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 22 #define LM3530_LED_DEV "lcd-backlight" 23 #define LM3530_NAME "lm3530-led" 24 25 #define LM3530_GEN_CONFIG 0x10 26 #define LM3530_ALS_CONFIG 0x20 27 #define LM3530_BRT_RAMP_RATE 0x30 28 #define LM3530_ALS_ZONE_REG 0x40 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 15 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 struct lm3530_mode_map { 83 const char *mode; 84 enum lm3530_mode mode_val; 85 }; 86 87 static struct lm3530_mode_map mode_map[] = { 88 { "man", LM3530_BL_MODE_MANUAL }, 89 { "als", LM3530_BL_MODE_ALS }, 90 { "pwm", LM3530_BL_MODE_PWM }, 91 }; 92 93 /** 94 * struct lm3530_data 95 * @led_dev: led class device 96 * @client: i2c client 97 * @pdata: LM3530 platform data 98 * @mode: mode of operation - manual, ALS, PWM 99 * @regulator: regulator 100 * @brighness: previous brightness value 101 * @enable: regulator is enabled 102 */ 103 struct lm3530_data { 104 struct led_classdev led_dev; 105 struct i2c_client *client; 106 struct lm3530_platform_data *pdata; 107 enum lm3530_mode mode; 108 struct regulator *regulator; 109 enum led_brightness brightness; 110 bool enable; 111 }; 112 113 static const u8 lm3530_reg[LM3530_REG_MAX] = { 114 LM3530_GEN_CONFIG, 115 LM3530_ALS_CONFIG, 116 LM3530_BRT_RAMP_RATE, 117 LM3530_ALS_ZONE_REG, 118 LM3530_ALS_IMP_SELECT, 119 LM3530_BRT_CTRL_REG, 120 LM3530_ALS_ZB0_REG, 121 LM3530_ALS_ZB1_REG, 122 LM3530_ALS_ZB2_REG, 123 LM3530_ALS_ZB3_REG, 124 LM3530_ALS_Z0T_REG, 125 LM3530_ALS_Z1T_REG, 126 LM3530_ALS_Z2T_REG, 127 LM3530_ALS_Z3T_REG, 128 LM3530_ALS_Z4T_REG, 129 }; 130 131 static int lm3530_get_mode_from_str(const char *str) 132 { 133 int i; 134 135 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 136 if (sysfs_streq(str, mode_map[i].mode)) 137 return mode_map[i].mode_val; 138 139 return -1; 140 } 141 142 static int lm3530_init_registers(struct lm3530_data *drvdata) 143 { 144 int ret = 0; 145 int i; 146 u8 gen_config; 147 u8 als_config = 0; 148 u8 brt_ramp; 149 u8 als_imp_sel = 0; 150 u8 brightness; 151 u8 reg_val[LM3530_REG_MAX]; 152 u8 zones[LM3530_ALS_ZB_MAX]; 153 u32 als_vmin, als_vmax, als_vstep; 154 struct lm3530_platform_data *pltfm = drvdata->pdata; 155 struct i2c_client *client = drvdata->client; 156 157 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | 158 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT); 159 160 if (drvdata->mode == LM3530_BL_MODE_MANUAL || 161 drvdata->mode == LM3530_BL_MODE_ALS) 162 gen_config |= (LM3530_ENABLE_I2C); 163 164 if (drvdata->mode == LM3530_BL_MODE_ALS) { 165 if (pltfm->als_vmax == 0) { 166 pltfm->als_vmin = als_vmin = 0; 167 pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV; 168 } 169 170 als_vmin = pltfm->als_vmin; 171 als_vmax = pltfm->als_vmax; 172 173 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV) 174 pltfm->als_vmax = als_vmax = 175 als_vmin + LM3530_ALS_WINDOW_mV; 176 177 /* n zone boundary makes n+1 zones */ 178 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1); 179 180 for (i = 0; i < LM3530_ALS_ZB_MAX; i++) 181 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) + 182 als_vstep + (i * als_vstep)) * LED_FULL) 183 / 1000; 184 185 als_config = 186 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | 187 (LM3530_ENABLE_ALS) | 188 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT); 189 190 als_imp_sel = 191 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | 192 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); 193 194 } 195 196 if (drvdata->mode == LM3530_BL_MODE_PWM) 197 gen_config |= (LM3530_ENABLE_PWM) | 198 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) | 199 (LM3530_ENABLE_PWM_SIMPLE); 200 201 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | 202 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); 