xref: /linux/drivers/media/i2c/ak7375.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
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 
13 struct 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 
41 static 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 
54 static 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 
68 static const char * const ak7375_supply_names[] = {
69 	"vdd",
70 	"vio",
71 };
72 
73 /* ak7375 device structure */
74 struct 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 
85 static 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 
90 static inline struct ak7375_device *sd_to_ak7375_vcm(struct v4l2_subdev *subdev)
91 {
92 	return container_of(subdev, struct ak7375_device, sd);
93 }
94 
95 static 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 
117 static 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 
129 static const struct v4l2_ctrl_ops ak7375_vcm_ctrl_ops = {
130 	.s_ctrl = ak7375_set_ctrl,
131 };
132 
133 static int ak7375_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
134 {
135 	return pm_runtime_resume_and_get(sd->dev);
136 }
137 
138 static 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 
145 static const struct v4l2_subdev_internal_ops ak7375_int_ops = {
146 	.open = ak7375_open,
147 	.close = ak7375_close,
148 };
149 
150 static const struct v4l2_subdev_ops ak7375_ops = { };
151 
152 static 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 
159 static 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 
178 static 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 
225 err_cleanup:
226 	v4l2_ctrl_handler_free(&ak7375_dev->ctrls_vcm);
227 	media_entity_cleanup(&ak7375_dev->sd.entity);
228 
229 	return ret;
230 }
231 
232 static 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  */
247 static 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  */
290 static 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 
331 static 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 };
336 MODULE_DEVICE_TABLE(of, ak7375_of_table);
337 
338 static 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 
343 static 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 };
352 module_i2c_driver(ak7375_i2c_driver);
353 
354 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
355 MODULE_AUTHOR("Bingbu Cao <bingbu.cao@intel.com>");
356 MODULE_DESCRIPTION("AK7375 VCM driver");
357 MODULE_LICENSE("GPL v2");
358