1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/media/i2c/ad5820.c
4 *
5 * AD5820 DAC driver for camera voice coil focus.
6 *
7 * Copyright (C) 2008 Nokia Corporation
8 * Copyright (C) 2007 Texas Instruments
9 * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz>
10 *
11 * Contact: Tuukka Toivonen <tuukkat76@gmail.com>
12 *	    Sakari Ailus <sakari.ailus@iki.fi>
13 *
14 * Based on af_d88.c by Texas Instruments.
15 */
16
17#include <linux/errno.h>
18#include <linux/i2c.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/regulator/consumer.h>
22#include <linux/gpio/consumer.h>
23
24#include <media/v4l2-ctrls.h>
25#include <media/v4l2-device.h>
26#include <media/v4l2-subdev.h>
27
28/* Register definitions */
29#define AD5820_POWER_DOWN		(1 << 15)
30#define AD5820_DAC_SHIFT		4
31#define AD5820_RAMP_MODE_LINEAR		(0 << 3)
32#define AD5820_RAMP_MODE_64_16		(1 << 3)
33
34#define CODE_TO_RAMP_US(s)	((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
35#define RAMP_US_TO_CODE(c)	fls(((c) + ((c)>>1)) / 50)
36
37#define to_ad5820_device(sd)	container_of(sd, struct ad5820_device, subdev)
38
39struct ad5820_device {
40	struct v4l2_subdev subdev;
41	struct ad5820_platform_data *platform_data;
42	struct regulator *vana;
43
44	struct v4l2_ctrl_handler ctrls;
45	u32 focus_absolute;
46	u32 focus_ramp_time;
47	u32 focus_ramp_mode;
48
49	struct gpio_desc *enable_gpio;
50
51	struct mutex power_lock;
52	int power_count;
53
54	bool standby;
55};
56
57static int ad5820_write(struct ad5820_device *coil, u16 data)
58{
59	struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
60	struct i2c_msg msg;
61	__be16 be_data;
62	int r;
63
64	if (!client->adapter)
65		return -ENODEV;
66
67	be_data = cpu_to_be16(data);
68	msg.addr  = client->addr;
69	msg.flags = 0;
70	msg.len   = 2;
71	msg.buf   = (u8 *)&be_data;
72
73	r = i2c_transfer(client->adapter, &msg, 1);
74	if (r < 0) {
75		dev_err(&client->dev, "write failed, error %d\n", r);
76		return r;
77	}
78
79	return 0;
80}
81
82/*
83 * Calculate status word and write it to the device based on current
84 * values of V4L2 controls. It is assumed that the stored V4L2 control
85 * values are properly limited and rounded.
86 */
87static int ad5820_update_hw(struct ad5820_device *coil)
88{
89	u16 status;
90
91	status = RAMP_US_TO_CODE(coil->focus_ramp_time);
92	status |= coil->focus_ramp_mode
93		? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
94	status |= coil->focus_absolute << AD5820_DAC_SHIFT;
95
96	if (coil->standby)
97		status |= AD5820_POWER_DOWN;
98
99	return ad5820_write(coil, status);
100}
101
102/*
103 * Power handling
104 */
105static int ad5820_power_off(struct ad5820_device *coil, bool standby)
106{
107	int ret = 0, ret2;
108
109	/*
110	 * Go to standby first as real power off my be denied by the hardware
111	 * (single power line control for both coil and sensor).
112	 */
113	if (standby) {
114		coil->standby = true;
115		ret = ad5820_update_hw(coil);
116	}
117
118	gpiod_set_value_cansleep(coil->enable_gpio, 0);
119
120	ret2 = regulator_disable(coil->vana);
121	if (ret)
122		return ret;
123	return ret2;
124}
125
126static int ad5820_power_on(struct ad5820_device *coil, bool restore)
127{
128	int ret;
129
130	ret = regulator_enable(coil->vana);
131	if (ret < 0)
132		return ret;
133
134	gpiod_set_value_cansleep(coil->enable_gpio, 1);
135
136	if (restore) {
137		/* Restore the hardware settings. */
138		coil->standby = false;
139		ret = ad5820_update_hw(coil);
140		if (ret)
141			goto fail;
142	}
143	return 0;
144
145fail:
146	gpiod_set_value_cansleep(coil->enable_gpio, 0);
147	coil->standby = true;
148	regulator_disable(coil->vana);
149
150	return ret;
151}
152
153/*
154 * V4L2 controls
155 */
156static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
157{
158	struct ad5820_device *coil =
159		container_of(ctrl->handler, struct ad5820_device, ctrls);
160
161	switch (ctrl->id) {
162	case V4L2_CID_FOCUS_ABSOLUTE:
163		coil->focus_absolute = ctrl->val;
164		return ad5820_update_hw(coil);
165	}
166
167	return 0;
168}
169
170static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
171	.s_ctrl = ad5820_set_ctrl,
172};
173
174
175static int ad5820_init_controls(struct ad5820_device *coil)
176{
177	v4l2_ctrl_handler_init(&coil->ctrls, 1);
178
179	/*
180	 * V4L2_CID_FOCUS_ABSOLUTE
181	 *
182	 * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
183	 * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA]
184	 * for focus position, because it is meaningless for user. Meaningful
185	 * would be to use focus distance or even its inverse, but since the
186	 * driver doesn't have sufficiently knowledge to do the conversion, we
187	 * will just use abstract codes here. In any case, smaller value = focus
188	 * position farther from camera. The default zero value means focus at
189	 * infinity, and also least current consumption.
