1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * max8660.c -- Voltage regulation for the Maxim 8660/8661 4 * 5 * based on max1586.c and wm8400-regulator.c 6 * 7 * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K. 8 * 9 * Some info: 10 * 11 * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf 12 * 13 * This chip is a bit nasty because it is a write-only device. Thus, the driver 14 * uses shadow registers to keep track of its values. The main problem appears 15 * to be the initialization: When Linux boots up, we cannot know if the chip is 16 * in the default state or not, so we would have to pass such information in 17 * platform_data. As this adds a bit of complexity to the driver, this is left 18 * out for now until it is really needed. 19 * 20 * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2. 21 * 22 * If the driver is feature complete, it might be worth to check if one set of 23 * functions for V3-V7 is sufficient. For maximum flexibility during 24 * development, they are separated for now. 25 */ 26 27 #include <linux/module.h> 28 #include <linux/err.h> 29 #include <linux/i2c.h> 30 #include <linux/platform_device.h> 31 #include <linux/regulator/driver.h> 32 #include <linux/slab.h> 33 #include <linux/regulator/max8660.h> 34 #include <linux/of.h> 35 #include <linux/of_device.h> 36 #include <linux/regulator/of_regulator.h> 37 38 #define MAX8660_DCDC_MIN_UV 725000 39 #define MAX8660_DCDC_MAX_UV 1800000 40 #define MAX8660_DCDC_STEP 25000 41 #define MAX8660_DCDC_MAX_SEL 0x2b 42 43 #define MAX8660_LDO5_MIN_UV 1700000 44 #define MAX8660_LDO5_MAX_UV 2000000 45 #define MAX8660_LDO5_STEP 25000 46 #define MAX8660_LDO5_MAX_SEL 0x0c 47 48 #define MAX8660_LDO67_MIN_UV 1800000 49 #define MAX8660_LDO67_MAX_UV 3300000 50 #define MAX8660_LDO67_STEP 100000 51 #define MAX8660_LDO67_MAX_SEL 0x0f 52 53 enum { 54 MAX8660_OVER1, 55 MAX8660_OVER2, 56 MAX8660_VCC1, 57 MAX8660_ADTV1, 58 MAX8660_ADTV2, 59 MAX8660_SDTV1, 60 MAX8660_SDTV2, 61 MAX8660_MDTV1, 62 MAX8660_MDTV2, 63 MAX8660_L12VCR, 64 MAX8660_FPWM, 65 MAX8660_N_REGS, /* not a real register */ 66 }; 67 68 struct max8660 { 69 struct i2c_client *client; 70 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ 71 }; 72 73 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) 74 { 75 static const u8 max8660_addresses[MAX8660_N_REGS] = { 76 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 77 }; 78 79 int ret; 80 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; 81 82 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", 83 max8660_addresses[reg], reg_val); 84 85 ret = i2c_smbus_write_byte_data(max8660->client, 86 max8660_addresses[reg], reg_val); 87 if (ret == 0) 88 max8660->shadow_regs[reg] = reg_val; 89 90 return ret; 91 } 92 93 94 /* 95 * DCDC functions 96 */ 97 98 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) 99 { 100 struct max8660 *max8660 = rdev_get_drvdata(rdev); 101 u8 val = max8660->shadow_regs[MAX8660_OVER1]; 102 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 103 104 return !!(val & mask); 105 } 106 107 static int max8660_dcdc_enable(struct regulator_dev *rdev) 108 { 109 struct max8660 *max8660 = rdev_get_drvdata(rdev); 110 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 111 112 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); 113 } 114 115 static int max8660_dcdc_disable(struct regulator_dev *rdev) 116 { 117 struct max8660 *max8660 = rdev_get_drvdata(rdev); 118 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; 119 120 return max8660_write(max8660, MAX8660_OVER1, mask, 0); 121 } 122 123 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) 124 { 125 struct max8660 *max8660 = rdev_get_drvdata(rdev); 