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_ZONE_REG 0x40 30 #define LM3530_ALS_IMP_SELECT 0x41 31 #define LM3530_BRT_CTRL_REG 0xA0 32 #define LM3530_ALS_ZB0_REG 0x60 33 #define LM3530_ALS_ZB1_REG 0x61 34 #define LM3530_ALS_ZB2_REG 0x62 35 #define LM3530_ALS_ZB3_REG 0x63 36 #define LM3530_ALS_Z0T_REG 0x70 37 #define LM3530_ALS_Z1T_REG 0x71 38 #define LM3530_ALS_Z2T_REG 0x72 39 #define LM3530_ALS_Z3T_REG 0x73 40 #define LM3530_ALS_Z4T_REG 0x74 41 #define LM3530_REG_MAX 15 42 43 /* General Control Register */ 44 #define LM3530_EN_I2C_SHIFT (0) 45 #define LM3530_RAMP_LAW_SHIFT (1) 46 #define LM3530_MAX_CURR_SHIFT (2) 47 #define LM3530_EN_PWM_SHIFT (5) 48 #define LM3530_PWM_POL_SHIFT (6) 49 #define LM3530_EN_PWM_SIMPLE_SHIFT (7) 50 51 #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT) 52 #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT) 53 #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT) 54 #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT) 55 56 /* ALS Config Register Options */ 57 #define LM3530_ALS_AVG_TIME_SHIFT (0) 58 #define LM3530_EN_ALS_SHIFT (3) 59 #define LM3530_ALS_SEL_SHIFT (5) 60 61 #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT) 62 63 /* Brightness Ramp Rate Register */ 64 #define LM3530_BRT_RAMP_FALL_SHIFT (0) 65 #define LM3530_BRT_RAMP_RISE_SHIFT (3) 66 67 /* ALS Resistor Select */ 68 #define LM3530_ALS1_IMP_SHIFT (0) 69 #define LM3530_ALS2_IMP_SHIFT (4) 70 71 /* Zone Boundary Register defaults */ 72 #define LM3530_ALS_ZB_MAX (4) 73 #define LM3530_ALS_WINDOW_mV (1000) 74 #define LM3530_ALS_OFFSET_mV (4) 75 76 /* Zone Target Register defaults */ 77 #define LM3530_DEF_ZT_0 (0x7F) 78 #define LM3530_DEF_ZT_1 (0x66) 79 #define LM3530_DEF_ZT_2 (0x4C) 80 #define LM3530_DEF_ZT_3 (0x33) 81 #define LM3530_DEF_ZT_4 (0x19) 82 83 struct lm3530_mode_map { 84 const char *mode; 85 enum lm3530_mode mode_val; 86 }; 87 88 static struct lm3530_mode_map mode_map[] = { 89 { "man", LM3530_BL_MODE_MANUAL }, 90 { "als", LM3530_BL_MODE_ALS }, 91 { "pwm", LM3530_BL_MODE_PWM }, 92 }; 93 94 /** 95 * struct lm3530_data 96 * @led_dev: led class device 97 * @client: i2c client 98 * @pdata: LM3530 platform data 99 * @mode: mode of operation - manual, ALS, PWM 100 * @regulator: regulator 101 * @brighness: previous brightness value 102 * @enable: regulator is enabled 103 */ 104 struct lm3530_data { 105 struct led_classdev led_dev; 106 struct i2c_client *client; 107 struct lm3530_platform_data *pdata; 108 enum lm3530_mode mode; 109 struct regulator *regulator; 110 enum led_brightness brightness; 111 bool enable; 112 }; 113 114 static const u8 lm3530_reg[LM3530_REG_MAX] = { 115 LM3530_GEN_CONFIG, 116 LM3530_ALS_CONFIG, 117 LM3530_BRT_RAMP_RATE, 118 LM3530_ALS_ZONE_REG, 119 LM3530_ALS_IMP_SELECT, 120 LM3530_BRT_CTRL_REG, 121 LM3530_ALS_ZB0_REG, 122 LM3530_ALS_ZB1_REG, 123 LM3530_ALS_ZB2_REG, 124 LM3530_ALS_ZB3_REG, 125 LM3530_ALS_Z0T_REG, 126 LM3530_ALS_Z1T_REG, 127 LM3530_ALS_Z2T_REG, 128 LM3530_ALS_Z3T_REG, 129 LM3530_ALS_Z4T_REG, 130 }; 131 132 static int lm3530_get_mode_from_str(const char *str) 133 { 134 int i; 135 136 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 137 if (sysfs_streq(str, mode_map[i].mode)) 138 return mode_map[i].mode_val; 139 140 return -1; 141 } 142 143 static int lm3530_init_registers(struct lm3530_data *drvdata) 144 { 145 int ret = 0; 146 int i; 147 u8 gen_config; 148 u8 als_config = 0; 149 u8 brt_ramp; 150 u8 als_imp_sel = 0; 151 u8 brightness; 152 u8 reg_val[LM3530_REG_MAX]; 153 u8 zones[LM3530_ALS_ZB_MAX]; 154 u32 als_vmin, als_vmax, als_vstep; 155 struct lm3530_platform_data *pltfm = drvdata->pdata; 156 struct i2c_client *client = drvdata->client; 157 158 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | 159 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT); 160 161 if (drvdata->mode == LM3530_BL_MODE_MANUAL || 162 drvdata->mode == LM3530_BL_MODE_ALS) 163 gen_config |= (LM3530_ENABLE_I2C); 164 165 if (drvdata->mode == LM3530_BL_MODE_ALS) { 166 if (pltfm->als_vmax == 0) { 167 pltfm->als_vmin = als_vmin = 0; 168 pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV; 169 } 170 171 als_vmin = pltfm->als_vmin; 172 als_vmax = pltfm->als_vmax; 173 174 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV) 175 pltfm->als_vmax = als_vmax = 176 als_vmin + LM3530_ALS_WINDOW_mV; 177 178 /* n zone boundary makes n+1 zones */ 179 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1); 180 181 for (i = 0; i < LM3530_ALS_ZB_MAX; i++) 182 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) + 183 als_vstep + (i * als_vstep)) * LED_FULL) 184 / 1000; 185 186 als_config = 187 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | 188 (LM3530_ENABLE_ALS) | 189 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT); 190 191 als_imp_sel = 192 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | 193 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); 194 195 } 196 197 if (drvdata->mode == LM3530_BL_MODE_PWM) 198 gen_config |= (LM3530_ENABLE_PWM) | 199 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) | 200 (LM3530_ENABLE_PWM_SIMPLE); 201 202 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | 203 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); 204 205 if (drvdata->brightness) 206 brightness = drvdata->brightness; 207 else 208 brightness = drvdata->brightness = pltfm->brt_val; 209 210 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */ 211 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */ 212 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */ 213 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */ 214 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */ 215 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */ 216 reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */ 217 reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */ 218 reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */ 219 reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */ 220 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ 221 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ 222 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ 223 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ 224 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ 225 226 if (!drvdata->enable) { 227 ret = regulator_enable(drvdata->regulator); 228 if (ret) { 229 dev_err(&drvdata->client->dev, 230 "Enable regulator failed\n"); 231 return ret; 232 } 233 drvdata->enable = true; 234 } 235 236 for (i = 0; i < LM3530_REG_MAX; i++) { 237 ret = i2c_smbus_write_byte_data(client, 238 lm3530_reg[i], reg_val[i]); 239 if (ret) 240 break; 241 } 242 243 return ret; 244 } 245 246 static void lm3530_brightness_set(struct led_classdev *led_cdev, 247 enum led_brightness brt_val) 248 { 249 int err; 250 struct lm3530_data *drvdata = 251 container_of(led_cdev, struct lm3530_data, led_dev); 252 253 switch (drvdata->mode) { 254 case LM3530_BL_MODE_MANUAL: 255 256 if (!drvdata->enable) { 257 err = lm3530_init_registers(drvdata); 258 if (err) { 259 dev_err(&drvdata->client->dev, 260 "Register Init failed: %d\n", err); 261 break; 262 } 263 } 264 265 /* set the brightness in brightness control register*/ 266 err = i2c_smbus_write_byte_data(drvdata->client, 267 LM3530_BRT_CTRL_REG, brt_val / 2); 268 if (err) 269 dev_err(&drvdata->client->dev, 270 "Unable to set brightness: %d\n", err); 271 else 272 drvdata->brightness = brt_val / 2; 273 274 if (brt_val == 0) { 275 err = regulator_disable(drvdata->regulator); 276 if (err) 277 dev_err(&drvdata->client->dev, 278 "Disable regulator failed\n"); 279 drvdata->enable = false; 280 } 281 break; 282 case LM3530_BL_MODE_ALS: 283 break; 284 case LM3530_BL_MODE_PWM: 285 break; 286 default: 287 break; 288 } 289 } 290 291 static ssize_t lm3530_mode_get(struct device *dev, 292 struct device_attribute *attr, char *buf) 293 { 294 struct i2c_client *client = container_of( 295 dev->parent, struct