root/drivers/media/i2c/ak7375.c

DEFINITIONS

1. to_ak7375_vcm
2. sd_to_ak7375_vcm
3. ak7375_i2c_write
4. ak7375_set_ctrl
5. ak7375_open
6. ak7375_close
7. ak7375_subdev_cleanup
8. ak7375_init_controls
9. ak7375_probe
10. ak7375_remove
11. ak7375_vcm_suspend
12. ak7375_vcm_resume

   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         int ret;
  91 
  92         ret = pm_runtime_get_sync(sd->dev);
  93         if (ret < 0) {
  94                 pm_runtime_put_noidle(sd->dev);
  95                 return ret;
  96         }
  97 
  98         return 0;
  99 }
 100 
 101 static int ak7375_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 102 {
 103         pm_runtime_put(sd->dev);
 104 
 105         return 0;
 106 }
 107 
 108 static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
 109         .open = ak7375_open,
 110         .close = ak7375_close,
 111 };
 112 
 113 static const struct v4l2_subdev_ops ak7375_ops = { };
 114 
 115 static void ak7375_subdev_cleanup(struct ak7375_device *ak7375_dev)
 116 {
 117         v4l2_async_unregister_subdev(&ak7375_dev->sd);
 118         v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
 119         media_entity_cleanup(&ak7375_dev->sd.entity);
 120 }
 121 
 122 static int ak7375_init_controls(struct ak7375_device *dev_vcm)
 123 {
 124         struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
 125         const struct v4l2_ctrl_ops *ops = &ak7375_vcm_ctrl_ops;
 126 
 127         v4l2_ctrl_handler_init(hdl, 1);
 128 
 129         dev_vcm->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
 130                 0, AK7375_MAX_FOCUS_POS, AK7375_FOCUS_STEPS, 0);
 131 
 132         if (hdl->error)
 133                 dev_err(dev_vcm->sd.dev, "%s fail error: 0x%x\n",
 134                         __func__, hdl->error);
 135         dev_vcm->sd.ctrl_handler = hdl;
 136 
 137         return hdl->error;
 138 }
 139 
 140 static int ak7375_probe(struct i2c_client *client)
 141 {
 142         struct ak7375_device *ak7375_dev;
 143         int ret;
 144 
 145         ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
 146                                   GFP_KERNEL);
 147         if (!ak7375_dev)
 148                 return -ENOMEM;
 149 
 150         v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
 151         ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 152         ak7375_dev->sd.internal_ops = &ak7375_int_ops;
 153         ak7375_dev->sd.entity.function = MEDIA_ENT_F_LENS;
 154 
 155         ret = ak7375_init_controls(ak7375_dev);
 156         if (ret)
 157                 goto err_cleanup;
 158 
 159         ret = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL);
 160         if (ret < 0)
 161                 goto err_cleanup;
 162 
 163         ret = v4l2_async_register_subdev(&ak7375_dev->sd);
 164         if (ret < 0)
 165                 goto err_cleanup;
 166 
 167         pm_runtime_set_active(&client->dev);
 168         pm_runtime_enable(&client->dev);
 169         pm_runtime_idle(&client->dev);
 170 
 171         return 0;
 172 
 173 err_cleanup:
 174         v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
 175         media_entity_cleanup(&ak7375_dev->sd.entity);
 176 
 177         return ret;
 178 }
 179 
 180 static int ak7375_remove(struct i2c_client *client)
 181 {
 182         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 183         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 184 
 185         ak7375_subdev_cleanup(ak7375_dev);
 186         pm_runtime_disable(&client->dev);
 187         pm_runtime_set_suspended(&client->dev);
 188 
 189         return 0;
 190 }
 191 
 192 /*
 193  * This function sets the vcm position, so it consumes least current
 194  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
 195  * to make the movements smoothly.
 196  */
 197 static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
 198 {
 199 
 200         struct i2c_client *client = to_i2c_client(dev);
 201         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 202         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 203         int ret, val;
 204 
 205         if (!ak7375_dev->active)
 206                 return 0;
 207 
 208         for (val = ak7375_dev->focus->val & ~(AK7375_CTRL_STEPS - 1);
 209              val >= 0; val -= AK7375_CTRL_STEPS) {
 210                 ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
 211                                        val << 4, 2);
 212                 if (ret)
 213                         dev_err_once(dev, "%s I2C failure: %d\n",
 214                                      __func__, ret);
 215                 usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
 216         }
 217 
 218         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
 219                                AK7375_MODE_STANDBY, 1);
 220         if (ret)
 221                 dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
 222 
 223         ak7375_dev->active = false;
 224 
 225         return 0;
 226 }
 227 
 228 /*
 229  * This function sets the vcm position to the value set by the user
 230  * through v4l2_ctrl_ops s_ctrl handler
 231  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
 232  * to make the movements smoothly.
 233  */
 234 static int __maybe_unused ak7375_vcm_resume(struct device *dev)
 235 {
 236         struct i2c_client *client = to_i2c_client(dev);
 237         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 238         struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
 239         int ret, val;
 240 
 241         if (ak7375_dev->active)
 242                 return 0;
 243 
 244         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
 245                 AK7375_MODE_ACTIVE, 1);
 246         if (ret) {
 247                 dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
 248                 return ret;
 249         }
 250 
 251         for (val = ak7375_dev->focus->val % AK7375_CTRL_STEPS;
 252              val <= ak7375_dev->focus->val;
 253              val += AK7375_CTRL_STEPS) {
 254                 ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
 255                                        val << 4, 2);
 256                 if (ret)
 257                         dev_err_ratelimited(dev, "%s I2C failure: %d\n",
 258                                                 __func__, ret);
 259                 usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
 260         }
 261 
 262         ak7375_dev->active = true;
 263 
 264         return 0;
 265 }
 266 
 267 static const struct of_device_id ak7375_of_table[] = {
 268         { .compatible = "asahi-kasei,ak7375" },
 269         { /* sentinel */ }
 270 };
 271 MODULE_DEVICE_TABLE(of, ak7375_of_table);
 272 
 273 static const struct dev_pm_ops ak7375_pm_ops = {
 274         SET_SYSTEM_SLEEP_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume)
 275         SET_RUNTIME_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume, NULL)
 276 };
 277 
 278 static struct i2c_driver ak7375_i2c_driver = {
 279         .driver = {
 280                 .name = "ak7375",
 281                 .pm = &ak7375_pm_ops,
 282                 .of_match_table = ak7375_of_table,
 283         },
 284         .probe_new = ak7375_probe,
 285         .remove = ak7375_remove,
 286 };
 287 module_i2c_driver(ak7375_i2c_driver);
 288 
 289 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
 290 MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
 291 MODULE_DESCRIPTION("AK7375 VCM driver");
 292 MODULE_LICENSE("GPL v2");