1 /* 2 * max8660.c -- Voltage regulation for the Maxim 8660/8661 3 * 4 * based on max1586.c and wm8400-regulator.c 5 * 6 * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K. 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the Free 10 * Software Foundation; version 2 of the License. 11 * 12 * This program is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 * 17 * You should have received a copy of the GNU General Public License along with 18 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 19 * Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 * Some info: 22 * 23 * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf 24 * 25 * This chip is a bit nasty because it is a write-only device. Thus, the driver 26 * uses shadow registers to keep track of its values. The main problem appears 27 * to be the initialization: When Linux boots up, we cannot know if the chip is 28 * in the default state or not, so we would have to pass such information in 29 * platform_data. As this adds a bit of complexity to the driver, this is left 30 * out for now until it is really needed. 31 * 32 * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2. 33 * 34 * If the driver is feature complete, it might be worth to check if one set of 35 * functions for V3-V7 is sufficient. For maximum flexibility during 36 * development, they are separated for now. 37 * 38 */ 39 40 #include <linux/module.h> 41 #include <linux/err.h> 42 #include <linux/i2c.h> 43 #include <linux/platform_device.h> 44 #include <linux/regulator/driver.h> 45 #include <linux/slab.h> 46 #include <linux/regulator/max8660.h> 47 #include <linux/of.h> 48 #include <linux/of_device.h> 49 #include <linux/regulator/of_regulator.h> 50 51 #define MAX8660_DCDC_MIN_UV 725000 52 #define MAX8660_DCDC_MAX_UV 1800000 53 #define MAX8660_DCDC_STEP 25000 54 #define MAX8660_DCDC_MAX_SEL 0x2b 55 56 #define MAX8660_LDO5_MIN_UV 1700000 57 #define MAX8660_LDO5_MAX_UV 2000000 58 #define MAX8660_LDO5_STEP 25000 59 #define MAX8660_LDO5_MAX_SEL 0x0c 60 61 #define MAX8660_LDO67_MIN_UV 1800000 62 #define MAX8660_LDO67_MAX_UV 3300000 63 #define MAX8660_LDO67_STEP 100000 64 #define MAX8660_LDO67_MAX_SEL 0x0f 65 66 enum { 67 MAX8660_OVER1, 68 MAX8660_OVER2, 69 MAX8660_VCC1, 70 MAX8660_ADTV1, 71 MAX8660_ADTV2, 72 MAX8660_SDTV1, 73 MAX8660_SDTV2, 74 MAX8660_MDTV1, 75 MAX8660_MDTV2, 76 MAX8660_L12VCR, 77 MAX8660_FPWM, 78 MAX8660_N_REGS, /* not a real register */ 79 }; 80 81 struct max8660 { 82 struct i2c_client *client; 83 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ 84 }; 85 86 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) 87 { 88 static const u8 max8660_addresses[MAX8660_N_REGS] = { 89 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 90 }; 91 92 int ret; 93 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; 94 95 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", 96 max8660_addresses[reg], reg_val); 97 98 ret = i2c_smbus_write_byte_data(max8660->client, 99 max8660_addresses[reg], reg_val); 100 if (ret == 0) 101 max8660->shadow_regs[reg] = reg_val; 102 103 return ret; 104 } 105 106 107 /* 108 * DCDC functions 109 */ 110 111 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) 112 { 113 struct max8660 *max8660 = rdev_get_drvdata(rdev); 114 u8 val = max8660->shadow_regs[MAX8660_OVER1]; 115 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 116 117 return !!