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/i2c-sensor.h>
  27 #include <linux/i2c-vid.h>
  28
  29 MODULE_LICENSE("GPL");
  30 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
  31 MODULE_VERSION("0.6.2");
  32 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
  33
  34 #define ATXP1_VID       0x00
  35 #define ATXP1_CVID      0x01
  36 #define ATXP1_GPIO1     0x06
  37 #define ATXP1_GPIO2     0x0a
  38 #define ATXP1_VIDENA    0x20
  39 #define ATXP1_VIDMASK   0x1f
  40 #define ATXP1_GPIO1MASK 0x0f
  41
  42 static unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
  43 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
  44
  45 SENSORS_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         .owner          = THIS_MODULE,
  54         .name           = "atxp1",
  55         .flags          = I2C_DF_NOTIFY,
  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 semaphore update_lock;
  63         unsigned long last_updated;
  64         u8 valid;
  65         struct {
  66                 u8 vid;         /* VID output register */
  67                 u8 cpu_vid; /* VID input from CPU */
  68                 u8 gpio1;   /* General purpose I/O register 1 */
  69                 u8 gpio2;   /* General purpose I/O register 2 */
  70         } reg;
  71         u8 vrm;                 /* Detected CPU VRM */
  72 };
  73
  74 static struct atxp1_data * atxp1_update_device(struct device *dev)
  75 {
  76         struct i2c_client *client;
  77         struct atxp1_data *data;
  78
  79         client = to_i2c_client(dev);
  80         data = i2c_get_clientdata(client);
  81
  82         down(&data->update_lock);
  83
  84         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  85
  86                 /* Update local register data */
  87                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
  88                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID);
  89                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
  90                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
  91
  92                 data->valid = 1;
  93         }
  94
  95         up(&data->update_lock);
  96
  97         return(data);
  98 }
  99
 100 /* sys file functions for cpu0_vid */
 101 static ssize_t atxp1_showvcore(struct device *dev, struct device_attribute *attr, char *buf)
 102 {
 103         int size;
 104         struct atxp1_data *data;
 105
 106         data = atxp1_update_device(dev);
 107
 108         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm));
 109
 110         return size;
 111 }
 112
 113 static ssize_t atxp1_storevcore(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 114 {
 115         struct atxp1_data *data;
 116         struct i2c_client *client;
 117         char vid;
 118         char cvid;
 119         unsigned int vcore;
 120
 121         client = to_i2c_client(dev);
 122         data = atxp1_update_device(dev);
 123
 124         vcore = simple_strtoul(buf, NULL, 10);
 125         vcore /= 25;
 126         vcore *= 25;
 127
 128         /* Calculate VID */
 129         vid = vid_to_reg(vcore, data->vrm);
 130
 131         if (vid < 0) {
 132                 dev_err(dev, "VID calculation failed.\n");
 133                 return -1;
 134         }
 135
 136         /* If output enabled, use control register value. Otherwise original CPU VID */
 137         if (data->reg.vid & ATXP1_VIDENA)
 138                 cvid = data->reg.vid & ATXP1_VIDMASK;
 139         else
 140                 cvid = data->reg.cpu_vid;
 141
 142         /* Nothing changed, aborting */
 143         if (vid == cvid)
 144                 return count;
 145
 146         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", vcore, vid);
 147
 148         /* Write every 25 mV step to increase stability */
 149         if (cvid > vid) {
 150                 for (; cvid >= vid; cvid--) {
 151                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 152                 }
 153         }
 154         else {
 155                 for (; cvid <= vid; cvid++) {
 156                         i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA);
 157                 }
 158         }
 159
 160         data->valid = 0;
 161
 162         return count;
 163 }
 164
 165 /* CPU core reference voltage
 166     unit: millivolt
 167 */
 168 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, atxp1_storevcore);
 169
 170 /* sys file functions for GPIO1 */
 171 static ssize_t atxp1_showgpio1(struct device *dev, 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, struct device_attribute *attr, const char*buf, size_t count)
 184 {
 185         struct atxp1_data *data;
 186         struct i2c_client *client;
 187         unsigned int value;
 188
 189         client = to_i2c_client(dev);
 190         data = atxp1_update_device(dev);
 191
 192         value = simple_strtoul(buf, NULL, 16);
 193
 194         value &= ATXP1_GPIO1MASK;
 195
 196         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 197                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 198