203 204 if (drvdata->brightness) 205 brightness = drvdata->brightness; 206 else 207 brightness = drvdata->brightness = pltfm->brt_val; 208 209 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */ 210 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */ 211 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */ 212 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */ 213 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */ 214 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */ 215 reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */ 216 reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */ 217 reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */ 218 reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */ 219 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ 220 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ 221 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ 222 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ 223 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ 224 225 if (!drvdata->enable) { 226 ret = regulator_enable(drvdata->regulator); 227 if (ret) { 228 dev_err(&drvdata->client->dev, 229 "Enable regulator failed\n"); 230 return ret; 231 } 232 drvdata->enable = true; 233 } 234 235 for (i = 0; i < LM3530_REG_MAX; i++) { 236 ret = i2c_smbus_write_byte_data(client, 237 lm3530_reg[i], reg_val[i]); 238 if (ret) 239 break; 240 } 241 242 return ret; 243 } 244 245 static void lm3530_brightness_set(struct led_classdev *led_cdev, 246 enum led_brightness brt_val) 247 { 248 int err; 249 struct lm3530_data *drvdata = 250 container_of(led_cdev, struct lm3530_data, led_dev); 251 252 switch (drvdata->mode) { 253 case LM3530_BL_MODE_MANUAL: 254 255 if (!drvdata->enable) { 256 err = lm3530_init_registers(drvdata); 257 if (err) { 258 dev_err(&drvdata->client->dev, 259 "Register Init failed: %d\n", err); 260 break; 261 } 262 } 263 264 /* set the brightness in brightness control register*/ 265 err = i2c_smbus_write_byte_data(drvdata->client, 266 LM3530_BRT_CTRL_REG, brt_val / 2); 267 if (err) 268 dev_err(&drvdata->client->dev, 269 "Unable to set brightness: %d\n", err); 270 else 271 drvdata->brightness = brt_val / 2; 272 273 if (brt_val == 0) { 274 err = regulator_disable(drvdata->regulator); 275 if (err) 276 dev_err(&drvdata->client->dev, 277 "Disable regulator failed\n"); 278 drvdata->enable = false; 279 } 280 break; 281 case LM3530_BL_MODE_ALS: 282 break; 283 case LM3530_BL_MODE_PWM: 284 break; 285 default: 286 break; 287 } 288 } 289 290 static ssize_t lm3530_mode_get(struct device *dev, 291 struct device_attribute *attr, char *buf) 292 { 293 struct i2c_client *client = container_of( 294 dev->parent, struct i2c_client, dev); 295 struct lm3530_data *drvdata = i2c_get_clientdata(client); 296 int i, len = 0; 297 298 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 299 if (drvdata->mode == mode_map[i].mode_val) 300 len += sprintf(buf + len, "[%s] ", mode_map[i].mode); 301 else 302 len += sprintf(buf + len, "%s ", mode_map[i].mode); 303 304 len += sprintf(buf + len, "\n"); 305 306 return len; 307 } 308 309 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute 310 *attr, const char *buf, size_t size) 311 { 312 int err; 313 struct i2c_client *client = container_of( 314 dev->parent, struct i2c_client, dev); 315 struct lm3530_data *drvdata = i2c_get_clientdata(client); 316 int mode; 317 318 mode = lm3530_get_mode_from_str(buf); 319 if (mode < 0) { 320 dev_err(dev, "Invalid mode\n"); 321 return -EINVAL; 322 } 323 324 if (mode == LM3530_BL_MODE_MANUAL) 325 drvdata->mode = LM3530_BL_MODE_MANUAL; 326 else if (mode == LM3530_BL_MODE_ALS) 327 drvdata->mode = LM3530_BL_MODE_ALS; 328 else if (mode == LM3530_BL_MODE_PWM) { 329 dev_err(dev, "PWM mode not