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_get_voltage_sel(struct regulator_dev *rdev) 130 { 131 struct max8660 *max8660 = rdev_get_drvdata(rdev); 132 133 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 134 u8 selector = max8660->shadow_regs[reg]; 135 return selector; 136 } 137 138 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, 139 unsigned int selector) 140 { 141 struct max8660 *max8660 = rdev_get_drvdata(rdev); 142 u8 reg, bits; 143 int ret; 144 145 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; 146 ret = max8660_write(max8660, reg, 0, selector); 147 if (ret) 148 return ret; 149 150 /* Select target voltage register and activate regulation */ 151 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; 152 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); 153 } 154 155 static struct regulator_ops max8660_dcdc_ops = { 156 .is_enabled = max8660_dcdc_is_enabled, 157 .list_voltage = regulator_list_voltage_linear, 158 .map_voltage = regulator_map_voltage_linear, 159 .set_voltage_sel = max8660_dcdc_set_voltage_sel, 160 .get_voltage_sel = max8660_dcdc_get_voltage_sel, 161 }; 162 163 164 /* 165 * LDO5 functions 166 */ 167 168 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) 169 { 170 struct max8660 *max8660 = rdev_get_drvdata(rdev); 171 172 u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; 173 return selector; 174 } 175 176 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, 177 unsigned int selector) 178 { 179 struct max8660 *max8660 = rdev_get_drvdata(rdev); 180 int ret; 181 182 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); 183 if (ret) 184 return ret; 185 186 /* Select target voltage register and activate regulation */ 187 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); 188 } 189 190 static struct regulator_ops max8660_ldo5_ops = { 191 .list_voltage = regulator_list_voltage_linear, 192 .map_voltage = regulator_map_voltage_linear, 193 .set_voltage_sel = max8660_ldo5_set_voltage_sel, 194 .get_voltage_sel = max8660_ldo5_get_voltage_sel, 195 }; 196 197 198 /* 199 * LDO67 functions 200 */ 201 202 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) 203 { 204 struct max8660 *max8660 = rdev_get_drvdata(rdev); 205 u8 val = max8660->shadow_regs[MAX8660_OVER2]; 206 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 207 return !!(val & mask); 208 } 209 210 static int max8660_ldo67_enable(struct regulator_dev *rdev) 211 { 212 struct max8660 *max8660 = rdev_get_drvdata(rdev); 213 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; 214 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); 215 } 216 217 static int max8660_ldo67_disable(struct regulator_dev *rdev) 218 { 219 struct max8660 *max8660 = rdev_get_drvdata(rdev); 220 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; 221 return max8660_write(max8660, MAX8660_OVER2, mask, 0); 222 } 223 224 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) 225 { 226 struct max8660 *max8660 = rdev_get_drvdata(rdev); 227 228 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; 229 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; 230 return selector; 231 } 232 233 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, 234 unsigned int selector) 235 { 236 struct max8660 *max8660 = rdev_get_drvdata(rdev); 237 238 if (rdev_get_id(rdev) == MAX8660_V6) 239 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); 240 else 241 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, 242 selector << 4); 243 } 244 245 static struct regulator_ops max8660_ldo67_ops = { 246 .is_enabled = max8660_ldo67_is_enabled, 247 .enable = max8660_ldo67_enable, 248 .disable = max8660_ldo67_disable, 249 .list_voltage = regulator_list_voltage_linear, 250 .map_voltage = regulator_map_voltage_linear, 251 .get_voltage_sel = max8660_ldo67_get_voltage_sel, 252 .set_voltage_sel = max8660_ldo67_set_voltage_sel, 253 }; 254 255 static const struct regulator_desc max8660_reg[] = { 256 { 257 .name = "V3(DCDC)", 258 .id = MAX8660_V3, 259 .ops = &max8660_dcdc_ops, 260 .type = REGULATOR_VOLTAGE, 261 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 262 .owner = THIS_MODULE, 263 .min_uV = MAX8660_DCDC_MIN_UV, 264 .uV_step = MAX8660_DCDC_STEP, 265 }, 266 { 267 .name = "V4(DCDC)", 268 .id = MAX8660_V4, 269 .ops = &max8660_dcdc_ops, 270 .type = REGULATOR_VOLTAGE, 271 .n_voltages = MAX8660_DCDC_MAX_SEL + 1, 272 .owner = THIS_MODULE, 273 .min_uV = MAX8660_DCDC_MIN_UV, 274 .uV_step = MAX8660_DCDC_STEP, 275 }, 276 { 277 .name = "V5(LDO)", 278 .id = MAX8660_V5, 279 .ops = &max8660_ldo5_ops, 280 .type = REGULATOR_VOLTAGE, 281 .n_voltages = MAX8660_LDO5_MAX_SEL + 1, 282 .owner = THIS_MODULE, 283 .min_uV = MAX8660_LDO5_MIN_UV, 