1 /* 2 * Copyright (C) 2011 ST-Ericsson SA. 3 * Copyright (C) 2009 Motorola, Inc. 4 * 5 * License Terms: GNU General Public License v2 6 * 7 * Simple driver for National Semiconductor LM3530 Backlight driver chip 8 * 9 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com> 10 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com> 11 */ 12 13 #include <linux/i2c.h> 14 #include <linux/leds.h> 15 #include <linux/slab.h> 16 #include <linux/platform_device.h> 17 #include <linux/input.h> 18 #include <linux/led-lm3530.h> 19 #include <linux/types.h> 20 #include <linux/regulator/consumer.h> 21 #include <linux/module.h> 22 23 #define LM3530_LED_DEV "lcd-backlight" 24 #define LM3530_NAME "lm3530-led" 25 26 #define LM3530_GEN_CONFIG 0x10 27 #define LM3530_ALS_CONFIG 0x20 28 #define LM3530_BRT_RAMP_RATE 0x30 29 #define LM3530_ALS_IMP_SELECT 0x41 30 #define LM3530_BRT_CTRL_REG 0xA0 31 #define LM3530_ALS_ZB0_REG 0x60 32 #define LM3530_ALS_ZB1_REG 0x61 33 #define LM3530_ALS_ZB2_REG 0x62 34 #define LM3530_ALS_ZB3_REG 0x63 35 #define LM3530_ALS_Z0T_REG 0x70 36 #define LM3530_ALS_Z1T_REG 0x71 37 #define LM3530_ALS_Z2T_REG 0x72 38 #define LM3530_ALS_Z3T_REG 0x73 39 #define LM3530_ALS_Z4T_REG 0x74 40 #define LM3530_REG_MAX 14 41 42 /* General Control Register */ 43 #define LM3530_EN_I2C_SHIFT (0) 44 #define LM3530_RAMP_LAW_SHIFT (1) 45 #define LM3530_MAX_CURR_SHIFT (2) 46 #define LM3530_EN_PWM_SHIFT (5) 47 #define LM3530_PWM_POL_SHIFT (6) 48 #define LM3530_EN_PWM_SIMPLE_SHIFT (7) 49 50 #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT) 51 #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT) 52 #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT) 53 #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT) 54 55 /* ALS Config Register Options */ 56 #define LM3530_ALS_AVG_TIME_SHIFT (0) 57 #define LM3530_EN_ALS_SHIFT (3) 58 #define LM3530_ALS_SEL_SHIFT (5) 59 60 #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT) 61 62 /* Brightness Ramp Rate Register */ 63 #define LM3530_BRT_RAMP_FALL_SHIFT (0) 64 #define LM3530_BRT_RAMP_RISE_SHIFT (3) 65 66 /* ALS Resistor Select */ 67 #define LM3530_ALS1_IMP_SHIFT (0) 68 #define LM3530_ALS2_IMP_SHIFT (4) 69 70 /* Zone Boundary Register defaults */ 71 #define LM3530_ALS_ZB_MAX (4) 72 #define LM3530_ALS_WINDOW_mV (1000) 73 #define LM3530_ALS_OFFSET_mV (4) 74 75 /* Zone Target Register defaults */ 76 #define LM3530_DEF_ZT_0 (0x7F) 77 #define LM3530_DEF_ZT_1 (0x66) 78 #define LM3530_DEF_ZT_2 (0x4C) 79 #define LM3530_DEF_ZT_3 (0x33) 80 #define LM3530_DEF_ZT_4 (0x19) 81 82 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */ 83 #define MAX_BRIGHTNESS (127) 84 85 struct lm3530_mode_map { 86 const char *mode; 87 enum lm3530_mode mode_val; 88 }; 89 90 static struct lm3530_mode_map mode_map[] = { 91 { "man", LM3530_BL_MODE_MANUAL }, 92 { "als", LM3530_BL_MODE_ALS }, 93 { "pwm", LM3530_BL_MODE_PWM }, 94 }; 95 96 /** 97 * struct lm3530_data 98 * @led_dev: led class device 99 * @client: i2c client 100 * @pdata: LM3530 platform data 101 * @mode: mode of operation - manual, ALS, PWM 102 * @regulator: regulator 103 * @brighness: previous brightness value 104 * @enable: regulator is enabled 105 */ 106 struct lm3530_data { 107 struct led_classdev led_dev; 108 struct i2c_client *client; 109 struct lm3530_platform_data *pdata; 110 enum lm3530_mode mode; 111 struct regulator *regulator; 112 enum led_brightness brightness; 113 bool enable; 114 }; 115 116 static const u8 lm3530_reg[LM3530_REG_MAX] = { 117 LM3530_GEN_CONFIG, 