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/kstrtox.h> 20 #include <linux/mutex.h> 21 #include <linux/sysfs.h> 22 #include <linux/slab.h> 23 24 MODULE_LICENSE("GPL"); 25 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); 26 MODULE_VERSION("0.6.3"); 27 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>"); 28 29 #define ATXP1_VID 0x00 30 #define ATXP1_CVID 0x01 31 #define ATXP1_GPIO1 0x06 32 #define ATXP1_GPIO2 0x0a 33 #define ATXP1_VIDENA 0x20 34 #define ATXP1_VIDMASK 0x1f 35 #define ATXP1_GPIO1MASK 0x0f 36 37 struct atxp1_data { 38 struct i2c_client *client; 39 struct mutex update_lock; 40 unsigned long last_updated; 41 bool valid; 42 struct { 43 u8 vid; /* VID output register */ 44 u8 cpu_vid; /* VID input from CPU */ 45 u8 gpio1; /* General purpose I/O register 1 */ 46 u8 gpio2; /* General purpose I/O register 2 */ 47 } reg; 48 u8 vrm; /* Detected CPU VRM */ 49 }; 50 51 static struct atxp1_data *atxp1_update_device(struct device *dev) 52 { 53 struct atxp1_data *data = dev_get_drvdata(dev); 54 struct i2c_client *client = data->client; 55 56 mutex_lock(&data->update_lock); 57 58 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 59 60 /* Update local register data */ 61 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); 62 data->reg.cpu_vid = i2c_smbus_read_byte_data(client, 63 ATXP1_CVID); 64 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); 65 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); 66 67 data->valid = true; 68 } 69 70 mutex_unlock(&data->update_lock); 71 72 return data; 73 } 74 75 /* sys file functions for cpu0_vid */ 76 static ssize_t cpu0_vid_show(struct device *dev, 77 struct device_attribute *attr, char *buf) 78 { 79 int size; 80 struct atxp1_data *data; 81 82 data = atxp1_update_device(dev); 83 84 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, 85 data->vrm)); 86 87 return size; 88 } 89 90 static ssize_t cpu0_vid_store(struct device *dev, 91 struct device_attribute *attr, const char *buf, 92 size_t count) 93 { 94 struct atxp1_data *data = atxp1_update_device(dev); 95 struct i2c_client *client = data->client; 96 int vid, cvid; 97 unsigned long vcore; 98 int err; 99 100 err = kstrtoul(buf, 10, &vcore); 101 if (err) 102 return err; 103 104 vcore /= 25; 105 vcore *= 25; 106 107 /* Calculate VID */ 108 vid = vid_to_reg(vcore, data->vrm); 109 if (vid < 0) { 110 dev_err(dev, "VID calculation failed.\n"); 111 return vid; 112 } 113 114 /* 115 * If output enabled, use control register value. 116 * Otherwise original CPU VID 117 */ 118 if (data->reg.vid & ATXP1_VIDENA) 119 cvid = data->reg.vid & ATXP1_VIDMASK; 120 else 121 cvid = data->reg.cpu_vid; 122 123 /* Nothing changed, aborting */ 124 if (vid == cvid) 125 return count; 126 127 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); 128 129 /* Write every 25 mV step to increase stability */ 130 if (cvid > vid) { 131 for (; cvid >= vid; cvid--) 132 i2c_smbus_write_byte_data(client, 133 ATXP1_VID, cvid | ATXP1_VIDENA); 134 } else { 135 for (; cvid <= vid; cvid++) 136 i2c_smbus_write_byte_data(client, 137 ATXP1_VID, cvid | ATXP1_VIDENA); 138 } 139 140 data->valid = false; 141 142 return count; 143 } 144 145 /* 146 * CPU core reference voltage 147 * unit: millivolt 148 */ 149 static DEVICE_ATTR_RW(cpu0_vid); 150 151 /* sys file functions for GPIO1 */ 152 static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr, 153 char *buf) 154 { 155 int size; 156 struct atxp1_data *data; 157 158 data = atxp1_update_device(dev); 159 160 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); 161 162 return size; 163 } 164 165 static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr, 166 const char *buf, size_t count) 167 { 168 struct atxp1_data *data = atxp1_update_device(dev); 169 struct i2c_client *client = data->client; 170 unsigned long value; 171 int err; 172 173 err = kstrtoul(buf, 16, &value); 174 if (err) 175 return err; 176 177 value &= ATXP1_GPIO1MASK; 178 179 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { 180 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 181 182 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); 183 184 data->valid = false; 185 } 186 187 return count; 188 } 189 190 /* 191 * GPIO1 data register 192 * unit: Four bit as hex (e.g. 0x0f) 193 */ 194 static DEVICE_ATTR_RW(gpio1); 195 196 /* sys file functions for GPIO2 */ 197 static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr, 198 char *buf) 199 { 200 int size; 201 struct atxp1_data *data; 202 203 data = atxp1_update_device(dev); 204 205 size = sprintf(buf, "0x%02x\n", data->reg.gpio2); 206 207 return size; 208 } 209 210 static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr, 211 const char *buf, size_t count) 212 { 213 struct atxp1_data *data = atxp1_update_device(dev); 214 struct i2c_client *client = data->client; 215 unsigned long value; 216 int err; 217 218 err = kstrtoul(buf, 16, &value); 219 if (err) 220 return err; 221 value &= 0xff; 222 223 if (value != data->reg.gpio2) { 224 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); 225 226 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); 227 228 data->valid = false; 229 } 230 231 return count; 232 } 233 234 /* 235 * GPIO2 data register 236 * unit: Eight bit as hex (e.g. 0xff) 237 */ 238 static DEVICE_ATTR_RW(gpio2); 239 240 static struct attribute *atxp1_attrs[] = { 241 &dev_attr_gpio1.attr, 242 &dev_attr_gpio2.attr, 243 &dev_attr_cpu0_vid.attr, 244 NULL 245 }; 246 ATTRIBUTE_GROUPS(atxp1); 247 248 static int atxp1_probe(struct i2c_client *client) 249 { 250 struct device *dev = &client->dev; 251 struct atxp1_data *data; 252 struct device *hwmon_dev; 253 254 data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL); 255 if (!data) 256 return -ENOMEM; 257 258 /* Get VRM */ 259 data->vrm = vid_which_vrm(); 260 if (data->vrm != 90 && data->vrm != 91) { 261 dev_err(dev, "atxp1: Not supporting VRM %d.%d\n", 262 data->vrm / 10, data->vrm % 10); 263 return -ENODEV; 264 } 265 266 data->client = client; 267 mutex_init(&data->update_lock); 268 269 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 270 data, 271 atxp1_groups); 272 if (IS_ERR(hwmon_dev)) 273 return PTR_ERR(hwmon_dev); 274 275 dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10); 276 277 return 0; 278 }; 279 280 static const struct i2c_device_id atxp1_id[] = { 281 { "atxp1", 0 }, 282 { } 283 }; 284 MODULE_DEVICE_TABLE(i2c, atxp1_id); 285 286 static struct i2c_driver atxp1_driver = { 287 .class = I2C_CLASS_HWMON, 288 .driver = { 289 .name = "atxp1", 290 }, 291 .probe_new = atxp1_probe, 292 .id_table = atxp1_id, 293 }; 294 295 module_i2c_driver(atxp1_driver); 296