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/regulator/max8660.h> 46 47 #define MAX8660_DCDC_MIN_UV 725000 48 #define MAX8660_DCDC_MAX_UV 1800000 49 #define MAX8660_DCDC_STEP 25000 50 #define MAX8660_DCDC_MAX_SEL 0x2b 51 52 #define MAX8660_LDO5_MIN_UV 1700000 53 #define MAX8660_LDO5_MAX_UV 2000000 54 #define MAX8660_LDO5_STEP 25000 55 #define MAX8660_LDO5_MAX_SEL 0x0c 56 57 #define MAX8660_LDO67_MIN_UV 1800000 58 #define MAX8660_LDO67_MAX_UV 3300000 59 #define MAX8660_LDO67_STEP 100000 60 #define MAX8660_LDO67_MAX_SEL 0x0f 61 62 enum { 63 MAX8660_OVER1, 64 MAX8660_OVER2, 65 MAX8660_VCC1, 66 MAX8660_ADTV1, 67 MAX8660_ADTV2, 68 MAX8660_SDTV1, 69 MAX8660_SDTV2, 70 MAX8660_MDTV1, 71 MAX8660_MDTV2, 72 MAX8660_L12VCR, 73 MAX8660_FPWM, 74 MAX8660_N_REGS, /* not a real register */ 75 }; 76 77 struct max8660 { 78 struct i2c_client *client; 79 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ 80 struct regulator_dev *rdev[]; 81 }; 82 83 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) 84 { 85 static const u8 max8660_addresses[MAX8660_N_REGS] = 86 { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 }; 87 88 int ret; 89 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; 90 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", 91 max8660_addresses[reg], reg_val); 92 93 ret = i2c_smbus_write_byte_data(max8660->client, 94 max8660_addresses[reg], reg_val); 95 if (ret == 0) 96 max8660->shadow_regs[reg] = reg_val; 97 98 return ret; 99 } 100 101 102 /* 103 * DCDC functions 104 */ 105 106 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) 107 { 108 struct max8660 *max8660 = rdev_get_drvdata(rdev); 109 u8 val = max8660->shadow_regs[MAX8660_OVER1]; 110 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 111 return !!(val & mask); 112 } 113 114 static int max8660_dcdc_enable(struct regulator_dev *rdev) 115 { 116 struct max8660 *max8660 = rdev_get_drvdata(rdev); 117 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; 118 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); 119 } 120 121 static int max8660_dcdc_disable(struct regulator_dev *rdev) 122 { 123 struct max8660 *max8660 = rdev_get_drvdata(rdev); 124 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; 125 return max8660_write(max8660, MAX8660_OVER1, mask, 0); 126 } 127 128 static int max8660_dcdc_list(struct regulator_dev *rdev, unsigned selector) 129 { 130 if (selector > MAX8660_DCDC_MAX_SEL) 131 return -EINVAL; 132 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP; 133 } 134 135 static int max8660_dcdc_get(struct regulator_dev *rdev) 136 { 137 struct max8660 *max8660 = rdev_get_drvdata(rdev); 138 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 139 u8 selector = max8660->shadow_regs[reg]; 140 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP; 141 } 142 143 static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV) 144 { 145 struct max8660 *max8660 = rdev_get_drvdata(rdev); 146 u8 reg, selector, bits; 147 int ret; 148 149 if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV) 150 return -EINVAL; 151 if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV) 152 return -EINVAL; 153 154 selector = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1)) 155 / MAX8660_DCDC_STEP; 156 157 ret = max8660_dcdc_list(rdev, selector); 158 if (ret < 0 || ret > max_uV) 159 return -EINVAL; 160 161 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 162 ret = max8660_write(max8660, reg, 0, selector); 163 if (ret) 164 return ret; 165 166 /* Select target voltage register and activate regulation */ 167 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 168 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 169 } 170 171 static struct regulator_ops max8660_dcdc_ops = { 172 .is_enabled = max8660_dcdc_is_enabled, 173 .list_voltage = max8660_dcdc_list, 174 .set_voltage = max8660_dcdc_set, 175 .get_voltage = max8660_dcdc_get, 176 }; 177 178 179 /* 180 * LDO5 functions 181 */ 182 183 static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector) 184 { 185 if (selector > MAX8660_LDO5_MAX_SEL) 186 return -EINVAL; 187 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 188 } 189 190 static int max8660_ldo5_get(struct regulator_dev *rdev) 191 { 192 struct max8660 *max8660 = rdev_get_drvdata(rdev); 193 