 199                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 200
 201                 data->valid = 0;
 202         }
 203
 204         return count;
 205 }
 206
 207 /* GPIO1 data register
 208     unit: Four bit as hex (e.g. 0x0f)
 209 */
 210 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 211
 212 /* sys file functions for GPIO2 */
 213 static ssize_t atxp1_showgpio2(struct device *dev, struct device_attribute *attr, char *buf)
 214 {
 215         int size;
 216         struct atxp1_data *data;
 217
 218         data = atxp1_update_device(dev);
 219
 220         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 221
 222         return size;
 223 }
 224
 225 static ssize_t atxp1_storegpio2(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 226 {
 227         struct atxp1_data *data;
 228         struct i2c_client *client;
 229         unsigned int value;
 230
 231         client = to_i2c_client(dev);
 232         data = atxp1_update_device(dev);
 233
 234         value = simple_strtoul(buf, NULL, 16) & 0xff;
 235
 236         if (value != data->reg.gpio2) {
 237                 dev_info(dev, "Writing 0x%x to GPIO1.\n", value);
 238
 239                 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
 240
 241                 data->valid = 0;
 242         }
 243
 244         return count;
 245 }
 246
 247 /* GPIO2 data register
 248     unit: Eight bit as hex (e.g. 0xff)
 249 */
 250 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
 251
 252
 253 static int atxp1_attach_adapter(struct i2c_adapter *adapter)
 254 {
 255         return i2c_detect(adapter, &addr_data, &atxp1_detect);
 256 };
 257
 258 static int atxp1_detect(struct i2c_adapter *adapter, int address, int kind)
 259 {
 260         struct i2c_client * new_client;
 261         struct atxp1_data * data;
 262         int err = 0;
 263         u8 temp;
 264
 265         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 266                 goto exit;
 267
 268         if (!(data = kmalloc(sizeof(struct atxp1_data), GFP_KERNEL))) {
 269                 err = -ENOMEM;
 270                 goto exit;
 271         }
 272
 273         memset(data, 0, sizeof(struct atxp1_data));
 274         new_client = &data->client;
 275         i2c_set_clientdata(new_client, data);
 276
 277         new_client->addr = address;
 278         new_client->adapter = adapter;
 279         new_client->driver = &atxp1_driver;
 280         new_client->flags = 0;
 281
 282         /* Detect ATXP1, checking if vendor ID registers are all zero */
 283         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 284              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 285              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 286              (i2c_smbus_read_byte_data(new_client, 0xff) == 0) )) {
 287
 288                 /* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 289                  * showing the same as register 0x00 */
 290                 temp = i2c_smbus_read_byte_data(new_client, 0x00);
 291
 292                 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 293                          (i2c_smbus_read_byte_data(new_client, 0x11) == temp) ))
 294                         goto exit_free;
 295         }
 296
 297         /* Get VRM */
 298         data->vrm = i2c_which_vrm();
 299
 300         if ((data->vrm != 90) && (data->vrm != 91)) {
 301                 dev_err(&new_client->dev, "Not supporting VRM %d.%d\n",
 302                                 data->vrm / 10, data->vrm % 10);
 303                 goto exit_free;
 304         }
 305
 306         strncpy(new_client->name, "atxp1", I2C_NAME_SIZE);
 307
 308         data->valid = 0;
 309
 310         init_MUTEX(&data->update_lock);
 311
 312         err = i2c_attach_client(new_client);
 313
 314         if (err)
 315         {
 316                 dev_err(&new_client->dev, "Attach client error.\n");
 317                 goto exit_free;
 318         }
 319
 320         device_create_file(&new_client->dev, &dev_attr_gpio1);
 321         device_create_file(&new_client->dev, &dev_attr_gpio2);
 322         device_create_file(&new_client->dev, &dev_attr_cpu0_vid);
 323
 324         dev_info(&new_client->dev, "Using VRM: %d.%d\n",
 325                          data->vrm / 10, data->vrm % 10);
 326
 327         return 0;
 328
 329 exit_free:
 330         kfree(data);
 331 exit:
 332         return err;
 333 };
 334
 335 static int atxp1_detach_client(struct i2c_client * client)
 336 {
 337         int err;
 338
 339         err = i2c_detach_client(client);
 340
 341         if (err)
 342                 dev_err(&client->dev, "Failed to detach client.\n");
 343         else
 344                 kfree(i2c_get_clientdata(client));
 345
 346         return err;
 347 };
 348
 349 static int __init atxp1_init(void)
 350 {
 351         return i2c_add_driver(&atxp1_driver);
 352 };
 353
 354 static void __exit atxp1_exit(void)
 355 {
 356         i2c_del_driver(&atxp1_driver);
 357 };
 358
 359 module_init(atxp1_init);
 360 module_exit(atxp1_exit);