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 struct atxp1_data {
  49         struct device *hwmon_dev;
  50         struct mutex update_lock;
  51         unsigned long last_updated;
  52         u8 valid;
  53         struct {
  54                 u8 vid;         /* VID output register */
  55                 u8 cpu_vid; /* VID input from CPU */
  56                 u8 gpio1;   /* General purpose I/O register 1 */
  57                 u8 gpio2;   /* General purpose I/O register 2 */
  58         } reg;
  59         u8 vrm;                 /* Detected CPU VRM */
  60 };
  61
  62 static struct atxp1_data *atxp1_update_device(struct device *dev)
  63 {
  64         struct i2c_client *client;
  65         struct atxp1_data *data;
  66
  67         client = to_i2c_client(dev);
  68         data = i2c_get_clientdata(client);
  69
  70         mutex_lock(&data->update_lock);
  71
  72         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  73
  74                 /* Update local register data */
  75                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
  76                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
  77                                                              ATXP1_CVID);
  78                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
  79                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
  80
  81                 data->valid = 1;
  82         }
  83
  84         mutex_unlock(&data->update_lock);
  85
  86         return data;
  87 }
  88
  89 /* sys file functions for cpu0_vid */
  90 static ssize_t atxp1_showvcore(struct device *dev,
  91                                struct device_attribute *attr, char *buf)
  92 {
  93         int size;
  94         struct atxp1_data *data;
  95
  96         data = atxp1_update_device(dev);
  97
  98         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
  99                                                  data->vrm));
 100
 101         return size;
 102 }
 103
 104 static ssize_t atxp1_storevcore(struct device *dev,
 105                                 struct device_attribute *attr,
 106                                 const char *buf, size_t count)
 107 {
 108         struct atxp1_data *data;
 109         struct i2c_client *client;
 110         int vid, cvid;
 111         unsigned long vcore;
 112         int err;
 113
 114         client = to_i2c_client(dev);
 115         data = atxp1_update_device(dev);
 116
 117         err = kstrtoul(buf, 10, &vcore);
 118         if (err)
 119                 return err;
 120
 121         vcore /= 25;
 122         vcore *= 25;
 123
 124         /* Calculate VID */
 125         vid = vid_to_reg(vcore, data->vrm);
 126         if (vid < 0) {
 127                 dev_err(dev, "VID calculation failed.\n");
 128                 return vid;
 129         }
 130
 131         /*
 132          * If output enabled, use control register value.
 133          * Otherwise original CPU VID
 134          */
 135         if (data->reg.vid & ATXP1_VIDENA)
 136                 cvid = data->reg.vid & ATXP1_VIDMASK;
 137         else
 138                 cvid = data->reg.cpu_vid;
 139
 140         /* Nothing changed, aborting */
 141         if (vid == cvid)
 142                 return count;
 143
 144         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
 145
 146         /* Write every 25 mV step to increase stability */
 147         if (cvid > vid) {
 148                 for (; cvid >= vid; cvid--)
 149                         i2c_smbus_write_byte_data(client,
 150                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 151         } else {
 152                 for (; cvid <= vid; cvid++)
 153                         i2c_smbus_write_byte_data(client,
 154                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 155         }
 156
 157         data->valid = 0;
 158
 159         return count;
 160 }
 161
 162 /*
 163  * CPU core reference voltage
 164  * unit: millivolt
 165  */
 166 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
 167                    atxp1_storevcore);
 168
 169 /* sys file functions for GPIO1 */
 170 static ssize_t atxp1_showgpio1(struct device *dev,
 171                                struct device_attribute *attr, char *buf)
 172 {
 173         int size;
 174         struct atxp1_data *data;
 175
 176         data = atxp1_update_device(dev);
 177
 178         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 179
 180         return size;
 181 }
 182
 183 static ssize_t atxp1_storegpio1(struct device *dev,
 184                                 struct device_attribute *attr, const char *buf,
 185                                 size_t count)
 186 {
 187         struct atxp1_data *data;
 188         struct i2c_client *client;
 189         unsigned long value;
 190         int err;
 191
 192         client = to_i2c_client(dev);
 193         data = atxp1_update_device(dev);
 194
 195         err = kstrtoul(buf, 16, &value);
 196         if (err)
 197                 return err;
 198
 199         value &= ATXP1_GPIO1MASK;
 200
 201         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 202                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
 203
 204                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 205
 206                 data->valid = 0;
 207         }
 208
 209         return count;
 210 }
 211
 212 /*
 213  * GPIO1 data register
 214  * unit: Four bit as hex (e.g. 0x0f)
 215  */
 216 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 217
 218 /* sys file functions for GPIO2 */
 219 static ssize_t atxp1_showgpio2(struct device *dev,
 220                                struct device_attribute *attr, char *buf)
 221 {
 222         int size;
 223         struct atxp1_data *data;
 224
 225         data = atxp1_update_device(dev);
 226
 227         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 228
 229         return size;
 230 }
 231
 232 static ssize_t atxp1_storegpio2(struct device *dev,
 233                                 struct device_attribute *attr,
 234                                 const char *buf, size_t count)
 235 {
 236         struct atxp1_data *data = atxp1_update_device(dev);
 237         struct i2c_client *client = to_i2c_client(dev);
 238         unsigned long value;
 239         int err;
 240
 241         err = kstrtoul(buf, 16, &value);
 242         if (err)
 243                 return err;
 244         value &= 0xff;
 245
 246         if (value != data->reg.gpio2) {
 247                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)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 /*
 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         /*
 294          * No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 295          * showing the same as register 0x00
 296          */
 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 = devm_kzalloc(&new_client->dev, sizeof(struct atxp1_data),
 324                             GFP_KERNEL);
 325         if (!data)
 326                 return -ENOMEM;
 327
 328         /* Get VRM */
 329         data->vrm = vid_which_vrm();
 330
 331         i2c_set_clientdata(new_client, data);
 332         mutex_init(&data->update_lock);
 333
 334         /* Register sysfs hooks */
 335         err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group);
 336         if (err)
 337                 return err;
 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         return err;
 353 };
 354
 355 static int atxp1_remove(struct i2c_client *client)
 356 {
 357         struct atxp1_data *data = i2c_get_clientdata(client);
 358
 359         hwmon_device_unregister(data->hwmon_dev);
 360         sysfs_remove_group(&client->dev.kobj, &atxp1_group);
 361
 362         return 0;
 363 };
 364
 365 static const struct i2c_device_id atxp1_id[] = {
 366         { "atxp1", 0 },
 367         { }
 368 };
 369 MODULE_DEVICE_TABLE(i2c, atxp1_id);
 370
 371 static struct i2c_driver atxp1_driver = {
 372         .class          = I2C_CLASS_HWMON,
 373         .driver = {
 374                 .name   = "atxp1",
 375         },
 376         .probe          = atxp1_probe,
 377         .remove         = atxp1_remove,
 378         .id_table       = atxp1_id,
 379         .detect         = atxp1_detect,
 380         .address_list   = normal_i2c,
 381 };
 382
 383 module_i2c_driver(atxp1_driver);