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 struct regulator_dev *rdev[]; 85 }; 86 87 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) 88 { 89 static const u8 max8660_addresses[MAX8660_N_REGS] = 90 { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 }; 91 92 int ret; 93 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; 94 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", 95 max8660_addresses[reg], reg_val); 96 97 ret = i2c_smbus_write_byte_data(max8660->client, 98 max8660_addresses[reg], reg_val); 99 if (ret == 0) 100 max8660->shadow_regs[reg] = reg_val; 101 102 return ret; 103 } 104 105 106 /* 107 * DCDC functions 108 */ 109 110 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) 111 { 112 struct max8660 *max8660 = rdev_get_drvdata(rdev); 113 u8 val = max8660->shadow_regs[MAX8660_OVER1]; 114 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 115 return !!(val & mask); 116 } 117 118 static int max8660_dcdc_enable(struct regulator_dev *rdev) 119 { 120 struct max8660 *max8660 = rdev_get_drvdata(rdev); 121 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 122 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); 123 } 124 125 static int max8660_dcdc_disable(struct regulator_dev *rdev) 126 { 127 struct max8660 *max8660 = rdev_get_drvdata(rdev); 128 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; 129 return max8660_write(max8660, MAX8660_OVER1, mask, 0); 130 } 131 132 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) 133 { 134 struct max8660 *max8660 = rdev_get_drvdata(rdev); 135 136 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 137 u8 selector = max8660->shadow_regs[reg]; 138 return selector; 139 } 140 141 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, 142 unsigned int selector) 143 { 144 struct max8660 *max8660 = rdev_get_drvdata(rdev); 145 u8 reg, bits; 146 int ret; 147 148 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 149 ret = max8660_write(max8660, reg, 0, selector); 150 if (ret) 151 return ret; 152 153 /* Select target voltage register and activate regulation */ 154 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 155 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 156 } 157 158 static struct regulator_ops max8660_dcdc_ops = { 159 .is_enabled = max8660_dcdc_is_enabled, 160 .list_voltage = regulator_list_voltage_linear, 161 .map_voltage = regulator_map_voltage_linear, 162 .set_voltage_sel = max8660_dcdc_set_voltage_sel, 163 .get_voltage_sel = max8660_dcdc_get_voltage_sel, 164 }; 165 166 167 /* 168 * LDO5 functions 169 */ 170 171 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) 172 { 173 struct max8660 *max8660 = rdev_get_drvdata(rdev); 174 175 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 176 return selector; 177 } 178 179 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, 180 unsigned int selector) 181 { 182 struct max8660 *max8660 = rdev_get_drvdata(rdev); 183 int ret; 184 185 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 186 if (ret) 187 return ret; 188 189 /* Select target voltage register and activate regulation */ 190 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 191 } 192 193 static struct regulator_ops max8660_ldo5_ops = { 194 .list_voltage = regulator_list_voltage_linear, 195 .map_voltage = regulator_map_voltage_linear, 196 .set_voltage_sel = max8660_ldo5_set_voltage_sel, 197 .get_voltage_sel = max8660_ldo5_get_voltage_sel, 198 }; 199 200 201 /* 202 * LDO67 functions 203 */ 204 205 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 206 { 207 struct max8660 *max8660 = rdev_get_drvdata(rdev); 208 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 209 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 210 return !!