i2c_client, dev); 296 struct lm3530_data *drvdata = i2c_get_clientdata(client); 297 int i, len = 0; 298 299 for (i = 0; i < ARRAY_SIZE(mode_map); i++) 300 if (drvdata->mode == mode_map[i].mode_val) 301 len += sprintf(buf + len, "[%s] ", mode_map[i].mode); 302 else 303 len += sprintf(buf + len, "%s ", mode_map[i].mode); 304 305 len += sprintf(buf + len, "\n"); 306 307 return len; 308 } 309 310 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute 311 *attr, const char *buf, size_t size) 312 { 313 int err; 314 struct i2c_client *client = container_of( 315 dev->parent, struct i2c_client, dev); 316 struct lm3530_data *drvdata = i2c_get_clientdata(client); 317 int mode; 318 319 mode = lm3530_get_mode_from_str(buf); 320 if (mode < 0) { 321 dev_err(dev, "Invalid mode\n"); 322 return -EINVAL; 323 } 324 325 if (mode == LM3530_BL_MODE_MANUAL) 326 drvdata->mode = LM3530_BL_MODE_MANUAL; 327 else if (mode == LM3530_BL_MODE_ALS) 328 drvdata->mode = LM3530_BL_MODE_ALS; 329 else if (mode == LM3530_BL_MODE_PWM) { 330 dev_err(dev, "PWM mode not supported\n"); 331 return -EINVAL; 332 } 333 334 err = lm3530_init_registers(drvdata); 335 if (err) { 336 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err); 337 return err; 338 } 339 340 return sizeof(drvdata->mode); 341 } 342 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set); 343 344 static int __devinit lm3530_probe(struct i2c_client *client, 345 const struct i2c_device_id *id) 346 { 347 struct lm3530_platform_data *pdata = client->dev.platform_data; 348 struct lm3530_data *drvdata; 349 int err = 0; 350 351 if (pdata == NULL) { 352 dev_err(&client->dev, "platform data required\n"); 353 err = -ENODEV; 354 goto err_out; 355 } 356 357 /* BL mode */ 358 if (pdata->mode > LM3530_BL_MODE_PWM) { 359 dev_err(&client->dev, "Illegal Mode request\n"); 360 err = -EINVAL; 361 goto err_out; 362 } 363 364 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 365 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); 366 err = -EIO; 367 goto err_out; 368 } 369 370 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL); 371 if (drvdata == NULL) { 372 err = -ENOMEM; 373 goto err_out; 374 } 375 376 drvdata->mode = pdata->mode; 377 drvdata->client = client; 378 drvdata->pdata = pdata; 379 drvdata->brightness = LED_OFF; 380 drvdata->enable = false; 381 drvdata->led_dev.name = LM3530_LED_DEV; 382 drvdata->led_dev.brightness_set = lm3530_brightness_set; 383 384 i2c_set_clientdata(client, drvdata); 385 386 drvdata->regulator = regulator_get(&client->dev, "vin"); 387 if (IS_ERR(drvdata->regulator)) { 388 dev_err(&client->dev, "regulator get failed\n"); 389 err = PTR_ERR(drvdata->regulator); 390 drvdata->regulator = NULL; 391 goto err_regulator_get; 392 } 393 394 if (drvdata->pdata->brt_val) { 395 err = lm3530_init_registers(drvdata); 396 if (err < 0) { 397 dev_err(&client->dev, 398 "Register Init failed: %d\n", err); 399 err = -ENODEV; 400 goto err_reg_init; 401 } 402 } 403 err = led_classdev_register(&client->dev, &drvdata->led_dev); 404 if (err < 0) { 405 dev_err(&client->dev, "Register led class failed: %d\n", err); 406 err = -ENODEV; 407 goto err_class_register; 408 } 409 410 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode); 411 if (err < 0) { 412 dev_err(&client->dev, "File device creation failed: %d\n", err); 413 err = -ENODEV; 414 goto err_create_file; 415 } 416 417 return 0; 418 419 err_create_file: 420 led_classdev_unregister(&drvdata->led_dev); 421 err_class_register: 422 err_reg_init: 423 regulator_put(drvdata->regulator); 424 err_regulator_get: 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 = __devexit_p(lm3530_remove), 453 .id_table = lm3530_id, 454 .driver = { 455 .name = LM3530_NAME, 456 .owner = THIS_MODULE, 457 }, 458 }; 459 460 module_i2c_driver(lm3530_i2c_driver); 461 462 MODULE_DESCRIPTION("Back Light driver for LM3530"); 463 MODULE_LICENSE("GPL v2"); 464 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>"); 465