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); 361