drivers/media/i2c/ak7375.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Intel Corporation
   3
   4 #include <linux/acpi.h>
   5 #include <linux/delay.h>
   6 #include <linux/i2c.h>
   7 #include <linux/module.h>
   8 #include <linux/pm_runtime.h>
   9 #include <linux/regulator/consumer.h>
  10 #include <media/v4l2-ctrls.h>
  11 #include <media/v4l2-device.h>
  12
  13 #define AK7375_MAX_FOCUS_POS    4095
  14 /*
  15  * This sets the minimum granularity for the focus positions.
  16  * A value of 1 gives maximum accuracy for a desired focus position
  17  */
  18 #define AK7375_FOCUS_STEPS      1
  19 /*
  20  * This acts as the minimum granularity of lens movement.
  21  * Keep this value power of 2, so the control steps can be
  22  * uniformly adjusted for gradual lens movement, with desired
  23  * number of control steps.
  24  */
  25 #define AK7375_CTRL_STEPS       64
  26 #define AK7375_CTRL_DELAY_US    1000
  27 /*
  28  * The vcm may take up 10 ms (tDELAY) to power on and start taking
  29  * I2C messages. Based on AK7371 datasheet.
  30  */
  31 #define AK7375_POWER_DELAY_US   10000
  32
  33 #define AK7375_REG_POSITION     0x0
  34 #define AK7375_REG_CONT         0x2
  35 #define AK7375_MODE_ACTIVE      0x0
  36 #define AK7375_MODE_STANDBY     0x40
  37
  38 static const char * const ak7375_supply_names[] = {
  39         "vdd",
  40         "vio",
  41 };
  42
  43 /* ak7375 device structure */
  44 struct ak7375_device {
  45         struct v4l2_ctrl_handler ctrls_vcm;
  46         struct v4l2_subdev sd;
  47         struct v4l2_ctrl *focus;
  48         struct regulator_bulk_data supplies[ARRAY_SIZE(ak7375_supply_names)];
  49
  50         /* active or standby mode */
  51         bool active;
  52 };
  53
  54 static inline struct ak7375_device *to_ak7375_vcm(struct v4l2_ctrl *ctrl)
  55 {
  56         return container_of(ctrl->handler, struct ak7375_device, ctrls_vcm);
  57 }
  58
  59 static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
  60 {
  61         return container_of(subdev, struct ak7375_device, sd);
  62 }
  63
  64 static int ak7375_i2c_write(struct ak7375_device *ak7375,
  65         u8 addr, u16 data, u8 size)
  66 {
  67         struct i2c_client *client = v4l2_get_subdevdata(&ak7375->sd);
  68         u8 buf[3];
  69         int ret;
  70
  71         if (size != 1 && size != 2)
  72                 return -EINVAL;
  73         buf[0] = addr;
  74         buf[size] = data & 0xff;
  75         if (size == 2)
  76                 buf[1] = (data >> 8) & 0xff;
  77         ret = i2c_master_send(client, (const char *)buf, size + 1);
  78         if (ret < 0)
  79                 return ret;
  80         if (ret != size + 1)
  81                 return -EIO;
  82
  83         return 0;
  84 }
  85
  86 static int ak7375_set_ctrl(struct v4l2_ctrl *ctrl)
  87 {
  88         struct ak7375_device *dev_vcm = to_ak7375_vcm(ctrl);
  89
  90         if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
  91                 return ak7375_i2c_write(dev_vcm, AK7375_REG_POSITION,
  92                                         ctrl->val << 4, 2);
  93
  94         return -EINVAL;
  95 }
  96
  97 static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
  98         .s_ctrl = ak7375_set_ctrl,
  99 };
 100
 101 static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 102 {
 103         return pm_runtime_resume_and_get(sd->dev);
 104 }
 105
 106 static int ak7375_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 107 {
 108         pm_runtime_put(sd->dev);
 109
 110         return 0;
 111 }
 112
 113 static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
 114         .open = ak7375_open,
 115         .close = ak7375_close,
 116 };
 117
 118 static const struct v4l2_subdev_ops ak7375_ops = { };
 119
 120 static void ak7375_subdev_cleanup(struct ak7375_device *ak7375_dev)
 121 {
 122         v4l2_async_unregister_subdev(&ak7375_dev->sd);
 123         v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
 124         media_entity_cleanup(&ak7375_dev->sd.entity);
 125 }
 126
 127 static int ak7375_init_controls(struct ak7375_device *dev_vcm)
 128 {
 129         struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
 130         const struct v4l2_ctrl_ops *ops = &ak7375_vcm_ctrl_ops;
 131
 132         v4l2_ctrl_handler_init(hdl, 1);
 133
 134         dev_vcm->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
 135                 0, AK7375_MAX_FOCUS_POS, AK7375_FOCUS_STEPS, 0);
 136
 137         if (hdl->error)
 138                 dev_err(dev_vcm->sd.dev, "%s fail error: 0x%x\n",
 139                         __func__, hdl->error);
 140         dev_vcm->sd.ctrl_handler = hdl;
 141
 142         return hdl->error;
 143 }
 144
 145 static int ak7375_probe(struct i2c_client *client)
 146 {
 147         struct ak7375_device *ak7375_dev;
 148         int ret;
 149         unsigned int i;
 150
 151         ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
 152                                   GFP_KERNEL);
 153         if (!ak7375_dev)
 154                 return -ENOMEM;
 155
 156         for (i = 0; i < ARRAY_SIZE(ak7375_supply_names); i++)
 157                 ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
 158
 159         ret = devm_regulator_bulk_get(&client->dev,
 160                                       ARRAY_SIZE(ak7375_supply_names),
 161                                       ak7375_dev->supplies);
 162         if (ret) {
 163                 dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
 164                 return ret;
 165         }
 166
 167         v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