284 .uV_step = MAX8660_LDO5_STEP, 285 }, 286 { 287 .name = "V6(LDO)", 288 .id = MAX8660_V6, 289 .ops = &max8660_ldo67_ops, 290 .type = REGULATOR_VOLTAGE, 291 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 292 .owner = THIS_MODULE, 293 .min_uV = MAX8660_LDO67_MIN_UV, 294 .uV_step = MAX8660_LDO67_STEP, 295 }, 296 { 297 .name = "V7(LDO)", 298 .id = MAX8660_V7, 299 .ops = &max8660_ldo67_ops, 300 .type = REGULATOR_VOLTAGE, 301 .n_voltages = MAX8660_LDO67_MAX_SEL + 1, 302 .owner = THIS_MODULE, 303 .min_uV = MAX8660_LDO67_MIN_UV, 304 .uV_step = MAX8660_LDO67_STEP, 305 }, 306 }; 307 308 static int max8660_probe(struct i2c_client *client, 309 const struct i2c_device_id *i2c_id) 310 { 311 struct regulator_dev **rdev; 312 struct max8660_platform_data *pdata = client->dev.platform_data; 313 struct regulator_config config = { }; 314 struct max8660 *max8660; 315 int boot_on, i, id, ret = -EINVAL; 316 317 if (pdata->num_subdevs > MAX8660_V_END) { 318 dev_err(&client->dev, "Too many regulators found!\n"); 319 return -EINVAL; 320 } 321 322 max8660 = devm_kzalloc(&client->dev, sizeof(struct max8660) + 323 sizeof(struct regulator_dev *) * MAX8660_V_END, 324 GFP_KERNEL); 325 if (!max8660) 326 return -ENOMEM; 327 328 max8660->client = client; 329 rdev = max8660->rdev; 330 331 if (pdata->en34_is_high) { 332 /* Simulate always on */ 333 max8660->shadow_regs[MAX8660_OVER1] = 5; 334 } else { 335 /* Otherwise devices can be toggled via software */ 336 max8660_dcdc_ops.enable = max8660_dcdc_enable; 337 max8660_dcdc_ops.disable = max8660_dcdc_disable; 338 } 339 340 /* 341 * First, set up shadow registers to prevent glitches. As some 342 * registers are shared between regulators, everything must be properly 343 * set up for all regulators in advance. 344 */ 345 max8660->shadow_regs[MAX8660_ADTV1] = 346 max8660->shadow_regs[MAX8660_ADTV2] = 347 max8660->shadow_regs[MAX8660_SDTV1] = 348 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; 349 max8660->shadow_regs[MAX8660_MDTV1] = 350 max8660->shadow_regs[MAX8660_MDTV2] = 0x04; 351 352 for (i = 0; i < pdata->num_subdevs; i++) { 353 354 if (!pdata->subdevs[i].platform_data) 355 goto err_out; 356 357 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; 358 359 switch (pdata->subdevs[i].id) { 360 case MAX8660_V3: 361 if (boot_on) 362 max8660->shadow_regs[MAX8660_OVER1] |= 1; 363 break; 364 365 case MAX8660_V4: 366 if (boot_on) 367 max8660->shadow_regs[MAX8660_OVER1] |= 4; 368 break; 369 370 case MAX8660_V5: 371 break; 372 373 case MAX8660_V6: 374 if (boot_on) 375 max8660->shadow_regs[MAX8660_OVER2] |= 2; 376 break; 377 378 case MAX8660_V7: 379 if (!strcmp(i2c_id->name, "max8661")) { 380 dev_err(&client->dev, "Regulator not on this chip!\n"); 381 goto err_out; 382 } 383 384 if (boot_on) 385 max8660->shadow_regs[MAX8660_OVER2] |= 4; 386 break; 387 388 default: 389 dev_err(&client->dev, "invalid regulator %s\n", 390 pdata->subdevs[i].name); 391 goto err_out; 392 } 393 } 394 395 /* Finally register devices */ 396 for (i = 0; i < pdata->num_subdevs; i++) { 397 398 id = pdata->subdevs[i].id; 399 400 config.dev = &client->dev; 401 config.init_data = pdata->subdevs[i].platform_data; 402 config.driver_data = max8660; 403 404 rdev[i] = regulator_register(&max8660_reg[id], &config); 405 if (IS_ERR(rdev[i])) { 406 ret = PTR_ERR(rdev[i]); 407 dev_err(&client->dev, "failed to register %s\n", 408 max8660_reg[id].name); 409 goto err_unregister; 410 } 411 } 412 413 i2c_set_clientdata(client, max8660); 414 return 0; 415 416 err_unregister: 417 while (--i >= 0) 418 regulator_unregister(rdev[i]); 419 err_out: 420 return ret; 421 } 422 423 static int max8660_remove(struct i2c_client *client) 424 { 425 struct max8660 *max8660 = i2c_get_clientdata(client); 426 int i; 427 428 for (i = 0; i < MAX8660_V_END; i++) 429 if (max8660->rdev[i]) 430 regulator_unregister(max8660->rdev[i]); 431 return 0; 432 } 433 434 static const struct i2c_device_id max8660_id[] = { 435 { "max8660", 0 }, 436 { "max8661", 0 }, 437 { } 438 }; 439 MODULE_DEVICE_TABLE(i2c, max8660_id); 440 441 static struct i2c_driver max8660_driver = { 442 .probe = max8660_probe, 443 .remove = max8660_remove, 444 .driver = { 445 .name = "max8660", 446 .owner = THIS_MODULE, 447 }, 448 .id_table = max8660_id, 449 }; 450 451 static int __init max8660_init(void) 452 { 453 return i2c_add_driver(&max8660_driver); 454 } 455 subsys_initcall(max8660_init); 456 457 static void __exit max8660_exit(void) 458 { 459 i2c_del_driver(&max8660_driver); 460 } 461 module_exit(max8660_exit); 462 463 /* Module information */ 464 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); 465 MODULE_AUTHOR("Wolfram Sang"); 466 MODULE_LICENSE("GPL v2"); 467