xref: /linux/drivers/media/i2c/ad5820.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd) 
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 
39 struct 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 
57 static 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  */
87 static 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  */
105 static 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 
126 static 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 
145 fail:
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  */
156 static 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 
170 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
171 	.s_ctrl = ad5820_set_ctrl,
172 };
173 
174 
175 static 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  */
209 static 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 
216 static int
217 ad5820_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 
239 done:
240 	mutex_unlock(&coil->power_lock);
241 	return ret;
242 }
243 
244 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
245 {
246 	return ad5820_set_power(sd, 1);
247 }
248 
249 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
250 {
251 	return ad5820_set_power(sd, 0);
252 }
253 
254 static const struct v4l2_subdev_core_ops ad5820_core_ops = {
255 	.s_power = ad5820_set_power,
256 };
257 
258 static const struct v4l2_subdev_ops ad5820_ops = {
259 	.core = &ad5820_core_ops,
260 };
261 
262 static 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  */
271 static int __maybe_unused ad5820_suspend(struct device *dev)
272 {
273 	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
274 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
275 	struct ad5820_device *coil = to_ad5820_device(subdev);
276 
277 	if (!coil->power_count)
278 		return 0;
279 
280 	return ad5820_power_off(coil, false);
281 }
282 
283 static int __maybe_unused ad5820_resume(struct device *dev)
284 {
285 	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
286 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
287 	struct ad5820_device *coil = to_ad5820_device(subdev);
288 
289 	if (!coil->power_count)
290 		return 0;
291 
292 	return ad5820_power_on(coil, true);
293 }
294 
295 static int ad5820_probe(struct i2c_client *client,
296 			const struct i2c_device_id *devid)
297 {
298 	struct ad5820_device *coil;
299 	int ret;
300 
301 	coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL);
302 	if (!coil)
303 		return -ENOMEM;
304 
305 	coil->vana = devm_regulator_get(&client->dev, "VANA");
306 	if (IS_ERR(coil->vana)) {
307 		ret = PTR_ERR(coil->vana);
308 		if (ret != -EPROBE_DEFER)
309 			dev_err(&client->dev, "could not get regulator for vana\n");
310 		return ret;
311 	}
312 
313 	coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
314 						    GPIOD_OUT_LOW);
315 	if (IS_ERR(coil->enable_gpio)) {
316 		ret = PTR_ERR(coil->enable_gpio);
317 		if (ret != -EPROBE_DEFER)
318 			dev_err(&client->dev, "could not get enable gpio\n");
319 		return ret;
320 	}
321 
322 	mutex_init(&coil->power_lock);
323 
324 	v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
325 	coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
326 	coil->subdev.internal_ops = &ad5820_internal_ops;
327 	coil->subdev.entity.function = MEDIA_ENT_F_LENS;
328 	strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name));
329 
330 	ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
331 	if (ret < 0)
332 		goto cleanup2;
333 
334 	ret = v4l2_async_register_subdev(&coil->subdev);
335 	if (ret < 0)
336 		goto cleanup;
337 
338 	return ret;
339 
340 cleanup2:
341 	mutex_destroy(&coil->power_lock);
342 cleanup:
343 	media_entity_cleanup(&coil->subdev.entity);
344 	return ret;
345 }
346 
347 static int ad5820_remove(struct i2c_client *client)
348 {
349 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
350 	struct ad5820_device *coil = to_ad5820_device(subdev);
351 
352 	v4l2_async_unregister_subdev(&coil->subdev);
353 	v4l2_ctrl_handler_free(&coil->ctrls);
354 	media_entity_cleanup(&coil->subdev.entity);
355 	mutex_destroy(&coil->power_lock);
356 	return 0;
357 }
358 
359 static const struct i2c_device_id ad5820_id_table[] = {
360 	{ "ad5820", 0 },
361 	{ "ad5821", 0 },
362 	{ "ad5823", 0 },
363 	{ }
364 };
365 MODULE_DEVICE_TABLE(i2c, ad5820_id_table);
366 
367 static const struct of_device_id ad5820_of_table[] = {
368 	{ .compatible = "adi,ad5820" },
369 	{ .compatible = "adi,ad5821" },
370 	{ .compatible = "adi,ad5823" },
371 	{ }
372 };
373 MODULE_DEVICE_TABLE(of, ad5820_of_table);
374 
375 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);
376 
377 static struct i2c_driver ad5820_i2c_driver = {
378 	.driver		= {
379 		.name	= "ad5820",
380 		.pm	= &ad5820_pm,
381 		.of_match_table = ad5820_of_table,
382 	},
383 	.probe		= ad5820_probe,
384 	.remove		= ad5820_remove,
385 	.id_table	= ad5820_id_table,
386 };
387 
388 module_i2c_driver(ad5820_i2c_driver);
389 
390 MODULE_AUTHOR("Tuukka Toivonen");
391 MODULE_DESCRIPTION("AD5820 camera lens driver");
392 MODULE_LICENSE("GPL");
393