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
13struct ak73xx_chipdef {
14	u8 reg_position;
15	u8 reg_cont;
16	u8 shift_pos;
17	u8 mode_active;
18	u8 mode_standby;
19	bool has_standby;	/* Some chips may not have standby mode */
20	u16 focus_pos_max;
21	/*
22	 * This sets the minimum granularity for the focus positions.
23	 * A value of 1 gives maximum accuracy for a desired focus position
24	 */
25	u16 focus_steps;
26	/*
27	 * This acts as the minimum granularity of lens movement.
28	 * Keep this value power of 2, so the control steps can be
29	 * uniformly adjusted for gradual lens movement, with desired
30	 * number of control steps.
31	 */
32	u16 ctrl_steps;
33	u16 ctrl_delay_us;
34	/*
35	 * The vcm may take time (tDELAY) to power on and start taking
36	 * I2C messages.
37	 */
38	u16 power_delay_us;
39};
40
41static const struct ak73xx_chipdef ak7345_cdef = {
42	.reg_position	= 0x0,
43	.reg_cont	= 0x2,
44	.shift_pos	= 7,	/* 9 bits position values, need to << 7 */
45	.mode_active	= 0x0,
46	.has_standby	= false,
47	.focus_pos_max	= 511,
48	.focus_steps	= 1,
49	.ctrl_steps	= 16,
50	.ctrl_delay_us	= 1000,
51	.power_delay_us	= 20000,
52};
53
54static const struct ak73xx_chipdef ak7375_cdef = {
55	.reg_position	= 0x0,
56	.reg_cont	= 0x2,
57	.shift_pos	= 4,	/* 12 bits position values, need to << 4 */
58	.mode_active	= 0x0,
59	.mode_standby	= 0x40,
60	.has_standby	= true,
61	.focus_pos_max	= 4095,
62	.focus_steps	= 1,
63	.ctrl_steps	= 64,
64	.ctrl_delay_us	= 1000,
65	.power_delay_us	= 10000,
66};
67
68static const char * const ak7375_supply_names[] = {
69	"vdd",
70	"vio",
71};
72
73/* ak7375 device structure */
74struct ak7375_device {
75	const struct ak73xx_chipdef *cdef;
76	struct v4l2_ctrl_handler ctrls_vcm;
77	struct v4l2_subdev sd;
78	struct v4l2_ctrl *focus;
79	struct regulator_bulk_data supplies[ARRAY_SIZE(ak7375_supply_names)];
80
81	/* active or standby mode */
82	bool active;
83};
84
85static inline struct ak7375_device *to_ak7375_vcm(struct v4l2_ctrl *ctrl)
86{
87	return container_of(ctrl->handler, struct ak7375_device, ctrls_vcm);
88}
89
90static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
91{
92	return container_of(subdev, struct ak7375_device, sd);
93}
94
95static int ak7375_i2c_write(struct ak7375_device *ak7375,
96	u8 addr, u16 data, u8 size)
97{
98	struct i2c_client *client = v4l2_get_subdevdata(&ak7375->sd);
99	u8 buf[3];
100	int ret;
101
102	if (size != 1 && size != 2)
103		return -EINVAL;
104	buf[0] = addr;
105	buf[size] = data & 0xff;
106	if (size == 2)
107		buf[1] = (data >> 8) & 0xff;
108	ret = i2c_master_send(client, (const char *)buf, size + 1);
109	if (ret < 0)
110		return ret;
111	if (ret != size + 1)
112		return -EIO;
113
114	return 0;
115}
116
117static int ak7375_set_ctrl(struct v4l2_ctrl *ctrl)
118{
119	struct ak7375_device *dev_vcm = to_ak7375_vcm(ctrl);
120	const struct ak73xx_chipdef *cdef = dev_vcm->cdef;
121
122	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
123		return ak7375_i2c_write(dev_vcm, cdef->reg_position,
124					ctrl->val << cdef->shift_pos, 2);
125
126	return -EINVAL;
127}
128
129static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
130	.s_ctrl = ak7375_set_ctrl,
131};
132
