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 * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is 16 * not auto-detected by the driver and must be instantiated explicitly. 17 * See Documentation/i2c/instantiating-devices for more information. 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/init.h> 22 #include <linux/module.h> 23 #include <linux/jiffies.h> 24 #include <linux/i2c.h> 25 #include <linux/hwmon.h> 26 #include <linux/hwmon-vid.h> 27 #include <linux/err.h> 28 #include <linux/mutex.h> 29 #include <linux/sysfs.h> 30 #include <linux/slab.h> 31 32 MODULE_LICENSE("GPL"); 33 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); 34 MODULE_VERSION("0.6.3"); 35 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>"); 36 37 #define ATXP1_VID 0x00 38 #define ATXP1_CVID 0x01 39 #define ATXP1_GPIO1 0x06 40 #define ATXP1_GPIO2 0x0a 41 #define ATXP1_VIDENA 0x20 42 #define ATXP1_VIDMASK 0x1f 43 #define ATXP1_GPIO1MASK 0x0f 44 45 struct atxp1_data { 46 struct i2c_client *client; 47 struct mutex update_lock; 48 unsigned long last_updated; 49 u8 valid; 50 struct { 51 u8 vid; /* VID output register */ 52 u8 cpu_vid; /* VID input from CPU */ 53 u8 gpio1; /* General purpose I/O register 1 */ 54 u8 gpio2; /* General purpose I/O register 2 */ 55 } reg; 56 u8 vrm; /* Detected CPU VRM */ 57 }; 58 59 static struct atxp1_data *atxp1_update_device(struct device *dev) 60 { 61 struct atxp1_data *data = dev_get_drvdata(dev); 62 struct i2c_client *client = data->client; 63 64 mutex_lock(&data->update_lock); 65 66 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 67 68 /* Update local register data */ 69 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); 70 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, 71 ATXP1_CVID); 72 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); 73 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); 74 75 data->valid = 1; 76 } 77 78 mutex_unlock(&data->update_lock); 79 80 return data; 81 } 82 83 /* sys file functions for cpu0_vid */ 84 static ssize_t atxp1_showvcore(struct device *dev, 85 struct device_attribute *attr, char *buf) 86 { 87 int size; 88 struct atxp1_data *data; 89 90 data = atxp1_update_device(dev); 91 92 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, 93 data->vrm)); 94 95 return size; 96 } 97 98 static ssize_t atxp1_storevcore(struct device *dev, 99 struct device_attribute *attr, 100 const char *buf, size_t count) 101 { 102 struct atxp1_data *data = atxp1_update_device(dev); 103 struct i2c_client *client = data->client; 104 int vid, cvid; 105 unsigned long vcore; 106 int err; 107 108 err = kstrtoul(buf, 10, &vcore); 109 if (err) 110 return err; 111 112 vcore /= 25; 113 vcore *= 25; 114 115 /* Calculate VID */ 116 vid = vid_to_reg(vcore, data->vrm); 117 if (vid < 0) { 118 dev_err(dev, "VID calculation failed.\n"); 119 return vid; 120 } 121 122 /* 123 * If output enabled, use control register value. 124 * Otherwise original CPU VID 125 */ 126 if (data->reg.vid & ATXP1_VIDENA) 127 cvid = data->reg.vid & ATXP1_VIDMASK; 128 else 129 cvid = data->reg.cpu_vid; 130 131 /* Nothing changed, aborting */ 132 if (vid == cvid) 133 return count; 134 135 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); 136 137 /* Write every 25 mV step to increase stability */ 138 if (cvid > vid) { 139 for (; cvid >= vid; cvid--) 140 i2c_smbus_write_byte_data(client, 141 ATXP1_VID, cvid | ATXP1_VIDENA); 142 } else { 143 for (; cvid <= vid; cvid++) 144 i2c_smbus_write_byte_data(client, 145 ATXP1_VID, cvid | ATXP1_VIDENA); 146 } 147 148 data->valid = 0; 149 150 return count; 151 } 152 153 /* 154 * CPU core reference