1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * atxp1.c - kernel module for setting CPU VID and general purpose 4 * I/Os using the Attansic ATXP1 chip. 5 * 6 * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is 7 * not auto-detected by the driver and must be instantiated explicitly. 8 * See Documentation/i2c/instantiating-devices.rst for more information. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/jiffies.h> 15 #include <linux/i2c.h> 16 #include <linux/hwmon.h> 17 #include <linux/hwmon-vid.h> 18 #include <linux/err.h> 19 #include <linux/mutex.h> 20 #include <linux/sysfs.h> 21 #include <linux/slab.h> 22 23 MODULE_LICENSE("GPL"); 24 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); 25 MODULE_VERSION("0.6.3"); 26 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>"); 27 28 #define ATXP1_VID 0x00 29 #define ATXP1_CVID 0x01 30 #define ATXP1_GPIO1 0x06 31 #define ATXP1_GPIO2 0x0a 32 #define ATXP1_VIDENA 0x20 33 #define ATXP1_VIDMASK 0x1f 34 #define ATXP1_GPIO1MASK 0x0f 35 36 struct atxp1_data { 37 struct i2c_client *client; 38 struct mutex update_lock; 39 unsigned long last_updated; 40 u8 valid; 41 struct { 42 u8 vid; /* VID output register */ 43 u8 cpu_vid; /* VID input from CPU */ 44 u8 gpio1; /* General purpose I/O register 1 */ 45 u8 gpio2; /* General purpose I/O register 2 */ 46 } reg; 47 u8 vrm; /* Detected CPU VRM */ 48 }; 49 50 static struct atxp1_data *atxp1_update_device(struct device *dev) 51 { 52 struct atxp1_data *data = dev_get_drvdata(dev); 53 struct i2c_client *client = data->client; 54 55 mutex_lock(&data->update_lock); 56 57 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 58 59 /* Update local register data */ 60 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); 61 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, 62 ATXP1_CVID); 63 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); 64 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); 65 66 data->valid = 1; 67 } 68 69 mutex_unlock(&data->update_lock); 70 71 return data; 72 } 73 74 /* sys file functions for cpu0_vid */ 75 static ssize_t cpu0_vid_show(struct device *dev, 76 struct device_attribute *attr, char *buf) 77 { 78 int size; 79 struct atxp1_data *data; 80 81 data = atxp1_update_device(dev); 82 83 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, 84 data->vrm)); 85 86 return size; 87 } 88 89 static ssize_t cpu0_vid_store(struct device *dev, 90 struct device_attribute *attr, const char *buf, 91 size_t count) 92 { 93 struct atxp1_data *data = atxp1_update_device(dev); 94 struct i2c_client *client = data->client; 95 int vid, cvid; 96 unsigned long vcore; 97 int err; 98 99 err = kstrtoul(buf, 10, &vcore); 100 if (err) 101 return err; 102 103 vcore /= 25; 104 vcore *= 25; 105 106 /* Calculate VID */ 107 vid = vid_to_reg(vcore, data->vrm); 108 if (vid < 0) { 109 dev_err(dev, "VID calculation failed.\n"); 110 return vid; 111 } 112 113 /* 114 * If output enabled, use control register value. 115 * Otherwise original CPU VID 116 */ 117 if (data->reg.vid & ATXP1_VIDENA) 118 cvid = data->reg.vid & ATXP1_VIDMASK; 119 else 120 cvid = data->reg.cpu_vid; 121 122 /* Nothing changed, aborting */ 123 if (vid == cvid) 124 return count; 125 126 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); 127 128 /* Write every 25 mV step to increase stability */ 129 if (cvid > vid) { 130 for (; cvid >= vid; cvid--) 131 i2c_smbus_write_byte_data(client, 132 ATXP1_VID, cvid | ATXP1_VIDENA); 133 } else { 134 for (; cvid <= vid; cvid++) 135 i2c_smbus_write_byte_data(client, 136 ATXP1_VID, cvid | ATXP1_VIDENA); 137 } 138 139 data->valid = 0; 140 141 return count; 142 } 143 144 /* 145 * CPU core reference voltage 146 * unit: millivolt 147 */ 148 static DEVICE_ATTR_RW(cpu0_vid); 149 150 /* sys file functions for GPIO1 */ 151 static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr, 152 char *buf) 153 { 154 int size; 155 struct atxp1_data *data; 156 157 data = atxp1_update_device(dev); 158 159 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 160 161 return size; 162 } 163 164 static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr, 165 const char *buf, size_t count) 166 { 167 struct atxp1_data *data = atxp1_update_device(dev); 168 struct i2c_client *client = data->client; 169 unsigned long value; 170 int err; 171 172 err = kstrtoul(buf, 16, &value); 173 if (err) 174 return err; 175 176 value &= ATXP1_GPIO1MASK; 177 178 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 179 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 180 181 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 182 183 data->valid = 0; 184 } 185 186 return count; 187 } 188 189 /* 190 * GPIO1 data register 191 * unit: Four bit as hex (e.g. 0x0f) 192 */ 193 static DEVICE_ATTR_RW(gpio1); 194 195 /* sys file functions for GPIO2 */ 196 static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr, 197 char *buf) 198 { 199 int size; 200 struct atxp1_data *data; 201 202 data = atxp1_update_device(dev); 203 204 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 205 206 return size; 207 } 208 209 static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr, 210 const char *buf, size_t count) 211 { 212 struct atxp1_data *data = atxp1_update_device(dev); 213 struct i2c_client *client = data->client; 214 unsigned long value; 215 int err; 216 217 err = kstrtoul(buf, 16, &value); 218 if (err) 219 return err; 220 value &= 0xff; 221 222 if (value != data->reg.gpio2) { 223 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 224 225 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 226 227 data->valid = 0; 228 } 229 230 return count; 231 } 232 233 /* 234 * GPIO2 data register 235 * unit: Eight bit as hex (e.g. 0xff) 236 */ 237 static DEVICE_ATTR_RW(gpio2); 238 239 static struct attribute *atxp1_attrs[] = { 240 &dev_attr_gpio1.attr, 241 &dev_attr_gpio2.attr, 242 &dev_attr_cpu0_vid.attr, 243 NULL 244 }; 245 ATTRIBUTE_GROUPS(atxp1); 246 247 static int atxp1_probe(struct i2c_client *client) 248 { 249 struct device *dev = &client->dev; 250 struct atxp1_data *data; 251 struct device *hwmon_dev; 252 253 data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL); 254 if (!data) 255 return -ENOMEM; 256 257 /* Get VRM */ 258 data->vrm = vid_which_vrm(); 259 if (data->vrm != 90 && data->vrm != 91) { 260 dev_err(dev, "atxp1: Not supporting VRM %d.%d\n", 261 data->vrm / 10, data->vrm % 10); 262 return -ENODEV; 263 } 264 265 data->client = client; 266 mutex_init(&data->update_lock); 267 268 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 269 data, 270 atxp1_groups); 271 if (IS_ERR(hwmon_dev)) 272 return PTR_ERR(hwmon_dev); 273 274 dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10); 275 276 return 0; 277 }; 278 279 static const struct i2c_device_id atxp1_id[] = { 280 { "atxp1", 0 }, 281 { } 282 }; 283 MODULE_DEVICE_TABLE(i2c, atxp1_id); 284 285 static struct i2c_driver atxp1_driver = { 286 .class = I2C_CLASS_HWMON, 287 .driver = { 288 .name = "atxp1", 289 }, 290 .probe_new = atxp1_probe, 291 .id_table = atxp1_id, 292 }; 293 294 module_i2c_driver(atxp1_driver); 295