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 194 195 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP; 196 } 197 198 static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV) 199 { 200 struct max8660 *max8660 = rdev_get_drvdata(rdev); 201 u8 selector; 202 int ret; 203 204 if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV) 205 return -EINVAL; 206 if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV) 207 return -EINVAL; 208 209 selector = (min_uV - (MAX8660_LDO5_MIN_UV - MAX8660_LDO5_STEP + 1)) 210 / MAX8660_LDO5_STEP; 211 ret = max8660_ldo5_list(rdev, selector); 212 if (ret < 0 || ret > max_uV) 213 return -EINVAL; 214 215 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 216 if (ret) 217 return ret; 218 219 /* Select target voltage register and activate regulation */ 220 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 221 } 222 223 static struct regulator_ops max8660_ldo5_ops = { 224 .list_voltage = max8660_ldo5_list, 225 .set_voltage = max8660_ldo5_set, 226 .get_voltage = max8660_ldo5_get, 227 }; 228 229 230 /* 231 * LDO67 functions 232 */ 233 234 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 235 { 236 struct max8660 *max8660 = rdev_get_drvdata(rdev); 237 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 238 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 239 return !!(val & mask); 240 } 241 242 static int max8660_ldo67_enable(struct regulator_dev *rdev) 243 { 244 struct max8660 *max8660 = rdev_get_drvdata(rdev); 245 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 246 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 247 } 248 249 static int max8660_ldo67_disable(struct regulator_dev *rdev) 250 { 251 struct max8660 *max8660 = rdev_get_drvdata(rdev); 252 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 253 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 254 } 255 256 static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector) 257 { 258 if (selector > MAX8660_LDO67_MAX_SEL) 259 return -EINVAL; 260 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 261 } 262 263 static int max8660_ldo67_get(struct regulator_dev *rdev) 264 { 265 struct max8660 *max8660 = rdev_get_drvdata(rdev); 266 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 267 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 268 269 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP; 270 } 271 272 static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV, int max_uV) 273 { 274 struct max8660 *max8660 = rdev_get_drvdata(rdev); 275 u8 selector; 276 int ret; 277 278 if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV) 279 return -EINVAL; 280 if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV) 281 return -EINVAL; 282 283 selector = (min_uV - (MAX8660_LDO67_MIN_UV - MAX8660_LDO67_STEP + 1)) 284 / MAX8660_LDO67_STEP; 285 286 ret = max8660_ldo67_list(rdev, selector); 287 if (ret < 0 || ret > max_uV) 288 return -EINVAL; 289 290 if (rdev_get_id(rdev) == MAX8660_V6) 291 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 292 else 293 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4); 294 } 295 296 static struct regulator_ops max8660_ldo67_ops = { 297 .is_enabled = max8660_ldo67_is_enabled, 298 .enable = max8660_ldo67_enable, 299 .disable = max8660_ldo67_disable, 300 .list_voltage = max8660_ldo67_list, 301 .get_voltage = max8660_ldo67_get, 302 .set_voltage = max8660_ldo67_set, 303 }; 304 305 static struct regulator_desc max8660_reg[] = { 306 { 307 .name = "V3(DCDC)", 308 .id = MAX8660_V3, 309 .ops = &max8660_dcdc_ops, 310 .type = REGULATOR_VOLTAGE, 311 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 312 .owner = THIS_MODULE, 313 }, 314 { 315 .name = "V4(DCDC)", 316 .id = MAX8660_V4, 317 .ops = &max8660_dcdc_ops, 318 .type = REGULATOR_VOLTAGE, 319 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 320 .owner = THIS_MODULE, 321 }, 322 { 323 .name = "V5(LDO)", 324 .id = MAX8660_V5, 325 .ops = &max8660_ldo5_ops, 326 .type = REGULATOR_VOLTAGE, 327 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 328 .owner = THIS_MODULE, 329 }, 330 { 331 .name = "V6(LDO)", 332 .id = MAX8660_V6, 333 .ops = &max8660_ldo67_ops, 334 .type = REGULATOR_VOLTAGE, 335 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 336 .owner = THIS_MODULE, 337 }, 338 { 339 .name = "V7(LDO)", 340 .id = MAX8660_V7, 341 .ops = &max8660_ldo67_ops, 342 .type = REGULATOR_VOLTAGE, 343 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 344 .owner = THIS_MODULE, 345 }, 346 }; 347 348 static int max8660_probe(struct i2c_client *client, 349 const struct i2c_device_id *i2c_id) 350 { 351 struct regulator_dev **rdev; 352 struct max8660_platform_data *pdata = client->dev.platform_data; 353 struct max8660 *max8660; 354 int boot_on, i, id, ret = -EINVAL; 355 356 if (pdata->num_subdevs > MAX8660_V_END) { 357 dev_err(&client->dev, "Too much regulators found!