190	 */
191	v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
192			  V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
193
194	if (coil->ctrls.error)
195		return coil->ctrls.error;
196
197	coil->focus_absolute = 0;
198	coil->focus_ramp_time = 0;
199	coil->focus_ramp_mode = 0;
200
201	coil->subdev.ctrl_handler = &coil->ctrls;
202
203	return 0;
204}
205
206/*
207 * V4L2 subdev operations
208 */
209static int ad5820_registered(struct v4l2_subdev *subdev)
210{
211	struct ad5820_device *coil = to_ad5820_device(subdev);
212
213	return ad5820_init_controls(coil);
214}
215
216static int
217ad5820_set_power(struct v4l2_subdev *subdev, int on)
218{
219	struct ad5820_device *coil = to_ad5820_device(subdev);
220	int ret = 0;
221
222	mutex_lock(&coil->power_lock);
223
224	/*
225	 * If the power count is modified from 0 to != 0 or from != 0 to 0,
226	 * update the power state.
227	 */
228	if (coil->power_count == !on) {
229		ret = on ? ad5820_power_on(coil, true) :
230			ad5820_power_off(coil, true);
231		if (ret < 0)
232			goto done;
233	}
234
235	/* Update the power count. */
236	coil->power_count += on ? 1 : -1;
237	WARN_ON(coil->power_count < 0);
238
239done:
240	mutex_unlock(&coil->power_lock);
241	return ret;
242}
243
244static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
245{
246	return ad5820_set_power(sd, 1);
247}
248
249static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
250{
251	return ad5820_set_power(sd, 0);
252}
253
254static const struct v4l2_subdev_core_ops ad5820_core_ops = {
255	.s_power = ad5820_set_power,
256};
257
258static const struct v4l2_subdev_ops ad5820_ops = {
259	.core = &ad5820_core_ops,
260};
261
262static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
263	.registered = ad5820_registered,
264	.open = ad5820_open,
265	.close = ad5820_close,
266};
267
268/*
269 * I2C driver
270 */
271static int __maybe_unused ad5820_suspend(struct device *dev)
272{
273	struct v4l2_subdev *subdev = dev_get_drvdata(dev);
274	struct ad5820_device *coil = to_ad5820_device(subdev);
275
276	if (!coil->power_count)
277		return 0;
278
279	return ad5820_power_off(coil, false);
280}
281
282static int __maybe_unused ad5820_resume(struct device *dev)
283{
284	struct v4l2_subdev *subdev = dev_get_drvdata(dev);
285	struct ad5820_device *coil = to_ad5820_device(subdev);
286
287	if (!coil->power_count)
288		return 0;
289
290	return ad5820_power_on(coil, true);
291}
292
293static int ad5820_probe(struct i2c_client *client)
294{
295	struct ad5820_device *coil;
296	int ret;
297
298	coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL);
299	if (!coil)
300		return -ENOMEM;
301
302	coil->vana = devm_regulator_get(&client->dev, "VANA");
303	if (IS_ERR(coil->vana))
304		return dev_err_probe(&client->dev, PTR_ERR(coil->vana),
305				     "could not get regulator for vana\n");
306
307	coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
308						    GPIOD_OUT_LOW);
309	if (IS_ERR(coil->enable_gpio))
310		return dev_err_probe(&client->dev, PTR_ERR(coil->enable_gpio),
311				     "could not get enable gpio\n");
312
313	mutex_init(&coil->power_lock);
314
315	v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
316	coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
317	coil->subdev.internal_ops = &ad5820_internal_ops;
318	coil->subdev.entity.function = MEDIA_ENT_F_LENS;
319	strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name));
320
321	ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
322	if (ret < 0)
323		goto clean_mutex;
324
325	ret = v4l2_async_register_subdev(&coil->subdev);
326	if (ret < 0)
327		goto clean_entity;
328
329	return ret;
330
331clean_entity:
332	media_entity_cleanup(&coil->subdev.entity);
333clean_mutex:
334	mutex_destroy(&coil->power_lock);
335	return ret;
336}
337
338static void ad5820_remove(struct i2c_client *client)
339{
340	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
341	struct ad5820_device *coil = to_ad5820_device(subdev);
342
343	v4l2_async_unregister_subdev(&coil->subdev);
344	v4l2_ctrl_handler_free(&coil->ctrls);
345	media_entity_cleanup(&coil->subdev.entity);
346	mutex_destroy(&coil->power_lock);
347}
348
349static const struct i2c_device_id ad5820_id_table[] = {
350	{ "ad5820", 0 },
351	{ "ad5821", 0 },
352	{ }
353};
354MODULE_DEVICE_TABLE(i2c, ad5820_id_table);
355
356static const struct of_device_id ad5820_of_table[] = {
357	{ .compatible = "adi,ad5820" },
358	{ .compatible = "adi,ad5821" },
359	{ }
360};
361MODULE_DEVICE_TABLE(of, ad5820_of_table);
362
363static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);
364
365static struct i2c_driver ad5820_i2c_driver = {
366	.driver		= {
367		.name	= "ad5820",
368		.pm	= &ad5820_pm,
369		.of_match_table = ad5820_of_table,
370	},
371	.probe		= ad5820_probe,
372	.remove		= ad5820_remove,
373	.id_table	= ad5820_id_table,
374};
375
376module_i2c_driver(ad5820_i2c_driver);
377
378MODULE_AUTHOR("Tuukka Toivonen");
379MODULE_DESCRIPTION("AD5820 camera lens driver");
380MODULE_LICENSE("GPL");
381