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
  30 MODULE_LICENSE("GPL");
  31 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
  32 MODULE_VERSION("0.6.2");
  33 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
  34
  35 #define ATXP1_VID       0x00
  36 #define ATXP1_CVID      0x01
  37 #define ATXP1_GPIO1     0x06
  38 #define ATXP1_GPIO2     0x0a
  39 #define ATXP1_VIDENA    0x20
  40 #define ATXP1_VIDMASK   0x1f
  41 #define ATXP1_GPIO1MASK 0x0f
  42
  43 static unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
  44
  45 I2C_CLIENT_INSMOD_1(atxp1);
  46
  47 static int atxp1_attach_adapter(struct i2c_adapter * adapter);
  48 static int atxp1_detach_client(struct i2c_client * client);
  49 static struct atxp1_data * atxp1_update_device(struct device *dev);
  50 static int atxp1_detect(struct i2c_adapter *adapter, int address, int kind);
  51
  52 static struct i2c_driver atxp1_driver = {
  53         .driver = {
  54                 .name   = "atxp1",
  55         },
  56         .attach_adapter = atxp1_attach_adapter,
  57         .detach_client  = atxp1_detach_client,
  58 };
  59
  60 struct atxp1_data {
  61         struct i2c_client client;
  62         struct class_device *class_dev;
  63         struct semaphore update_lock;
  64         unsigned long last_updated;
  65         u8 valid;
  66         struct {
  67                 u8 vid;         /* VID output register */
  68                 u8 cpu_vid; /* VID input from CPU */
  69                 u8 gpio1;   /* General purpose I/O register 1 */
  70                 u8 gpio2;   /* General purpose I/O register 2 */
  71         } reg;
  72         u8 vrm;                 /* Detected CPU VRM */
  73 };
  74
  75 static struct atxp1_data * atxp1_update_device(struct device *dev)
  76 {
  77         struct i2c_client *client;
  78         struct atxp1_data *data;
  79
  80         client = to_i2c_client(dev);
  81         data = i2c_get_clientdata(client);
  82
  83         down(&data->update_lock);
  84
  85         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  86
  87                 /* Update local register data */
  88                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
  89                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID);
  90                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
  91                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
  92
  93                 data->valid = 1;
  94         }
  95
  96         up(&data->update_lock);
  97
  98         return(data);
  99 }
 100
 101 /* sys file functions for cpu0_vid */
 102 static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf)
 103 {
 104         int size;
 105         struct atxp1_data *data;
 106
 107         data = atxp1_update_device(dev);
 108
 109         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm));
 110
 111         return size;
 112 }
 113
 114 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 115 {
 116         struct atxp1_data *data;
 117         struct i2c_client *client;
 118         char vid;
 119         char cvid;
 120         unsigned int vcore;
 121
 122         client = to_i2c_client(dev);
 123         data = atxp1_update_device(dev);
 124
 125         vcore = simple_strtoul(buf, NULL, 10);
 126         vcore /= 25;
 127         vcore *= 25;
 128
 129         /* Calculate VID */
 130         vid = vid_to_reg(vcore, data->vrm);
 131
 132         if (vid < 0) {
 133                 dev_err(dev, "VID calculation failed.\n");
 134                 return -1;
 135         }
 136
 137         /* If output enabled, use control register value. Otherwise original CPU VID */
 138         if (data->reg.vid & ATXP1_VIDENA)
 139                 cvid = data->reg.vid & ATXP1_VIDMASK;
 140         else
 141                 cvid = data->reg.cpu_vid;
 142
 143         /* Nothing changed, aborting */
 144         if (vid == cvid)
 145                 return count;
 146
 147         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
 148
 149         /* Write every 25 mV step to increase stability */
 150         if (cvid > vid) {
 151                 for (; cvid >= vid; cvid--) {
 152                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 153                 }
 154         }
 155         else {
 156                 for (; cvid <= vid; cvid++) {
 157                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 158                 }
 159         }
 160
 161         data->valid = 0;
 162
 163         return count;
 164 }
 165
 166 /* CPU core reference voltage
 167     unit: millivolt
 168 */
 169 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
 170
 171 /* sys file functions for GPIO1 */
 172 static ssize_t atxp1_showgpio1(struct device *dev, struct device_attribute *attr, char *buf)
 173 {
 174         int size;
 175         struct atxp1_data *data;
 176
 177         data = atxp1_update_device(dev);
 178
 179         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 180
 181         return size;
 182 }
 183
 184 static ssize_t atxp1_storegpio1(struct device *dev, struct device_attribute *attr, const char*buf, size_t count)
 185 {
 186         struct atxp1_data *data;
 187         struct i2c_client *client;
 188         unsigned int value;
 189
 190         client = to_i2c_client(dev);
 191         data = atxp1_update_device(dev);
 192
 193         value = simple_strtoul(buf, NULL, 16);
 194
 195         value &= ATXP1_GPIO1MASK;
 196