133static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
134{
135	return pm_runtime_resume_and_get(sd->dev);
136}
137
138static int ak7375_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
139{
140	pm_runtime_put(sd->dev);
141
142	return 0;
143}
144
145static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
146	.open = ak7375_open,
147	.close = ak7375_close,
148};
149
150static const struct v4l2_subdev_ops ak7375_ops = { };
151
152static void ak7375_subdev_cleanup(struct ak7375_device *ak7375_dev)
153{
154	v4l2_async_unregister_subdev(&ak7375_dev->sd);
155	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
156	media_entity_cleanup(&ak7375_dev->sd.entity);
157}
158
159static int ak7375_init_controls(struct ak7375_device *dev_vcm)
160{
161	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
162	const struct v4l2_ctrl_ops *ops = &ak7375_vcm_ctrl_ops;
163	const struct ak73xx_chipdef *cdef = dev_vcm->cdef;
164
165	v4l2_ctrl_handler_init(hdl, 1);
166
167	dev_vcm->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
168		0, cdef->focus_pos_max, cdef->focus_steps, 0);
169
170	if (hdl->error)
171		dev_err(dev_vcm->sd.dev, "%s fail error: 0x%x\n",
172			__func__, hdl->error);
173	dev_vcm->sd.ctrl_handler = hdl;
174
175	return hdl->error;
176}
177
178static int ak7375_probe(struct i2c_client *client)
179{
180	struct ak7375_device *ak7375_dev;
181	int ret;
182	unsigned int i;
183
184	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
185				  GFP_KERNEL);
186	if (!ak7375_dev)
187		return -ENOMEM;
188
189	ak7375_dev->cdef = device_get_match_data(&client->dev);
190
191	for (i = 0; i < ARRAY_SIZE(ak7375_supply_names); i++)
192		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
193
194	ret = devm_regulator_bulk_get(&client->dev,
195				      ARRAY_SIZE(ak7375_supply_names),
196				      ak7375_dev->supplies);
197	if (ret) {
198		dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
199		return ret;
200	}
201
202	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
203	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
204	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
205	ak7375_dev->sd.entity.function = MEDIA_ENT_F_LENS;
206
207	ret = ak7375_init_controls(ak7375_dev);
208	if (ret)
209		goto err_cleanup;
210
211	ret = media_entity_pads_init(&ak7375_dev->sd.entity, 0, NULL);
212	if (ret < 0)
213		goto err_cleanup;
214
215	ret = v4l2_async_register_subdev(&ak7375_dev->sd);
216	if (ret < 0)
217		goto err_cleanup;
218
219	pm_runtime_set_active(&client->dev);
220	pm_runtime_enable(&client->dev);
221	pm_runtime_idle(&client->dev);
222
223	return 0;
224
225err_cleanup:
226	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
227	media_entity_cleanup(&ak7375_dev->sd.entity);
228
229	return ret;
230}
231
232static void ak7375_remove(struct i2c_client *client)
233{
234	struct v4l2_subdev *sd = i2c_get_clientdata(client);
235	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
236
237	ak7375_subdev_cleanup(ak7375_dev);
238	pm_runtime_disable(&client->dev);
239	pm_runtime_set_suspended(&client->dev);
240}
241
242/*
243 * This function sets the vcm position, so it consumes least current
244 * The lens position is gradually moved in units of ctrl_steps,
245 * to make the movements smoothly.
