| 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>"); |