supported\n"); 330 return -EINVAL; 331 } 332 333 err = lm3530_init_registers(drvdata); 334 if (err) { 335 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err); 336 return err; 337 } 338 339 return sizeof(drvdata->mode); 340 } 341 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set); 342 343 static int __devinit lm3530_probe(struct i2c_client *client, 344 const struct i2c_device_id *id) 345 { 346 struct lm3530_platform_data *pdata = client->dev.platform_data; 347 struct lm3530_data *drvdata; 348 int err = 0; 349 350 if (pdata == NULL) { 351 dev_err(&client->dev, "platform data required\n"); 352 err = -ENODEV; 353 goto err_out; 354 } 355 356 /* BL mode */ 357 if (pdata->mode > LM3530_BL_MODE_PWM) { 358 dev_err(&client->dev, "Illegal Mode request\n"); 359 err = -EINVAL; 360 goto err_out; 361 } 362 363 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 364 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); 365 err = -EIO; 366 goto err_out; 367 } 368 369 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL); 370 if (drvdata == NULL) { 371 err = -ENOMEM; 372 goto err_out; 373 } 374 375 drvdata->mode = pdata->mode; 376 drvdata->client = client; 377 drvdata->pdata = pdata; 378 drvdata->brightness = LED_OFF; 379 drvdata->enable = false; 380 drvdata->led_dev.name = LM3530_LED_DEV; 381 drvdata->led_dev.brightness_set = lm3530_brightness_set; 382 383 i2c_set_clientdata(client, drvdata); 384 385 drvdata->regulator = regulator_get(&client->dev, "vin"); 386 if (IS_ERR(drvdata->regulator)) { 387 dev_err(&client->dev, "regulator get failed\n"); 388 err = PTR_ERR(drvdata->regulator); 389 drvdata->regulator = NULL; 390 goto err_regulator_get; 391 } 392 393 if (drvdata->pdata->brt_val) { 394 err = lm3530_init_registers(drvdata); 395 if (err < 0) { 396 dev_err(&client->dev, 397 "Register Init failed: %d\n", err); 398 err = -ENODEV; 399 goto err_reg_init; 400 } 401 } 402 err = led_classdev_register(&client->dev, &drvdata->led_dev); 403 if (err < 0) { 404 dev_err(&client->dev, "Register led class failed: %d\n", err); 405 err = -ENODEV; 406 goto err_class_register; 407 } 408 409 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode); 410 if (err < 0) { 411 dev_err(&client->dev, "File device creation failed: %d\n", err); 412 err = -ENODEV; 413 goto err_create_file; 414 } 415 416 return 0; 417 418 err_create_file: 419 led_classdev_unregister(&drvdata->led_dev); 420 err_class_register: 421 err_reg_init: 422 regulator_put(drvdata->regulator); 423 err_regulator_get: 424 i2c_set_clientdata(client, NULL); 425 kfree(drvdata); 426 err_out: 427 return err; 428 } 429 430 static int __devexit lm3530_remove(struct i2c_client *client) 431 { 432 struct lm3530_data *drvdata = i2c_get_clientdata(client); 433 434 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode); 435 436 if (drvdata->enable) 437 regulator_disable(drvdata->regulator); 438 regulator_put(drvdata->regulator); 439 led_classdev_unregister(&drvdata->led_dev); 440 kfree(drvdata); 441 return 0; 442 } 443 444 static const struct i2c_device_id lm3530_id[] = { 445 {LM3530_NAME, 0}, 446 {} 447 }; 448 MODULE_DEVICE_TABLE(i2c, lm3530_id); 449 450 static struct i2c_driver lm3530_i2c_driver = { 451 .probe = lm3530_probe, 452 .remove = lm3530_remove, 453 .id_table = lm3530_id, 454 .driver = { 455 .name = LM3530_NAME, 456 .owner = THIS_MODULE, 457 }, 458 }; 459 460 static int __init lm3530_init(void) 461 { 462 return i2c_add_driver(&lm3530_i2c_driver); 463 } 464 465 static void __exit lm3530_exit(void) 466 { 467 i2c_del_driver(&lm3530_i2c_driver); 468 } 469 470 module_init(lm3530_init); 471 module_exit(lm3530_exit); 472 473 MODULE_DESCRIPTION("Back Light driver for LM3530"); 474 MODULE_LICENSE("GPL v2"); 475 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>"); 476