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