126 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 127 u8 selector = max8660->shadow_regs[reg]; 128 129 return selector; 130 } 131 132 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, 133 unsigned int selector) 134 { 135 struct max8660 *max8660 = rdev_get_drvdata(rdev); 136 u8 reg, bits; 137 int ret; 138 139 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 140 ret = max8660_write(max8660, reg, 0, selector); 141 if (ret) 142 return ret; 143 144 /* Select target voltage register and activate regulation */ 145 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 146 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 147 } 148 149 static struct regulator_ops max8660_dcdc_ops = { 150 .is_enabled = max8660_dcdc_is_enabled, 151 .list_voltage = regulator_list_voltage_linear, 152 .map_voltage = regulator_map_voltage_linear, 153 .set_voltage_sel = max8660_dcdc_set_voltage_sel, 154 .get_voltage_sel = max8660_dcdc_get_voltage_sel, 155 }; 156 157 158 /* 159 * LDO5 functions 160 */ 161 162 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) 163 { 164 struct max8660 *max8660 = rdev_get_drvdata(rdev); 165 166 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 167 return selector; 168 } 169 170 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, 171 unsigned int selector) 172 { 173 struct max8660 *max8660 = rdev_get_drvdata(rdev); 174 int ret; 175 176 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 177 if (ret) 178 return ret; 179 180 /* Select target voltage register and activate regulation */ 181 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 182 } 183 184 static const struct regulator_ops max8660_ldo5_ops = { 185 .list_voltage = regulator_list_voltage_linear, 186 .map_voltage = regulator_map_voltage_linear, 187 .set_voltage_sel = max8660_ldo5_set_voltage_sel, 188 .get_voltage_sel = max8660_ldo5_get_voltage_sel, 189 }; 190 191 192 /* 193 * LDO67 functions 194 */ 195 196 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 197 { 198 struct max8660 *max8660 = rdev_get_drvdata(rdev); 199 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 200 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 201 202 return !!(val & mask); 203 } 204 205 static int max8660_ldo67_enable(struct regulator_dev *rdev) 206 { 207 struct max8660 *max8660 = rdev_get_drvdata(rdev); 208 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 209 210 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 211 } 212 213 static int max8660_ldo67_disable(struct regulator_dev *rdev) 214 { 215 struct max8660 *max8660 = rdev_get_drvdata(rdev); 216 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 217 218 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 219 } 220 221 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) 222 { 223 struct max8660 *max8660 = rdev_get_drvdata(rdev); 224 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 225 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 226 227 return selector; 228 } 229 230 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, 231 unsigned int selector) 232 { 233 struct max8660 *max8660 = rdev_get_drvdata(rdev); 234 235 if (rdev_get_id(rdev) == MAX8660_V6) 236 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 237 else 238 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, 239 selector << 4); 240 } 241 242 static const struct regulator_ops max8660_ldo67_ops = { 243 .is_enabled = max8660_ldo67_is_enabled, 244 .enable = max8660_ldo67_enable, 245 .disable = max8660_ldo67_disable, 246 .list_voltage = regulator_list_voltage_linear, 247 .map_voltage = regulator_map_voltage_linear, 248 .get_voltage_sel = max8660_ldo67_get_voltage_sel, 