(val & mask); 118 } 119 120 static int max8660_dcdc_enable(struct regulator_dev *rdev) 121 { 122 struct max8660 *max8660 = rdev_get_drvdata(rdev); 123 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 124 125 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); 126 } 127 128 static int max8660_dcdc_disable(struct regulator_dev *rdev) 129 { 130 struct max8660 *max8660 = rdev_get_drvdata(rdev); 131 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; 132 133 return max8660_write(max8660, MAX8660_OVER1, mask, 0); 134 } 135 136 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) 137 { 138 struct max8660 *max8660 = rdev_get_drvdata(rdev); 139 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 140 u8 selector = max8660->shadow_regs[reg]; 141 142 return selector; 143 } 144 145 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, 146 unsigned int selector) 147 { 148 struct max8660 *max8660 = rdev_get_drvdata(rdev); 149 u8 reg, bits; 150 int ret; 151 152 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 153 ret = max8660_write(max8660, reg, 0, selector); 154 if (ret) 155 return ret; 156 157 /* Select target voltage register and activate regulation */ 158 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 159 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 160 } 161 162 static struct regulator_ops max8660_dcdc_ops = { 163 .is_enabled = max8660_dcdc_is_enabled, 164 .list_voltage = regulator_list_voltage_linear, 165 .map_voltage = regulator_map_voltage_linear, 166 .set_voltage_sel = max8660_dcdc_set_voltage_sel, 167 .get_voltage_sel = max8660_dcdc_get_voltage_sel, 168 }; 169 170 171 /* 172 * LDO5 functions 173 */ 174 175 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) 176 { 177 struct max8660 *max8660 = rdev_get_drvdata(rdev); 178 179 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 180 return selector; 181 } 182 183 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, 184 unsigned int selector) 185 { 186 struct max8660 *max8660 = rdev_get_drvdata(rdev); 187 int ret; 188 189 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 190 if (ret) 191 return ret; 192 193 /* Select target voltage register and activate regulation */ 194 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 195 } 196 197 static const struct regulator_ops max8660_ldo5_ops = { 198 .list_voltage = regulator_list_voltage_linear, 199 .map_voltage = regulator_map_voltage_linear, 200 .set_voltage_sel = max8660_ldo5_set_voltage_sel, 201 .get_voltage_sel = max8660_ldo5_get_voltage_sel, 202 }; 203 204 205 /* 206 * LDO67 functions 207 */ 208 209 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 210 { 211 struct max8660 *max8660 = rdev_get_drvdata(rdev); 212 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 213 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 214 215 return !!(val & mask); 216 } 217 218 static int max8660_ldo67_enable(struct regulator_dev *rdev) 219 { 220 struct max8660 *max8660 = rdev_get_drvdata(rdev); 221 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 222 223 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 224 } 225 226 static int max8660_ldo67_disable(struct regulator_dev *rdev) 227 { 228 struct max8660 *max8660 = rdev_get_drvdata(rdev); 229 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 230 231 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 232 } 233 234 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) 235 { 236 struct max8660 *max8660 = rdev_get_drvdata(rdev); 237 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 238 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 239 240 return selector; 241 } 242 243 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, 244 unsigned int selector) 245 { 246 struct max8660 *max8660 = rdev_get_drvdata(rdev); 247 248 if (rdev_get_id(rdev) == MAX8660_V6) 249 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 250 else 251 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, 252 selector << 4); 253 } 254 255 static const struct regulator_ops max8660_ldo67_ops = { 256 .is_enabled = max8660_ldo67_is_enabled, 257 .enable = max8660_ldo67_enable, 258 .disable = max8660_ldo67_disable, 259 .list_voltage = regulator_list_voltage_linear, 260 .map_voltage = regulator_map_voltage_linear, 261 .get_voltage_sel = max8660_ldo67_get_voltage_sel, 262 .set_voltage_sel = max8660_ldo67_set_voltage_sel, 263 }; 264 265 static const struct regulator_desc max8660_reg[] = { 266 { 267 .name = "V3(DCDC)", 268 .id = MAX8660_V3, 269 .ops = &max8660_dcdc_ops, 270 .type = REGULATOR_VOLTAGE, 271 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 272 .owner = THIS_MODULE, 273 .min_uV = MAX8660_DCDC_MIN_UV, 274 .uV_step = MAX8660_DCDC_STEP, 275 }, 276 { 277 .name = "V4(DCDC)", 278 .id = MAX8660_V4, 279 .ops = &max8660_dcdc_ops, 280 .type = REGULATOR_VOLTAGE, 281 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 282 .owner = THIS_MODULE, 283 .min_uV = MAX8660_DCDC_MIN_UV, 284 .uV_step = MAX8660_DCDC_STEP, 285 }, 286 { 287 .name = "V5(LDO)", 288 .id = MAX8660_V5, 289 .ops = &max8660_ldo5_ops, 290 .type = REGULATOR_VOLTAGE, 291 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 292 .owner = THIS_MODULE, 293 .min_uV = MAX8660_LDO5_MIN_UV, 294 .uV_step = MAX8660_LDO5_STEP, 295 }, 296 { 297 .name = "V6(LDO)", 298 .id = MAX8660_V6, 299 .ops = &max8660_ldo67_ops, 300 .type = REGULATOR_VOLTAGE, 301 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 302 .owner = THIS_MODULE, 303 .min_uV = MAX8660_LDO67_MIN_UV, 304 .uV_step = MAX8660_LDO67_STEP, 305 }, 306 { 307 .name = "V7(LDO)", 308 .id = MAX8660_V7, 309 .ops = &max8660_ldo67_ops, 310 .type = REGULATOR_VOLTAGE, 311 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 312 .owner = THIS_MODULE, 313 .min_uV = MAX8660_LDO67_MIN_UV, 314 .uV_step = MAX8660_LDO67_STEP, 315 }, 316 }; 317 318 enum { 319 MAX8660 = 0, 320 MAX8661 = 1, 321 }; 322 323 #ifdef CONFIG_OF 324 static const struct of_device_id max8660_dt_ids[] = { 325 { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, 326 { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, 327 { } 328 }; 329 MODULE_DEVICE_TABLE(of, max8660_dt_ids); 330 331 static int max8660_pdata_from_dt(struct device *dev, 332 struct device_node **of_node, 333 struct max8660_platform_data *pdata) 334 { 335 int matched, i; 336 struct device_node *np; 337 struct max8660_subdev_data *sub; 338 struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { }; 339 340 np = of_get_child_by_name(dev->of_node, "regulators"); 341 if (!np) { 342 dev_err(dev, "missing 'regulators' subnode in DT\n"); 343 return -EINVAL; 344 } 345 346 for (i = 0; i < ARRAY_SIZE(rmatch); i++) 347 rmatch[i].name = max8660_reg[i].name; 348 349 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); 350 of_node_put(np); 351 if (matched <= 0) 352 return matched; 353 354 pdata->subdevs = devm_kcalloc(dev, 355 matched, 356 sizeof(struct max8660_subdev_data), 357 GFP_KERNEL); 358 if (!pdata->subdevs) 359 return -ENOMEM; 360 361 pdata->num_subdevs = matched; 362 sub = pdata->subdevs; 363 364 for (i = 0; i < matched; i++) { 365 sub->id = i; 366 sub->name = rmatch[i].name; 367 sub->platform_data = rmatch[i].init_data; 368 of_node[i] = rmatch[i].of_node; 369 sub++; 370 } 371 372 return 0; 373 } 374 #else 375 static inline int max8660_pdata_from_dt(struct device *dev, 376 struct device_node **of_node, 377 struct max8660_platform_data *pdata) 378 { 379 return 0; 380 } 381 #endif 382 383 static int max8660_probe(struct i2c_client *client, 384 const struct i2c_device_id *i2c_id) 385 { 386 struct device *dev = &client->dev; 387 struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); 388 struct regulator_config config = { }; 389 struct max8660 *max8660; 390 int boot_on, i, id, ret = -EINVAL; 391 struct device_node *of_node[MAX8660_V_END]; 392 unsigned long type; 393 394 if (dev->of_node && !pdata) { 395 const struct of_device_id *id; 396 397 id = of_match_device(of_match_ptr(max8660_dt_ids), dev); 398 if (!id) 399 return -ENODEV; 400 401 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); 402 if (ret < 0) 403 return ret; 404 405 pdata = &pdata_of; 406 type = (unsigned long) id->data; 407 } else { 408 type = i2c_id->driver_data; 409 memset(of_node, 0, sizeof(of_node)); 410 } 411 412 if (pdata->num_subdevs > MAX8660_V_END) { 413 dev_err(dev, "Too many regulators found!