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("0.6.2");
  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 unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
  46
  47 I2C_CLIENT_INSMOD_1(atxp1);
  48
  49 static int atxp1_attach_adapter(struct i2c_adapter * adapter);
  50 static int atxp1_detach_client(struct i2c_client * client);
  51 static struct atxp1_data * atxp1_update_device(struct device *dev);
  52 static int atxp1_detect(struct i2c_adapter *adapter, int address, int kind);
  53
  54 static struct i2c_driver atxp1_driver = {
  55         .driver = {
  56                 .name   = "atxp1",
  57         },
  58         .attach_adapter = atxp1_attach_adapter,
  59         .detach_client  = atxp1_detach_client,
  60 };
  61
  62 struct atxp1_data {
  63         struct i2c_client client;
  64         struct class_device *class_dev;
  65         struct mutex update_lock;
  66         unsigned long last_updated;
  67         u8 valid;
  68         struct {
  69                 u8 vid;         /* VID output register */
  70                 u8 cpu_vid; /* VID input from CPU */
  71                 u8 gpio1;   /* General purpose I/O register 1 */
  72                 u8 gpio2;   /* General purpose I/O register 2 */
  73         } reg;
  74         u8 vrm;                 /* Detected CPU VRM */
  75 };
  76
  77 static struct atxp1_data * atxp1_update_device(struct device *dev)
  78 {
  79         struct i2c_client *client;
  80         struct atxp1_data *data;
  81
  82         client = to_i2c_client(dev);
  83         data = i2c_get_clientdata(client);
  84
  85         mutex_lock(&data->update_lock);
  86
  87         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  88
  89                 /* Update local register data */
  90                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
  91                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID);
  92                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
  93                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
  94
  95                 data->valid = 1;
  96         }
  97
  98         mutex_unlock(&data->update_lock);
  99
 100         return(data);
 101 }
 102
 103 /* sys file functions for cpu0_vid */
 104 static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf)
 105 {
 106         int size;
 107         struct atxp1_data *data;
 108
 109         data = atxp1_update_device(dev);
 110
 111         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm));
 112
 113         return size;
 114 }
 115
 116 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 117 {
 118         struct atxp1_data *data;
 119         struct i2c_client *client;
 120         int vid, cvid;
 121         unsigned int vcore;
 122
 123         client = to_i2c_client(dev);
 124         data = atxp1_update_device(dev);
 125
 126         vcore = simple_strtoul(buf, NULL, 10);
 127         vcore /= 25;
 128         vcore *= 25;
 129
 130         /* Calculate VID */
 131         vid = vid_to_reg(vcore, data->vrm);
 132
 133         if (vid < 0) {
 134                 dev_err(dev, "VID calculation failed.\n");
 135                 return -1;
 136         }
 137
 138         /* If output enabled, use control register value. Otherwise original CPU VID */
 139         if (data->reg.vid & ATXP1_VIDENA)
 140                 cvid = data->reg.vid & ATXP1_VIDMASK;
 141         else
 142                 cvid = data->reg.cpu_vid;
 143
 144         /* Nothing changed, aborting */
 145         if (vid == cvid)
 146                 return count;
 147
 148         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
 149
 150         /* Write every 25 mV step to increase stability */
 151         if (cvid > vid) {
 152                 for (; cvid >= vid; cvid--) {
 153                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 154                 }
 155         }
 156         else {
 157                 for (; cvid <= vid; cvid++) {
 158                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 159                 }
 160         }
 161
 162         data->valid = 0;
 163
 164         return count;
 165 }
 166
 167 /* CPU core reference voltage
 168     unit: millivolt
 169 */
 170 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
 171
 172 /* sys file functions for GPIO1 */
 173 static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf)
 174 {
 175         int size;
 176         struct atxp1_data *data;
 177
 178         data = atxp1_update_device(dev);
 179
 180         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 181
 182         return size;
 183 }
 184
 185 static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count)
 186 {
 187         struct atxp1_data *data;
 188         struct i2c_client *client;
 189         unsigned int value;
 190
 191         client = to_i2c_client(dev);
 192         data = atxp1_update_device(dev);
 193
 194         value = simple_strtoul(buf, NULL, 16);
 195
 196         value &= ATXP1_GPIO1MASK;
 197
 198         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 199                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 200
 201                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 202
 203                 data->valid = 0;
 204         }
 205
 206         return count;
 207 }
 208
 209 /* GPIO1 data register
