drivers/hwmon/atxp1.c

   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);