118 LM3530_ALS_CONFIG, 119 LM3530_BRT_RAMP_RATE, 120 LM3530_ALS_IMP_SELECT, 121 LM3530_BRT_CTRL_REG, 122 LM3530_ALS_ZB0_REG, 123 LM3530_ALS_ZB1_REG, 124 LM3530_ALS_ZB2_REG, 125 LM3530_ALS_ZB3_REG, 126 LM3530_ALS_Z0T_REG, 127 LM3530_ALS_Z1T_REG, 128 LM3530_ALS_Z2T_REG, 129 LM3530_ALS_Z3T_REG, 130 LM3530_ALS_Z4T_REG, 131 }; 132 133 static int lm3530_get_mode_from_str(const char *str) 134 { 135 int i; 136 137 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 138 if (sysfs_streq(str, mode_map[i].mode)) 139 return mode_map[i].mode_val; 140 141 return -1; 142 } 143 144 static int lm3530_init_registers(struct lm3530_data *drvdata) 145 { 146 int ret = 0; 147 int i; 148 u8 gen_config; 149 u8 als_config = 0; 150 u8 brt_ramp; 151 u8 als_imp_sel = 0; 152 u8 brightness; 153 u8 reg_val[LM3530_REG_MAX]; 154 u8 zones[LM3530_ALS_ZB_MAX]; 155 u32 als_vmin, als_vmax, als_vstep; 156 struct lm3530_platform_data *pdata = drvdata->pdata; 157 struct i2c_client *client = drvdata->client; 158 struct lm3530_pwm_data *pwm = &pdata->pwm_data; 159 160 gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | 161 ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT); 162 163 switch (drvdata->mode) { 164 case LM3530_BL_MODE_MANUAL: 165 case LM3530_BL_MODE_ALS: 166 gen_config |= LM3530_ENABLE_I2C; 167 break; 168 case LM3530_BL_MODE_PWM: 169 gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE | 170 (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT); 171 break; 172 } 173 174 if (drvdata->mode == LM3530_BL_MODE_ALS) { 175 if (pdata->als_vmax == 0) { 176 pdata->als_vmin = 0; 177 pdata->als_vmax = LM3530_ALS_WINDOW_mV; 178 } 179 180 als_vmin = pdata->als_vmin; 181 als_vmax = pdata->als_vmax; 182 183 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV) 184 pdata->als_vmax = als_vmax = 185 als_vmin + LM3530_ALS_WINDOW_mV; 186 187 /* n zone boundary makes n+1 zones */ 188 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1); 189 190 for (i = 0; i < LM3530_ALS_ZB_MAX; i++) 191 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) + 192 als_vstep + (i * als_vstep)) * LED_FULL) 193 / 1000; 194 195 als_config = 196 (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | 197 (LM3530_ENABLE_ALS) | 198 (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT); 199 200 als_imp_sel = 201 (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | 202 (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); 203 204 } 205 206 brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | 207 (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); 208 209 if (drvdata->brightness) 210 brightness = drvdata->brightness; 211 else 212 brightness = drvdata->brightness = pdata->brt_val; 213 214 if (brightness > drvdata->led_dev.max_brightness) 215 brightness = drvdata->led_dev.max_brightness; 216 217 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */ 218 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */ 219 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */ 220 reg_val[3] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */ 221 reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */ 222 reg_val[5] = zones[0]; /* LM3530_ALS_ZB0_REG */ 223 reg_val[6] = zones[1]; /* LM3530_ALS_ZB1_REG */ 224 reg_val[7] = zones[2]; /* LM3530_ALS_ZB2_REG */ 225 reg_val[8] = zones[3]; /* LM3530_ALS_ZB3_REG */ 226 reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ 227 reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ 228 reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ 