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
 151         if (vid < 0) {
 152                 dev_err(dev, "VID calculation failed.\n");
 153                 return -1;
 154         }
 155
 156         /*
 157          * If output enabled, use control register value.
 158          * Otherwise original CPU VID
 159          */
 160         if (data->reg.vid & ATXP1_VIDENA)
 161                 cvid = data->reg.vid & ATXP1_VIDMASK;
 162         else
 163                 cvid = data->reg.cpu_vid;
 164
 165         /* Nothing changed, aborting */
 166         if (vid == cvid)
 167                 return count;
 168
 169         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
 170
 171         /* Write every 25 mV step to increase stability */
 172         if (cvid > vid) {
 173                 for (; cvid >= vid; cvid--)
 174                         i2c_smbus_write_byte_data(client,
 175                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 176         } else {
 177                 for (; cvid <= vid; cvid++)
 178                         i2c_smbus_write_byte_data(client,
 179                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 180         }
 181
 182         data->valid = 0;
 183
 184         return count;
 185 }
 186
 187 /*
 188  * CPU core reference voltage
 189  * unit: millivolt
 190  */
 191 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
 192                    atxp1_storevcore);
 193
 194 /* sys file functions for GPIO1 */
 195 static ssize_t atxp1_showgpio1(struct device *dev,
 196                                struct device_attribute *attr, char *buf)
 197 {
 198         int size;
 199         struct atxp1_data *data;
 200
 201         data = atxp1_update_device(dev);
 202
 203         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 204
 205         return size;
 206 }
 207
 208 static ssize_t atxp1_storegpio1(struct device *dev,
 209                                 struct device_attribute *attr, const char *buf,
 210                                 size_t count)
 211 {
 212         struct atxp1_data *data;
 213         struct i2c_client *client;
 214         unsigned long value;
 215         int err;
 216
 217         client = to_i2c_client(dev);
 218         data = atxp1_update_device(dev);
 219
 220         err = kstrtoul(buf, 16, &value);
 221         if (err)
 222                 return err;
 223
 224         value &= ATXP1_GPIO1MASK;
 225
 226         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 227                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
 228
 229                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 230
 231                 data->valid = 0;
 232         }
 233
 234         return count;
 235 }
 236
 237 /*
 238  * GPIO1 data register
 239  * unit: Four bit as hex (e.g. 0x0f)
 240  */
 241 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 242
 243 /* sys file functions for GPIO2 */
 244 static ssize_t atxp1_showgpio2(struct device *dev,
 245                                struct device_attribute *attr, char *buf)
 246 {
 247         int size;
 248         struct atxp1_data *data;
 249
 250         data = atxp1_update_device(dev);
 251
 252         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 253
 254         return size;
 255 }
 256
 257 static ssize_t atxp1_storegpio2(struct device *dev,
 258                                 struct device_attribute *attr,
 259                                 const char *buf, size_t count)
 260 {
 261         struct atxp1_data *data = atxp1_update_device(dev);
 262         struct i2c_client *client = to_i2c_client(dev);
 263         unsigned long value;
 264         int err;
 265
 266         err = kstrtoul(buf, 16, &value);
 267         if (err)
 268                 return err;
 269         value &= 0xff;
 270
 271         if (value != data->reg.gpio2) {
 272                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
 273
 274                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 275
 276                 data->valid = 0;
 277         }
 278
 279         return count;
 280 }
 281
 282 /*
 283  * GPIO2 data register
 284  * unit: Eight bit as hex (e.g. 0xff)
 285  */
 286 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
 287
 288 static struct attribute *atxp1_attributes[] = {
 289         &dev_attr_gpio1.attr,
 290         &dev_attr_gpio2.attr,
 291         &dev_attr_cpu0_vid.attr,
 292         NULL
 293 };
 294
 295 static const struct attribute_group atxp1_group = {
 296         .attrs = atxp1_attributes,
 297 };
 298
 299
 300 /* Return 0 if detection is successful, -ENODEV otherwise */
 301 static int atxp1_detect(struct i2c_client *new_client,
 302                         struct i2c_board_info *info)
 303 {
 304         struct i2c_adapter *adapter = new_client->adapter;
 305
 306         u8 temp;
 307
 308         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 309                 return -ENODEV;
 310
 311         /* Detect ATXP1, checking if vendor ID registers are all zero */
 312         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 313              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 314              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 315              (i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
 316                 return -ENODEV;
 317
 318         /*
 319          * No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 320          * showing the same as register 0x00
 321          */
 322         temp = i2c_smbus_read_byte_data(new_client, 0x00);
 323
 324         if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 325               (i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
 326                 return -ENODEV;
 327
 328         /* Get VRM */
 329         temp = vid_which_vrm();
 330
 331         if ((temp != 90) && (temp != 91)) {
 332                 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
 333                                 temp / 10, temp % 10);
 334                 return -ENODEV;
 335         }
 336
 337         strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
 338
 339         return 0;
 340 }
 341
 342 static int atxp1_probe(struct i2c_client *new_client,
 343                        const struct i2c_device_id *id)
 344 {
 345         struct atxp1_data *data;
 346         int err;
 347
 348         data = devm_kzalloc(&new_client->dev, sizeof(struct atxp1_data),
 349                             GFP_KERNEL);
 350         if (!data)
 351                 return -ENOMEM;
 352
 353         /* Get VRM */
 354         data->vrm = vid_which_vrm();
 355
 356         i2c_set_clientdata(new_client, data);
 357         data->valid = 0;
 358
 359         mutex_init(&data->update_lock);
 360
 361         /* Register sysfs hooks */
 362         err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group);
 363         if (err)
 364                 return err;
 365
 366         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 367         if (IS_ERR(data->hwmon_dev)) {
 368                 err = PTR_ERR(data->hwmon_dev);
 369                 goto exit_remove_files;
 370         }
 371
 372         dev_info(&new_client->dev, "Using VRM: %d.%d\n",
 373                          data->vrm / 10, data->vrm % 10);
 374
 375         return 0;
 376
 377 exit_remove_files:
 378         sysfs_remove_group(&new_client->dev.kobj, &atxp1_group);
 379         return err;
 380 };
 381
 382 static int atxp1_remove(struct i2c_client *client)
 383 {
 384         struct atxp1_data *data = i2c_get_clientdata(client);
 385
 386         hwmon_device_unregister(data->hwmon_dev);
 387         sysfs_remove_group(&client->dev.kobj, &atxp1_group);
 388
 389         return 0;
 390 };
 391
 392 module_i2c_driver(atxp1_driver);