drivers/media/i2c/ad5820.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/media/i2c/ad5820.c
   4  *
   5  * AD5820 DAC driver for camera voice coil focus.
   6  *
   7  * Copyright (C) 2008 Nokia Corporation
   8  * Copyright (C) 2007 Texas Instruments
   9  * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz>
  10  *
  11  * Contact: Tuukka Toivonen <tuukkat76@gmail.com>
  12  *          Sakari Ailus <sakari.ailus@iki.fi>
  13  *
  14  * Based on af_d88.c by Texas Instruments.
  15  */
  16
  17 #include <linux/errno.h>
  18 #include <linux/i2c.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/regulator/consumer.h>
  22 #include <linux/gpio/consumer.h>
  23
  24 #include <media/v4l2-ctrls.h>
  25 #include <media/v4l2-device.h>
  26 #include <media/v4l2-subdev.h>
  27
  28 /* Register definitions */
  29 #define AD5820_POWER_DOWN               (1 << 15)
  30 #define AD5820_DAC_SHIFT                4
  31 #define AD5820_RAMP_MODE_LINEAR         (0 << 3)
  32 #define AD5820_RAMP_MODE_64_16          (1 << 3)
  33
  34 #define CODE_TO_RAMP_US(s)      ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
  35 #define RAMP_US_TO_CODE(c)      fls(((c) + ((c)>>1)) / 50)
  36
  37 #define to_ad5820_device(sd)    container_of(sd, struct ad5820_device, subdev)
  38
  39 struct ad5820_device {
  40         struct v4l2_subdev subdev;
  41         struct ad5820_platform_data *platform_data;
  42         struct regulator *vana;
  43
  44         struct v4l2_ctrl_handler ctrls;
  45         u32 focus_absolute;
  46         u32 focus_ramp_time;
  47         u32 focus_ramp_mode;
  48
  49         struct gpio_desc *enable_gpio;
  50
  51         struct mutex power_lock;
  52         int power_count;
  53
  54         bool standby;
  55 };
  56
  57 static int ad5820_write(struct ad5820_device *coil, u16 data)
  58 {
  59         struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
  60         struct i2c_msg msg;
  61         __be16 be_data;
  62         int r;
  63
  64         if (!client->adapter)
  65                 return -ENODEV;
  66
  67         be_data = cpu_to_be16(data);
  68         msg.addr  = client->addr;
  69         msg.flags = 0;
  70         msg.len   = 2;
  71         msg.buf   = (u8 *)&be_data;
  72
  73         r = i2c_transfer(client->adapter, &msg, 1);
  74         if (r < 0) {
  75                 dev_err(&client->dev, "write failed, error %d\n", r);
  76                 return r;
  77         }
  78
  79         return 0;
  80 }
  81
  82 /*
  83  * Calculate status word and write it to the device based on current
  84  * values of V4L2 controls. It is assumed that the stored V4L2 control
  85  * values are properly limited and rounded.
  86  */
  87 static int ad5820_update_hw(struct ad5820_device *coil)
  88 {
  89         u16 status;
  90
  91         status = RAMP_US_TO_CODE(coil->focus_ramp_time);
  92         status |= coil->focus_ramp_mode
  93                 ? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
  94         status |= coil->focus_absolute << AD5820_DAC_SHIFT;
  95
  96         if (coil->standby)
  97                 status |= AD5820_POWER_DOWN;
  98
  99         return ad5820_write(coil, status);
 100 }
 101
 102 /*
 103  * Power handling
 104  */
 105 static int ad5820_power_off(struct ad5820_device *coil, bool standby)
 106 {
 107         int ret = 0, ret2;
 108
 109         /*
 110          * Go to standby first as real power off my be denied by the hardware
 111          * (single power line control for both coil and sensor).