229 reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ 230 reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ 231 232 if (!drvdata->enable) { 233 ret = regulator_enable(drvdata->regulator); 234 if (ret) { 235 dev_err(&drvdata->client->dev, 236 "Enable regulator failed\n"); 237 return ret; 238 } 239 drvdata->enable = true; 240 } 241 242 for (i = 0; i < LM3530_REG_MAX; i++) { 243 /* do not update brightness register when pwm mode */ 244 if (lm3530_reg[i] == LM3530_BRT_CTRL_REG && 245 drvdata->mode == LM3530_BL_MODE_PWM) { 246 if (pwm->pwm_set_intensity) 247 pwm->pwm_set_intensity(reg_val[i], 248 drvdata->led_dev.max_brightness); 249 continue; 250 } 251 252 ret = i2c_smbus_write_byte_data(client, 253 lm3530_reg[i], reg_val[i]); 254 if (ret) 255 break; 256 } 257 258 return ret; 259 } 260 261 static void lm3530_brightness_set(struct led_classdev *led_cdev, 262 enum led_brightness brt_val) 263 { 264 int err; 265 struct lm3530_data *drvdata = 266 container_of(led_cdev, struct lm3530_data, led_dev); 267 struct lm3530_platform_data *pdata = drvdata->pdata; 268 struct lm3530_pwm_data *pwm = &pdata->pwm_data; 269 u8 max_brightness = led_cdev->max_brightness; 270 271 switch (drvdata->mode) { 272 case LM3530_BL_MODE_MANUAL: 273 274 if (!drvdata->enable) { 275 err = lm3530_init_registers(drvdata); 276 if (err) { 277 dev_err(&drvdata->client->dev, 278 "Register Init failed: %d\n", err); 279 break; 280 } 281 } 282 283 /* set the brightness in brightness control register*/ 284 err = i2c_smbus_write_byte_data(drvdata->client, 285 LM3530_BRT_CTRL_REG, brt_val); 286 if (err) 287 dev_err(&drvdata->client->dev, 288 "Unable to set brightness: %d\n", err); 289 else 290 drvdata->brightness = brt_val; 291 292 if (brt_val == 0) { 293 err = regulator_disable(drvdata->regulator); 294 if (err) 295 dev_err(&drvdata->client->dev, 296 "Disable regulator failed\n"); 297 drvdata->enable = false; 298 } 299 break; 300 case LM3530_BL_MODE_ALS: 301 break; 302 case LM3530_BL_MODE_PWM: 303 if (pwm->pwm_set_intensity) 304 pwm->pwm_set_intensity(brt_val, max_brightness); 305 break; 306 default: 307 break; 308 } 309 } 310 311 static ssize_t lm3530_mode_get(struct device *dev, 312 struct device_attribute *attr, char *buf) 313 { 314 struct led_classdev *led_cdev = dev_get_drvdata(dev); 315 struct lm3530_data *drvdata; 316 int i, len = 0; 317 318 drvdata = container_of(led_cdev, struct lm3530_data, led_dev); 319 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 320 if (drvdata->mode == mode_map[i].mode_val) 321 len += sprintf(buf + len, "[%s] ", mode_map[i].mode); 322 else 323 len += sprintf(buf + len, "%s ", mode_map[i].mode); 324 325 len += sprintf(buf + len, "\n"); 326 327 return len; 328 } 329 330 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute 331 *attr, const char *buf, size_t size) 332 { 333 struct led_classdev *led_cdev = dev_get_drvdata(dev); 334 struct lm3530_data *drvdata; 335 struct lm3530_pwm_data *pwm; 336 u8 max_brightness; 337 int mode, err; 338 339 drvdata = container_of(led_cdev, struct lm3530_data, led_dev); 340 pwm = &drvdata->pdata->pwm_data; 341 max_brightness = led_cdev->max_brightness; 342 mode = lm3530_get_mode_from_str(buf); 343 if (mode < 0) { 344 dev_err(dev, "Invalid mode\n"); 345 return -EINVAL; 346 } 347 348 drvdata->mode = mode; 349 350 /* set pwm to low if unnecessary */ 351 if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity) 352 pwm->pwm_set_intensity(0, max_brightness); 353 354 err = lm3530_init_registers(drvdata); 