249 .set_voltage_sel = max8660_ldo67_set_voltage_sel, 250 }; 251 252 static const struct regulator_desc max8660_reg[] = { 253 { 254 .name = "V3(DCDC)", 255 .id = MAX8660_V3, 256 .ops = &max8660_dcdc_ops, 257 .type = REGULATOR_VOLTAGE, 258 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 259 .owner = THIS_MODULE, 260 .min_uV = MAX8660_DCDC_MIN_UV, 261 .uV_step = MAX8660_DCDC_STEP, 262 }, 263 { 264 .name = "V4(DCDC)", 265 .id = MAX8660_V4, 266 .ops = &max8660_dcdc_ops, 267 .type = REGULATOR_VOLTAGE, 268 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 269 .owner = THIS_MODULE, 270 .min_uV = MAX8660_DCDC_MIN_UV, 271 .uV_step = MAX8660_DCDC_STEP, 272 }, 273 { 274 .name = "V5(LDO)", 275 .id = MAX8660_V5, 276 .ops = &max8660_ldo5_ops, 277 .type = REGULATOR_VOLTAGE, 278 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 279 .owner = THIS_MODULE, 280 .min_uV = MAX8660_LDO5_MIN_UV, 281 .uV_step = MAX8660_LDO5_STEP, 282 }, 283 { 284 .name = "V6(LDO)", 285 .id = MAX8660_V6, 286 .ops = &max8660_ldo67_ops, 287 .type = REGULATOR_VOLTAGE, 288 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 289 .owner = THIS_MODULE, 290 .min_uV = MAX8660_LDO67_MIN_UV, 291 .uV_step = MAX8660_LDO67_STEP, 292 }, 293 { 294 .name = "V7(LDO)", 295 .id = MAX8660_V7, 296 .ops = &max8660_ldo67_ops, 297 .type = REGULATOR_VOLTAGE, 298 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 299 .owner = THIS_MODULE, 300 .min_uV = MAX8660_LDO67_MIN_UV, 301 .uV_step = MAX8660_LDO67_STEP, 302 }, 303 }; 304 305 enum { 306 MAX8660 = 0, 307 MAX8661 = 1, 308 }; 309 310 #ifdef CONFIG_OF 311 static const struct of_device_id max8660_dt_ids[] = { 312 { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, 313 { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, 314 { } 315 }; 316 MODULE_DEVICE_TABLE(of, max8660_dt_ids); 317 318 static int max8660_pdata_from_dt(struct device *dev, 319 struct device_node **of_node, 320 struct max8660_platform_data *pdata) 321 { 322 int matched, i; 323 struct device_node *np; 324 struct max8660_subdev_data *sub; 325 struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { }; 326 327 np = of_get_child_by_name(dev->of_node, "regulators"); 328 if (!np) { 329 dev_err(dev, "missing 'regulators' subnode in DT\n"); 330 return -EINVAL; 331 } 332 333 for (i = 0; i < ARRAY_SIZE(rmatch); i++) 334 rmatch[i].name = max8660_reg[i].name; 335 336 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); 337 of_node_put(np); 338 if (matched <= 0) 339 return matched; 340 341 pdata->subdevs = devm_kcalloc(dev, 342 matched, 343 sizeof(struct max8660_subdev_data), 344 GFP_KERNEL); 345 if (!pdata->subdevs) 346 return -ENOMEM; 347 348 pdata->num_subdevs = matched; 349 sub = pdata->subdevs; 350 351 for (i = 0; i < matched; i++) { 352 sub->id = i; 353 sub->name = rmatch[i].name; 354 sub->platform_data = rmatch[i].init_data; 355 of_node[i] = rmatch[i].of_node; 356 sub++; 357 } 358 359 return 0; 360 } 361 #else 362 static inline int max8660_pdata_from_dt(struct device *dev, 363 struct device_node **of_node, 364 struct max8660_platform_data *pdata) 365 { 366 return 0; 367 } 368 #endif 369 370 static int max8660_probe(struct i2c_client *client) 371 { 372 const struct i2c_device_id *i2c_id = i2c_client_get_device_id(client); 373 struct device *dev = &client->dev; 374 struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); 375 struct regulator_config config = { }; 376 struct max8660 *max8660; 377 int boot_on, i, id, ret = -EINVAL; 378 struct device_node *of_node[MAX8660_V_END]; 379 unsigned long type; 380 381 if (dev->of_node && !pdata) { 382 const struct of_device_id *id; 383 384 id = of_match_device(of_match_ptr(max8660_dt_ids), dev); 385 if (!id) 386 return -ENODEV; 387 388 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); 389 if (ret < 0) 390 return ret; 391 392 pdata = &pdata_of; 393 type = (unsigned long) id->data; 394 } else { 395 type = i2c_id->driver_data; 396 memset(of_node, 0, sizeof(of_node)); 397 } 398 399 if (pdata->num_subdevs > MAX8660_V_END) { 400 dev_err(dev, "Too many regulators found!