1 /* 2 * Hardware monitoring driver for ZL6100 and compatibles 3 * 4 * Copyright (c) 2011 Ericsson AB. 5 * Copyright (c) 2012 Guenter Roeck 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 20 */ 21 22 #include <linux/bitops.h> 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/init.h> 26 #include <linux/err.h> 27 #include <linux/slab.h> 28 #include <linux/i2c.h> 29 #include <linux/ktime.h> 30 #include <linux/delay.h> 31 #include "pmbus.h" 32 33 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105, 34 zl9101, zl9117 }; 35 36 struct zl6100_data { 37 int id; 38 ktime_t access; /* chip access time */ 39 int delay; /* Delay between chip accesses in uS */ 40 struct pmbus_driver_info info; 41 }; 42 43 #define to_zl6100_data(x) container_of(x, struct zl6100_data, info) 44 45 #define ZL6100_MFR_CONFIG 0xd0 46 #define ZL6100_DEVICE_ID 0xe4 47 48 #define ZL6100_MFR_XTEMP_ENABLE BIT(7) 49 50 #define MFR_VMON_OV_FAULT_LIMIT 0xf5 51 #define MFR_VMON_UV_FAULT_LIMIT 0xf6 52 #define MFR_READ_VMON 0xf7 53 54 #define VMON_UV_WARNING BIT(5) 55 #define VMON_OV_WARNING BIT(4) 56 #define VMON_UV_FAULT BIT(1) 57 #define VMON_OV_FAULT BIT(0) 58 59 #define ZL6100_WAIT_TIME 1000 /* uS */ 60 61 static ushort delay = ZL6100_WAIT_TIME; 62 module_param(delay, ushort, 0644); 63 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS"); 64 65 /* Convert linear sensor value to milli-units */ 66 static long zl6100_l2d(s16 l) 67 { 68 s16 exponent; 69 s32 mantissa; 70 long val; 71 72 exponent = l >> 11; 73 mantissa = ((s16)((l & 0x7ff) << 5)) >> 5; 74 75 val = mantissa; 76 77 /* scale result to milli-units */ 78 val = val * 1000L; 79 80 if (exponent >= 0) 81 val <<= exponent; 82 else 83 val >>= -exponent; 84 85 return val; 86 } 87 88 #define MAX_MANTISSA (1023 * 1000) 89 #define MIN_MANTISSA (511 * 1000) 90 91 static u16 zl6100_d2l(long val) 92 { 93 s16 exponent = 0, mantissa; 94 bool negative = false; 95 96 /* simple case */ 97 if (val == 0) 98 return 0; 99 100 if (val < 0) { 101 negative = true; 102 val = -val; 103 } 104 105 /* Reduce large mantissa until it fits into 10 bit */ 106 while (val >= MAX_MANTISSA && exponent < 15) { 107 exponent++; 108 val >>= 1; 109 } 110 /* Increase small mantissa to improve precision */ 111 while (val < MIN_MANTISSA && exponent > -15) { 112 exponent--; 113 val <<= 1; 114 } 115 116 /* Convert mantissa from milli-units to units */ 117 mantissa = DIV_ROUND_CLOSEST(val, 1000); 118 119 /* Ensure that resulting number is within range */ 120 if (mantissa > 0x3ff) 121 mantissa = 0x3ff; 122 123 /* restore sign */ 124 if (negative) 125 mantissa = -mantissa; 126 127 /* Convert to 5 bit exponent, 11 bit mantissa */ 128 return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800); 129 } 130 131 /* Some chips need a delay between accesses */ 132 static inline void zl6100_wait(const struct zl6100_data *data) 133 { 134 if (data->delay) { 135 s64 delta = ktime_us_delta(ktime_get(), data->access); 136 if (delta < data->delay) 137 udelay(data->delay - delta); 138 } 139 } 140 141 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg) 142 { 143 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 144 struct zl6100_data *data = to_zl6100_data(info); 145 int ret, vreg; 146 147 if (page > 0) 148 return -ENXIO; 149 150 if (data->id == zl2005) { 151 /* 152 * Limit register detection is not reliable on ZL2005. 153 * Make sure registers are not erroneously detected. 