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/iopoll.h>
8#include <linux/module.h>
9#include <linux/pm_runtime.h>
10#include <media/v4l2-ctrls.h>
11#include <media/v4l2-device.h>
12
13#define DW9807_MAX_FOCUS_POS	1023
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 DW9807_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 DW9807_CTRL_STEPS	16
26#define DW9807_CTRL_DELAY_US	1000
27
28#define DW9807_CTL_ADDR		0x02
29/*
30 * DW9807 separates two registers to control the VCM position.
31 * One for MSB value, another is LSB value.
32 */
33#define DW9807_MSB_ADDR		0x03
34#define DW9807_LSB_ADDR		0x04
35#define DW9807_STATUS_ADDR	0x05
36#define DW9807_MODE_ADDR	0x06
37#define DW9807_RESONANCE_ADDR	0x07
38
39#define MAX_RETRY		10
40
41struct dw9807_device {
42	struct v4l2_ctrl_handler ctrls_vcm;
43	struct v4l2_subdev sd;
44	u16 current_val;
45};
46
47static inline struct dw9807_device *sd_to_dw9807_vcm(
48					struct v4l2_subdev *subdev)
49{
50	return container_of(subdev, struct dw9807_device, sd);
51}
52
53static int dw9807_i2c_check(struct i2c_client *client)
54{
55	const char status_addr = DW9807_STATUS_ADDR;
56	char status_result;
57	int ret;
58
59	ret = i2c_master_send(client, &status_addr, sizeof(status_addr));
60	if (ret < 0) {
61		dev_err(&client->dev, "I2C write STATUS address fail ret = %d\n",
62			ret);
63		return ret;
64	}
65
66	ret = i2c_master_recv(client, &status_result, sizeof(status_result));
67	if (ret < 0) {
68		dev_err(&client->dev, "I2C read STATUS value fail ret = %d\n",
69			ret);
70		return ret;
71	}
72
73	return status_result;
74}
75
76static int dw9807_set_dac(struct i2c_client *client, u16 data)
77{
78	const char tx_data[3] = {
79		DW9807_MSB_ADDR, ((data >> 8) & 0x03), (data & 0xff)
80	};
81	int val, ret;
82
83	/*
84	 * According to the datasheet, need to check the bus status before we
85	 * write VCM position. This ensure that we really write the value
86	 * into the register
87	 */
88	ret = readx_poll_timeout(dw9807_i2c_check, client, val, val <= 0,
89			DW9807_CTRL_DELAY_US, MAX_RETRY * DW9807_CTRL_DELAY_US);
90
91	if (ret || val < 0) {
92		if (ret) {
93			dev_warn(&client->dev,
94				"Cannot do the write operation because VCM is busy\n");
95		}
96
97		return ret ? -EBUSY : val;
98	}
99
100	/* Write VCM position to registers */
101	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
102	if (ret < 0) {
103		dev_err(&client->dev,
104			"I2C write MSB fail ret=%d\n", ret);
105
106		return ret;
107	}
108
109	return 0;
110}
111
112static int dw9807_set_ctrl(struct v4l2_ctrl *ctrl)
113{
114	struct dw9807_device *dev_vcm = container_of(ctrl->handler,
115		struct dw9807_device, ctrls_vcm);
116
117	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE) {
118		struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd);
119
120		dev_vcm->current_val = ctrl->val;
121		return dw9807_set_dac(client, ctrl->val);
122	}
123
124	return -EINVAL;
125}
126
127static const struct v4l2_ctrl_ops dw9807_vcm_ctrl_ops = {
128	.s_ctrl = dw9807_set_ctrl,
129};
130
131static int dw9807_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
132{
133	int rval;
134
135	rval = pm_runtime_get_sync(sd->dev);
136	if (rval < 0) {
137		pm_runtime_put_noidle(sd->dev);
138		return rval;
139	}
140
141	return 0;
142}
143
144static int dw9807_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
145{
146	pm_runtime_put(sd->dev);
147
148	return 0;
149}
150
151static const struct v4l2_subdev_internal_ops dw9807_int_ops = {
152	.open = dw9807_open,
153	.close = dw9807_close,
154};
155
156static const struct v4l2_subdev_ops dw9807_ops = { };
157
158static void dw9807_subdev_cleanup(struct dw9807_device *dw9807_dev)
159{
160	v4l2_async_unregister_subdev(&dw9807_dev->sd);
161	v4l2_ctrl_handler_free(&dw9807_dev->ctrls_vcm);
162	media_entity_cleanup(&dw9807_dev->sd.entity);
163}
164
165static int dw9807_init_controls(struct dw9807_device *dev_vcm)
166{
167	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
168	const struct v4l2_ctrl_ops *ops = &dw9807_vcm_ctrl_ops;
169	struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd);
170
171	v4l2_ctrl_handler_init(hdl, 1);
172
173	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
174			  0, DW9807_MAX_FOCUS_POS, DW9807_FOCUS_STEPS, 0);
175
176	dev_vcm->sd.ctrl_handler = hdl;
177	if (hdl->error) {
178		dev_err(&client->dev, "%s fail error: 0x%x\n",
179			__func__, hdl->error);