\n"); 401 return -EINVAL; 402 } 403 404 max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); 405 if (!max8660) 406 return -ENOMEM; 407 408 max8660->client = client; 409 410 if (pdata->en34_is_high) { 411 /* Simulate always on */ 412 max8660->shadow_regs[MAX8660_OVER1] = 5; 413 } else { 414 /* Otherwise devices can be toggled via software */ 415 max8660_dcdc_ops.enable = max8660_dcdc_enable; 416 max8660_dcdc_ops.disable = max8660_dcdc_disable; 417 } 418 419 /* 420 * First, set up shadow registers to prevent glitches. As some 421 * registers are shared between regulators, everything must be properly 422 * set up for all regulators in advance. 423 */ 424 max8660->shadow_regs[MAX8660_ADTV1] = 425 max8660->shadow_regs[MAX8660_ADTV2] = 426 max8660->shadow_regs[MAX8660_SDTV1] = 427 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 428 max8660->shadow_regs[MAX8660_MDTV1] = 429 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 430 431 for (i = 0; i < pdata->num_subdevs; i++) { 432 433 if (!pdata->subdevs[i].platform_data) 434 boot_on = false; 435 else 436 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 437 438 switch (pdata->subdevs[i].id) { 439 case MAX8660_V3: 440 if (boot_on) 441 max8660->shadow_regs[MAX8660_OVER1] |= 1; 442 break; 443 444 case MAX8660_V4: 445 if (boot_on) 446 max8660->shadow_regs[MAX8660_OVER1] |= 4; 447 break; 448 449 case MAX8660_V5: 450 break; 451 452 case MAX8660_V6: 453 if (boot_on) 454 max8660->shadow_regs[MAX8660_OVER2] |= 2; 455 break; 456 457 case MAX8660_V7: 458 if (type == MAX8661) { 459 dev_err(dev, "Regulator not on this chip!\n"); 460 return -EINVAL; 461 } 462 463 if (boot_on) 464 max8660->shadow_regs[MAX8660_OVER2] |= 4; 465 break; 466 467 default: 468 dev_err(dev, "invalid regulator %s\n", 469 pdata->subdevs[i].name); 470 return ret; 471 } 472 } 473 474 /* Finally register devices */ 475 for (i = 0; i < pdata->num_subdevs; i++) { 476 struct regulator_dev *rdev; 477 478 id = pdata->subdevs[i].id; 479 480 config.dev = dev; 481 config.init_data = pdata->subdevs[i].platform_data; 482 config.of_node = of_node[i]; 483 config.driver_data = max8660; 484 485 rdev = devm_regulator_register(&client->dev, 486 &max8660_reg[id], &config); 487 if (IS_ERR(rdev)) { 488 dev_err(&client->dev, "failed to register %s\n", 489 max8660_reg[id].name); 490 return PTR_ERR(rdev); 491 } 492 } 493 494 i2c_set_clientdata(client, max8660); 495 return 0; 496 } 497 498 static const struct i2c_device_id max8660_id[] = { 499 { .name = "max8660", .driver_data = MAX8660 }, 500 { .name = "max8661", .driver_data = MAX8661 }, 501 { } 502 }; 503 MODULE_DEVICE_TABLE(i2c, max8660_id); 504 505 static struct i2c_driver max8660_driver = { 506 .probe = max8660_probe, 507 .driver = { 508 .name = "max8660", 509 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 510 }, 511 .id_table = max8660_id, 512 }; 513 514 static int __init max8660_init(void) 515 { 516 return i2c_add_driver(&max8660_driver); 517 } 518 subsys_initcall(max8660_init); 519 520 static void __exit max8660_exit(void) 521 { 522 i2c_del_driver(&max8660_driver); 523 } 524 module_exit(max8660_exit); 525 526 /* Module information */ 527 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 528 MODULE_AUTHOR("Wolfram Sang"); 529 MODULE_LICENSE("GPL v2"); 530