 168         ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 169         ak7375_dev->sd.internal_ops = &ak7375_int_ops;
 170         ak7375_dev->sd.entity.function = MEDIA_ENT_F_LENS;
 171
 172         ret = ak7375_init_controls(ak7375_dev);
 173         if (ret)
 174                 goto err_cleanup;
 175
 176         ret = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL);
 177         if (ret < 0)
 178                 goto err_cleanup;
 179
 180         ret = v4l2_async_register_subdev(&ak7375_dev->sd);
 181         if (ret < 0)
 182                 goto err_cleanup;
 183
 184         pm_runtime_set_active(&client->dev);
 185         pm_runtime_enable(&client->dev);
 186         pm_runtime_idle(&client->dev);
 187
 188         return 0;
 189
 190 err_cleanup:
 191         v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
 192         media_entity_cleanup(&ak7375_dev->sd.entity);
 193
 194         return ret;
 195 }
 196
 197 static void ak7375_remove(struct i2c_client *client)
 198 {
 199         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 200         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 201
 202         ak7375_subdev_cleanup(ak7375_dev);
 203         pm_runtime_disable(&client->dev);
 204         pm_runtime_set_suspended(&client->dev);
 205 }
 206
 207 /*
 208  * This function sets the vcm position, so it consumes least current
 209  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
 210  * to make the movements smoothly.
 211  */
 212 static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
 213 {
 214         struct v4l2_subdev *sd = dev_get_drvdata(dev);
 215         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 216         int ret, val;
 217
 218         if (!ak7375_dev->active)
 219                 return 0;
 220
 221         for (val = ak7375_dev->focus->val & ~(AK7375_CTRL_STEPS - 1);
 222              val >= 0; val -= AK7375_CTRL_STEPS) {
 223                 ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
 224                                        val << 4, 2);
 225                 if (ret)
 226                         dev_err_once(dev, "%s I2C failure: %d\n",
 227                                      __func__, ret);
 228                 usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
 229         }
 230
 231         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
 232                                AK7375_MODE_STANDBY, 1);
 233         if (ret)
 234                 dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
 235
 236         ret = regulator_bulk_disable(ARRAY_SIZE(ak7375_supply_names),
 237                                      ak7375_dev->supplies);
 238         if (ret)
 239                 return ret;
 240
 241         ak7375_dev->active = false;
 242
 243         return 0;
 244 }
 245
 246 /*
 247  * This function sets the vcm position to the value set by the user
 248  * through v4l2_ctrl_ops s_ctrl handler
 249  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
 250  * to make the movements smoothly.
 251  */
 252 static int __maybe_unused ak7375_vcm_resume(struct device *dev)
 253 {
 254         struct v4l2_subdev *sd = dev_get_drvdata(dev);
 255         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 256         int ret, val;
 257
 258         if (ak7375_dev->active)
 259                 return 0;
 260
 261         ret = regulator_bulk_enable(ARRAY_SIZE(ak7375_supply_names),
 262                                     ak7375_dev->supplies);
 263         if (ret)
 264                 return ret;
 265
 266         /* Wait for vcm to become ready */
 267         usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
 268
 269         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
 270                 AK7375_MODE_ACTIVE, 1);
 271         if (ret) {
 272                 dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
 273                 return ret;
 274         }
 275
 276         for (val = ak7375_dev->focus->val % AK7375_CTRL_STEPS;
 277              val <= ak7375_dev->focus->val;
 278              val += AK7375_CTRL_STEPS) {
 279                 ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
 280                                        val << 4, 2);
 281                 if (ret)
 282                         dev_err_ratelimited(dev, "%s I2C failure: %d\n",
 283                                                 __func__, ret);
 284                 usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
 285         }
 286
 287         ak7375_dev->active = true;
 288
 289         return 0;
 290 }
 291
 292 static const struct of_device_id ak7375_of_table[] = {
 293         { .compatible = "asahi-kasei,ak7375" },
 294         { /* sentinel */ }
 295 };
 296 MODULE_DEVICE_TABLE(of, ak7375_of_table);
 297
 298 static const struct dev_pm_ops ak7375_pm_ops = {
 299         SET_SYSTEM_SLEEP_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume)
 300         SET_RUNTIME_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume, NULL)
 301 };
 302
 303 static struct i2c_driver ak7375_i2c_driver = {
 304         .driver = {
 305                 .name = "ak7375",
 306                 .pm = &ak7375_pm_ops,
 307                 .of_match_table = ak7375_of_table,
 308         },
 309         .probe = ak7375_probe,
 310         .remove = ak7375_remove,
 311 };
 312 module_i2c_driver(ak7375_i2c_driver);
 313
 314 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
 315 MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
 316 MODULE_DESCRIPTION("AK7375 VCM driver");
 317 MODULE_LICENSE("GPL v2");