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