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 63 enum { 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 78 struct 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 84 static 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 */ 106 107 static 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 } 114 115 static 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 } 121 122 static 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 } 128 129 static 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 } 135 136 static 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 } 143 144 static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV, 145 unsigned int *s) 146 { 147 struct max8660 *max8660 = rdev_get_drvdata(rdev); 148 u8 reg, selector, bits; 149 int ret; 150 151 if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV) 152 return -EINVAL; 153 if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV) 154 return -EINVAL; 155 156 selector = DIV_ROUND_UP(min_uV - MAX8660_DCDC_MIN_UV, 157 MAX8660_DCDC_STEP); 158 159 ret = max8660_dcdc_list(rdev, selector); 160 if (ret < 0 || ret > max_uV) 161 return -EINVAL; 162 163 *s = selector; 164 165 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 166 ret = max8660_write(max8660, reg, 0, selector); 167 if (ret) 168 return ret; 169 170 /* Select target voltage register and activate regulation */ 171 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 172 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 173 } 174 175 static struct regulator_ops max8660_dcdc_ops = { 176 .is_enabled = max8660_dcdc_is_enabled, 177 .list_voltage = max8660_dcdc_list, 178 .set_voltage = max8660_dcdc_set, 179 .get_voltage = max8660_dcdc_get, 180 }; 181 182 183 /* 184 * LDO5 functions 185 */ 186 187 static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector) 188 { 189 if (selector > MAX8660_LDO5_MAX_SEL) 190 return -EINVAL; 191 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 192 } 193 194 static int max8660_ldo5_get(struct regulator_dev *rdev) 195 { 196 struct max8660 *max8660 = rdev_get_drvdata(rdev); 197 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 198 199 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 200 } 201 202 static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV, 203 unsigned int *s) 204 { 205 struct max8660 *max8660 = rdev_get_drvdata(rdev); 206 u8 selector; 207 int ret; 208 209 if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV) 210 return -EINVAL; 211 if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV) 212 return -EINVAL; 213 214 selector = DIV_ROUND_UP(min_uV - MAX8660_LDO5_MIN_UV, 215 MAX8660_LDO5_STEP); 216 217 ret = max8660_ldo5_list(rdev, selector); 218 if (ret < 0 || ret > max_uV) 219 return -EINVAL; 220 221 *s = selector; 222 223 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 224 if (ret) 225 return ret; 226 227 /* Select target voltage register and activate regulation */ 228 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 229 } 230 231 static struct regulator_ops max8660_ldo5_ops = { 232 .list_voltage = max8660_ldo5_list, 233 .set_voltage = max8660_ldo5_set, 234 .get_voltage = max8660_ldo5_get, 235 }; 236 237 238 /* 239 * LDO67 functions 240 */ 241 242 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 243 { 244 struct max8660 *max8660 = rdev_get_drvdata(rdev); 245 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 246 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 247 return !!(val & mask); 248 } 249 250 static int max8660_ldo67_enable(struct regulator_dev *rdev) 251 { 252 struct max8660 *max8660 = rdev_get_drvdata(rdev); 253 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 254 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 255 } 256 257 static int max8660_ldo67_disable(struct regulator_dev *rdev) 258 { 259 struct max8660 *max8660 = rdev_get_drvdata(rdev); 260 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 261 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 262 } 263 264 static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector) 265 { 266 if (selector > MAX8660_LDO67_MAX_SEL) 267 return -EINVAL; 268 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 269 } 270 271 static int max8660_ldo67_get(struct regulator_dev *rdev) 272 { 273 struct max8660 *max8660 = rdev_get_drvdata(rdev); 274 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 275 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 276 277 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 278 } 279 280 static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV, 281 int max_uV, unsigned int *s) 282 { 283 struct max8660 *max8660 = rdev_get_drvdata(rdev); 284 u8 selector; 285 int ret; 286 287 if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV) 288 return -EINVAL; 289 if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV) 290 return -EINVAL; 291 292 selector = DIV_ROUND_UP(min_uV - MAX8660_LDO67_MIN_UV, 293 MAX8660_LDO67_STEP); 294 295 ret = max8660_ldo67_list(rdev, selector); 296 if (ret < 0 || ret > max_uV) 297 return -EINVAL; 298 299 *s = selector; 300 301 if (rdev_get_id(rdev) == MAX8660_V6) 302 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 303 else 304 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4); 305 } 306 307 static struct regulator_ops max8660_ldo67_ops = { 308 .is_enabled = max8660_ldo67_is_enabled, 309 .enable = max8660_ldo67_enable, 310 .disable = max8660_ldo67_disable, 311 .list_voltage = max8660_ldo67_list, 312 .get_voltage = max8660_ldo67_get, 313 .set_voltage = max8660_ldo67_set, 314 }; 315 316 static struct regulator_desc max8660_reg[] = { 317 { 318 .name = "V3(DCDC)", 319 .id = MAX8660_V3, 320 .ops = &max8660_dcdc_ops, 321 .type = REGULATOR_VOLTAGE, 322 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 323 .owner = THIS_MODULE, 324 }, 325 { 326 .name = "V4(DCDC)", 327 .id = MAX8660_V4, 328 .ops = &max8660_dcdc_ops, 329 .type = REGULATOR_VOLTAGE, 330 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 331 .owner = THIS_MODULE, 332 }, 333 { 334 .name = "V5(LDO)", 335 .id = MAX8660_V5, 336 .ops = &max8660_ldo5_ops, 337 .type = REGULATOR_VOLTAGE, 338 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 339 .owner = THIS_MODULE, 340 }, 341 { 342 .name = "V6(LDO)", 343 .id = MAX8660_V6, 344 .ops = &max8660_ldo67_ops, 345 .type = REGULATOR_VOLTAGE, 346 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 347 .owner = THIS_MODULE, 348 }, 349 { 350 .name = "V7(LDO)", 351 .id = MAX8660_V7, 352 .ops = &max8660_ldo67_ops, 353 .type = REGULATOR_VOLTAGE, 354 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 355 .owner = THIS_MODULE, 356 }, 357 }; 358 359 static int __devinit max8660_probe(struct i2c_client *client, 360 const struct i2c_device_id *i2c_id) 361 { 362 struct regulator_dev **rdev; 363 struct max8660_platform_data *pdata = client->dev.platform_data; 364 struct max8660 *max8660; 365 int boot_on, i, id, ret = -EINVAL; 366 367 if (pdata->num_subdevs > MAX8660_V_END) { 368 dev_err(&client->dev, "Too many regulators found!\n"); 369 goto out; 370 } 371 372 max8660 = kzalloc(sizeof(struct max8660) + 373 sizeof(struct regulator_dev *) * MAX8660_V_END, 374 GFP_KERNEL); 375 if (!max8660) { 376 ret = -ENOMEM; 377 goto out; 378 } 379 380 max8660->client = client; 381 rdev = max8660->rdev; 382 383 if (pdata->en34_is_high) { 384 /* Simulate always on */ 385 max8660->shadow_regs[MAX8660_OVER1] = 5; 386 } else { 387 /* Otherwise devices can be toggled via software */ 388 max8660_dcdc_ops.enable = max8660_dcdc_enable; 389 max8660_dcdc_ops.disable = max8660_dcdc_disable; 390 } 391 392 /* 393 * First, set up shadow registers to prevent glitches. As some 394 * registers are shared between regulators, everything must be properly 395 * set up for all regulators in advance. 396 */ 397 max8660->shadow_regs[MAX8660_ADTV1] = 398 max8660->shadow_regs[MAX8660_ADTV2] = 399 max8660->shadow_regs[MAX8660_SDTV1] = 400 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 401 max8660->shadow_regs[MAX8660_MDTV1] = 402 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 403 404 for (i = 0; i < pdata->num_subdevs; i++) { 405 406 if (!pdata->subdevs[i].platform_data) 407 goto err_free; 408 409 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 410 411 switch (pdata->subdevs[i].id) { 412 case MAX8660_V3: 413 if (boot_on) 414 max8660->shadow_regs[MAX8660_OVER1] |= 1; 415 break; 416 417 case MAX8660_V4: 418 if (boot_on) 419 max8660->shadow_regs[MAX8660_OVER1] |= 4; 420 break; 421 422 case MAX8660_V5: 423 break; 424 425 case MAX8660_V6: 426 if (boot_on) 427 max8660->shadow_regs[MAX8660_OVER2] |= 2; 428 break; 429 430 case MAX8660_V7: 431 if (!strcmp(i2c_id->name, "max8661")) { 432 dev_err(&client->dev, "Regulator not on this chip!\n"); 433 goto err_free; 434 } 435 436 if (boot_on) 437 max8660->shadow_regs[MAX8660_OVER2] |= 4; 438 break; 439 440 default: 441 dev_err(&client->dev, "invalid regulator %s\n", 442 pdata->subdevs[i].name); 443 goto err_free; 444 } 445 } 446 447 /* Finally register devices */ 448 for (i = 0; i < pdata->num_subdevs; i++) { 449 450 id = pdata->subdevs[i].id; 451 452 rdev[i] = regulator_register(&max8660_reg[id], &client->dev, 453 pdata->subdevs[i].platform_data, 454 max8660, NULL); 455 if (IS_ERR(rdev[i])) { 456 ret = PTR_ERR(rdev[i]); 457 dev_err(&client->dev, "failed to register %s\n", 458 max8660_reg[id].name); 459 goto err_unregister; 460 } 461 } 462 463 i2c_set_clientdata(client, max8660); 464 dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n"); 465 return 0; 466 467 err_unregister: 468 while (--i >= 0) 469 regulator_unregister(rdev[i]); 470 err_free: 471 kfree(max8660); 472 out: 473 return ret; 474 } 475 476 static int __devexit max8660_remove(struct i2c_client *client) 477 { 478 struct max8660 *max8660 = i2c_get_clientdata(client); 479 int i; 480 481 for (i = 0; i < MAX8660_V_END; i++) 482 if (max8660->rdev[i]) 483 regulator_unregister(max8660->rdev[i]); 484 kfree(max8660); 485 486 return 0; 487 } 488 489 static const struct i2c_device_id max8660_id[] = { 490 { "max8660", 0 }, 491 { "max8661", 0 }, 492 { } 493 }; 494 MODULE_DEVICE_TABLE(i2c, max8660_id); 495 496 static struct i2c_driver max8660_driver = { 497 .probe = max8660_probe, 498 .remove = __devexit_p(max8660_remove), 499 .driver = { 500 .name = "max8660", 501 .owner = THIS_MODULE, 502 }, 503 .id_table = max8660_id, 504 }; 505 506 static int __init max8660_init(void) 507 { 508 return i2c_add_driver(&max8660_driver); 509 } 510 subsys_initcall(max8660_init); 511 512 static void __exit max8660_exit(void) 513 { 514 i2c_del_driver(&max8660_driver); 515 } 516 module_exit(max8660_exit); 517 518 /* Module information */ 519 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 520 MODULE_AUTHOR("Wolfram Sang"); 521 MODULE_LICENSE("GPL v2"); 522