drivers/media/i2c/lm3646.c

   1 /*
   2  * drivers/media/i2c/lm3646.c
   3  * General device driver for TI lm3646, Dual FLASH LED Driver
   4  *
   5  * Copyright (C) 2014 Texas Instruments
   6  *
   7  * Contact: Daniel Jeong <gshark.jeong@gmail.com>
   8  *                      Ldd-Mlp <ldd-mlp@list.ti.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * version 2 as published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/i2c.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/regmap.h>
  20 #include <linux/videodev2.h>
  21 #include <media/lm3646.h>
  22 #include <media/v4l2-ctrls.h>
  23 #include <media/v4l2-device.h>
  24
  25 /* registers definitions */
  26 #define REG_ENABLE              0x01
  27 #define REG_TORCH_BR    0x05
  28 #define REG_FLASH_BR    0x05
  29 #define REG_FLASH_TOUT  0x04
  30 #define REG_FLAG                0x08
  31 #define REG_STROBE_SRC  0x06
  32 #define REG_LED1_FLASH_BR 0x06
  33 #define REG_LED1_TORCH_BR 0x07
  34
  35 #define MASK_ENABLE             0x03
  36 #define MASK_TORCH_BR   0x70
  37 #define MASK_FLASH_BR   0x0F
  38 #define MASK_FLASH_TOUT 0x07
  39 #define MASK_FLAG               0xFF
  40 #define MASK_STROBE_SRC 0x80
  41
  42 /* Fault Mask */
  43 #define FAULT_TIMEOUT   (1<<0)
  44 #define FAULT_SHORT_CIRCUIT     (1<<1)
  45 #define FAULT_UVLO              (1<<2)
  46 #define FAULT_IVFM              (1<<3)
  47 #define FAULT_OCP               (1<<4)
  48 #define FAULT_OVERTEMP  (1<<5)
  49 #define FAULT_NTC_TRIP  (1<<6)
  50 #define FAULT_OVP               (1<<7)
  51
  52 enum led_mode {
  53         MODE_SHDN = 0x0,
  54         MODE_TORCH = 0x2,
  55         MODE_FLASH = 0x3,
  56 };
  57
  58 /*
  59  * struct lm3646_flash
  60  *
  61  * @pdata: platform data
  62  * @regmap: reg. map for i2c
  63  * @lock: muxtex for serial access.
  64  * @led_mode: V4L2 LED mode
  65  * @ctrls_led: V4L2 contols
  66  * @subdev_led: V4L2 subdev
  67  * @mode_reg : mode register value
  68  */
  69 struct lm3646_flash {
  70         struct device *dev;
  71         struct lm3646_platform_data *pdata;
  72         struct regmap *regmap;
  73
  74         struct v4l2_ctrl_handler ctrls_led;
  75         struct v4l2_subdev subdev_led;
  76
  77         u8 mode_reg;
  78 };
  79
  80 #define to_lm3646_flash(_ctrl)  \
  81         container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)
  82
  83 /* enable mode control */
  84 static int lm3646_mode_ctrl(struct lm3646_flash *flash,
  85                             enum v4l2_flash_led_mode led_mode)
  86 {
  87         switch (led_mode) {
  88         case V4L2_FLASH_LED_MODE_NONE:
  89                 return regmap_write(flash->regmap,
  90                                     REG_ENABLE, flash->mode_reg | MODE_SHDN);
  91         case V4L2_FLASH_LED_MODE_TORCH:
  92                 return regmap_write(flash->regmap,
  93                                     REG_ENABLE, flash->mode_reg | MODE_TORCH);
  94         case V4L2_FLASH_LED_MODE_FLASH:
  95                 return regmap_write(flash->regmap,
  96                                     REG_ENABLE, flash->mode_reg | MODE_FLASH);
  97         }
  98         return -EINVAL;
  99 }
 100
 101 /* V4L2 controls  */
 102 static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
 103 {
 104         struct lm3646_flash *flash = to_lm3646_flash(ctrl);
 105         unsigned int reg_val;
 106         int rval;
 107
 108         if (ctrl->id != V4L2_CID_FLASH_FAULT)
 109                 return -EINVAL;
 110
 111         rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
 112         if (rval < 0)
 113                 return rval;
 114
 115         ctrl->val = 0;
 116         if (reg_val & FAULT_TIMEOUT)
 117                 ctrl->val |= V4L2_FLASH_FAULT_TIMEOUT;
 118         if (reg_val & FAULT_SHORT_CIRCUIT)
 119                 ctrl->val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
 120         if (reg_val & FAULT_UVLO)
 121                 ctrl->val |= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
 122         if (reg_val & FAULT_IVFM)
 123                 ctrl->val |= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
 124         if (reg_val & FAULT_OCP)
 125                 ctrl->val |= V4L2_FLASH_FAULT_OVER_CURRENT;
 126         if (reg_val & FAULT_OVERTEMP)
 127                 ctrl->val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
 128         if (reg_val & FAULT_NTC_TRIP)
 129                 ctrl->val |= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
 130         if (reg_val & FAULT_OVP)
 131                 ctrl->val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;
 132
 133         return 0;
 134 }
 135
 136 static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
 137 {
 138         struct lm3646_flash *flash = to_lm3646_flash(ctrl);
 139         unsigned int reg_val;
 140         int rval = -EINVAL;
 141
 142         switch (ctrl->id) {
 143         case V4L2_CID_FLASH_LED_MODE:
 144
 145                 if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
 146                         return lm3646_mode_ctrl(flash, ctrl->val);
 147                 /* switch to SHDN mode before flash strobe on */
 148                 return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
 149
 150         case V4L2_CID_FLASH_STROBE_SOURCE:
 151                 return regmap_update_bits(flash->regmap,
 152                                           REG_STROBE_SRC, MASK_STROBE_SRC,
 153                                           (ctrl->val) << 7);
 154
 155         case V4L2_CID_FLASH_STROBE:
 156
 157                 /* read and check current mode of chip to start flash */
 158                 rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 159                 if (rval < 0 || ((reg_val & MASK_ENABLE) != MODE_SHDN))
 160                         return rval;
 161                 /* flash on */
 162                 return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);
 163
 164         case V4L2_CID_FLASH_STROBE_STOP:
 165
 166                 /*
 167                  * flash mode will be turned automatically
 168                  * from FLASH mode to SHDN mode after flash duration timeout
 169                  * read and check current mode of chip to stop flash
 170                  */
 171                 rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 172                 if (rval < 0)
 173                         return rval;
 174                 if ((reg_val & MASK_ENABLE) == MODE_FLASH)
 175                         return lm3646_mode_ctrl(flash,
 176                                                 V4L2_FLASH_LED_MODE_NONE);
 177                 return rval;
 178
 179         case V4L2_CID_FLASH_TIMEOUT:
 180                 return regmap_update_bits(flash->regmap,
 181                                           REG_FLASH_TOUT, MASK_FLASH_TOUT,
 182                                           LM3646_FLASH_TOUT_ms_TO_REG
 183                                           (ctrl->val));
 184
 185         case V4L2_CID_FLASH_INTENSITY:
 186                 return regmap_update_bits(flash->regmap,
 187                                           REG_FLASH_BR, MASK_FLASH_BR,
 188                                           LM3646_TOTAL_FLASH_BRT_uA_TO_REG
 189                                           (ctrl->val));
 190
 191         case V4L2_CID_FLASH_TORCH_INTENSITY:
 192                 return regmap_update_bits(flash->regmap,
 193                                           REG_TORCH_BR, MASK_TORCH_BR,
 194                                           LM3646_TOTAL_TORCH_BRT_uA_TO_REG
 195                                           (ctrl->val) << 4);
 196         }
 197
 198         return -EINVAL;
 199 }
 200
 201 static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
 202         .g_volatile_ctrl = lm3646_get_ctrl,
 203         .s_ctrl = lm3646_set_ctrl,
 204 };
 205
 206 static int lm3646_init_controls(struct lm3646_flash *flash)
 207 {
 208         struct v4l2_ctrl *fault;
 209         struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
 210         const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;
 211
 212         v4l2_ctrl_handler_init(hdl, 8);
 213         /* flash mode */
 214         v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
 215                                V4L2_FLASH_LED_MODE_TORCH, ~0x7,
 216                                V4L2_FLASH_LED_MODE_NONE);
 217
 218         /* flash source */
 219         v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
 220                                0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
 221
 222         /* flash strobe */
 223         v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
 224         /* flash strobe stop */
 225         v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
 226
 227         /* flash strobe timeout */
 228         v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
 229                           LM3646_FLASH_TOUT_MIN,
 230                           LM3646_FLASH_TOUT_MAX,
 231                           LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);
 232
 233         /* max flash current */
 234         v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
 235                           LM3646_TOTAL_FLASH_BRT_MIN,
 236                           LM3646_TOTAL_FLASH_BRT_MAX,
 237                           LM3646_TOTAL_FLASH_BRT_STEP,
 238                           LM3646_TOTAL_FLASH_BRT_MAX);
 239
 240         /* max torch current */
 241         v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
 242                           LM3646_TOTAL_TORCH_BRT_MIN,
 243                           LM3646_TOTAL_TORCH_BRT_MAX,
 244                           LM3646_TOTAL_TORCH_BRT_STEP,
 245                           LM3646_TOTAL_TORCH_BRT_MAX);
 246
 247         /* fault */
 248         fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
 249                                   V4L2_FLASH_FAULT_OVER_VOLTAGE
 250                                   | V4L2_FLASH_FAULT_OVER_TEMPERATURE
 251                                   | V4L2_FLASH_FAULT_SHORT_CIRCUIT
 252                                   | V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
 253         if (fault != NULL)
 254                 fault->flags |= V4L2_CTRL_FLAG_VOLATILE;
 255
 256         if (hdl->error)
 257                 return hdl->error;
 258
 259         flash->subdev_led.ctrl_handler = hdl;
 260         return 0;
 261 }
 262
 263 /* initialize device */
 264 static const struct v4l2_subdev_ops lm3646_ops = {
 265         .core = NULL,
 266 };
 267
 268 static const struct regmap_config lm3646_regmap = {
