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
23 #include <media/v4l2-ctrls.h>
24 #include <media/v4l2-device.h>
25 #include <media/v4l2-subdev.h>
26
27 #define AD5820_NAME "ad5820"
28
29 /* Register definitions */
30 #define AD5820_POWER_DOWN (1 << 15)
31 #define AD5820_DAC_SHIFT 4
32 #define AD5820_RAMP_MODE_LINEAR (0 << 3)
33 #define AD5820_RAMP_MODE_64_16 (1 << 3)
34
35 #define CODE_TO_RAMP_US(s) ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
36 #define RAMP_US_TO_CODE(c) fls(((c) + ((c)>>1)) / 50)
37
38 #define to_ad5820_device(sd) container_of(sd, struct ad5820_device, subdev)
39
40 struct ad5820_device {
41 struct v4l2_subdev subdev;
42 struct ad5820_platform_data *platform_data;
43 struct regulator *vana;
44
45 struct v4l2_ctrl_handler ctrls;
46 u32 focus_absolute;
47 u32 focus_ramp_time;
48 u32 focus_ramp_mode;
49
50 struct mutex power_lock;
51 int power_count;
52
53 bool standby;
54 };
55
ad5820_write(struct ad5820_device * coil,u16 data)56 static int ad5820_write(struct ad5820_device *coil, u16 data)
57 {
58 struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
59 struct i2c_msg msg;
60 __be16 be_data;
61 int r;
62
63 if (!client->adapter)
64 return -ENODEV;
65
66 be_data = cpu_to_be16(data);
67 msg.addr = client->addr;
68 msg.flags = 0;
69 msg.len = 2;
70 msg.buf = (u8 *)&be_data;
71
72 r = i2c_transfer(client->adapter, &msg, 1);
73 if (r < 0) {
74 dev_err(&client->dev, "write failed, error %d\n", r);
75 return r;
76 }
77
78 return 0;
79 }
80
81 /*
82 * Calculate status word and write it to the device based on current
83 * values of V4L2 controls. It is assumed that the stored V4L2 control
84 * values are properly limited and rounded.
85 */
ad5820_update_hw(struct ad5820_device * coil)86 static int ad5820_update_hw(struct ad5820_device *coil)
87 {
88 u16 status;
89
90 status = RAMP_US_TO_CODE(coil->focus_ramp_time);
91 status |= coil->focus_ramp_mode
92 ? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
93 status |= coil->focus_absolute << AD5820_DAC_SHIFT;
94
95 if (coil->standby)
96 status |= AD5820_POWER_DOWN;
97
98 return ad5820_write(coil, status);
99 }
100
101 /*
102 * Power handling
103 */
ad5820_power_off(struct ad5820_device * coil,bool standby)104 static int ad5820_power_off(struct ad5820_device *coil, bool standby)
105 {
106 int ret = 0, ret2;
107
108 /*
109 * Go to standby first as real power off my be denied by the hardware
110 * (single power line control for both coil and sensor).
111 */
112 if (standby) {
113 coil->standby = true;
114 ret = ad5820_update_hw(coil);
115 }
116
117 ret2 = regulator_disable(coil->vana);
118 if (ret)
119 return ret;
120 return ret2;
121 }
122
ad5820_power_on(struct ad5820_device * coil,bool restore)123 static int ad5820_power_on(struct ad5820_device *coil, bool restore)
124 {
125 int ret;
126
127 ret = regulator_enable(coil->vana);
128 if (ret < 0)
129 return ret;
130
131 if (restore) {
132 /* Restore the hardware settings. */
133 coil->standby = false;
134 ret = ad5820_update_hw(coil);
135 if (ret)
136 goto fail;
137 }
138 return 0;
139
140 fail:
141 coil->standby = true;
142 regulator_disable(coil->vana);
143
144 return ret;
145 }
146
147 /*
148 * V4L2 controls
149 */
ad5820_set_ctrl(struct v4l2_ctrl * ctrl)150 static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
151 {
152 struct ad5820_device *coil =
153 container_of(ctrl->handler, struct ad5820_device, ctrls);
154
155 switch (ctrl->id) {
156 case V4L2_CID_FOCUS_ABSOLUTE:
157 coil->focus_absolute = ctrl->val;
158 return ad5820_update_hw(coil);
159 }
160
161 return 0;
162 }
163
164 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
165 .s_ctrl = ad5820_set_ctrl,
166 };
167
168
ad5820_init_controls(struct ad5820_device * coil)169 static int ad5820_init_controls(struct ad5820_device *coil)
170 {
171 v4l2_ctrl_handler_init(&coil->ctrls, 1);
172
173 /*
174 * V4L2_CID_FOCUS_ABSOLUTE
175 *
176 * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
177 * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA]
178 * for focus position, because it is meaningless for user. Meaningful
179 * would be to use focus distance or even its inverse, but since the
180 * driver doesn't have sufficiently knowledge to do the conversion, we
181 * will just use abstract codes here. In any case, smaller value = focus
182 * position farther from camera. The default zero value means focus at
183 * infinity, and also least current consumption.