(val & mask); 211 } 212 213 static int max8660_ldo67_enable(struct regulator_dev *rdev) 214 { 215 struct max8660 *max8660 = rdev_get_drvdata(rdev); 216 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 217 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 218 } 219 220 static int max8660_ldo67_disable(struct regulator_dev *rdev) 221 { 222 struct max8660 *max8660 = rdev_get_drvdata(rdev); 223 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 224 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 225 } 226 227 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) 228 { 229 struct max8660 *max8660 = rdev_get_drvdata(rdev); 230 231 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 232 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 233 return selector; 234 } 235 236 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, 237 unsigned int selector) 238 { 239 struct max8660 *max8660 = rdev_get_drvdata(rdev); 240 241 if (rdev_get_id(rdev) == MAX8660_V6) 242 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 243 else 244 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, 245 selector << 4); 246 } 247 248 static struct regulator_ops max8660_ldo67_ops = { 249 .is_enabled = max8660_ldo67_is_enabled, 250 .enable = max8660_ldo67_enable, 251 .disable = max8660_ldo67_disable, 252 .list_voltage = regulator_list_voltage_linear, 253 .map_voltage = regulator_map_voltage_linear, 254 .get_voltage_sel = max8660_ldo67_get_voltage_sel, 255 .set_voltage_sel = max8660_ldo67_set_voltage_sel, 256 }; 257 258 static const struct regulator_desc max8660_reg[] = { 259 { 260 .name = "V3(DCDC)", 261 .id = MAX8660_V3, 262 .ops = &max8660_dcdc_ops, 263 .type = REGULATOR_VOLTAGE, 264 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 265 .owner = THIS_MODULE, 266 .min_uV = MAX8660_DCDC_MIN_UV, 267 .uV_step = MAX8660_DCDC_STEP, 268 }, 269 { 270 .name = "V4(DCDC)", 271 .id = MAX8660_V4, 272 .ops = &max8660_dcdc_ops, 273 .type = REGULATOR_VOLTAGE, 274 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 275 .owner = THIS_MODULE, 276 .min_uV = MAX8660_DCDC_MIN_UV, 277 .uV_step = MAX8660_DCDC_STEP, 278 }, 279 { 280 .name = "V5(LDO)", 281 .id = MAX8660_V5, 282 .ops = &max8660_ldo5_ops, 283 .type = REGULATOR_VOLTAGE, 284 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 285 .owner = THIS_MODULE, 286 .min_uV = MAX8660_LDO5_MIN_UV, 287 .uV_step = MAX8660_LDO5_STEP, 288 }, 289 { 290 .name = "V6(LDO)", 291 .id = MAX8660_V6, 292 .ops = &max8660_ldo67_ops, 293 .type = REGULATOR_VOLTAGE, 294 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 295 .owner = THIS_MODULE, 296 .min_uV = MAX8660_LDO67_MIN_UV, 297 .uV_step = MAX8660_LDO67_STEP, 298 }, 299 { 300 .name = "V7(LDO)", 301 .id = MAX8660_V7, 302 .ops = &max8660_ldo67_ops, 303 .type = REGULATOR_VOLTAGE, 304 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 305 .owner = THIS_MODULE, 306 .min_uV = MAX8660_LDO67_MIN_UV, 307 .uV_step = MAX8660_LDO67_STEP, 308 }, 309 }; 310 311 enum { 312 MAX8660 = 0, 313 MAX8661 = 1, 314 }; 315 316 #ifdef CONFIG_OF 317 static const struct of_device_id max8660_dt_ids[] = { 318 { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, 319 { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, 320 { } 321 }; 322 MODULE_DEVICE_TABLE(of, max8660_dt_ids); 323 324 static int max8660_pdata_from_dt(struct device *dev, 325 struct device_node **of_node, 326 struct max8660_platform_data *pdata) 327 { 328 int matched, i; 329 struct device_node *np; 330 struct max8660_subdev_data *sub; 331 struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)]; 332 333 np = of_find_node_by_name(dev->of_node, "regulators"); 334 if (!np) { 335 dev_err(dev, "missing 'regulators' subnode in DT\n"); 336 return -EINVAL; 337 } 338 339 for (i = 0; i < ARRAY_SIZE(rmatch); i++) 340 rmatch[i].name = max8660_reg[i].name; 341 342 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); 343 if (matched <= 0) 344 return matched; 345 346 pdata->subdevs = devm_kzalloc(dev, sizeof(struct max8660_subdev_data) * 347 matched, GFP_KERNEL); 348 if (!pdata->subdevs) 349 return -ENOMEM; 350 351 pdata->num_subdevs = matched; 352 sub = pdata->subdevs; 353 354 for (i = 0; i < matched; i++) { 355 sub->id = i; 356 sub->name = rmatch[i].name; 357 sub->platform_data = rmatch[i].init_data; 358 of_node[i] = rmatch[i].of_node; 359 sub++; 360 } 361 362 return 0; 363 } 364 #else 365 static inline int max8660_pdata_from_dt(struct device *dev, 366 struct device_node **of_node, 367 struct max8660_platform_data *pdata) 368 { 369 return 0; 370 } 371 #endif 372 373 static int max8660_probe(struct i2c_client *client, 374 const struct i2c_device_id *i2c_id) 375 { 376 struct regulator_dev **rdev; 377 struct device *dev = &client->dev; 378 struct max8660_platform_data *pdata = dev_get_platdata(dev); 379 struct regulator_config config = { }; 380 struct max8660 *max8660; 381 int boot_on, i, id, ret = -EINVAL; 382 struct device_node *of_node[MAX8660_V_END]; 383 unsigned long type; 384 385 if (dev->of_node && !pdata) { 386 const struct of_device_id *id; 387 struct max8660_platform_data pdata_of; 388 389 id = of_match_device(of_match_ptr(max8660_dt_ids), dev); 390 if (!id) 391 return -ENODEV; 392 393 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); 394 if (ret < 0) 395 return ret; 396 397 pdata = &pdata_of; 398 type = (unsigned long) id->data; 399 } else { 400 type = i2c_id->driver_data; 401 memset(of_node, 0, sizeof(of_node)); 402 } 403 404 if (pdata->num_subdevs > MAX8660_V_END) { 405 dev_err(dev, "Too many regulators found!