246 */
247static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
248{
249	struct v4l2_subdev *sd = dev_get_drvdata(dev);
250	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
251	const struct ak73xx_chipdef *cdef = ak7375_dev->cdef;
252	int ret, val;
253
254	if (!ak7375_dev->active)
255		return 0;
256
257	for (val = ak7375_dev->focus->val & ~(cdef->ctrl_steps - 1);
258	     val >= 0; val -= cdef->ctrl_steps) {
259		ret = ak7375_i2c_write(ak7375_dev, cdef->reg_position,
260				       val << cdef->shift_pos, 2);
261		if (ret)
262			dev_err_once(dev, "%s I2C failure: %d\n",
263				     __func__, ret);
264		usleep_range(cdef->ctrl_delay_us, cdef->ctrl_delay_us + 10);
265	}
266
267	if (cdef->has_standby) {
268		ret = ak7375_i2c_write(ak7375_dev, cdef->reg_cont,
269				       cdef->mode_standby, 1);
270		if (ret)
271			dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
272	}
273
274	ret = regulator_bulk_disable(ARRAY_SIZE(ak7375_supply_names),
275				     ak7375_dev->supplies);
276	if (ret)
277		return ret;
278
279	ak7375_dev->active = false;
280
281	return 0;
282}
283
284/*
285 * This function sets the vcm position to the value set by the user
286 * through v4l2_ctrl_ops s_ctrl handler
287 * The lens position is gradually moved in units of ctrl_steps,
288 * to make the movements smoothly.
289 */
290static int __maybe_unused ak7375_vcm_resume(struct device *dev)
291{
292	struct v4l2_subdev *sd = dev_get_drvdata(dev);
293	struct ak7375_device *ak7375_dev = sd_to_ak7375_vcm(sd);
294	const struct ak73xx_chipdef *cdef = ak7375_dev->cdef;
295	int ret, val;
296
297	if (ak7375_dev->active)
298		return 0;
299
300	ret = regulator_bulk_enable(ARRAY_SIZE(ak7375_supply_names),
301				    ak7375_dev->supplies);
302	if (ret)
303		return ret;
304
305	/* Wait for vcm to become ready */
306	usleep_range(cdef->power_delay_us, cdef->power_delay_us + 500);
307
308	ret = ak7375_i2c_write(ak7375_dev, cdef->reg_cont,
309			       cdef->mode_active, 1);
310	if (ret) {
311		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
312		return ret;
313	}
314
315	for (val = ak7375_dev->focus->val % cdef->ctrl_steps;
316	     val <= ak7375_dev->focus->val;
317	     val += cdef->ctrl_steps) {
318		ret = ak7375_i2c_write(ak7375_dev, cdef->reg_position,
319				       val << cdef->shift_pos, 2);
320		if (ret)
321			dev_err_ratelimited(dev, "%s I2C failure: %d\n",
322						__func__, ret);
323		usleep_range(cdef->ctrl_delay_us, cdef->ctrl_delay_us + 10);
324	}
325
326	ak7375_dev->active = true;
327
328	return 0;
329}
330
331static const struct of_device_id ak7375_of_table[] = {
332	{ .compatible = "asahi-kasei,ak7345", .data = &ak7345_cdef, },
333	{ .compatible = "asahi-kasei,ak7375", .data = &ak7375_cdef, },
334	{ /* sentinel */ }
335};
336MODULE_DEVICE_TABLE(of, ak7375_of_table);
337
338static const struct dev_pm_ops ak7375_pm_ops = {
339	SET_SYSTEM_SLEEP_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume)
340	SET_RUNTIME_PM_OPS(ak7375_vcm_suspend, ak7375_vcm_resume, NULL)
341};
342
343static struct i2c_driver ak7375_i2c_driver = {
344	.driver = {
345		.name = "ak7375",
346		.pm = &ak7375_pm_ops,
347		.of_match_table = ak7375_of_table,
348	},
349	.probe = ak7375_probe,
350	.remove = ak7375_remove,
351};
352module_i2c_driver(ak7375_i2c_driver);
353
354MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
355MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
356MODULE_DESCRIPTION("AK7375 VCM driver");
357MODULE_LICENSE("GPL v2");
358