media/i2c/ak7375.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 // Copyright (C) 2018 Intel Corporation
0003
0004 #include <linux/acpi.h>
0005 #include <linux/delay.h>
0006 #include <linux/i2c.h>
0007 #include <linux/module.h>
0008 #include <linux/pm_runtime.h>
0009 #include <media/v4l2-ctrls.h>
0010 #include <media/v4l2-device.h>
0011
0012 #define AK7375_MAX_FOCUS_POS    4095
0013 /*
0014  * This sets the minimum granularity for the focus positions.
0015  * A value of 1 gives maximum accuracy for a desired focus position
0016  */
0017 #define AK7375_FOCUS_STEPS  1
0018 /*
0019  * This acts as the minimum granularity of lens movement.
0020  * Keep this value power of 2, so the control steps can be
0021  * uniformly adjusted for gradual lens movement, with desired
0022  * number of control steps.
0023  */
0024 #define AK7375_CTRL_STEPS   64
0025 #define AK7375_CTRL_DELAY_US    1000
0026
0027 #define AK7375_REG_POSITION 0x0
0028 #define AK7375_REG_CONT     0x2
0029 #define AK7375_MODE_ACTIVE  0x0
0030 #define AK7375_MODE_STANDBY 0x40
0031
0032 /* ak7375 device structure */
0033 struct ak7375_device {
0034     struct v4l2_ctrl_handler ctrls_vcm;
0035     struct v4l2_subdev sd;
0036     struct v4l2_ctrl *focus;
0037     /* active or standby mode */
0038     bool active;
0039 };
0040
0041 static inline struct ak7375_device *to_ak7375_vcm(struct v4l2_ctrl *ctrl)
0042 {
0043     return container_of(ctrl->handler, struct ak7375_device, ctrls_vcm);
0044 }
0045
0046 static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
0047 {
0048     return container_of(subdev, struct ak7375_device, sd);
0049 }
0050
0051 static int ak7375_i2c_write(struct ak7375_device *ak7375,
0052     u8 addr, u16 data, u8 size)
0053 {
0054     struct i2c_client *client = v4l2_get_subdevdata(&ak7375->sd);
0055     u8 buf[3];
0056     int ret;
0057
0058     if (size != 1 && size != 2)
0059         return -EINVAL;
0060     buf[0] = addr;
0061     buf[size] = data & 0xff;
0062     if (size == 2)
0063         buf[1] = (data >> 8) & 0xff;
0064     ret = i2c_master_send(client, (const char *)buf, size + 1);
0065     if (ret < 0)
0066         return ret;
0067     if (ret != size + 1)
0068         return -EIO;
0069
0070     return 0;
0071 }
0072
0073 static int ak7375_set_ctrl(struct v4l2_ctrl *ctrl)
0074 {
0075     struct ak7375_device *dev_vcm = to_ak7375_vcm(ctrl);
0076
0077     if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
0078         return ak7375_i2c_write(dev_vcm, AK7375_REG_POSITION,
0079                     ctrl->val << 4, 2);
0080
0081     return -EINVAL;
0082 }
0083
0084 static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
0085     .s_ctrl = ak7375_set_ctrl,
0086 };
0087
0088 static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
0089 {
0090     return pm_runtime_resume_and_get(sd->dev);
0091 }
0092
0093 static int ak7375_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
0094 {
0095     pm_runtime_put(sd->dev);
0096
0097     return 0;
0098 }
0099
0100 static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
0101     .open = ak7375_open,
0102     .close = ak7375_close,
0103 };
0104
0105 static const struct v4l2_subdev_ops ak7375_ops = { };
0106
0107 static void ak7375_subdev_cleanup(struct ak7375_device *ak7375_dev)
0108 {
0109     v4l2_async_unregister_subdev(&ak7375_dev->sd);
0110     v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
0111     media_entity_cleanup(&ak7375_dev->sd.entity);
0112 }
0113
0114 static int ak7375_init_controls(struct ak7375_device *dev_vcm)
0115 {
0116     struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
0117     const struct v4l2_ctrl_ops *ops = &ak7375_vcm_ctrl_ops;
0118
0119     v4l2_ctrl_handler_init(hdl, 1);
0120
0121     dev_vcm->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
0122         0, AK7375_MAX_FOCUS_POS, AK7375_FOCUS_STEPS, 0);
0123
0124     if (hdl->error)
0125         dev_err(dev_vcm->sd.dev, "%s fail error: 0x%x\n",
0126             __func__, hdl->error);
0127     dev_vcm->sd.ctrl_handler = hdl;
0128
0129     return hdl->error;
0130 }
0131
0132 static int ak7375_probe(struct i2c_client *client)
0133 {
0134     struct ak7375_device *ak7375_dev;
0135     int ret;
0136
0137     ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
0138                   GFP_KERNEL);
0139     if (!ak7375_dev)
0140         return -ENOMEM;
0141
0142     v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
0143     ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
0144     ak7375_dev->sd.internal_ops = &ak7375_int_ops;