\n"); 406 return -EINVAL; 407 } 408 409 max8660 = devm_kzalloc(dev, sizeof(struct max8660) + 410 sizeof(struct regulator_dev *) * MAX8660_V_END, 411 GFP_KERNEL); 412 if (!max8660) 413 return -ENOMEM; 414 415 max8660->client = client; 416 rdev = max8660->rdev; 417 418 if (pdata->en34_is_high) { 419 /* Simulate always on */ 420 max8660->shadow_regs[MAX8660_OVER1] = 5; 421 } else { 422 /* Otherwise devices can be toggled via software */ 423 max8660_dcdc_ops.enable = max8660_dcdc_enable; 424 max8660_dcdc_ops.disable = max8660_dcdc_disable; 425 } 426 427 /* 428 * First, set up shadow registers to prevent glitches. As some 429 * registers are shared between regulators, everything must be properly 430 * set up for all regulators in advance. 431 */ 432 max8660->shadow_regs[MAX8660_ADTV1] = 433 max8660->shadow_regs[MAX8660_ADTV2] = 434 max8660->shadow_regs[MAX8660_SDTV1] = 435 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 436 max8660->shadow_regs[MAX8660_MDTV1] = 437 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 438 439 for (i = 0; i < pdata->num_subdevs; i++) { 440 441 if (!pdata->subdevs[i].platform_data) 442 goto err_out; 443 444 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 445 446 switch (pdata->subdevs[i].id) { 447 case MAX8660_V3: 448 if (boot_on) 449 max8660->shadow_regs[MAX8660_OVER1] |= 1; 450 break; 451 452 case MAX8660_V4: 453 if (boot_on) 454 max8660->shadow_regs[MAX8660_OVER1] |= 4; 455 break; 456 457 case MAX8660_V5: 458 break; 459 460 case MAX8660_V6: 461 if (boot_on) 462 max8660->shadow_regs[MAX8660_OVER2] |= 2; 463 break; 464 465 case MAX8660_V7: 466 if (type == MAX8661) { 467 dev_err(dev, "Regulator not on this chip!\n"); 468 goto err_out; 469 } 470 471 if (boot_on) 472 max8660->shadow_regs[MAX8660_OVER2] |= 4; 473 break; 474 475 default: 476 dev_err(dev, "invalid regulator %s\n", 477 pdata->subdevs[i].name); 478 goto err_out; 479 } 480 } 481 482 /* Finally register devices */ 483 for (i = 0; i < pdata->num_subdevs; i++) { 484 485 id = pdata->subdevs[i].id; 486 487 config.dev = dev; 488 config.init_data = pdata->subdevs[i].platform_data; 489 config.of_node = of_node[i]; 490 config.driver_data = max8660; 491 492 rdev[i] = regulator_register(&max8660_reg[id], &config); 493 if (IS_ERR(rdev[i])) { 494 ret = PTR_ERR(rdev[i]); 495 dev_err(dev, "failed to register %s\n", 496 max8660_reg[id].name); 497 goto err_unregister; 498 } 499 } 500 501 i2c_set_clientdata(client, max8660); 502 return 0; 503 504 err_unregister: 505 while (--i >= 0) 506 regulator_unregister(rdev[i]); 507 err_out: 508 return ret; 509 } 510 511 static int max8660_remove(struct i2c_client *client) 512 { 513 struct max8660 *max8660 = i2c_get_clientdata(client); 514 int i; 515 516 for (i = 0; i < MAX8660_V_END; i++) 517 regulator_unregister(max8660->rdev[i]); 518 return 0; 519 } 520 521 static const struct i2c_device_id max8660_id[] = { 522 { .name = "max8660", .driver_data = MAX8660 }, 523 { .name = "max8661", .driver_data = MAX8661 }, 524 { } 525 }; 526 MODULE_DEVICE_TABLE(i2c, max8660_id); 527 528 static struct i2c_driver max8660_driver = { 529 .probe = max8660_probe, 530 .remove = max8660_remove, 531 .driver = { 532 .name = "max8660", 533 .owner = THIS_MODULE, 534 }, 535 .id_table = max8660_id, 536 }; 537 538 static int __init max8660_init(void) 539 { 540 return i2c_add_driver(&max8660_driver); 541 } 542 subsys_initcall(max8660_init); 543 544 static void __exit max8660_exit(void) 545 { 546 i2c_del_driver(&max8660_driver); 547 } 548 module_exit(max8660_exit); 549 550 /* Module information */ 551 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 552 MODULE_AUTHOR("Wolfram Sang"); 553 MODULE_LICENSE("GPL v2"); 554