180		return hdl->error;
181	}
182
183	return 0;
184}
185
186static int dw9807_probe(struct i2c_client *client)
187{
188	struct dw9807_device *dw9807_dev;
189	int rval;
190
191	dw9807_dev = devm_kzalloc(&client->dev, sizeof(*dw9807_dev),
192				  GFP_KERNEL);
193	if (dw9807_dev == NULL)
194		return -ENOMEM;
195
196	v4l2_i2c_subdev_init(&dw9807_dev->sd, client, &dw9807_ops);
197	dw9807_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
198	dw9807_dev->sd.internal_ops = &dw9807_int_ops;
199
200	rval = dw9807_init_controls(dw9807_dev);
201	if (rval)
202		goto err_cleanup;
203
204	rval = media_entity_pads_init(&dw9807_dev->sd.entity, 0, NULL);
205	if (rval < 0)
206		goto err_cleanup;
207
208	dw9807_dev->sd.entity.function = MEDIA_ENT_F_LENS;
209
210	rval = v4l2_async_register_subdev(&dw9807_dev->sd);
211	if (rval < 0)
212		goto err_cleanup;
213
214	pm_runtime_set_active(&client->dev);
215	pm_runtime_enable(&client->dev);
216	pm_runtime_idle(&client->dev);
217
218	return 0;
219
220err_cleanup:
221	v4l2_ctrl_handler_free(&dw9807_dev->ctrls_vcm);
222	media_entity_cleanup(&dw9807_dev->sd.entity);
223
224	return rval;
225}
226
227static int dw9807_remove(struct i2c_client *client)
228{
229	struct v4l2_subdev *sd = i2c_get_clientdata(client);
230	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
231
232	pm_runtime_disable(&client->dev);
233
234	dw9807_subdev_cleanup(dw9807_dev);
235
236	return 0;
237}
238
239/*
240 * This function sets the vcm position, so it consumes least current
241 * The lens position is gradually moved in units of DW9807_CTRL_STEPS,
242 * to make the movements smoothly.
243 */
244static int __maybe_unused dw9807_vcm_suspend(struct device *dev)
245{
246	struct i2c_client *client = to_i2c_client(dev);
247	struct v4l2_subdev *sd = i2c_get_clientdata(client);
248	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
249	const char tx_data[2] = { DW9807_CTL_ADDR, 0x01 };
250	int ret, val;
251
252	for (val = dw9807_dev->current_val & ~(DW9807_CTRL_STEPS - 1);
253	     val >= 0; val -= DW9807_CTRL_STEPS) {
254		ret = dw9807_set_dac(client, val);
255		if (ret)
256			dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
257		usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10);
258	}
259
260	/* Power down */
261	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
262	if (ret < 0) {
263		dev_err(&client->dev, "I2C write CTL fail ret = %d\n", ret);
264		return ret;
265	}
266
267	return 0;
268}
269
270/*
271 * This function sets the vcm position to the value set by the user
272 * through v4l2_ctrl_ops s_ctrl handler
273 * The lens position is gradually moved in units of DW9807_CTRL_STEPS,
274 * to make the movements smoothly.
275 */
276static int  __maybe_unused dw9807_vcm_resume(struct device *dev)
277{
278	struct i2c_client *client = to_i2c_client(dev);
279	struct v4l2_subdev *sd = i2c_get_clientdata(client);
280	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
281	const char tx_data[2] = { DW9807_CTL_ADDR, 0x00 };
282	int ret, val;
283
284	/* Power on */
285	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
286	if (ret < 0) {
287		dev_err(&client->dev, "I2C write CTL fail ret = %d\n", ret);
288		return ret;
289	}
290
291	for (val = dw9807_dev->current_val % DW9807_CTRL_STEPS;
292	     val < dw9807_dev->current_val + DW9807_CTRL_STEPS - 1;
293	     val += DW9807_CTRL_STEPS) {
294		ret = dw9807_set_dac(client, val);
295		if (ret)
296			dev_err_ratelimited(dev, "%s I2C failure: %d",
297						__func__, ret);
298		usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10);
299	}
300
301	return 0;
302}
303
304static const struct of_device_id dw9807_of_table[] = {
305	{ .compatible = "dongwoon,dw9807-vcm" },
306	{ /* sentinel */ }
307};
308MODULE_DEVICE_TABLE(of, dw9807_of_table);
309
310static const struct dev_pm_ops dw9807_pm_ops = {
311	SET_SYSTEM_SLEEP_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume)
312	SET_RUNTIME_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume, NULL)
313};
314
315static struct i2c_driver dw9807_i2c_driver = {
316	.driver = {
317		.name = "dw9807",
318		.pm = &dw9807_pm_ops,
319		.of_match_table = dw9807_of_table,
320	},
321	.probe_new = dw9807_probe,
322	.remove = dw9807_remove,
323};
324
325module_i2c_driver(dw9807_i2c_driver);
326
327MODULE_AUTHOR("Chiang, Alan");
328MODULE_DESCRIPTION("DW9807 VCM driver");
329MODULE_LICENSE("GPL v2");
330