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 66enum { 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 81struct max8660 { 82 struct i2c_client *client; 83 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ 84}; 85 86static 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 111static 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 120static 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 128static 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 136static 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 145static 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 162static 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 175static 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 183static 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 197static 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 209static 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 218static 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 226static 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 234static 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 243static 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 255static 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 265static 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 318enum { 319 MAX8660 = 0, 320 MAX8661 = 1, 321}; 322 323#ifdef CONFIG_OF 324static const struct of_device_id max8660_dt_ids[] = { 325 { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, 326 { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, 327 { } 328}; 329MODULE_DEVICE_TABLE(of, max8660_dt_ids); 330 331static 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_kzalloc(dev, sizeof(struct max8660_subdev_data) * 355 matched, GFP_KERNEL); 356 if (!pdata->subdevs) 357 return -ENOMEM; 358 359 pdata->num_subdevs = matched; 360 sub = pdata->subdevs; 361 362 for (i = 0; i < matched; i++) { 363 sub->id = i; 364 sub->name = rmatch[i].name; 365 sub->platform_data = rmatch[i].init_data; 366 of_node[i] = rmatch[i].of_node; 367 sub++; 368 } 369 370 return 0; 371} 372#else 373static inline int max8660_pdata_from_dt(struct device *dev, 374 struct device_node **of_node, 375 struct max8660_platform_data *pdata) 376{ 377 return 0; 378} 379#endif 380 381static int max8660_probe(struct i2c_client *client, 382 const struct i2c_device_id *i2c_id) 383{ 384 struct device *dev = &client->dev; 385 struct max8660_platform_data *pdata = dev_get_platdata(dev); 386 struct regulator_config config = { }; 387 struct max8660 *max8660; 388 int boot_on, i, id, ret = -EINVAL; 389 struct device_node *of_node[MAX8660_V_END]; 390 unsigned long type; 391 392 if (dev->of_node && !pdata) { 393 const struct of_device_id *id; 394 struct max8660_platform_data pdata_of; 395 396 id = of_match_device(of_match_ptr(max8660_dt_ids), dev); 397 if (!id) 398 return -ENODEV; 399 400 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); 401 if (ret < 0) 402 return ret; 403 404 pdata = &pdata_of; 405 type = (unsigned long) id->data; 406 } else { 407 type = i2c_id->driver_data; 408 memset(of_node, 0, sizeof(of_node)); 409 } 410 411 if (pdata->num_subdevs > MAX8660_V_END) { 412 dev_err(dev, "Too many regulators found!\n"); 413 return -EINVAL; 414 } 415 416 max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); 417 if (!max8660) 418 return -ENOMEM; 419 420 max8660->client = client; 421 422 if (pdata->en34_is_high) { 423 /* Simulate always on */ 424 max8660->shadow_regs[MAX8660_OVER1] = 5; 425 } else { 426 /* Otherwise devices can be toggled via software */ 427 max8660_dcdc_ops.enable = max8660_dcdc_enable; 428 max8660_dcdc_ops.disable = max8660_dcdc_disable; 429 } 430 431 /* 432 * First, set up shadow registers to prevent glitches. As some 433 * registers are shared between regulators, everything must be properly 434 * set up for all regulators in advance. 435 */ 436 max8660->shadow_regs[MAX8660_ADTV1] = 437 max8660->shadow_regs[MAX8660_ADTV2] = 438 max8660->shadow_regs[MAX8660_SDTV1] = 439 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 440 max8660->shadow_regs[MAX8660_MDTV1] = 441 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 442 443 for (i = 0; i < pdata->num_subdevs; i++) { 444 445 if (!pdata->subdevs[i].platform_data) 446 return ret; 447 448 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 449 450 switch (pdata->subdevs[i].id) { 451 case MAX8660_V3: 452 if (boot_on) 453 max8660->shadow_regs[MAX8660_OVER1] |= 1; 454 break; 455 456 case MAX8660_V4: 457 if (boot_on) 458 max8660->shadow_regs[MAX8660_OVER1] |= 4; 459 break; 460 461 case MAX8660_V5: 462 break; 463 464 case MAX8660_V6: 465 if (boot_on) 466 max8660->shadow_regs[MAX8660_OVER2] |= 2; 467 break; 468 469 case MAX8660_V7: 470 if (type == MAX8661) { 471 dev_err(dev, "Regulator not on this chip!\n"); 472 return -EINVAL; 473 } 474 475 if (boot_on) 476 max8660->shadow_regs[MAX8660_OVER2] |= 4; 477 break; 478 479 default: 480 dev_err(dev, "invalid regulator %s\n", 481 pdata->subdevs[i].name); 482 return ret; 483 } 484 } 485 486 /* Finally register devices */ 487 for (i = 0; i < pdata->num_subdevs; i++) { 488 struct regulator_dev *rdev; 489 490 id = pdata->subdevs[i].id; 491 492 config.dev = dev; 493 config.init_data = pdata->subdevs[i].platform_data; 494 config.of_node = of_node[i]; 495 config.driver_data = max8660; 496 497 rdev = devm_regulator_register(&client->dev, 498 &max8660_reg[id], &config); 499 if (IS_ERR(rdev)) { 500 ret = PTR_ERR(rdev); 501 dev_err(&client->dev, "failed to register %s\n", 502 max8660_reg[id].name); 503 return PTR_ERR(rdev); 504 } 505 } 506 507 i2c_set_clientdata(client, max8660); 508 return 0; 509} 510 511static const struct i2c_device_id max8660_id[] = { 512 { .name = "max8660", .driver_data = MAX8660 }, 513 { .name = "max8661", .driver_data = MAX8661 }, 514 { } 515}; 516MODULE_DEVICE_TABLE(i2c, max8660_id); 517 518static struct i2c_driver max8660_driver = { 519 .probe = max8660_probe, 520 .driver = { 521 .name = "max8660", 522 .owner = THIS_MODULE, 523 }, 524 .id_table = max8660_id, 525}; 526 527static int __init max8660_init(void) 528{ 529 return i2c_add_driver(&max8660_driver); 530} 531subsys_initcall(max8660_init); 532 533static void __exit max8660_exit(void) 534{ 535 i2c_del_driver(&max8660_driver); 536} 537module_exit(max8660_exit); 538 539/* Module information */ 540MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 541MODULE_AUTHOR("Wolfram Sang"); 542MODULE_LICENSE("GPL v2"); 543