target/linux/bcm27xx/patches-5.15/950-0773-media-i2c-Add-driver-for-AD5398-VCM-lens-driver.patch

   1 From 838b1d352c8b7a8380fc2f00c42948e8307f51de Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Wed, 29 Sep 2021 14:04:28 +0100
   4 Subject: [PATCH] media: i2c: Add driver for AD5398 VCM lens driver
   5
   6 Adds a driver for the Analog Devices AD5398 10 bit
   7 I2C DAC which is commonly used for driving VCM lens
   8 mechanisms.
   9
  10 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  11 ---
  12  drivers/media/i2c/Kconfig  |   7 +
  13  drivers/media/i2c/Makefile |   1 +
  14  drivers/media/i2c/ad5398.c | 342 +++++++++++++++++++++++++++++++++++++
  15  3 files changed, 350 insertions(+)
  16  create mode 100644 drivers/media/i2c/ad5398.c
  17
  18 --- a/drivers/media/i2c/Kconfig
  19 +++ b/drivers/media/i2c/Kconfig
  20 @@ -1451,6 +1451,13 @@ endmenu
  21  menu "Lens drivers"
  22         visible if MEDIA_CAMERA_SUPPORT
  23
  24 +config VIDEO_AD5398
  25 +       tristate "AD5398 lens voice coil support"
  26 +       depends on GPIOLIB && I2C && VIDEO_V4L2
  27 +       select MEDIA_CONTROLLER
  28 +       help
  29 +         This is a driver for the AD5398 camera lens voice coil.
  30 +
  31  config VIDEO_AD5820
  32         tristate "AD5820 lens voice coil support"
  33         depends on GPIOLIB && I2C && VIDEO_V4L2
  34 --- a/drivers/media/i2c/Makefile
  35 +++ b/drivers/media/i2c/Makefile
  36 @@ -21,6 +21,7 @@ obj-$(CONFIG_VIDEO_SAA717X) += saa717x.o
  37  obj-$(CONFIG_VIDEO_SAA7127) += saa7127.o
  38  obj-$(CONFIG_VIDEO_SAA7185) += saa7185.o
  39  obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o
  40 +obj-$(CONFIG_VIDEO_AD5398)  += ad5398.o
  41  obj-$(CONFIG_VIDEO_AD5820)  += ad5820.o
  42  obj-$(CONFIG_VIDEO_AK7375)  += ak7375.o
  43  obj-$(CONFIG_VIDEO_DW9714)  += dw9714.o
  44 --- /dev/null
  45 +++ b/drivers/media/i2c/ad5398.c
  46 @@ -0,0 +1,342 @@
  47 +// SPDX-License-Identifier: GPL-2.0-only
  48 +/*
  49 + * AD5398 DAC driver for camera voice coil focus.
  50 + * Copyright (C) 2021 Raspberry Pi (Trading) Ltd.
  51 + *
  52 + * Based on AD5820 DAC driver by Nokia and TI.
  53 + *
  54 + * This driver uses the regulator framework notification hooks on the
  55 + * assumption that the VCM and sensor share a regulator. This means the VCM
  56 + * position will be restored when either the sensor or VCM subdevices are opened
  57 + * or powered up. The client can therefore choose to ignore the VCM subdevice,
  58 + * and the lens position will be as previously requested. Without that, there
  59 + * is a hard requirement to have the VCM subdevice open in order for the VCM
  60 + * to be powered and at the requested position.
