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 48#define MAX8660_DCDC_MIN_UV 725000 49#define MAX8660_DCDC_MAX_UV 1800000 50#define MAX8660_DCDC_STEP 25000 51#define MAX8660_DCDC_MAX_SEL 0x2b 52 53#define MAX8660_LDO5_MIN_UV 1700000 54#define MAX8660_LDO5_MAX_UV 2000000 55#define MAX8660_LDO5_STEP 25000 56#define MAX8660_LDO5_MAX_SEL 0x0c 57 58#define MAX8660_LDO67_MIN_UV 1800000 59#define MAX8660_LDO67_MAX_UV 3300000 60#define MAX8660_LDO67_STEP 100000 61#define MAX8660_LDO67_MAX_SEL 0x0f 62 63enum { 64 MAX8660_OVER1, 65 MAX8660_OVER2, 66 MAX8660_VCC1, 67 MAX8660_ADTV1, 68 MAX8660_ADTV2, 69 MAX8660_SDTV1, 70 MAX8660_SDTV2, 71 MAX8660_MDTV1, 72 MAX8660_MDTV2, 73 MAX8660_L12VCR, 74 MAX8660_FPWM, 75 MAX8660_N_REGS, /* not a real register */ 76}; 77 78struct max8660 { 79 struct i2c_client *client; 80 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ 81 struct regulator_dev *rdev[]; 82}; 83 84static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) 85{ 86 static const u8 max8660_addresses[MAX8660_N_REGS] = 87 { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 }; 88 89 int ret; 90 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; 91 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", 92 max8660_addresses[reg], reg_val); 93 94 ret = i2c_smbus_write_byte_data(max8660->client, 95 max8660_addresses[reg], reg_val); 96 if (ret == 0) 97 max8660->shadow_regs[reg] = reg_val; 98 99 return ret; 100} 101 102 103/* 104 * DCDC functions 105 */ 106 107static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) 108{ 109 struct max8660 *max8660 = rdev_get_drvdata(rdev); 110 u8 val = max8660->shadow_regs[MAX8660_OVER1]; 111 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 112 return !!(val & mask); 113} 114 115static int max8660_dcdc_enable(struct regulator_dev *rdev) 116{ 117 struct max8660 *max8660 = rdev_get_drvdata(rdev); 118 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 119 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); 120} 121 122static int max8660_dcdc_disable(struct regulator_dev *rdev) 123{ 124 struct max8660 *max8660 = rdev_get_drvdata(rdev); 125 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; 126 return max8660_write(max8660, MAX8660_OVER1, mask, 0); 127} 128 129static int max8660_dcdc_list(struct regulator_dev *rdev, unsigned selector) 130{ 131 if (selector > MAX8660_DCDC_MAX_SEL) 132 return -EINVAL; 133 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP; 134} 135 136static int max8660_dcdc_get(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 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP; 142} 143 144static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV) 145{ 146 struct max8660 *max8660 = rdev_get_drvdata(rdev); 147 u8 reg, selector, bits; 148 int ret; 149 150 if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV) 151 return -EINVAL; 152 if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV) 153 return -EINVAL; 154 155 selector = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1)) 156 / MAX8660_DCDC_STEP; 157 158 ret = max8660_dcdc_list(rdev, selector); 159 if (ret < 0 || ret > max_uV) 160 return -EINVAL; 161 162 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 163 ret = max8660_write(max8660, reg, 0, selector); 164 if (ret) 165 return ret; 166 167 /* Select target voltage register and activate regulation */ 168 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 169 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 170} 171 172static struct regulator_ops max8660_dcdc_ops = { 173 .is_enabled = max8660_dcdc_is_enabled, 174 .list_voltage = max8660_dcdc_list, 175 .set_voltage = max8660_dcdc_set, 176 .get_voltage = max8660_dcdc_get, 177}; 178 179 180/* 181 * LDO5 functions 182 */ 183 184static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector) 185{ 186 if (selector > MAX8660_LDO5_MAX_SEL) 187 return -EINVAL; 188 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 189} 190 191static int max8660_ldo5_get(struct regulator_dev *rdev) 192{ 193 struct max8660 *max8660 = rdev_get_drvdata(rdev); 194 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 195 196 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 197} 198 