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); 350