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 cpu0_vid_show(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 cpu0_vid_store(struct device *dev, 99 struct device_attribute *attr, const char *buf, 100 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_RW(cpu0_vid); 158 159 /* sys file functions for GPIO1 */ 160 static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr, 161 char *buf) 162 { 163 int size; 164 struct atxp1_data *data; 165 166 data = atxp1_update_device(dev); 167 168 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 169 170 return size; 171 } 172 173 static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr, 174 const char *buf, size_t count) 175 { 176 struct atxp1_data *data = atxp1_update_device(dev); 177 struct i2c_client *client = data->client; 178 unsigned long value; 179 int err; 180 181 err = kstrtoul(buf, 16, &value); 182 if (err) 183 return err; 184 185 value &= ATXP1_GPIO1MASK; 186 187 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 188 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 189 190 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 191 192 data->valid = 0; 193 } 194 195 return count; 196 } 197 198 /* 199 * GPIO1 data register 200 * unit: Four bit as hex (e.g. 0x0f) 201 */ 202 static DEVICE_ATTR_RW(gpio1); 203 204 /* sys file functions for GPIO2 */ 205 static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr, 206 char *buf) 207 { 208 int size; 209 struct atxp1_data *data; 210 211 data = atxp1_update_device(dev); 212 213 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 214 215 return size; 216 } 217 218 static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr, 219 const char *buf, size_t count) 220 { 221 struct atxp1_data *data = atxp1_update_device(dev); 222 struct i2c_client *client = data->client; 223 unsigned long value; 224 int err; 225 226 err = kstrtoul(buf, 16, &value); 227 if (err) 228 return err; 229 value &= 0xff; 230 231 if (value != data->reg.gpio2) { 232 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 233 234 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 235 236 data->valid = 0; 237 } 238 239 return count; 240 } 241 242 /* 243 * GPIO2 data register 244 * unit: Eight bit as hex (e.g. 0xff) 245 */ 246 static DEVICE_ATTR_RW(gpio2); 247 248 static struct attribute *atxp1_attrs[] = { 249 &dev_attr_gpio1.attr, 250 &dev_attr_gpio2.attr, 251 &dev_attr_cpu0_vid.attr, 252 NULL 253 }; 254 ATTRIBUTE_GROUPS(atxp1); 255 256 static int atxp1_probe(struct i2c_client *client, 257 const struct i2c_device_id *id) 258 { 259 struct device *dev = &client->dev; 260 struct atxp1_data *data; 261 struct device *hwmon_dev; 262 263 data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL); 264 if (!data) 265 return -ENOMEM; 266 267 /* Get VRM */ 268 data->vrm = vid_which_vrm(); 269 if (data->vrm != 90 && data->vrm != 91) { 270 dev_err(dev, "atxp1: Not supporting VRM %d.%d\n", 271 data->vrm / 10, data->vrm % 10); 272 return -ENODEV; 273 } 274 275 data->client = client; 276 mutex_init(&data->update_lock); 277 278 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 279 data, 280 atxp1_groups); 281 if (IS_ERR(hwmon_dev)) 282 return PTR_ERR(hwmon_dev); 283 284 dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10); 285 286 return 0; 287 }; 288 289 static const struct i2c_device_id atxp1_id[] = { 290 { "atxp1", 0 }, 291 { } 292 }; 293 MODULE_DEVICE_TABLE(i2c, atxp1_id); 294 295 static struct i2c_driver atxp1_driver = { 296 .class = I2C_CLASS_HWMON, 297 .driver = { 298 .name = "atxp1", 299 }, 300 .probe = atxp1_probe, 301 .id_table = atxp1_id, 302 }; 303 304 module_i2c_driver(atxp1_driver); 305