184 */
185 v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
186 V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
187
188 if (coil->ctrls.error)
189 return coil->ctrls.error;
190
191 coil->focus_absolute = 0;
192 coil->focus_ramp_time = 0;
193 coil->focus_ramp_mode = 0;
194
195 coil->subdev.ctrl_handler = &coil->ctrls;
196
197 return 0;
198 }
199
200 /*
201 * V4L2 subdev operations
202 */
ad5820_registered(struct v4l2_subdev * subdev)203 static int ad5820_registered(struct v4l2_subdev *subdev)
204 {
205 struct ad5820_device *coil = to_ad5820_device(subdev);
206
207 return ad5820_init_controls(coil);
208 }
209
210 static int
ad5820_set_power(struct v4l2_subdev * subdev,int on)211 ad5820_set_power(struct v4l2_subdev *subdev, int on)
212 {
213 struct ad5820_device *coil = to_ad5820_device(subdev);
214 int ret = 0;
215
216 mutex_lock(&coil->power_lock);
217
218 /*
219 * If the power count is modified from 0 to != 0 or from != 0 to 0,
220 * update the power state.
221 */
222 if (coil->power_count == !on) {
223 ret = on ? ad5820_power_on(coil, true) :
224 ad5820_power_off(coil, true);
225 if (ret < 0)
226 goto done;
227 }
228
229 /* Update the power count. */
230 coil->power_count += on ? 1 : -1;
231 WARN_ON(coil->power_count < 0);
232
233 done:
234 mutex_unlock(&coil->power_lock);
235 return ret;
236 }
237
ad5820_open(struct v4l2_subdev * sd,struct v4l2_subdev_fh * fh)238 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
239 {
240 return ad5820_set_power(sd, 1);
241 }
242
ad5820_close(struct v4l2_subdev * sd,struct v4l2_subdev_fh * fh)243 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
244 {
245 return ad5820_set_power(sd, 0);
246 }
247
248 static const struct v4l2_subdev_core_ops ad5820_core_ops = {
249 .s_power = ad5820_set_power,
250 };
251
252 static const struct v4l2_subdev_ops ad5820_ops = {
253 .core = &ad5820_core_ops,
254 };
255
256 static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
257 .registered = ad5820_registered,
258 .open = ad5820_open,
259 .close = ad5820_close,
260 };
261
262 /*
263 * I2C driver
264 */
ad5820_suspend(struct device * dev)265 static int __maybe_unused ad5820_suspend(struct device *dev)
266 {
267 struct i2c_client *client = container_of(dev, struct i2c_client, dev);
268 struct v4l2_subdev *subdev = i2c_get_clientdata(client);
269 struct ad5820_device *coil = to_ad5820_device(subdev);
270
271 if (!coil->power_count)
272 return 0;
273
274 return ad5820_power_off(coil, false);
275 }
276
ad5820_resume(struct device * dev)277 static int __maybe_unused ad5820_resume(struct device *dev)
278 {
279 struct i2c_client *client = container_of(dev, struct i2c_client, dev);
280 struct v4l2_subdev *subdev = i2c_get_clientdata(client);
281 struct ad5820_device *coil = to_ad5820_device(subdev);
282
283 if (!coil->power_count)
284 return 0;
285
286 return ad5820_power_on(coil, true);
287 }
288
ad5820_probe(struct i2c_client * client,const struct i2c_device_id * devid)289 static int ad5820_probe(struct i2c_client *client,
290 const struct i2c_device_id *devid)
291 {
292 struct ad5820_device *coil;
293 int ret;
294
295 coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL);
296 if (!coil)
297 return -ENOMEM;
298
299 coil->vana = devm_regulator_get(&client->dev, "VANA");
300 if (IS_ERR(coil->vana)) {
301 ret = PTR_ERR(coil->vana);
302 if (ret != -EPROBE_DEFER)
303 dev_err(&client->dev, "could not get regulator for vana\n");
304 return ret;
305 }
306
307 mutex_init(&coil->power_lock);
308
309 v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
310 coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
311 coil->subdev.internal_ops = &ad5820_internal_ops;
312 strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name));
313
314 ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
315 if (ret < 0)
316 goto cleanup2;
317
318 ret = v4l2_async_register_subdev(&coil->subdev);
319 if (ret < 0)
320 goto cleanup;
321
322 return ret;
323
324 cleanup2:
325 mutex_destroy(&coil->power_lock);
326 cleanup:
327 media_entity_cleanup(&coil->subdev.entity);
328 return ret;
329 }
330
ad5820_remove(struct i2c_client * client)331 static int ad5820_remove(struct i2c_client *client)
332 {
333 struct v4l2_subdev *subdev = i2c_get_clientdata(client);
334 struct ad5820_device *coil = to_ad5820_device(subdev);
335
336 v4l2_async_unregister_subdev(&coil->subdev);
337 v4l2_ctrl_handler_free(&coil->ctrls);
338 media_entity_cleanup(&coil->subdev.entity);
339 mutex_destroy(&coil->power_lock);
340 return 0;
341 }
342
343 static const struct i2c_device_id ad5820_id_table[] = {
344 { AD5820_NAME, 0 },
345 { }
346 };
347 MODULE_DEVICE_TABLE(i2c, ad5820_id_table);
348
349 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);
350
351 static struct i2c_driver ad5820_i2c_driver = {
352 .driver = {
353 .name = AD5820_NAME,
354 .pm = &ad5820_pm,
355 },
356 .probe = ad5820_probe,
357 .remove = ad5820_remove,
358 .id_table = ad5820_id_table,
359 };
360
361 module_i2c_driver(ad5820_i2c_driver);
362
363 MODULE_AUTHOR("Tuukka Toivonen");
364 MODULE_DESCRIPTION("AD5820 camera lens driver");
365 MODULE_LICENSE("GPL");
366