 112          */
 113         if (standby) {
 114                 coil->standby = true;
 115                 ret = ad5820_update_hw(coil);
 116         }
 117
 118         gpiod_set_value_cansleep(coil->enable_gpio, 0);
 119
 120         ret2 = regulator_disable(coil->vana);
 121         if (ret)
 122                 return ret;
 123         return ret2;
 124 }
 125
 126 static int ad5820_power_on(struct ad5820_device *coil, bool restore)
 127 {
 128         int ret;
 129
 130         ret = regulator_enable(coil->vana);
 131         if (ret < 0)
 132                 return ret;
 133
 134         gpiod_set_value_cansleep(coil->enable_gpio, 1);
 135
 136         if (restore) {
 137                 /* Restore the hardware settings. */
 138                 coil->standby = false;
 139                 ret = ad5820_update_hw(coil);
 140                 if (ret)
 141                         goto fail;
 142         }
 143         return 0;
 144
 145 fail:
 146         gpiod_set_value_cansleep(coil->enable_gpio, 0);
 147         coil->standby = true;
 148         regulator_disable(coil->vana);
 149
 150         return ret;
 151 }
 152
 153 /*
 154  * V4L2 controls
 155  */
 156 static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
 157 {
 158         struct ad5820_device *coil =
 159                 container_of(ctrl->handler, struct ad5820_device, ctrls);
 160
 161         switch (ctrl->id) {
 162         case V4L2_CID_FOCUS_ABSOLUTE:
 163                 coil->focus_absolute = ctrl->val;
 164                 return ad5820_update_hw(coil);
 165         }
 166
 167         return 0;
 168 }
 169
 170 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
 171         .s_ctrl = ad5820_set_ctrl,
 172 };
 173
 174
 175 static int ad5820_init_controls(struct ad5820_device *coil)
 176 {
 177         v4l2_ctrl_handler_init(&coil->ctrls, 1);
 178
 179         /*
 180          * V4L2_CID_FOCUS_ABSOLUTE
 181          *
 182          * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
 183          * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA]
 184          * for focus position, because it is meaningless for user. Meaningful
 185          * would be to use focus distance or even its inverse, but since the
 186          * driver doesn't have sufficiently knowledge to do the conversion, we
 187          * will just use abstract codes here. In any case, smaller value = focus
 188          * position farther from camera. The default zero value means focus at
 189          * infinity, and also least current consumption.
 190          */
 191         v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
 192                           V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
 193
 194         if (coil->ctrls.error)
 195                 return coil->ctrls.error;
 196
 197         coil->focus_absolute = 0;
 198         coil->focus_ramp_time = 0;
 199         coil->focus_ramp_mode = 0;
 200
 201         coil->subdev.ctrl_handler = &coil->ctrls;
 202
 203         return 0;
 204 }
 205
 206 /*
 207  * V4L2 subdev operations
 208  */
 209 static int ad5820_registered(struct v4l2_subdev *subdev)
 210 {
 211         struct ad5820_device *coil = to_ad5820_device(subdev);
 212
 213         return ad5820_init_controls(coil);
 214 }
 215
 216 static int
 217 ad5820_set_power(struct v4l2_subdev *subdev, int on)
 218 {
 219         struct ad5820_device *coil = to_ad5820_device(subdev);
 220         int ret = 0;
 221
 222         mutex_lock(&coil->power_lock);
 223
 224         /*
 225          * If the power count is modified from 0 to != 0 or from != 0 to 0,
 226          * update the power state.
