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 I2C_CLIENT_INSMOD_1(atxp1);
  48
  49 static int atxp1_probe(struct i2c_client *client,
  50                        const struct i2c_device_id *id);
  51 static int atxp1_remove(struct i2c_client *client);
  52 static struct atxp1_data * atxp1_update_device(struct device *dev);
  53 static int atxp1_detect(struct i2c_client *client, int kind,
  54                         struct i2c_board_info *info);
  55
  56 static const struct i2c_device_id atxp1_id[] = {
  57         { "atxp1", atxp1 },
  58         { }
  59 };
  60 MODULE_DEVICE_TABLE(i2c, atxp1_id);
  61
  62 static struct i2c_driver atxp1_driver = {
  63         .class          = I2C_CLASS_HWMON,
  64         .driver = {
  65                 .name   = "atxp1",
  66         },
  67         .probe          = atxp1_probe,
  68         .remove         = atxp1_remove,
  69         .id_table       = atxp1_id,
  70         .detect         = atxp1_detect,
  71         .address_data   = &addr_data,
  72 };
  73
  74 struct atxp1_data {
  75         struct device *hwmon_dev;
  76         struct mutex update_lock;
  77         unsigned long last_updated;
  78         u8 valid;
  79         struct {
  80                 u8 vid;         /* VID output register */
  81                 u8 cpu_vid; /* VID input from CPU */
  82                 u8 gpio1;   /* General purpose I/O register 1 */
  83                 u8 gpio2;   /* General purpose I/O register 2 */
  84         } reg;
  85         u8 vrm;                 /* Detected CPU VRM */
  86 };
  87
  88 static struct atxp1_data * atxp1_update_device(struct device *dev)
  89 {
  90         struct i2c_client *client;
  91         struct atxp1_data *data;
  92
  93         client = to_i2c_client(dev);
  94         data = i2c_get_clientdata(client);
  95
  96         mutex_lock(&data->update_lock);
  97
  98         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  99
 100                 /* Update local register data */
 101                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
 102                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID);
 103                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
 104                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
 105
 106                 data->valid = 1;
 107         }
 108
 109         mutex_unlock(&data->update_lock);
 110
 111         return(data);
 112 }
 113
 114 /* sys file functions for cpu0_vid */
 115 static ssize_t atxp1_showvcore(struct device *dev, 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, data->vrm));
 123
 124         return size;
 125 }
 126
 127 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 128 {
 129         struct atxp1_data *data;
 130         struct i2c_client *client;
 131         int vid, cvid;
 132         unsigned int vcore;
 133
 134         client = to_i2c_client(dev);
 135         data = atxp1_update_device(dev);
 136
 137         vcore = simple_strtoul(buf, NULL, 10);
 138         vcore /= 25;
 139         vcore *= 25;
 140
 141         /* Calculate VID */
 142         vid = vid_to_reg(vcore, data->vrm);
 143
 144         if (vid < 0) {
 145                 dev_err(dev, "VID calculation failed.\n");
 146                 return -1;
 147         }
 148
 149         /* If output enabled, use control register value. Otherwise original CPU VID */
 150         if (data->reg.vid & ATXP1_VIDENA)
 151                 cvid = data->reg.vid & ATXP1_VIDMASK;
 152         else
 153                 cvid = data->reg.cpu_vid;
 154
 155         /* Nothing changed, aborting */
 156         if (vid == cvid)
 157                 return count;
 158
 159         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
 160
 161         /* Write every 25 mV step to increase stability */
 162         if (cvid > vid) {
 163                 for (; cvid >= vid; cvid--) {
 164                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 165                 }
 166         }
 167         else {
 168                 for (; cvid <= vid; cvid++) {
 169                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 170                 }
 171         }
 172
 173         data->valid = 0;
 174
 175         return count;
 176 }
 177
 178 /* CPU core reference voltage
 179     unit: millivolt
 180 */
 181 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
 182
 183 /* sys file functions for GPIO1 */
 184 static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf)
 185 {
 186         int size;
 187         struct atxp1_data *data;
 188
 189         data = atxp1_update_device(dev);
 190
 191         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 192
 193         return size;
 194 }
 195
 196 static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count)
 197 {
 198         struct atxp1_data *data;