 269         .reg_bits = 8,
 270         .val_bits = 8,
 271         .max_register = 0xFF,
 272 };
 273
 274 static int lm3646_subdev_init(struct lm3646_flash *flash)
 275 {
 276         struct i2c_client *client = to_i2c_client(flash->dev);
 277         int rval;
 278
 279         v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
 280         flash->subdev_led.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 281         strcpy(flash->subdev_led.name, LM3646_NAME);
 282         rval = lm3646_init_controls(flash);
 283         if (rval)
 284                 goto err_out;
 285         rval = media_entity_init(&flash->subdev_led.entity, 0, NULL, 0);
 286         if (rval < 0)
 287                 goto err_out;
 288         flash->subdev_led.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
 289         return rval;
 290
 291 err_out:
 292         v4l2_ctrl_handler_free(&flash->ctrls_led);
 293         return rval;
 294 }
 295
 296 static int lm3646_init_device(struct lm3646_flash *flash)
 297 {
 298         unsigned int reg_val;
 299         int rval;
 300
 301         /* read the value of mode register to reduce redundant i2c accesses */
 302         rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 303         if (rval < 0)
 304                 return rval;
 305         flash->mode_reg = reg_val & 0xfc;
 306
 307         /* output disable */
 308         rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
 309         if (rval < 0)
 310                 return rval;
 311
 312         /*
 313          * LED1 flash current setting
 314          * LED2 flash current = Total(Max) flash current - LED1 flash current
 315          */
 316         rval = regmap_update_bits(flash->regmap,
 317                                   REG_LED1_FLASH_BR, 0x7F,
 318                                   LM3646_LED1_FLASH_BRT_uA_TO_REG
 319                                   (flash->pdata->led1_flash_brt));
 320
 321         if (rval < 0)
 322                 return rval;
 323
 324         /*
 325          * LED1 torch current setting
 326          * LED2 torch current = Total(Max) torch current - LED1 torch current
 327          */
 328         rval = regmap_update_bits(flash->regmap,
 329                                   REG_LED1_TORCH_BR, 0x7F,
 330                                   LM3646_LED1_TORCH_BRT_uA_TO_REG
 331                                   (flash->pdata->led1_torch_brt));
 332         if (rval < 0)
 333                 return rval;
 334
 335         /* Reset flag register */
 336         return regmap_read(flash->regmap, REG_FLAG, &reg_val);
 337 }
 338
 339 static int lm3646_probe(struct i2c_client *client,
 340                         const struct i2c_device_id *devid)
 341 {
 342         struct lm3646_flash *flash;
 343         struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
 344         int rval;
 345
 346         flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
 347         if (flash == NULL)
 348                 return -ENOMEM;
 349
 350         flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
 351         if (IS_ERR(flash->regmap))
 352                 return PTR_ERR(flash->regmap);
 353
 354         /* check device tree if there is no platform data */
 355         if (pdata == NULL) {
 356                 pdata = devm_kzalloc(&client->dev,
 357                                      sizeof(struct lm3646_platform_data),
 358                                      GFP_KERNEL);
 359                 if (pdata == NULL)
 360                         return -ENOMEM;
 361                 /* use default data in case of no platform data */
 362                 pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
 363                 pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
 364                 pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
 365         }
 366         flash->pdata = pdata;
 367         flash->dev = &client->dev;
 368
 369         rval = lm3646_subdev_init(flash);
 370         if (rval < 0)
 371                 return rval;
 372
 373         rval = lm3646_init_device(flash);
 374         if (rval < 0)
 375                 return rval;
 376
 377         i2c_set_clientdata(client, flash);
 378
 379         return 0;
 380 }
 381
 382 static int lm3646_remove(struct i2c_client *client)
 383 {
 384         struct lm3646_flash *flash = i2c_get_clientdata(client);
 385
 386         v4l2_device_unregister_subdev(&flash->subdev_led);
 387         v4l2_ctrl_handler_free(&flash->ctrls_led);
 388         media_entity_cleanup(&flash->subdev_led.entity);
 389
 390         return 0;
 391 }
 392
 393 static const struct i2c_device_id lm3646_id_table[] = {
 394         {LM3646_NAME, 0},
 395         {}
 396 };
 397
 398 MODULE_DEVICE_TABLE(i2c, lm3646_id_table);
 399
 400 static struct i2c_driver lm3646_i2c_driver = {
 401         .driver = {
 402                    .name = LM3646_NAME,
 403                    },
 404         .probe = lm3646_probe,
 405         .remove = lm3646_remove,
 406         .id_table = lm3646_id_table,
 407 };
 408
 409 module_i2c_driver(lm3646_i2c_driver);
 410
 411 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
 412 MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
 413 MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
 414 MODULE_LICENSE("GPL");