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, ATXP1_CVID);
 101                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
 102                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
 103
 104                 data->valid = 1;
 105         }
 106
 107         mutex_unlock(&data->update_lock);
 108
 109         return(data);
 110 }
 111
 112 /* sys file functions for cpu0_vid */
 113 static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf)
 114 {
 115         int size;
 116         struct atxp1_data *data;
 117
 118         data = atxp1_update_device(dev);
 119
 120         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm));
 121
 122         return size;
 123 }
 124
 125 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 126 {
 127         struct atxp1_data *data;
 128         struct i2c_client *client;
 129         int vid, cvid;
 130         unsigned int vcore;
 131
 132         client = to_i2c_client(dev);
 133         data = atxp1_update_device(dev);
 134
 135         vcore = simple_strtoul(buf, NULL, 10);
 136         vcore /= 25;
 137         vcore *= 25;
 138
 139         /* Calculate VID */
 140         vid = vid_to_reg(vcore, data->vrm);
 141
 142         if (vid < 0) {
 143                 dev_err(dev, "VID calculation failed.\n");
 144                 return -1;
 145         }
 146
 147         /* If output enabled, use control register value. Otherwise original CPU VID */
 148         if (data->reg.vid & ATXP1_VIDENA)
 149                 cvid = data->reg.vid & ATXP1_VIDMASK;
 150         else
 151                 cvid = data->reg.cpu_vid;
 152
 153         /* Nothing changed, aborting */
 154         if (vid == cvid)
 155                 return count;
 156
 157         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
 158
 159         /* Write every 25 mV step to increase stability */
 160         if (cvid > vid) {
 161                 for (; cvid >= vid; cvid--) {
 162                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 163                 }
 164         }
 165         else {
 166                 for (; cvid <= vid; cvid++) {
 167                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 168                 }
 169         }
 170
 171         data->valid = 0;
 172
 173         return count;
 174 }
 175
 176 /* CPU core reference voltage
 177     unit: millivolt
 178 */
 179 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
 180
 181 /* sys file functions for GPIO1 */
 182 static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf)
 183 {
 184         int size;
 185         struct atxp1_data *data;
 186
 187         data = atxp1_update_device(dev);
 188
 189         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 190
 191         return size;
 192 }
 193
 194 static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count)
 195 {
 196         struct atxp1_data *data;
 197         struct i2c_client *client;
 198         unsigned int value;
 199
 200         client = to_i2c_client(dev);
 201         data = atxp1_update_device(dev);
 202
 203         value = simple_strtoul(buf, NULL, 16);
 204
 205         value &= ATXP1_GPIO1MASK;
 206
 207         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 208                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 209
 210                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 211
 212                 data->valid = 0;
 213         }
 214
 215         return count;
 216 }
 217
 218 /* GPIO1 data register
 219     unit: Four bit as hex (e.g. 0x0f)
 220 */
 221 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 222
 223 /* sys file functions for GPIO2 */
 224 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
 225 {
 226         int size;
 227         struct atxp1_data *data;
 228
 229         data = atxp1_update_device(dev);
 230
 231         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 232
 233         return size;
 234 }
 235
 236 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 237 {
 238         struct atxp1_data *data;
 239         struct i2c_client *client;
 240         unsigned int value;
 241
 242         client = to_i2c_client(dev);
 243         data = atxp1_update_device(dev);
 244
 245         value = simple_strtoul(buf, NULL, 16) & 0xff;
 246
 247         if (value != data->reg.gpio2) {
 248                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 249
 250                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 251
 252                 data->valid = 0;
 253         }
 254
 255         return count;
 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         /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 294          * showing the same as register 0x00 */
 295         temp = i2c_smbus_read_byte_data(new_client, 0x00);
 296
 297         if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 298               (i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
 299                 return -ENODEV;
 300
 301         /* Get VRM */
 302         temp = vid_which_vrm();
 303
 304         if ((temp != 90) && (temp != 91)) {
 305                 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
 306                                 temp / 10, temp % 10);
 307                 return -ENODEV;
 308         }
 309
 310         strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
 311
 312         return 0;
 313 }
 314
 315 static int atxp1_probe(struct i2c_client *new_client,
 316                        const struct i2c_device_id *id)
 317 {
 318         struct atxp1_data *data;
 319         int err;
 320
 321         data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL);
 322         if (!data) {
 323                 err = -ENOMEM;
 324                 goto exit;
 325         }
 326
 327         /* Get VRM */
 328         data->vrm = vid_which_vrm();
 329
 330         i2c_set_clientdata(new_client, data);
 331         data->valid = 0;
 332
 333         mutex_init(&data->update_lock);
 334
 335         /* Register sysfs hooks */
 336         if ((err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group)))
 337                 goto exit_free;
 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 exit_free:
 353         kfree(data);
 354 exit:
 355         return err;
 356 };
 357
 358 static int atxp1_remove(struct i2c_client *client)
 359 {
 360         struct atxp1_data * data = i2c_get_clientdata(client);
 361
 362         hwmon_device_unregister(data->hwmon_dev);
 363         sysfs_remove_group(&client->dev.kobj, &atxp1_group);
 364
 365         kfree(data);
 366
 367         return 0;
 368 };
 369
 370 static int __init atxp1_init(void)
 371 {
 372         return i2c_add_driver(&atxp1_driver);
 373 };
 374
 375 static void __exit atxp1_exit(void)
 376 {
 377         i2c_del_driver(&atxp1_driver);
 378 };
 379
 380 module_init(atxp1_init);
 381 module_exit(atxp1_exit);