199static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV) 200{ 201 struct max8660 *max8660 = rdev_get_drvdata(rdev); 202 u8 selector; 203 int ret; 204 205 if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV) 206 return -EINVAL; 207 if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV) 208 return -EINVAL; 209 210 selector = (min_uV - (MAX8660_LDO5_MIN_UV - MAX8660_LDO5_STEP + 1)) 211 / MAX8660_LDO5_STEP; 212 ret = max8660_ldo5_list(rdev, selector); 213 if (ret < 0 || ret > max_uV) 214 return -EINVAL; 215 216 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 217 if (ret) 218 return ret; 219 220 /* Select target voltage register and activate regulation */ 221 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 222} 223 224static struct regulator_ops max8660_ldo5_ops = { 225 .list_voltage = max8660_ldo5_list, 226 .set_voltage = max8660_ldo5_set, 227 .get_voltage = max8660_ldo5_get, 228}; 229 230 231/* 232 * LDO67 functions 233 */ 234 235static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 236{ 237 struct max8660 *max8660 = rdev_get_drvdata(rdev); 238 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 239 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 240 return !!(val & mask); 241} 242 243static int max8660_ldo67_enable(struct regulator_dev *rdev) 244{ 245 struct max8660 *max8660 = rdev_get_drvdata(rdev); 246 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 247 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 248} 249 250static int max8660_ldo67_disable(struct regulator_dev *rdev) 251{ 252 struct max8660 *max8660 = rdev_get_drvdata(rdev); 253 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 254 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 255} 256 257static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector) 258{ 259 if (selector > MAX8660_LDO67_MAX_SEL) 260 return -EINVAL; 261 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 262} 263 264static int max8660_ldo67_get(struct regulator_dev *rdev) 265{ 266 struct max8660 *max8660 = rdev_get_drvdata(rdev); 267 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 268 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 269 270 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 271} 272 273static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV, int max_uV) 274{ 275 struct max8660 *max8660 = rdev_get_drvdata(rdev); 276 u8 selector; 277 int ret; 278 279 if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV) 280 return -EINVAL; 281 if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV) 282 return -EINVAL; 283 284 selector = (min_uV - (MAX8660_LDO67_MIN_UV - MAX8660_LDO67_STEP + 1)) 285 / MAX8660_LDO67_STEP; 286 287 ret = max8660_ldo67_list(rdev, selector); 288 if (ret < 0 || ret > max_uV) 289 return -EINVAL; 290 291 if (rdev_get_id(rdev) == MAX8660_V6) 292 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 293 else 294 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4); 295} 296 297static struct regulator_ops max8660_ldo67_ops = { 298 .is_enabled = max8660_ldo67_is_enabled, 299 .enable = max8660_ldo67_enable, 300 .disable = max8660_ldo67_disable, 301 .list_voltage = max8660_ldo67_list, 302 .get_voltage = max8660_ldo67_get, 303 .set_voltage = max8660_ldo67_set, 304}; 305 306static struct regulator_desc max8660_reg[] = { 307 { 308 .name = "V3(DCDC)", 309 .id = MAX8660_V3, 310 .ops = &max8660_dcdc_ops, 311 .type = REGULATOR_VOLTAGE, 312 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 313 .owner = THIS_MODULE, 314 }, 315 { 316 .name = "V4(DCDC)", 317 .id = MAX8660_V4, 318 .ops = &max8660_dcdc_ops, 319 .type = REGULATOR_VOLTAGE, 320 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 321 .owner = THIS_MODULE, 322 }, 323 { 324 .name = "V5(LDO)", 325 .id = MAX8660_V5, 326 .ops = &max8660_ldo5_ops, 327 .type = REGULATOR_VOLTAGE, 328 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 329 .owner = THIS_MODULE, 330 }, 331 { 332 .name = "V6(LDO)", 333 .id = MAX8660_V6, 334 .ops = &max8660_ldo67_ops, 335 .type = REGULATOR_VOLTAGE, 336 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 337 .owner = THIS_MODULE, 338 }, 339 { 340 .name = "V7(LDO)", 341 .id = MAX8660_V7, 342 .ops = &max8660_ldo67_ops, 343 .type = REGULATOR_VOLTAGE, 344 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 345 .owner = THIS_MODULE, 346 }, 347}; 348 349static int __devinit max8660_probe(struct i2c_client *client, 350 const struct i2c_device_id *i2c_id) 351{ 352 struct regulator_dev **rdev; 353 struct max8660_platform_data *pdata = client->dev.platform_data; 354 struct max8660 *max8660; 355 int boot_on, i, id, ret = -EINVAL; 356 357 if (pdata->num_subdevs > MAX8660_V_END) { 358 dev_err(&client->dev, "Too many regulators found!