  61 + */
  62 +
  63 +#include <linux/errno.h>
  64 +#include <linux/i2c.h>
  65 +#include <linux/kernel.h>
  66 +#include <linux/module.h>
  67 +#include <linux/regulator/consumer.h>
  68 +#include <linux/gpio/consumer.h>
  69 +
  70 +#include <media/v4l2-ctrls.h>
  71 +#include <media/v4l2-device.h>
  72 +#include <media/v4l2-subdev.h>
  73 +
  74 +/* Register definitions */
  75 +#define AD5398_POWER_DOWN              BIT(15)
  76 +#define AD5398_DAC_SHIFT               4
  77 +
  78 +#define to_ad5398_device(sd)   container_of(sd, struct ad5398_device, subdev)
  79 +
  80 +struct ad5398_device {
  81 +       struct v4l2_subdev subdev;
  82 +       struct ad5398_platform_data *platform_data;
  83 +       struct regulator *vana;
  84 +       struct notifier_block nb;
  85 +
  86 +       struct v4l2_ctrl_handler ctrls;
  87 +       u32 focus_absolute;
  88 +
  89 +       bool standby;
  90 +};
  91 +
  92 +static int ad5398_write(struct ad5398_device *coil, u16 data)
  93 +{
  94 +       struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
  95 +       struct i2c_msg msg;
  96 +       __be16 be_data;
  97 +       int r;
  98 +
  99 +       if (!client->adapter)
 100 +               return -ENODEV;
 101 +
 102 +       be_data = cpu_to_be16(data);
 103 +       msg.addr  = client->addr;
 104 +       msg.flags = 0;
 105 +       msg.len   = 2;
 106 +       msg.buf   = (u8 *)&be_data;
 107 +
 108 +       r = i2c_transfer(client->adapter, &msg, 1);
 109 +       if (r < 0) {
 110 +               dev_err(&client->dev, "write failed, error %d\n", r);
 111 +               return r;
 112 +       }
 113 +
 114 +       return 0;
 115 +}
 116 +
 117 +/*
 118 + * Calculate status word and write it to the device based on current
 119 + * values of V4L2 controls. It is assumed that the stored V4L2 control
 120 + * values are properly limited and rounded.
 121 + */
 122 +static int ad5398_update_hw(struct ad5398_device *coil)
 123 +{
 124 +       u16 status;
 125 +
 126 +       status = coil->focus_absolute << AD5398_DAC_SHIFT;
 127 +
 128 +       if (coil->standby)
 129 +               status |= AD5398_POWER_DOWN;
 130 +
 131 +       return ad5398_write(coil, status);
 132 +}
 133 +
 134 +/*
 135 + * Power handling
 136 + */
 137 +static int ad5398_power_off(struct ad5398_device *coil)
 138 +{
 139 +       int ret = 0;
 140 +
 141 +       coil->standby = true;
 142 +       ret = ad5398_update_hw(coil);
 143 +
 144 +       return ret;
 145 +}
 146 +
 147 +static int ad5398_power_on(struct ad5398_device *coil)
 148 +{
 149 +       int ret;
 150 +
 151 +       /* Restore the hardware settings. */
 152 +       coil->standby = false;
 153 +       ret = ad5398_update_hw(coil);
 154 +       if (ret)
 155 +               goto fail;
 156 +
 157 +       return 0;
 158 +
 159 +fail:
 160 +       coil->standby = true;
 161 +
 162 +       return ret;
 163 +}
 164 +
 165 +/*
 166 + * V4L2 controls
 167 + */
 168 +static int ad5398_set_ctrl(struct v4l2_ctrl *ctrl)
 169 +{
 170 +       struct ad5398_device *coil =
 171 +               container_of(ctrl->handler, struct ad5398_device, ctrls);
 172 +
 173 +       switch (ctrl->id) {
 174 +       case V4L2_CID_FOCUS_ABSOLUTE:
 175 +               coil->focus_absolute = ctrl->val;
 176 +               return ad5398_update_hw(coil);
 177 +       }
 178 +
 179 +       return 0;
 180 +}
 181 +
 182 +static const struct v4l2_ctrl_ops ad5398_ctrl_ops = {
 183 +       .s_ctrl = ad5398_set_ctrl,
 184 +};
 185 +
 186 +static int ad5398_init_controls(struct ad5398_device *coil)
 187 +{
 188 +       v4l2_ctrl_handler_init(&coil->ctrls, 1);
 189 +
 190 +       /*
 191 +        * V4L2_CID_FOCUS_ABSOLUTE
 192 +        *
 193 +        * Minimum current is 0 mA, maximum is 120 mA. Thus, 1 code is
 194 +        * equivalent to 120/1023 = 0.1173 mA. Nevertheless, we do not use [mA]
 195 +        * for focus position, because it is meaningless for user. Meaningful
 196 +        * would be to use focus distance or even its inverse, but since the
 197 +        * driver doesn't have sufficient knowledge to do the conversion, we
 198 +        * will just use abstract codes here. In any case, smaller value = focus
 199 +        * position farther from camera. The default zero value means focus at
 200 +        * infinity, and also least current consumption.
