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
38static const char * const ak7375_supply_names[] = {
39	"vdd",
40	"vio",
41};
42
43/* ak7375 device structure */
44struct 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
54static 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
59static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
60{
61	return container_of(subdev, struct ak7375_device, sd);
62}
63
64static 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
86static 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
97static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
98	.s_ctrl = ak7375_set_ctrl,
99};
100
101static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
102{
103	return pm_runtime_resume_and_get(sd->dev);
104}
105
106static 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
113static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
114	.open = ak7375_open,
115	.close = ak7375_close,
116};
117
118static const struct v4l2_subdev_ops ak7375_ops = { };
119
120static 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
127static 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
145static 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
190err_cleanup:
191	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
192	media_entity_cleanup(&ak7375_dev->sd.entity);
193
194	return ret;
195}
196
197static 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 */
212static 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 */
252static 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
292static const struct of_device_id ak7375_of_table[] = {
293	{ .compatible = "asahi-kasei,ak7375" },
294	{ /* sentinel */ }
295};
296MODULE_DEVICE_TABLE(of, ak7375_of_table);
297
298static 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
303static 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};
312module_i2c_driver(ak7375_i2c_driver);
313
314MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
315MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
316MODULE_DESCRIPTION("AK7375 VCM driver");
317MODULE_LICENSE("GPL v2");
318