\n"); 359 goto out; 360 } 361 362 max8660 = kzalloc(sizeof(struct max8660) + 363 sizeof(struct regulator_dev *) * MAX8660_V_END, 364 GFP_KERNEL); 365 if (!max8660) { 366 ret = -ENOMEM; 367 goto out; 368 } 369 370 max8660->client = client; 371 rdev = max8660->rdev; 372 373 if (pdata->en34_is_high) { 374 /* Simulate always on */ 375 max8660->shadow_regs[MAX8660_OVER1] = 5; 376 } else { 377 /* Otherwise devices can be toggled via software */ 378 max8660_dcdc_ops.enable = max8660_dcdc_enable; 379 max8660_dcdc_ops.disable = max8660_dcdc_disable; 380 } 381 382 /* 383 * First, set up shadow registers to prevent glitches. As some 384 * registers are shared between regulators, everything must be properly 385 * set up for all regulators in advance. 386 */ 387 max8660->shadow_regs[MAX8660_ADTV1] = 388 max8660->shadow_regs[MAX8660_ADTV2] = 389 max8660->shadow_regs[MAX8660_SDTV1] = 390 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 391 max8660->shadow_regs[MAX8660_MDTV1] = 392 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 393 394 for (i = 0; i < pdata->num_subdevs; i++) { 395 396 if (!pdata->subdevs[i].platform_data) 397 goto err_free; 398 399 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 400 401 switch (pdata->subdevs[i].id) { 402 case MAX8660_V3: 403 if (boot_on) 404 max8660->shadow_regs[MAX8660_OVER1] |= 1; 405 break; 406 407 case MAX8660_V4: 408 if (boot_on) 409 max8660->shadow_regs[MAX8660_OVER1] |= 4; 410 break; 411 412 case MAX8660_V5: 413 break; 414 415 case MAX8660_V6: 416 if (boot_on) 417 max8660->shadow_regs[MAX8660_OVER2] |= 2; 418 break; 419 420 case MAX8660_V7: 421 if (!strcmp(i2c_id->name, "max8661")) { 422 dev_err(&client->dev, "Regulator not on this chip!\n"); 423 goto err_free; 424 } 425 426 if (boot_on) 427 max8660->shadow_regs[MAX8660_OVER2] |= 4; 428 break; 429 430 default: 431 dev_err(&client->dev, "invalid regulator %s\n", 432 pdata->subdevs[i].name); 433 goto err_free; 434 } 435 } 436 437 /* Finally register devices */ 438 for (i = 0; i < pdata->num_subdevs; i++) { 439 440 id = pdata->subdevs[i].id; 441 442 rdev[i] = regulator_register(&max8660_reg[id], &client->dev, 443 pdata->subdevs[i].platform_data, 444 max8660); 445 if (IS_ERR(rdev[i])) { 446 ret = PTR_ERR(rdev[i]); 447 dev_err(&client->dev, "failed to register %s\n", 448 max8660_reg[id].name); 449 goto err_unregister; 450 } 451 } 452 453 i2c_set_clientdata(client, max8660); 454 dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n"); 455 return 0; 456 457err_unregister: 458 while (--i >= 0) 459 regulator_unregister(rdev[i]); 460err_free: 461 kfree(max8660); 462out: 463 return ret; 464} 465 466static int __devexit max8660_remove(struct i2c_client *client) 467{ 468 struct max8660 *max8660 = i2c_get_clientdata(client); 469 int i; 470 471 for (i = 0; i < MAX8660_V_END; i++) 472 if (max8660->rdev[i]) 473 regulator_unregister(max8660->rdev[i]); 474 kfree(max8660); 475 476 return 0; 477} 478 479static const struct i2c_device_id max8660_id[] = { 480 { "max8660", 0 }, 481 { "max8661", 0 }, 482 { } 483}; 484MODULE_DEVICE_TABLE(i2c, max8660_id); 485 486static struct i2c_driver max8660_driver = { 487 .probe = max8660_probe, 488 .remove = __devexit_p(max8660_remove), 489 .driver = { 490 .name = "max8660", 491 .owner = THIS_MODULE, 492 }, 493 .id_table = max8660_id, 494}; 495 496static int __init max8660_init(void) 497{ 498 return i2c_add_driver(&max8660_driver); 499} 500subsys_initcall(max8660_init); 501 502static void __exit max8660_exit(void) 503{ 504 i2c_del_driver(&max8660_driver); 505} 506module_exit(max8660_exit); 507 508/* Module information */ 509MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 510MODULE_AUTHOR("Wolfram Sang"); 511MODULE_LICENSE("GPL v2"); 512