| 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 = atxp1_probe, |
| 292 | .id_table = atxp1_id, |
| 293 | }; |
| 294 | |
| 295 | module_i2c_driver(atxp1_driver); |