 201 +        */
 202 +       v4l2_ctrl_new_std(&coil->ctrls, &ad5398_ctrl_ops,
 203 +                         V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
 204 +
 205 +       if (coil->ctrls.error)
 206 +               return coil->ctrls.error;
 207 +
 208 +       coil->focus_absolute = 0;
 209 +
 210 +       coil->subdev.ctrl_handler = &coil->ctrls;
 211 +
 212 +       return 0;
 213 +}
 214 +
 215 +/*
 216 + * V4L2 subdev operations
 217 + */
 218 +static int ad5398_registered(struct v4l2_subdev *subdev)
 219 +{
 220 +       struct ad5398_device *coil = to_ad5398_device(subdev);
 221 +
 222 +       return ad5398_init_controls(coil);
 223 +}
 224 +
 225 +static int
 226 +ad5398_set_power(struct v4l2_subdev *subdev, int on)
 227 +{
 228 +       struct ad5398_device *coil = to_ad5398_device(subdev);
 229 +       int ret;
 230 +
 231 +       if (on)
 232 +               ret = regulator_enable(coil->vana);
 233 +       else
 234 +               ret = regulator_disable(coil->vana);
 235 +
 236 +       return ret;
 237 +}
 238 +
 239 +static int ad5398_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 240 +{
 241 +       struct ad5398_device *coil = to_ad5398_device(sd);
 242 +
 243 +       return regulator_enable(coil->vana);
 244 +}
 245 +
 246 +static int ad5398_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 247 +{
 248 +       struct ad5398_device *coil = to_ad5398_device(sd);
 249 +
 250 +       return regulator_disable(coil->vana);
 251 +}
 252 +
 253 +static const struct v4l2_subdev_core_ops ad5398_core_ops = {
 254 +       .s_power = ad5398_set_power,
 255 +};
 256 +
 257 +static const struct v4l2_subdev_ops ad5398_ops = {
 258 +       .core = &ad5398_core_ops,
 259 +};
 260 +
 261 +static const struct v4l2_subdev_internal_ops ad5398_internal_ops = {
 262 +       .registered = ad5398_registered,
 263 +       .open = ad5398_open,
 264 +       .close = ad5398_close,
 265 +};
 266 +
 267 +/*
 268 + * I2C driver
 269 + */
 270 +static int __maybe_unused ad5398_suspend(struct device *dev)
 271 +{
 272 +       struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 273 +       struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 274 +       struct ad5398_device *coil = to_ad5398_device(subdev);
 275 +
 276 +       return regulator_enable(coil->vana);
 277 +}
 278 +
 279 +static int __maybe_unused ad5398_resume(struct device *dev)
 280 +{
 281 +       struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 282 +       struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 283 +       struct ad5398_device *coil = to_ad5398_device(subdev);
 284 +
 285 +       return regulator_disable(coil->vana);
 286 +}
 287 +
 288 +static int ad5398_regulator_notifier(struct notifier_block *nb,
 289 +                                    unsigned long event,
 290 +                                    void *ignored)
 291 +{
 292 +       struct ad5398_device *coil = container_of(nb, struct ad5398_device, nb);
 293 +
 294 +       if (event == REGULATOR_EVENT_ENABLE)
 295 +               ad5398_power_on(coil);
 296 +       else if (event == REGULATOR_EVENT_PRE_DISABLE)
 297 +               ad5398_power_off(coil);
 298 +
 299 +       return NOTIFY_OK;