\n"); 414 return -EINVAL; 415 } 416 417 max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); 418 if (!max8660) 419 return -ENOMEM; 420 421 max8660->client = client; 422 423 if (pdata->en34_is_high) { 424 /* Simulate always on */ 425 max8660->shadow_regs[MAX8660_OVER1] = 5; 426 } else { 427 /* Otherwise devices can be toggled via software */ 428 max8660_dcdc_ops.enable = max8660_dcdc_enable; 429 max8660_dcdc_ops.disable = max8660_dcdc_disable; 430 } 431 432 /* 433 * First, set up shadow registers to prevent glitches. As some 434 * registers are shared between regulators, everything must be properly 435 * set up for all regulators in advance. 436 */ 437 max8660->shadow_regs[MAX8660_ADTV1] = 438 max8660->shadow_regs[MAX8660_ADTV2] = 439 max8660->shadow_regs[MAX8660_SDTV1] = 440 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 441 max8660->shadow_regs[MAX8660_MDTV1] = 442 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 443 444 for (i = 0; i < pdata->num_subdevs; i++) { 445 446 if (!pdata->subdevs[i].platform_data) 447 boot_on = false; 448 else 449 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 450 451 switch (pdata->subdevs[i].id) { 452 case MAX8660_V3: 453 if (boot_on) 454 max8660->shadow_regs[MAX8660_OVER1] |= 1; 455 break; 456 457 case MAX8660_V4: 458 if (boot_on) 459 max8660->shadow_regs[MAX8660_OVER1] |= 4; 460 break; 461 462 case MAX8660_V5: 463 break; 464 465 case MAX8660_V6: 466 if (boot_on) 467 max8660->shadow_regs[MAX8660_OVER2] |= 2; 468 break; 469 470 case MAX8660_V7: 471 if (type == MAX8661) { 472 dev_err(dev, "Regulator not on this chip!\n"); 473 return -EINVAL; 474 } 475 476 if (boot_on) 477 max8660->shadow_regs[MAX8660_OVER2] |= 4; 478 break; 479 480 default: 481 dev_err(dev, "invalid regulator %s\n", 482 pdata->subdevs[i].name); 483 return ret; 484 } 485 } 486 487 /* Finally register devices */ 488 for (i = 0; i < pdata->num_subdevs; i++) { 489 struct regulator_dev *rdev; 490 491 id = pdata->subdevs[i].id; 492 493 config.dev = dev; 494 config.init_data = pdata->subdevs[i].platform_data; 495 config.of_node = of_node[i]; 496 config.driver_data = max8660; 497 498 rdev = devm_regulator_register(&client->dev, 499 &max8660_reg[id], &config); 500 if (IS_ERR(rdev)) { 501 ret = PTR_ERR(rdev); 502 dev_err(&client->dev, "failed to register %s\n", 503 max8660_reg[id].name); 504 return PTR_ERR(rdev); 505 } 506 } 507 508 i2c_set_clientdata(client, max8660); 509 return 0; 510 } 511 512 static const struct i2c_device_id max8660_id[] = { 513 { .name = "max8660", .driver_data = MAX8660 }, 514 { .name = "max8661", .driver_data = MAX8661 }, 515 { } 516 }; 517 MODULE_DEVICE_TABLE(i2c, max8660_id); 518 519 static struct i2c_driver max8660_driver = { 520 .probe = max8660_probe, 521 .driver = { 522 .name = "max8660", 523 }, 524 .id_table = max8660_id, 525 }; 526 527 static int __init max8660_init(void) 528 { 529 return i2c_add_driver(&max8660_driver); 530 } 531 subsys_initcall(max8660_init); 532 533 static void __exit max8660_exit(void) 534 { 535 i2c_del_driver(&max8660_driver); 536 } 537 module_exit(max8660_exit); 538 539 /* Module information */ 540 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 541 MODULE_AUTHOR("Wolfram Sang"); 542 MODULE_LICENSE("GPL v2"); 543