 227          */
 228         if (coil->power_count == !on) {
 229                 ret = on ? ad5820_power_on(coil, true) :
 230                         ad5820_power_off(coil, true);
 231                 if (ret < 0)
 232                         goto done;
 233         }
 234
 235         /* Update the power count. */
 236         coil->power_count += on ? 1 : -1;
 237         WARN_ON(coil->power_count < 0);
 238
 239 done:
 240         mutex_unlock(&coil->power_lock);
 241         return ret;
 242 }
 243
 244 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 245 {
 246         return ad5820_set_power(sd, 1);
 247 }
 248
 249 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 250 {
 251         return ad5820_set_power(sd, 0);
 252 }
 253
 254 static const struct v4l2_subdev_core_ops ad5820_core_ops = {
 255         .s_power = ad5820_set_power,
 256 };
 257
 258 static const struct v4l2_subdev_ops ad5820_ops = {
 259         .core = &ad5820_core_ops,
 260 };
 261
 262 static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
 263         .registered = ad5820_registered,
 264         .open = ad5820_open,
 265         .close = ad5820_close,
 266 };
 267
 268 /*
 269  * I2C driver
 270  */
 271 static int __maybe_unused ad5820_suspend(struct device *dev)
 272 {
 273         struct v4l2_subdev *subdev = dev_get_drvdata(dev);
 274         struct ad5820_device *coil = to_ad5820_device(subdev);
 275
 276         if (!coil->power_count)
 277                 return 0;
 278
 279         return ad5820_power_off(coil, false);
 280 }
 281
 282 static int __maybe_unused ad5820_resume(struct device *dev)
 283 {
 284         struct v4l2_subdev *subdev = dev_get_drvdata(dev);
 285         struct ad5820_device *coil = to_ad5820_device(subdev);
 286
 287         if (!coil->power_count)
 288                 return 0;
 289
 290         return ad5820_power_on(coil, true);
 291 }
 292
 293 static int ad5820_probe(struct i2c_client *client,
 294                         const struct i2c_device_id *devid)
 295 {
 296         struct ad5820_device *coil;
 297         int ret;
 298
 299         coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL);
 300         if (!coil)
 301                 return -ENOMEM;
 302
 303         coil->vana = devm_regulator_get(&client->dev, "VANA");
 304         if (IS_ERR(coil->vana)) {
 305                 ret = PTR_ERR(coil->vana);
 306                 if (ret != -EPROBE_DEFER)
 307                         dev_err(&client->dev, "could not get regulator for vana\n");
 308                 return ret;
 309         }
 310
 311         coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
 312                                                     GPIOD_OUT_LOW);
 313         if (IS_ERR(coil->enable_gpio)) {
 314                 ret = PTR_ERR(coil->enable_gpio);
 315                 if (ret != -EPROBE_DEFER)
 316                         dev_err(&client->dev, "could not get enable gpio\n");
 317                 return ret;
 318         }
 319
 320         mutex_init(&coil->power_lock);
 321
 322         v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
 323         coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 324         coil->subdev.internal_ops = &ad5820_internal_ops;
 325         coil->subdev.entity.function = MEDIA_ENT_F_LENS;
 326         strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name));
 327
 328         ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
 329         if (ret < 0)
 330                 goto cleanup2;
 331
 332         ret = v4l2_async_register_subdev(&coil->subdev);
 333         if (ret < 0)
 334                 goto cleanup;
 335
 336         return ret;
 337
 338 cleanup2:
 339         mutex_destroy(&coil->power_lock);
 340 cleanup:
 341         media_entity_cleanup(&coil->subdev.entity);
 342         return ret;
 343 }
 344
 345 static int ad5820_remove(struct i2c_client *client)
 346 {
 347         struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 348         struct ad5820_device *coil = to_ad5820_device(subdev);
 349
 350         v4l2_async_unregister_subdev(&coil->subdev);
 351         v4l2_ctrl_handler_free(&coil->ctrls);
 352         media_entity_cleanup(&coil->subdev.entity);
 353         mutex_destroy(&coil->power_lock);
 354         return 0;
 355 }
 356
 357 static const struct i2c_device_id ad5820_id_table[] = {
 358         { "ad5820", 0 },
 359         { "ad5821", 0 },
 360         { "ad5823", 0 },
 361         { }
 362 };
 363 MODULE_DEVICE_TABLE(i2c, ad5820_id_table);
 364
 365 static const struct of_device_id ad5820_of_table[] = {
 366         { .compatible = "adi,ad5820" },
 367         { .compatible = "adi,ad5821" },
 368         { .compatible = "adi,ad5823" },
 369         { }
 370 };
 371 MODULE_DEVICE_TABLE(of, ad5820_of_table);
 372
 373 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);
 374
 375 static struct i2c_driver ad5820_i2c_driver = {
 376         .driver         = {
 377                 .name   = "ad5820",
 378                 .pm     = &ad5820_pm,
 379                 .of_match_table = ad5820_of_table,
 380         },
 381         .probe          = ad5820_probe,
 382         .remove         = ad5820_remove,
 383         .id_table       = ad5820_id_table,
 384 };
 385
 386 module_i2c_driver(ad5820_i2c_driver);
 387
 388 MODULE_AUTHOR("Tuukka Toivonen");
 389 MODULE_DESCRIPTION("AD5820 camera lens driver");
 390 MODULE_LICENSE("GPL");