154 */ 155 switch (reg) { 156 case PMBUS_VOUT_OV_WARN_LIMIT: 157 case PMBUS_VOUT_UV_WARN_LIMIT: 158 case PMBUS_IOUT_OC_WARN_LIMIT: 159 return -ENXIO; 160 } 161 } 162 163 switch (reg) { 164 case PMBUS_VIRT_READ_VMON: 165 vreg = MFR_READ_VMON; 166 break; 167 case PMBUS_VIRT_VMON_OV_WARN_LIMIT: 168 case PMBUS_VIRT_VMON_OV_FAULT_LIMIT: 169 vreg = MFR_VMON_OV_FAULT_LIMIT; 170 break; 171 case PMBUS_VIRT_VMON_UV_WARN_LIMIT: 172 case PMBUS_VIRT_VMON_UV_FAULT_LIMIT: 173 vreg = MFR_VMON_UV_FAULT_LIMIT; 174 break; 175 default: 176 if (reg >= PMBUS_VIRT_BASE) 177 return -ENXIO; 178 vreg = reg; 179 break; 180 } 181 182 zl6100_wait(data); 183 ret = pmbus_read_word_data(client, page, vreg); 184 data->access = ktime_get(); 185 if (ret < 0) 186 return ret; 187 188 switch (reg) { 189 case PMBUS_VIRT_VMON_OV_WARN_LIMIT: 190 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10)); 191 break; 192 case PMBUS_VIRT_VMON_UV_WARN_LIMIT: 193 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10)); 194 break; 195 } 196 197 return ret; 198 } 199 200 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg) 201 { 202 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 203 struct zl6100_data *data = to_zl6100_data(info); 204 int ret, status; 205 206 if (page > 0) 207 return -ENXIO; 208 209 zl6100_wait(data); 210 211 switch (reg) { 212 case PMBUS_VIRT_STATUS_VMON: 213 ret = pmbus_read_byte_data(client, 0, 214 PMBUS_STATUS_MFR_SPECIFIC); 215 if (ret < 0) 216 break; 217 218 status = 0; 219 if (ret & VMON_UV_WARNING) 220 status |= PB_VOLTAGE_UV_WARNING; 221 if (ret & VMON_OV_WARNING) 222 status |= PB_VOLTAGE_OV_WARNING; 223 if (ret & VMON_UV_FAULT) 224 status |= PB_VOLTAGE_UV_FAULT; 225 if (ret & VMON_OV_FAULT) 226 status |= PB_VOLTAGE_OV_FAULT; 227 ret = status; 228 break; 229 default: 230 ret = pmbus_read_byte_data(client, page, reg); 231 break; 232 } 233 data->access = ktime_get(); 234 235 return ret; 236 } 237 238 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg, 239 u16 word) 240 { 241 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 242 struct zl6100_data *data = to_zl6100_data(info); 243 int ret, vreg; 244 245 if (page > 0) 246 return -ENXIO; 247 248 switch (reg) { 249 case PMBUS_VIRT_VMON_OV_WARN_LIMIT: 250 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9)); 251 vreg = MFR_VMON_OV_FAULT_LIMIT; 252 pmbus_clear_cache(client); 253 break; 254 case PMBUS_VIRT_VMON_OV_FAULT_LIMIT: 255 vreg = MFR_VMON_OV_FAULT_LIMIT; 256 pmbus_clear_cache(client); 257 break; 258 case PMBUS_VIRT_VMON_UV_WARN_LIMIT: 259 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11)); 260 vreg = MFR_VMON_UV_FAULT_LIMIT; 261 pmbus_clear_cache(client); 262 break; 263 case PMBUS_VIRT_VMON_UV_FAULT_LIMIT: 264 vreg = MFR_VMON_UV_FAULT_LIMIT; 265 pmbus_clear_cache(client); 266 break; 267 default: 268 if (reg >= PMBUS_VIRT_BASE) 269 return -ENXIO; 270 vreg = reg; 271 } 272 273 zl6100_wait(data); 274 ret = pmbus_write_word_data(client, page, vreg, word); 275 data->access = ktime_get(); 276 277 return ret; 278 } 279 280 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value) 281 { 282 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 283 struct zl6100_data *data = to_zl6100_data(info); 284 int ret; 285 286 if (page > 0) 287 return -ENXIO; 288 289 zl6100_wait(data); 290 ret = pmbus_write_byte(client, page, value); 291 data->access = ktime_get(); 292 293 return ret; 294 } 295 296 static const struct i2c_device_id zl6100_id[] = { 297 {"bmr450", zl2005}, 