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 i2c_client *client;
  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 atxp1_data *data = dev_get_drvdata(dev);
  65         struct i2c_client *client = data->client;
  66
  67         mutex_lock(&data->update_lock);
  68
  69         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  70
  71                 /* Update local register data */
  72                 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
  73                 data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
  74                                                              ATXP1_CVID);
  75                 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
  76                 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
  77
  78                 data->valid = 1;
  79         }
  80
  81         mutex_unlock(&data->update_lock);
  82
  83         return data;
  84 }
  85
  86 /* sys file functions for cpu0_vid */
  87 static ssize_t atxp1_showvcore(struct device *dev,
  88                                struct device_attribute *attr, char *buf)
  89 {
  90         int size;
  91         struct atxp1_data *data;
  92
  93         data = atxp1_update_device(dev);
  94
  95         size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
  96                                                  data->vrm));
  97
  98         return size;
  99 }
 100
 101 static ssize_t atxp1_storevcore(struct device *dev,
 102                                 struct device_attribute *attr,
 103                                 const char *buf, size_t count)
 104 {
 105         struct atxp1_data *data = atxp1_update_device(dev);
 106         struct i2c_client *client = data->client;
 107         int vid, cvid;
 108         unsigned long vcore;
 109         int err;
 110
 111         err = kstrtoul(buf, 10, &vcore);
 112         if (err)
 113                 return err;
 114
 115         vcore /= 25;
 116         vcore *= 25;
 117
 118         /* Calculate VID */
 119         vid = vid_to_reg(vcore, data->vrm);
 120         if (vid < 0) {
 121                 dev_err(dev, "VID calculation failed.\n");
 122                 return vid;
 123         }
 124
 125         /*
 126          * If output enabled, use control register value.
 127          * Otherwise original CPU VID
 128          */
 129         if (data->reg.vid & ATXP1_VIDENA)
 130                 cvid = data->reg.vid & ATXP1_VIDMASK;
 131         else
 132                 cvid = data->reg.cpu_vid;
 133
 134         /* Nothing changed, aborting */
 135         if (vid == cvid)
 136                 return count;
 137
 138         dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
 139
 140         /* Write every 25 mV step to increase stability */
 141         if (cvid > vid) {
 142                 for (; cvid >= vid; cvid--)
 143                         i2c_smbus_write_byte_data(client,
 144                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 145         } else {
 146                 for (; cvid <= vid; cvid++)
 147                         i2c_smbus_write_byte_data(client,
 148                                                 ATXP1_VID, cvid | ATXP1_VIDENA);
 149         }
 150
 151         data->valid = 0;
 152
 153         return count;
 154 }
 155
 156 /*
 157  * CPU core reference voltage
 158  * unit: millivolt
 159  */
 160 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
 161                    atxp1_storevcore);
 162
 163 /* sys file functions for GPIO1 */
 164 static ssize_t atxp1_showgpio1(struct device *dev,
 165                                struct device_attribute *attr, char *buf)
 166 {
 167         int size;
 168         struct atxp1_data *data;
 169
 170         data = atxp1_update_device(dev);
 171
 172         size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
 173
 174         return size;
 175 }
 176
 177 static ssize_t atxp1_storegpio1(struct device *dev,
 178                                 struct device_attribute *attr, const char *buf,
 179                                 size_t count)
 180 {
 181         struct atxp1_data *data = atxp1_update_device(dev);
 182         struct i2c_client *client = data->client;
 183         unsigned long value;
 184         int err;
 185
 186         err = kstrtoul(buf, 16, &value);
 187         if (err)
 188                 return err;
 189
 190         value &= ATXP1_GPIO1MASK;
 191
 192         if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 193                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
 194
 195                 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
 196
 197                 data->valid = 0;
 198         }
 199
 200         return count;
 201 }
 202
 203 /*
 204  * GPIO1 data register
 205  * unit: Four bit as hex (e.g. 0x0f)
 206  */
 207 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
 208
 209 /* sys file functions for GPIO2 */
 210 static ssize_t atxp1_showgpio2(struct device *dev,
 211                                struct device_attribute *attr, char *buf)
 212 {
 213         int size;
 214         struct atxp1_data *data;
 215
 216         data = atxp1_update_device(dev);
 217
 218         size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
 219
 220         return size;
 221 }
 222
 223 static ssize_t atxp1_storegpio2(struct device *dev,
 224                                 struct device_attribute *attr,
 225                                 const char *buf, size_t count)
 226 {
 227         struct atxp1_data *data = atxp1_update_device(dev);
 228         struct i2c_client *client = data->client;
 229         unsigned long value;
 230         int err;
 231
 232         err = kstrtoul(buf, 16, &value);
 233         if (err)
 234                 return err;
 235         value &= 0xff;
 236
 237         if (value != data->reg.gpio2) {
 238                 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)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 /*
 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_attrs[] = {
 255         &dev_attr_gpio1.attr,
 256         &dev_attr_gpio2.attr,
 257         &dev_attr_cpu0_vid.attr,
 258         NULL
 259 };
 260 ATTRIBUTE_GROUPS(atxp1);
 261
 262 /* Return 0 if detection is successful, -ENODEV otherwise */
 263 static int atxp1_detect(struct i2c_client *new_client,
 264                         struct i2c_board_info *info)
 265 {
 266         struct i2c_adapter *adapter = new_client->adapter;
 267
 268         u8 temp;
 269
 270         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 271                 return -ENODEV;
 272
 273         /* Detect ATXP1, checking if vendor ID registers are all zero */
 274         if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
 275              (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
 276              (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
 277              (i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
 278                 return -ENODEV;
 279
 280         /*
 281          * No vendor ID, now checking if registers 0x10,0x11 (non-existent)
 282          * showing the same as register 0x00
 283          */
 284         temp = i2c_smbus_read_byte_data(new_client, 0x00);
 285
 286         if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
 287               (i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
 288                 return -ENODEV;
 289
 290         /* Get VRM */
 291         temp = vid_which_vrm();
 292
 293         if ((temp != 90) && (temp != 91)) {
 294                 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
 295                                 temp / 10, temp % 10);
 296                 return -ENODEV;
 297         }
 298
 299         strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
 300
 301         return 0;
 302 }
 303
 304 static int atxp1_probe(struct i2c_client *client,
 305                        const struct i2c_device_id *id)
 306 {
 307         struct device *dev = &client->dev;
 308         struct atxp1_data *data;
 309         struct device *hwmon_dev;
 310
 311         data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
 312         if (!data)
 313                 return -ENOMEM;
 314
 315         /* Get VRM */
 316         data->vrm = vid_which_vrm();
 317
 318         data->client = client;
 319         mutex_init(&data->update_lock);
 320
 321         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 322                                                            data,
 323                                                            atxp1_groups);
 324         if (IS_ERR(hwmon_dev))
 325                 return PTR_ERR(hwmon_dev);
 326
 327         dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);
 328
 329         return 0;
 330 };
 331
 332 static const struct i2c_device_id atxp1_id[] = {
 333         { "atxp1", 0 },
 334         { }
 335 };
 336 MODULE_DEVICE_TABLE(i2c, atxp1_id);
 337
 338 static struct i2c_driver atxp1_driver = {
 339         .class          = I2C_CLASS_HWMON,
 340         .driver = {
 341                 .name   = "atxp1",
 342         },
 343         .probe          = atxp1_probe,
 344         .id_table       = atxp1_id,
 345         .detect         = atxp1_detect,
 346         .address_list   = normal_i2c,
 347 };
 348
 349 module_i2c_driver(atxp1_driver);