\n"); 358 goto out; 359 } 360 361 max8660 = kzalloc(sizeof(struct max8660) + 362 sizeof(struct regulator_dev *) * MAX8660_V_END, 363 GFP_KERNEL); 364 if (!max8660) { 365 ret = -ENOMEM; 366 goto out; 367 } 368 369 max8660->client = client; 370 rdev = max8660->rdev; 371 372 if (pdata->en34_is_high) { 373 /* Simulate always on */ 374 max8660->shadow_regs[MAX8660_OVER1] = 5; 375 } else { 376 /* Otherwise devices can be toggled via software */ 377 max8660_dcdc_ops.enable = max8660_dcdc_enable; 378 max8660_dcdc_ops.disable = max8660_dcdc_disable; 379 } 380 381 /* 382 * First, set up shadow registers to prevent glitches. As some 383 * registers are shared between regulators, everything must be properly 384 * set up for all regulators in advance. 385 */ 386 max8660->shadow_regs[MAX8660_ADTV1] = 387 max8660->shadow_regs[MAX8660_ADTV2] = 388 max8660->shadow_regs[MAX8660_SDTV1] = 389 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 390 max8660->shadow_regs[MAX8660_MDTV1] = 391 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 392 393 for (i = 0; i < pdata->num_subdevs; i++) { 394 395 if (!pdata->subdevs[i].platform_data) 396 goto err_free; 397 398 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 399 400 switch (pdata->subdevs[i].id) { 401 case MAX8660_V3: 402 if (boot_on) 403 max8660->shadow_regs[MAX8660_OVER1] |= 1; 404 break; 405 406 case MAX8660_V4: 407 if (boot_on) 408 max8660->shadow_regs[MAX8660_OVER1] |= 4; 409 break; 410 411 case MAX8660_V5: 412 break; 413 414 case MAX8660_V6: 415 if (boot_on) 416 max8660->shadow_regs[MAX8660_OVER2] |= 2; 417 break; 418 419 case MAX8660_V7: 420 if (!strcmp(i2c_id->name, "max8661")) { 421 dev_err(&client->dev, "Regulator not on this chip!\n"); 422 goto err_free; 423 } 424 425 if (boot_on) 426 max8660->shadow_regs[MAX8660_OVER2] |= 4; 427 break; 428 429 default: 430 dev_err(&client->dev, "invalid regulator %s\n", 431 pdata->subdevs[i].name); 432 goto err_free; 433 } 434 } 435 436 /* Finally register devices */ 437 for (i = 0; i < pdata->num_subdevs; i++) { 438 439 id = pdata->subdevs[i].id; 440 441 rdev[i] = regulator_register(&max8660_reg[id], &client->dev, 442 pdata->subdevs[i].platform_data, 443 max8660); 444 if (IS_ERR(rdev[i])) { 445 ret = PTR_ERR(rdev[i]); 446 dev_err(&client->dev, "failed to register %s\n", 447 max8660_reg[id].name); 448 goto err_unregister; 449 } 450 } 451 452 i2c_set_clientdata(client, rdev); 453 dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n"); 454 return 0; 455 456 err_unregister: 457 while (--i >= 0) 458 regulator_unregister(rdev[i]); 459 err_free: 460 kfree(max8660); 461 out: 462 return ret; 463 } 464 465 static int max8660_remove(struct i2c_client *client) 466 { 467 struct regulator_dev **rdev = i2c_get_clientdata(client); 468 int i; 469 470 for (i = 0; i < MAX8660_V_END; i++) 471 if (rdev[i]) 472 regulator_unregister(rdev[i]); 473 kfree(rdev); 474 i2c_set_clientdata(client, NULL); 475 476 return 0; 477 } 478 479 static const struct i2c_device_id max8660_id[] = { 480 { "max8660", 0 }, 481 { "max8661", 0 }, 482 { } 483 }; 484 MODULE_DEVICE_TABLE(i2c, max8660_id); 485 486 static struct i2c_driver max8660_driver = { 487 .probe = max8660_probe, 488 .remove = max8660_remove, 489 .driver = { 490 .name = "max8660", 491 }, 492 .id_table = max8660_id, 493 }; 494 495 static int __init max8660_init(void) 496 { 497 return i2c_add_driver(&max8660_driver); 498 } 499 subsys_initcall(max8660_init); 500 501 static void __exit max8660_exit(void) 502 { 503 i2c_del_driver(&max8660_driver); 504 } 505 module_exit(max8660_exit); 506 507 /* Module information */ 508 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 509 MODULE_AUTHOR("Wolfram Sang"); 510 MODULE_LICENSE("GPL v2"); 511