298 {"bmr451", zl2005}, 299 {"bmr462", zl2008}, 300 {"bmr463", zl2008}, 301 {"bmr464", zl2008}, 302 {"zl2004", zl2004}, 303 {"zl2005", zl2005}, 304 {"zl2006", zl2006}, 305 {"zl2008", zl2008}, 306 {"zl2105", zl2105}, 307 {"zl2106", zl2106}, 308 {"zl6100", zl6100}, 309 {"zl6105", zl6105}, 310 {"zl9101", zl9101}, 311 {"zl9117", zl9117}, 312 { } 313 }; 314 MODULE_DEVICE_TABLE(i2c, zl6100_id); 315 316 static int zl6100_probe(struct i2c_client *client, 317 const struct i2c_device_id *id) 318 { 319 int ret; 320 struct zl6100_data *data; 321 struct pmbus_driver_info *info; 322 u8 device_id[I2C_SMBUS_BLOCK_MAX + 1]; 323 const struct i2c_device_id *mid; 324 325 if (!i2c_check_functionality(client->adapter, 326 I2C_FUNC_SMBUS_READ_WORD_DATA 327 | I2C_FUNC_SMBUS_READ_BLOCK_DATA)) 328 return -ENODEV; 329 330 ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID, 331 device_id); 332 if (ret < 0) { 333 dev_err(&client->dev, "Failed to read device ID\n"); 334 return ret; 335 } 336 device_id[ret] = '\0'; 337 dev_info(&client->dev, "Device ID %s\n", device_id); 338 339 mid = NULL; 340 for (mid = zl6100_id; mid->name[0]; mid++) { 341 if (!strncasecmp(mid->name, device_id, strlen(mid->name))) 342 break; 343 } 344 if (!mid->name[0]) { 345 dev_err(&client->dev, "Unsupported device\n"); 346 return -ENODEV; 347 } 348 if (id->driver_data != mid->driver_data) 349 dev_notice(&client->dev, 350 "Device mismatch: Configured %s, detected %s\n", 351 id->name, mid->name); 352 353 data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data), 354 GFP_KERNEL); 355 if (!data) 356 return -ENOMEM; 357 358 data->id = mid->driver_data; 359 360 /* 361 * According to information from the chip vendor, all currently 362 * supported chips are known to require a wait time between I2C 363 * accesses. 364 */ 365 data->delay = delay; 366 367 /* 368 * Since there was a direct I2C device access above, wait before 369 * accessing the chip again. 370 */ 371 data->access = ktime_get(); 372 zl6100_wait(data); 373 374 info = &data->info; 375 376 info->pages = 1; 377 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT 378 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT 379 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT 380 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP; 381 382 /* 383 * ZL2004, ZL9101M, and ZL9117M support monitoring an extra voltage 384 * (VMON for ZL2004, VDRV for ZL9101M and ZL9117M). Report it as vmon. 385 */ 386 if (data->id == zl2004 || data->id == zl9101 || data->id == zl9117) 387 info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON; 388 389 ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG); 390 if (ret < 0) 391 return ret; 392 393 if (ret & ZL6100_MFR_XTEMP_ENABLE) 394 info->func[0] |= PMBUS_HAVE_TEMP2; 395 396 data->access = ktime_get(); 397 zl6100_wait(data); 398 399 info->read_word_data = zl6100_read_word_data; 400 info->read_byte_data = zl6100_read_byte_data; 401 info->write_word_data = zl6100_write_word_data; 402 info->write_byte = zl6100_write_byte; 403 404 return pmbus_do_probe(client, mid, info); 405 } 406 407 static struct i2c_driver zl6100_driver = { 408 .driver = { 409 .name = "zl6100", 410 }, 411 .probe = zl6100_probe, 412 .remove = pmbus_do_remove, 413 .id_table = zl6100_id, 414 }; 415 416 module_i2c_driver(zl6100_driver); 417 418 MODULE_AUTHOR("Guenter Roeck"); 419 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles"); 420 MODULE_LICENSE("GPL"); 421