 300 +}
 301 +
 302 +static int ad5398_probe(struct i2c_client *client,
 303 +                       const struct i2c_device_id *devid)
 304 +{
 305 +       struct ad5398_device *coil;
 306 +       int ret;
 307 +
 308 +       coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL);
 309 +       if (!coil)
 310 +               return -ENOMEM;
 311 +
 312 +       coil->vana = devm_regulator_get(&client->dev, "VANA");
 313 +       if (IS_ERR(coil->vana)) {
 314 +               ret = PTR_ERR(coil->vana);
 315 +               if (ret != -EPROBE_DEFER)
 316 +                       dev_err(&client->dev, "could not get regulator for vana\n");
 317 +               return ret;
 318 +       }
 319 +
 320 +       v4l2_i2c_subdev_init(&coil->subdev, client, &ad5398_ops);
 321 +       coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 322 +       coil->subdev.internal_ops = &ad5398_internal_ops;
 323 +       coil->subdev.entity.function = MEDIA_ENT_F_LENS;
 324 +       strscpy(coil->subdev.name, "ad5398 focus", sizeof(coil->subdev.name));
 325 +
 326 +       coil->nb.notifier_call = &ad5398_regulator_notifier;
 327 +       ret = regulator_register_notifier(coil->vana, &coil->nb);
 328 +       if (ret < 0)
 329 +               return ret;
 330 +
 331 +       ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
 332 +       if (ret < 0)
 333 +               goto cleanup2;
 334 +
 335 +       ret = v4l2_async_register_subdev(&coil->subdev);
 336 +       if (ret < 0)
 337 +               goto cleanup;
 338 +
 339 +       return ret;
 340 +
 341 +cleanup:
 342 +       media_entity_cleanup(&coil->subdev.entity);
 343 +cleanup2:
 344 +       regulator_unregister_notifier(coil->vana, &coil->nb);
 345 +       return ret;
 346 +}
 347 +
 348 +static int ad5398_remove(struct i2c_client *client)
 349 +{
 350 +       struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 351 +       struct ad5398_device *coil = to_ad5398_device(subdev);
 352 +
 353 +       v4l2_async_unregister_subdev(&coil->subdev);
 354 +       v4l2_ctrl_handler_free(&coil->ctrls);
 355 +       media_entity_cleanup(&coil->subdev.entity);
 356 +       return 0;
 357 +}
 358 +
 359 +static const struct i2c_device_id ad5398_id_table[] = {
 360 +       { "ad5398", 0 },
 361 +       { }
 362 +};
 363 +MODULE_DEVICE_TABLE(i2c, ad5398_id_table);
 364 +
 365 +static const struct of_device_id ad5398_of_table[] = {
 366 +       { .compatible = "adi,ad5398" },
 367 +       { }
 368 +};
 369 +MODULE_DEVICE_TABLE(of, ad5398_of_table);
 370 +
 371 +static SIMPLE_DEV_PM_OPS(ad5398_pm, ad5398_suspend, ad5398_resume);
 372 +
 373 +static struct i2c_driver ad5398_i2c_driver = {
 374 +       .driver         = {
 375 +               .name   = "ad5398",
 376 +               .pm     = &ad5398_pm,
 377 +               .of_match_table = ad5398_of_table,
 378 +       },
 379 +       .probe          = ad5398_probe,
 380 +       .remove         = ad5398_remove,
 381 +       .id_table       = ad5398_id_table,
 382 +};
 383 +
 384 +module_i2c_driver(ad5398_i2c_driver);
 385 +
 386 +MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.com>");
 387 +MODULE_DESCRIPTION("AD5398 camera lens driver");
 388 +MODULE_LICENSE("GPL");