0145     ak7375_dev->sd.entity.function = MEDIA_ENT_F_LENS;
0146
0147     ret = ak7375_init_controls(ak7375_dev);
0148     if (ret)
0149         goto err_cleanup;
0150
0151     ret = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL);
0152     if (ret < 0)
0153         goto err_cleanup;
0154
0155     ret = v4l2_async_register_subdev(&ak7375_dev->sd);
0156     if (ret < 0)
0157         goto err_cleanup;
0158
0159     pm_runtime_set_active(&client->dev);
0160     pm_runtime_enable(&client->dev);
0161     pm_runtime_idle(&client->dev);
0162
0163     return 0;
0164
0165 err_cleanup:
0166     v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
0167     media_entity_cleanup(&ak7375_dev->sd.entity);
0168
0169     return ret;
0170 }
0171
0172 static int ak7375_remove(struct i2c_client *client)
0173 {
0174     struct v4l2_subdev *sd = i2c_get_clientdata(client);
0175     struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
0176
0177     ak7375_subdev_cleanup(ak7375_dev);
0178     pm_runtime_disable(&client->dev);
0179     pm_runtime_set_suspended(&client->dev);
0180
0181     return 0;
0182 }
0183
0184 /*
0185  * This function sets the vcm position, so it consumes least current
0186  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
0187  * to make the movements smoothly.
0188  */
0189 static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
0190 {
0191     struct v4l2_subdev *sd = dev_get_drvdata(dev);
0192     struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
0193     int ret, val;
0194
0195     if (!ak7375_dev->active)
0196         return 0;
0197
0198     for (val = ak7375_dev->focus->val & ~(AK7375_CTRL_STEPS - 1);
0199          val >= 0; val -= AK7375_CTRL_STEPS) {
0200         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
0201                        val << 4, 2);
0202         if (ret)
0203             dev_err_once(dev, "%s I2C failure: %d\n",
0204                      __func__, ret);
0205         usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
0206     }
0207
0208     ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
0209                    AK7375_MODE_STANDBY, 1);
0210     if (ret)
0211         dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
0212
0213     ak7375_dev->active = false;
0214
0215     return 0;
0216 }
0217
0218 /*
0219  * This function sets the vcm position to the value set by the user
0220  * through v4l2_ctrl_ops s_ctrl handler
0221  * The lens position is gradually moved in units of AK7375_CTRL_STEPS,
0222  * to make the movements smoothly.
0223  */
0224 static int __maybe_unused ak7375_vcm_resume(struct device *dev)
0225 {
0226     struct v4l2_subdev *sd = dev_get_drvdata(dev);
0227     struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
0228     int ret, val;
0229
0230     if (ak7375_dev->active)
0231         return 0;
0232
0233     ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
0234         AK7375_MODE_ACTIVE, 1);
0235     if (ret) {
0236         dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
0237         return ret;
0238     }
0239
0240     for (val = ak7375_dev->focus->val % AK7375_CTRL_STEPS;
0241          val <= ak7375_dev->focus->val;
0242          val += AK7375_CTRL_STEPS) {
0243         ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_POSITION,
0244                        val << 4, 2);
0245         if (ret)
0246             dev_err_ratelimited(dev, "%s I2C failure: %d\n",
0247                         __func__, ret);
0248         usleep_range(AK7375_CTRL_DELAY_US, AK7375_CTRL_DELAY_US + 10);
0249     }
0250
0251     ak7375_dev->active = true;
0252
0253     return 0;
0254 }
0255
0256 static const struct of_device_id ak7375_of_table[] = {
0257     { .compatible = "asahi-kasei,ak7375" },
0258     { /* sentinel */ }
0259 };
0260 MODULE_DEVICE_TABLE(of, ak7375_of_table);
0261
0262 static const struct dev_pm_ops ak7375_pm_ops = {
0263     SET_SYSTEM_SLEEP_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume)
0264     SET_RUNTIME_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume, NULL)
0265 };
0266
0267 static struct i2c_driver ak7375_i2c_driver = {
0268     .driver = {
0269         .name = "ak7375",
0270         .pm = &ak7375_pm_ops,
0271         .of_match_table = ak7375_of_table,
0272     },
0273     .probe_new = ak7375_probe,
0274     .remove = ak7375_remove,
0275 };
0276 module_i2c_driver(ak7375_i2c_driver);
0277
0278 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
0279 MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
0280 MODULE_DESCRIPTION("AK7375 VCM driver");
0281 MODULE_LICENSE("GPL v2");