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_DEF_ZB_0 (0x33) 72 #define LM3530_DEF_ZB_1 (0x66) 73 #define LM3530_DEF_ZB_2 (0x99) 74 #define LM3530_DEF_ZB_3 (0xCC) 75 76 /* Zone Target Register defaults */ 77 #define LM3530_DEF_ZT_0 (0x19) 78 #define LM3530_DEF_ZT_1 (0x33) 79 #define LM3530_DEF_ZT_2 (0x4C) 80 #define LM3530_DEF_ZT_3 (0x66) 81 #define LM3530_DEF_ZT_4 (0x7F) 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 struct lm3530_platform_data *pltfm = drvdata->pdata; 154 struct i2c_client *client = drvdata->client; 155 156 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | 157 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT); 158 159 if (drvdata->mode == LM3530_BL_MODE_MANUAL || 160 drvdata->mode == LM3530_BL_MODE_ALS) 161 gen_config |= (LM3530_ENABLE_I2C); 162 163 if (drvdata->mode == LM3530_BL_MODE_ALS) { 164 als_config = 165 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | 166 (LM3530_ENABLE_ALS) | 167 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT); 168 169 als_imp_sel = 170 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | 171 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); 172 } 173 174 if (drvdata->mode == LM3530_BL_MODE_PWM) 175 gen_config |= (LM3530_ENABLE_PWM) | 176 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) | 177 (LM3530_ENABLE_PWM_SIMPLE); 178 179 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | 180 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); 181 182 if (drvdata->brightness) 183 brightness = drvdata->brightness; 184 else 185 brightness = drvdata->brightness = pltfm->brt_val; 186 187 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */ 188 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */ 189 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */ 190 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */ 191 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */ 192 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */ 193 reg_val[6] = LM3530_DEF_ZB_0; /* LM3530_ALS_ZB0_REG */ 194 reg_val[7] = LM3530_DEF_ZB_1; /* LM3530_ALS_ZB1_REG */ 195 reg_val[8] = LM3530_DEF_ZB_2; /* LM3530_ALS_ZB2_REG */ 196 reg_val[9] = LM3530_DEF_ZB_3; /* LM3530_ALS_ZB3_REG */ 197 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ 198 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ 199 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ 200 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ 201 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ 202 203 if (!drvdata->enable) { 204 ret = regulator_enable(drvdata->regulator); 205 if (ret) { 206 dev_err(&drvdata->client->dev, 207 "Enable regulator failed\n"); 208 return ret; 209 } 210 drvdata->enable = true; 211 } 212 213 for (i = 0; i < LM3530_REG_MAX; i++) { 214 ret = i2c_smbus_write_byte_data(client, 215 lm3530_reg[i], reg_val[i]); 216 if (ret) 217 break; 218 } 219 220 return ret; 221 } 222 223 static void lm3530_brightness_set(struct led_classdev *led_cdev, 224 enum led_brightness brt_val) 225 { 226 int err; 227 struct lm3530_data *drvdata = 228 container_of(led_cdev, struct lm3530_data, led_dev); 229 230 switch (drvdata->mode) { 231 case LM3530_BL_MODE_MANUAL: 232 233 if (!drvdata->enable) { 234 err = lm3530_init_registers(drvdata); 235 if (err) { 236 dev_err(&drvdata->client->dev, 237 "Register Init failed: %d\n", err); 238 break; 239 } 240 } 241 242 /* set the brightness in brightness control register*/ 243 err = i2c_smbus_write_byte_data(drvdata->client, 244 LM3530_BRT_CTRL_REG, brt_val / 2); 245 if (err) 246 dev_err(&drvdata->client->dev, 247 "Unable to set brightness: %d\n", err); 248 else 249 drvdata->brightness = brt_val / 2; 250 251 if (brt_val == 0) { 252 err = regulator_disable(drvdata->regulator); 253 if (err) 254 dev_err(&drvdata->client->dev, 255 "Disable regulator failed\n"); 256 drvdata->enable = false; 257 } 258 break; 259 case LM3530_BL_MODE_ALS: 260 break; 261 case LM3530_BL_MODE_PWM: 262 break; 263 default: 264 break; 265 } 266 } 267 268 269 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute 270 *attr, const char *buf, size_t size) 271 { 272 int err; 273 struct i2c_client *client = container_of( 274 dev->parent, struct i2c_client, dev); 275 struct lm3530_data *drvdata = i2c_get_clientdata(client); 276 int mode; 277 278 mode = lm3530_get_mode_from_str(buf); 279 if (mode < 0) { 280 dev_err(dev, "Invalid mode\n"); 281 return -EINVAL; 282 } 283 284 if (mode == LM3530_BL_MODE_MANUAL) 285 drvdata->mode = LM3530_BL_MODE_MANUAL; 286 else if (mode == LM3530_BL_MODE_ALS) 287 drvdata->mode = LM3530_BL_MODE_ALS; 288 else if (mode == LM3530_BL_MODE_PWM) { 289 dev_err(dev, "PWM mode not supported\n"); 290 return -EINVAL; 291 } 292 293 err = lm3530_init_registers(drvdata); 294 if (err) { 295 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err); 296 return err; 297 } 298 299 return sizeof(drvdata->mode); 300 } 301 302 static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set); 303 304 static int __devinit lm3530_probe(struct i2c_client *client, 305 const struct i2c_device_id *id) 306 { 307 struct lm3530_platform_data *pdata = client->dev.platform_data; 308 struct lm3530_data *drvdata; 309 int err = 0; 310 311 if (pdata == NULL) { 312 dev_err(&client->dev, "platform data required\n"); 313 err = -ENODEV; 314 goto err_out; 315 } 316 317 /* BL mode */ 318 if (pdata->mode > LM3530_BL_MODE_PWM) { 319 dev_err(&client->dev, "Illegal Mode request\n"); 320 err = -EINVAL; 321 goto err_out; 322 } 323 324 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 325 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); 326 err = -EIO; 327 goto err_out; 328 } 329 330 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL); 331 if (drvdata == NULL) { 332 err = -ENOMEM; 333 goto err_out; 334 } 335 336 drvdata->mode = pdata->mode; 337 drvdata->client = client; 338 drvdata->pdata = pdata; 339 drvdata->brightness = LED_OFF; 340 drvdata->enable = false; 341 drvdata->led_dev.name = LM3530_LED_DEV; 342 drvdata->led_dev.brightness_set = lm3530_brightness_set; 343 344 i2c_set_clientdata(client, drvdata); 345 346 drvdata->regulator = regulator_get(&client->dev, "vin"); 347 if (IS_ERR(drvdata->regulator)) { 348 dev_err(&client->dev, "regulator get failed\n"); 349 err = PTR_ERR(drvdata->regulator); 350 drvdata->regulator = NULL; 351 goto err_regulator_get; 352 } 353 354 if (drvdata->pdata->brt_val) { 355 err = lm3530_init_registers(drvdata); 356 if (err < 0) { 357 dev_err(&client->dev, 358 "Register Init failed: %d\n", err); 359 err = -ENODEV; 360 goto err_reg_init; 361 } 362 } 363 err = led_classdev_register(&client->dev, &drvdata->led_dev); 364 if (err < 0) { 365 dev_err(&client->dev, "Register led class failed: %d\n", err); 366 err = -ENODEV; 367 goto err_class_register; 368 } 369 370 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode); 371 if (err < 0) { 372 dev_err(&client->dev, "File device creation failed: %d\n", err); 373 err = -ENODEV; 374 goto err_create_file; 375 } 376 377 return 0; 378 379 err_create_file: 380 led_classdev_unregister(&drvdata->led_dev); 381 err_class_register: 382 err_reg_init: 383 regulator_put(drvdata->regulator); 384 err_regulator_get: 385 i2c_set_clientdata(client, NULL); 386 kfree(drvdata); 387 err_out: 388 return err; 389 } 390 391 static int __devexit lm3530_remove(struct i2c_client *client) 392 { 393 struct lm3530_data *drvdata = i2c_get_clientdata(client); 394 395 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode); 396 397 if (drvdata->enable) 398 regulator_disable(drvdata->regulator); 399 regulator_put(drvdata->regulator); 400 led_classdev_unregister(&drvdata->led_dev); 401 kfree(drvdata); 402 return 0; 403 } 404 405 static const struct i2c_device_id lm3530_id[] = { 406 {LM3530_NAME, 0}, 407 {} 408 }; 409 MODULE_DEVICE_TABLE(i2c, lm3530_id); 410 411 static struct i2c_driver lm3530_i2c_driver = { 412 .probe = lm3530_probe, 413 .remove = lm3530_remove, 414 .id_table = lm3530_id, 415 .driver = { 416 .name = LM3530_NAME, 417 .owner = THIS_MODULE, 418 }, 419 }; 420 421 static int __init lm3530_init(void) 422 { 423 return i2c_add_driver(&lm3530_i2c_driver); 424 } 425 426 static void __exit lm3530_exit(void) 427 { 428 i2c_del_driver(&lm3530_i2c_driver); 429 } 430 431 module_init(lm3530_init); 432 module_exit(lm3530_exit); 433 434 MODULE_DESCRIPTION("Back Light driver for LM3530"); 435 MODULE_LICENSE("GPL v2"); 436 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>"); 437