voltage 155 * unit: millivolt 156 */ 157 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore, 158 atxp1_storevcore); 159 160 /* sys file functions for GPIO1 */ 161 static ssize_t atxp1_showgpio1(struct device *dev, 162 struct device_attribute *attr, char *buf) 163 { 164 int size; 165 struct atxp1_data *data; 166 167 data = atxp1_update_device(dev); 168 169 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 170 171 return size; 172 } 173 174 static ssize_t atxp1_storegpio1(struct device *dev, 175 struct device_attribute *attr, const char *buf, 176 size_t count) 177 { 178 struct atxp1_data *data = atxp1_update_device(dev); 179 struct i2c_client *client = data->client; 180 unsigned long value; 181 int err; 182 183 err = kstrtoul(buf, 16, &value); 184 if (err) 185 return err; 186 187 value &= ATXP1_GPIO1MASK; 188 189 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 190 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 191 192 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 193 194 data->valid = 0; 195 } 196 197 return count; 198 } 199 200 /* 201 * GPIO1 data register 202 * unit: Four bit as hex (e.g. 0x0f) 203 */ 204 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1); 205 206 /* sys file functions for GPIO2 */ 207 static ssize_t atxp1_showgpio2(struct device *dev, 208 struct device_attribute *attr, char *buf) 209 { 210 int size; 211 struct atxp1_data *data; 212 213 data = atxp1_update_device(dev); 214 215 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 216 217 return size; 218 } 219 220 static ssize_t atxp1_storegpio2(struct device *dev, 221 struct device_attribute *attr, 222 const char *buf, size_t count) 223 { 224 struct atxp1_data *data = atxp1_update_device(dev); 225 struct i2c_client *client = data->client; 226 unsigned long value; 227 int err; 228 229 err = kstrtoul(buf, 16, &value); 230 if (err) 231 return err; 232 value &= 0xff; 233 234 if (value != data->reg.gpio2) { 235 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 236 237 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 238 239 data->valid = 0; 240 } 241 242 return count; 243 } 244 245 /* 246 * GPIO2 data register 247 * unit: Eight bit as hex (e.g. 0xff) 248 */ 249 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2); 250 251 static struct attribute *atxp1_attrs[] = { 252 &dev_attr_gpio1.attr, 253 &dev_attr_gpio2.attr, 254 &dev_attr_cpu0_vid.attr, 255 NULL 256 }; 257 ATTRIBUTE_GROUPS(atxp1); 258 259 static int atxp1_probe(struct i2c_client *client, 260 const struct i2c_device_id *id) 261 { 262 struct device *dev = &client->dev; 263 struct atxp1_data *data; 264 struct device *hwmon_dev; 265 266 data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL); 267 if (!data) 268 return -ENOMEM; 269 270 /* Get VRM */ 271 data->vrm = vid_which_vrm(); 272 if (data->vrm != 90 && data->vrm != 91) { 273 dev_err(dev, "atxp1: Not supporting VRM %d.%d\n", 274 data->vrm / 10, data->vrm % 10); 275 return -ENODEV; 276 } 277 278 data->client = client; 279 mutex_init(&data->update_lock); 280 281 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 282 data, 283 atxp1_groups); 284 if (IS_ERR(hwmon_dev)) 285 return PTR_ERR(hwmon_dev); 286 287 dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10); 288 289 return 0; 290 }; 291 292 static const struct i2c_device_id atxp1_id[] = { 293 { "atxp1", 0 }, 294 { } 295 }; 296 MODULE_DEVICE_TABLE(i2c, atxp1_id); 297 298 static struct i2c_driver atxp1_driver = { 299 .class = I2C_CLASS_HWMON, 300 .driver = { 301 .name = "atxp1", 302 }, 303 .probe = atxp1_probe, 304 .id_table = atxp1_id, 305 }; 306 307 module_i2c_driver(atxp1_driver); 308