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