 197         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 198                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 199
 200                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 201
 202                 data->valid = 0;
 203         }
 204
 205         return count;
 206 }
 207
 208 /* GPIO1 data register
 209     unit: Four bit as hex (e.g. 0x0f)
 210 */
 211 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 212
 213 /* sys file functions for GPIO2 */
 214 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
 215 {
 216         int size;
 217         struct atxp1_data *data;
 218
 219         data = atxp1_update_device(dev);
 220
 221         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 222
 223         return size;
 224 }
 225
 226 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 227 {
 228         struct atxp1_data *data;
 229         struct i2c_client *client;
 230         unsigned int value;
 231
 232         client = to_i2c_client(dev);
 233         data = atxp1_update_device(dev);
 234
 235         value = simple_strtoul(buf, NULL, 16) & 0xff;
 236
 237         if (value != data->reg.gpio2) {
 238                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 239
 240                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 241
 242                 data->valid = 0;
 243         }
 244
 245         return count;
 246 }
 247
 248 /* GPIO2 data register
 249     unit: Eight bit as hex (e.g. 0xff)
 250 */
 251 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
 252
 253
 254 static int atxp1_attach_adapter(struct i2c_adapter *adapter)
 255 {
 256         if (!(adapter->class & I2C_CLASS_HWMON))
 257                 return 0;
 258         return i2c_probe(adapter, &addr_data, &atxp1_detect);
 259 };
 260
 261 static int atxp1_detect(struct i2c_adapter *adapter, int address, int kind)
 262 {
 263         struct i2c_client * new_client;
 264         struct atxp1_data * data;
 265         int err = 0;
 266         u8 temp;
 267
 268         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 269                 goto exit;
 270
 271         if (!(data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL))) {
 272                 err = -ENOMEM;
 273                 goto exit;
 274         }
 275
 276         new_client = &data->client;
 277         i2c_set_clientdata(new_client, data);
 278
 279         new_client->addr = address;
 280         new_client->adapter = adapter;
 281         new_client->driver = &atxp1_driver;
 282         new_client->flags = 0;
 283
 284         /* Detect ATXP1, checking if vendor ID registers are all zero */
 285         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 286              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 287              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 288              (i2c_smbus_read_byte_data(new_client, 0xff) == 0) )) {
 289
 290                 /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 291                  * showing the same as register 0x00 */
 292                 temp = i2c_smbus_read_byte_data(new_client, 0x00);
 293
 294                 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 295                          (i2c_smbus_read_byte_data(new_client, 0x11) == temp) ))
 296                         goto exit_free;
 297         }
 298
 299         /* Get VRM */
 300         data->vrm = vid_which_vrm();
 301
 302         if ((data->vrm != 90) && (data->vrm != 91)) {
 303                 dev_err(&new_client->dev, "Not supporting VRM %d.%d\n",
 304                                 data->vrm / 10, data->vrm % 10);
 305                 goto exit_free;
 306         }
 307
 308         strncpy(new_client->name, "atxp1", I2C_NAME_SIZE);
 309
 310         data->valid = 0;
 311
 312         init_MUTEX(&data->update_lock);
 313
 314         err = i2c_attach_client(new_client);
 315
 316         if (err)
 317         {
 318                 dev_err(&new_client->dev, "Attach client error.\n");
 319                 goto exit_free;
 320         }
 321
 322         data->class_dev = hwmon_device_register(&new_client->dev);
 323         if (IS_ERR(data->class_dev)) {
 324                 err = PTR_ERR(data->class_dev);
 325                 goto exit_detach;
 326         }
 327
 328         device_create_file(&new_client->dev, &dev_attr_gpio1);
 329         device_create_file(&new_client->dev, &dev_attr_gpio2);
 330         device_create_file(&new_client->dev, &dev_attr_cpu0_vid);
 331
 332         dev_info(&new_client->dev, "Using VRM: %d.%d\n",
 333                          data->vrm / 10, data->vrm % 10);
 334
 335         return 0;
 336
 337 exit_detach:
 338         i2c_detach_client(new_client);
 339 exit_free:
 340         kfree(data);
 341 exit:
 342         return err;
 343 };
 344
 345 static int atxp1_detach_client(struct i2c_client * client)
 346 {
 347         struct atxp1_data * data = i2c_get_clientdata(client);
 348         int err;
 349
 350         hwmon_device_unregister(data->class_dev);
 351
 352         err = i2c_detach_client(client);
 353
 354         if (err)
 355                 dev_err(&client->dev, "Failed to detach client.\n");
 356         else
 357                 kfree(data);
 358
 359         return err;
 360 };
 361
 362 static int __init atxp1_init(void)
 363 {
 364         return i2c_add_driver(&atxp1_driver);
 365 };
 366
 367 static void __exit atxp1_exit(void)
 368 {
 369         i2c_del_driver(&atxp1_driver);
 370 };
 371
 372 module_init(atxp1_init);
 373 module_exit(atxp1_exit);