /* General purpose I/O register 1 */ 57 u8 gpio2; /* General purpose I/O register 2 */ 58 } reg; 59 u8 vrm; /* Detected CPU VRM */ 60 }; 61 62 static struct atxp1_data *atxp1_update_device(struct device *dev) 63 { 64 struct i2c_client *client; 65 struct atxp1_data *data; 66 67 client = to_i2c_client(dev); 68 data = i2c_get_clientdata(client); 69 70 mutex_lock(&data->update_lock); 71 72 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 73 74 /* Update local register data */ 75 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); 76 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, 77 ATXP1_CVID); 78 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); 79 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); 80 81 data->valid = 1; 82 } 83 84 mutex_unlock(&data->update_lock); 85 86 return data; 87 } 88 89 /* sys file functions for cpu0_vid */ 90 static ssize_t atxp1_showvcore(struct device *dev, 91 struct device_attribute *attr, char *buf) 92 { 93 int size; 94 struct atxp1_data *data; 95 96 data = atxp1_update_device(dev); 97 98 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, 99 data->vrm)); 100 101 return size; 102 } 103 104 static ssize_t atxp1_storevcore(struct device *dev, 105 struct device_attribute *attr, 106 const char *buf, size_t count) 107 { 108 struct atxp1_data *data; 109 struct i2c_client *client; 110 int vid, cvid; 111 unsigned long vcore; 112 int err; 113 114 client = to_i2c_client(dev); 115 data = atxp1_update_device(dev); 116 117 err = kstrtoul(buf, 10, &vcore); 118 if (err) 119 return err; 120 121 vcore /= 25; 122 vcore *= 25; 123 124 /* Calculate VID */ 125 vid = vid_to_reg(vcore, data->vrm); 126 if (vid < 0) { 127 dev_err(dev, "VID calculation failed.\n"); 128 return vid; 129 } 130 131 /* 132 * If output enabled, use control register value. 133 * Otherwise original CPU VID 134 */ 135 if (data->reg.vid & ATXP1_VIDENA) 136 cvid = data->reg.vid & ATXP1_VIDMASK; 137 else 138 cvid = data->reg.cpu_vid; 139 140 /* Nothing changed, aborting */ 141 if (vid == cvid) 142 return count; 143 144 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); 145 146 /* Write every 25 mV step to increase stability */ 147 if (cvid > vid) { 148 for (; cvid >= vid; cvid--) 149 i2c_smbus_write_byte_data(client, 150 ATXP1_VID, cvid | ATXP1_VIDENA); 151 } else { 152 for (; cvid <= vid; cvid++) 153 i2c_smbus_write_byte_data(client, 154 ATXP1_VID, cvid | ATXP1_VIDENA); 155 } 156 157 data->valid = 0; 158 159 return count; 160 } 161 162 /* 163 * CPU core reference voltage 164 * unit: millivolt 165 */ 166 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, 167 atxp1_storevcore); 168 169 /* sys file functions for GPIO1 */ 170 static ssize_t atxp1_showgpio1(struct device *dev, 171 struct device_attribute *attr, char *buf) 172 { 173 int size; 174 struct atxp1_data *data; 175 176 data = atxp1_update_device(dev); 177 178 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 179 180 return size; 181 } 182 183 static ssize_t atxp1_storegpio1(struct device *dev, 184 struct device_attribute *attr, const char *buf, 185 size_t count) 186 { 187 struct atxp1_data *data; 188 struct i2c_client *client; 189 unsigned long value; 190 int err; 191 192 client = to_i2c_client(dev); 193 data = atxp1_update_device(dev); 194 195 err = kstrtoul(buf, 16, &value); 196 if (err) 197 return err; 198 199 value &= ATXP1_GPIO1MASK; 200 201 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 202 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 203 204 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 205 206 data->valid = 0; 207 } 208 209 return count; 210 } 211 212 /* 213 * GPIO1 data register 214 * unit: Four bit as hex (e.g. 0x0f) 215 */ 216 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1); 217 218 /* sys file functions for GPIO2 */ 219 static ssize_t atxp1_showgpio2(struct device *dev, 220 struct device_attribute *attr, char *buf) 221 { 222 int size; 223 struct atxp1_data *data; 224 225 data = atxp1_update_device(dev); 226 227 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 228 229 return size; 230 } 231 232 static ssize_t atxp1_storegpio2(struct device *dev, 233 struct device_attribute *attr, 234 const char *buf, size_t count) 235 { 236 struct atxp1_data *data = atxp1_update_device(dev); 237 struct i2c_client *client = to_i2c_client(dev); 238 unsigned long value; 239 int err; 240 241 err = kstrtoul(buf, 16, &value); 242 if (err) 243 return err; 244 value &= 0xff; 245 246 if (value != data->reg.gpio2) { 247 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 248 249 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 250 251 data->valid = 0; 252 } 253 254 return count; 255 } 256 257 /* 258 * GPIO2 data register 259 * unit: Eight bit as hex (e.g. 0xff) 260 */ 261 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2); 262 263 static struct attribute *atxp1_attributes[] = { 264 &dev_attr_gpio1.attr, 265 &dev_attr_gpio2.attr, 266 &dev_attr_cpu0_vid.attr, 267 NULL 268 }; 269 270 static const struct attribute_group atxp1_group = { 271 .attrs = atxp1_attributes, 272 }; 273 274 275 /* Return 0 if detection is successful, -ENODEV otherwise */ 276 static 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 /* 294 * No vendor ID, now checking if registers 0x10,0x11 (non-existent) 295 * showing the same as register 0x00 296 */ 297 temp = i2c_smbus_read_byte_data(new_client, 0x00); 298 299 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) && 300 (i2c_smbus_read_byte_data(new_client, 0x11) == temp))) 301 return -ENODEV; 302 303 /* Get VRM */ 304 temp = vid_which_vrm(); 305 306 if ((temp != 90) && (temp != 91)) { 307 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n", 308 temp / 10, temp % 10); 309 return -ENODEV; 310 } 311 312 strlcpy(info->type, "atxp1", I2C_NAME_SIZE); 313 314 return 0; 315 } 316 317 static int atxp1_probe(struct i2c_client *new_client, 318 const struct i2c_device_id *id) 319 { 320 struct atxp1_data *data; 321 int err; 322 323 data = devm_kzalloc(&new_client->dev, sizeof(struct atxp1_data), 324 GFP_KERNEL); 325 if (!data) 326 return -ENOMEM; 327 328 /* Get VRM */ 329 data->vrm = vid_which_vrm(); 330 331 i2c_set_clientdata(new_client, data); 332 mutex_init(&data->update_lock); 333 334 /* Register sysfs hooks */ 335 err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group); 336 if (err) 337 return err; 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; 349 350 exit_remove_files: 351 sysfs_remove_group(&new_client->dev.kobj, &atxp1_group); 352 return err; 353 }; 354 355 static int atxp1_remove(struct i2c_client *client) 356 { 357 struct atxp1_data *data = i2c_get_clientdata(client); 358 359 hwmon_device_unregister(data->hwmon_dev); 360 sysfs_remove_group(&client->dev.kobj, &atxp1_group); 361 362 return 0; 363 }; 364 365 static const struct i2c_device_id atxp1_id[] = { 366 { "atxp1", 0 }, 367 { } 368 }; 369 MODULE_DEVICE_TABLE(i2c, atxp1_id); 370 371 static struct i2c_driver atxp1_driver = { 372 .class = I2C_CLASS_HWMON, 373 .driver = { 374 .name = "atxp1", 375 }, 376 .probe = atxp1_probe, 377 .remove = atxp1_remove, 378 .id_table = atxp1_id, 379 .detect = atxp1_detect, 380 .address_list = normal_i2c, 381 }; 382 383 module_i2c_driver(atxp1_driver); 384