355 if (err) { 356 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err); 357 return err; 358 } 359 360 return sizeof(drvdata->mode); 361 } 362 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set); 363 364 static int __devinit lm3530_probe(struct i2c_client *client, 365 const struct i2c_device_id *id) 366 { 367 struct lm3530_platform_data *pdata = client->dev.platform_data; 368 struct lm3530_data *drvdata; 369 int err = 0; 370 371 if (pdata == NULL) { 372 dev_err(&client->dev, "platform data required\n"); 373 err = -ENODEV; 374 goto err_out; 375 } 376 377 /* BL mode */ 378 if (pdata->mode > LM3530_BL_MODE_PWM) { 379 dev_err(&client->dev, "Illegal Mode request\n"); 380 err = -EINVAL; 381 goto err_out; 382 } 383 384 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 385 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); 386 err = -EIO; 387 goto err_out; 388 } 389 390 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL); 391 if (drvdata == NULL) { 392 err = -ENOMEM; 393 goto err_out; 394 } 395 396 drvdata->mode = pdata->mode; 397 drvdata->client = client; 398 drvdata->pdata = pdata; 399 drvdata->brightness = LED_OFF; 400 drvdata->enable = false; 401 drvdata->led_dev.name = LM3530_LED_DEV; 402 drvdata->led_dev.brightness_set = lm3530_brightness_set; 403 drvdata->led_dev.max_brightness = MAX_BRIGHTNESS; 404 405 i2c_set_clientdata(client, drvdata); 406 407 drvdata->regulator = regulator_get(&client->dev, "vin"); 408 if (IS_ERR(drvdata->regulator)) { 409 dev_err(&client->dev, "regulator get failed\n"); 410 err = PTR_ERR(drvdata->regulator); 411 drvdata->regulator = NULL; 412 goto err_regulator_get; 413 } 414 415 if (drvdata->pdata->brt_val) { 416 err = lm3530_init_registers(drvdata); 417 if (err < 0) { 418 dev_err(&client->dev, 419 "Register Init failed: %d\n", err); 420 err = -ENODEV; 421 goto err_reg_init; 422 } 423 } 424 err = led_classdev_register(&client->dev, &drvdata->led_dev); 425 if (err < 0) { 426 dev_err(&client->dev, "Register led class failed: %d\n", err); 427 err = -ENODEV; 428 goto err_class_register; 429 } 430 431 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode); 432 if (err < 0) { 433 dev_err(&client->dev, "File device creation failed: %d\n", err); 434 err = -ENODEV; 435 goto err_create_file; 436 } 437 438 return 0; 439 440 err_create_file: 441 led_classdev_unregister(&drvdata->led_dev); 442 err_class_register: 443 err_reg_init: 444 regulator_put(drvdata->regulator); 445 err_regulator_get: 446 kfree(drvdata); 447 err_out: 448 return err; 449 } 450 451 static int __devexit lm3530_remove(struct i2c_client *client) 452 { 453 struct lm3530_data *drvdata = i2c_get_clientdata(client); 454 455 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode); 456 457 if (drvdata->enable) 458 regulator_disable(drvdata->regulator); 459 regulator_put(drvdata->regulator); 460 led_classdev_unregister(&drvdata->led_dev); 461 kfree(drvdata); 462 return 0; 463 } 464 465 static const struct i2c_device_id lm3530_id[] = { 466 {LM3530_NAME, 0}, 467 {} 468 }; 469 MODULE_DEVICE_TABLE(i2c, lm3530_id); 470 471 static struct i2c_driver lm3530_i2c_driver = { 472 .probe = lm3530_probe, 473 .remove = __devexit_p(lm3530_remove), 474 .id_table = lm3530_id, 475 .driver = { 476 .name = LM3530_NAME, 477 .owner = THIS_MODULE, 478 }, 479 }; 480 481 module_i2c_driver(lm3530_i2c_driver); 482 483 MODULE_DESCRIPTION("Back Light driver for LM3530"); 484 MODULE_LICENSE("GPL v2"); 485 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>"); 486