 199         struct i2c_client *client;
 200         unsigned int value;
 201
 202         client = to_i2c_client(dev);
 203         data = atxp1_update_device(dev);
 204
 205         value = simple_strtoul(buf, NULL, 16);
 206
 207         value &= ATXP1_GPIO1MASK;
 208
 209         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 210                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 211
 212                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 213
 214                 data->valid = 0;
 215         }
 216
 217         return count;
 218 }
 219
 220 /* GPIO1 data register
 221     unit: Four bit as hex (e.g. 0x0f)
 222 */
 223 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 224
 225 /* sys file functions for GPIO2 */
 226 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
 227 {
 228         int size;
 229         struct atxp1_data *data;
 230
 231         data = atxp1_update_device(dev);
 232
 233         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 234
 235         return size;
 236 }
 237
 238 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 239 {
 240         struct atxp1_data *data;
 241         struct i2c_client *client;
 242         unsigned int value;
 243
 244         client = to_i2c_client(dev);
 245         data = atxp1_update_device(dev);
 246
 247         value = simple_strtoul(buf, NULL, 16) & 0xff;
 248
 249         if (value != data->reg.gpio2) {
 250                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 251
 252                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 253
 254                 data->valid = 0;
 255         }
 256
 257         return count;
 258 }
 259
 260 /* GPIO2 data register
 261     unit: Eight bit as hex (e.g. 0xff)
 262 */
 263 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
 264
 265 static struct attribute *atxp1_attributes[] = {
 266         &dev_attr_gpio1.attr,
 267         &dev_attr_gpio2.attr,
 268         &dev_attr_cpu0_vid.attr,
 269         NULL
 270 };
 271
 272 static const struct attribute_group atxp1_group = {
 273         .attrs = atxp1_attributes,
 274 };
 275
 276
 277 /* Return 0 if detection is successful, -ENODEV otherwise */
 278 static int atxp1_detect(struct i2c_client *new_client, int kind,
 279                         struct i2c_board_info *info)
 280 {
 281         struct i2c_adapter *adapter = new_client->adapter;
 282
 283         u8 temp;
 284
 285         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 286                 return -ENODEV;
 287
 288         /* Detect ATXP1, checking if vendor ID registers are all zero */
 289         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 290              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 291              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 292              (i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
 293                 return -ENODEV;
 294
 295         /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 296          * showing the same as register 0x00 */
 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 = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL);
 324         if (!data) {
 325                 err = -ENOMEM;
 326                 goto exit;
 327         }
 328
 329         /* Get VRM */
 330         data->vrm = vid_which_vrm();
 331
 332         i2c_set_clientdata(new_client, data);
 333         data->valid = 0;
 334
 335         mutex_init(&data->update_lock);
 336
 337         /* Register sysfs hooks */
 338         if ((err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group)))
 339                 goto exit_free;
 340
 341         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 342         if (IS_ERR(data->hwmon_dev)) {
 343                 err = PTR_ERR(data->hwmon_dev);
 344                 goto exit_remove_files;
 345         }
 346
 347         dev_info(&new_client->dev, "Using VRM: %d.%d\n",
 348                          data->vrm / 10, data->vrm % 10);
 349
 350         return 0;
 351
 352 exit_remove_files:
 353         sysfs_remove_group(&new_client->dev.kobj, &atxp1_group);
 354 exit_free:
 355         kfree(data);
 356 exit:
 357         return err;
 358 };
 359
 360 static int atxp1_remove(struct i2c_client *client)
 361 {
 362         struct atxp1_data * data = i2c_get_clientdata(client);
 363
 364         hwmon_device_unregister(data->hwmon_dev);
 365         sysfs_remove_group(&client->dev.kobj, &atxp1_group);
 366
 367         kfree(data);
 368
 369         return 0;
 370 };
 371
 372 static int __init atxp1_init(void)
 373 {
 374         return i2c_add_driver(&atxp1_driver);
 375 };
 376
 377 static void __exit atxp1_exit(void)
 378 {
 379         i2c_del_driver(&atxp1_driver);
 380 };
 381
 382 module_init(atxp1_init);
 383 module_exit(atxp1_exit);