 210     unit: Four bit as hex (e.g. 0x0f)
 211 */
 212 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 213
 214 /* sys file functions for GPIO2 */
 215 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
 216 {
 217         int size;
 218         struct atxp1_data *data;
 219
 220         data = atxp1_update_device(dev);
 221
 222         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 223
 224         return size;
 225 }
 226
 227 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 228 {
 229         struct atxp1_data *data;
 230         struct i2c_client *client;
 231         unsigned int value;
 232
 233         client = to_i2c_client(dev);
 234         data = atxp1_update_device(dev);
 235
 236         value = simple_strtoul(buf, NULL, 16) & 0xff;
 237
 238         if (value != data->reg.gpio2) {
 239                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 240
 241                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 242
 243                 data->valid = 0;
 244         }
 245
 246         return count;
 247 }
 248
 249 /* GPIO2 data register
 250     unit: Eight bit as hex (e.g. 0xff)
 251 */
 252 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
 253
 254 static struct attribute *atxp1_attributes[] = {
 255         &dev_attr_gpio1.attr,
 256         &dev_attr_gpio2.attr,
 257         &dev_attr_cpu0_vid.attr,
 258         NULL
 259 };
 260
 261 static const struct attribute_group atxp1_group = {
 262         .attrs = atxp1_attributes,
 263 };
 264
 265
 266 static int atxp1_attach_adapter(struct i2c_adapter *adapter)
 267 {
 268         if (!(adapter->class & I2C_CLASS_HWMON))
 269                 return 0;
 270         return i2c_probe(adapter, &addr_data, &atxp1_detect);
 271 };
 272
 273 static int atxp1_detect(struct i2c_adapter *adapter, int address, int kind)
 274 {
 275         struct i2c_client * new_client;
 276         struct atxp1_data * data;
 277         int err = 0;
 278         u8 temp;
 279
 280         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 281                 goto exit;
 282
 283         if (!(data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL))) {
 284                 err = -ENOMEM;
 285                 goto exit;
 286         }
 287
 288         new_client = &data->client;
 289         i2c_set_clientdata(new_client, data);
 290
 291         new_client->addr = address;
 292         new_client->adapter = adapter;
 293         new_client->driver = &atxp1_driver;
 294         new_client->flags = 0;
 295
 296         /* Detect ATXP1, checking if vendor ID registers are all zero */
 297         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 298              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 299              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 300              (i2c_smbus_read_byte_data(new_client, 0xff) == 0) )) {
 301
 302                 /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 303                  * showing the same as register 0x00 */
 304                 temp = i2c_smbus_read_byte_data(new_client, 0x00);
 305
 306                 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 307                          (i2c_smbus_read_byte_data(new_client, 0x11) == temp) ))
 308                         goto exit_free;
 309         }
 310
 311         /* Get VRM */
 312         data->vrm = vid_which_vrm();
 313
 314         if ((data->vrm != 90) && (data->vrm != 91)) {
 315                 dev_err(&new_client->dev, "Not supporting VRM %d.%d\n",
 316                                 data->vrm / 10, data->vrm % 10);
 317                 goto exit_free;
 318         }
 319
 320         strncpy(new_client->name, "atxp1", I2C_NAME_SIZE);
 321
 322         data->valid = 0;
 323
 324         mutex_init(&data->update_lock);
 325
 326         err = i2c_attach_client(new_client);
 327
 328         if (err)
 329         {
 330                 dev_err(&new_client->dev, "Attach client error.\n");
 331                 goto exit_free;
 332         }
 333
 334         /* Register sysfs hooks */
 335         if ((err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group)))
 336                 goto exit_detach;
 337
 338         data->class_dev = hwmon_device_register(&new_client->dev);
 339         if (IS_ERR(data->class_dev)) {
 340                 err = PTR_ERR(data->class_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_detach:
 352         i2c_detach_client(new_client);
 353 exit_free:
 354         kfree(data);
 355 exit:
 356         return err;
 357 };
 358
 359 static int atxp1_detach_client(struct i2c_client * client)
 360 {
 361         struct atxp1_data * data = i2c_get_clientdata(client);
 362         int err;
 363
 364         hwmon_device_unregister(data->class_dev);
 365         sysfs_remove_group(&client->dev.kobj, &atxp1_group);
 366
 367         err = i2c_detach_client(client);
 368
 369         if (err)
 370                 dev_err(&client->dev, "Failed to detach client.\n");
 371         else
 372                 kfree(data);
 373
 374         return err;
 375 };
 376
 377 static int __init atxp1_init(void)
 378 {
 379         return i2c_add_driver(&atxp1_driver);
 380 };
 381
 382 static void __exit atxp1_exit(void)
 383 {
 384         i2c_del_driver(&atxp1_driver);
 385 };
 386
 387 module_init(atxp1_init);
 388 module_exit(atxp1_exit);