xref: /openbmc/linux/drivers/media/i2c/dw9714.c (revision bbecb07f)
1 /*
2  * Copyright (c) 2015--2017 Intel Corporation.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License version
6  * 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/i2c.h>
16 #include <linux/module.h>
17 #include <linux/pm_runtime.h>
18 #include <media/v4l2-ctrls.h>
19 #include <media/v4l2-device.h>
20 
21 #define DW9714_NAME		"dw9714"
22 #define DW9714_MAX_FOCUS_POS	1023
23 /*
24  * This sets the minimum granularity for the focus positions.
25  * A value of 1 gives maximum accuracy for a desired focus position
26  */
27 #define DW9714_FOCUS_STEPS	1
28 /*
29  * This acts as the minimum granularity of lens movement.
30  * Keep this value power of 2, so the control steps can be
31  * uniformly adjusted for gradual lens movement, with desired
32  * number of control steps.
33  */
34 #define DW9714_CTRL_STEPS	16
35 #define DW9714_CTRL_DELAY_US	1000
36 /*
37  * S[3:2] = 0x00, codes per step for "Linear Slope Control"
38  * S[1:0] = 0x00, step period
39  */
40 #define DW9714_DEFAULT_S 0x0
41 #define DW9714_VAL(data, s) ((data) << 4 | (s))
42 
43 /* dw9714 device structure */
44 struct dw9714_device {
45 	struct i2c_client *client;
46 	struct v4l2_ctrl_handler ctrls_vcm;
47 	struct v4l2_subdev sd;
48 	u16 current_val;
49 };
50 
51 static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl *ctrl)
52 {
53 	return container_of(ctrl->handler, struct dw9714_device, ctrls_vcm);
54 }
55 
56 static inline struct dw9714_device *sd_to_dw9714_vcm(struct v4l2_subdev *subdev)
57 {
58 	return container_of(subdev, struct dw9714_device, sd);
59 }
60 
61 static int dw9714_i2c_write(struct i2c_client *client, u16 data)
62 {
63 	int ret;
64 	u16 val = cpu_to_be16(data);
65 
66 	ret = i2c_master_send(client, (const char *)&val, sizeof(val));
67 	if (ret != sizeof(val)) {
68 		dev_err(&client->dev, "I2C write fail\n");
69 		return -EIO;
70 	}
71 	return 0;
72 }
73 
74 static int dw9714_t_focus_vcm(struct dw9714_device *dw9714_dev, u16 val)
75 {
76 	struct i2c_client *client = dw9714_dev->client;
77 
78 	dw9714_dev->current_val = val;
79 
80 	return dw9714_i2c_write(client, DW9714_VAL(val, DW9714_DEFAULT_S));
81 }
82 
83 static int dw9714_set_ctrl(struct v4l2_ctrl *ctrl)
84 {
85 	struct dw9714_device *dev_vcm = to_dw9714_vcm(ctrl);
86 
87 	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
88 		return dw9714_t_focus_vcm(dev_vcm, ctrl->val);
89 
90 	return -EINVAL;
91 }
92 
93 static const struct v4l2_ctrl_ops dw9714_vcm_ctrl_ops = {
94 	.s_ctrl = dw9714_set_ctrl,
95 };
96 
97 static int dw9714_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
98 {
99 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
100 	struct device *dev = &dw9714_dev->client->dev;
101 	int rval;
102 
103 	rval = pm_runtime_get_sync(dev);
104 	if (rval < 0) {
105 		pm_runtime_put_noidle(dev);
106 		return rval;
107 	}
108 
109 	return 0;
110 }
111 
112 static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
113 {
114 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
115 	struct device *dev = &dw9714_dev->client->dev;
116 
117 	pm_runtime_put(dev);
118 
119 	return 0;
120 }
121 
122 static const struct v4l2_subdev_internal_ops dw9714_int_ops = {
123 	.open = dw9714_open,
124 	.close = dw9714_close,
125 };
126 
127 static const struct v4l2_subdev_ops dw9714_ops = { };
128 
129 static void dw9714_subdev_cleanup(struct dw9714_device *dw9714_dev)
130 {
131 	v4l2_async_unregister_subdev(&dw9714_dev->sd);
132 	v4l2_ctrl_handler_free(&dw9714_dev->ctrls_vcm);
133 	media_entity_cleanup(&dw9714_dev->sd.entity);
134 }
135 
136 static int dw9714_init_controls(struct dw9714_device *dev_vcm)
137 {
138 	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
139 	const struct v4l2_ctrl_ops *ops = &dw9714_vcm_ctrl_ops;
140 	struct i2c_client *client = dev_vcm->client;
141 
142 	v4l2_ctrl_handler_init(hdl, 1);
143 
144 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
145 			  0, DW9714_MAX_FOCUS_POS, DW9714_FOCUS_STEPS, 0);
146 
147 	if (hdl->error)
148 		dev_err(&client->dev, "%s fail error: 0x%x\n",
149 			__func__, hdl->error);
150 	dev_vcm->sd.ctrl_handler = hdl;
151 	return hdl->error;
152 }
153 
154 static int dw9714_probe(struct i2c_client *client)
155 {
156 	struct dw9714_device *dw9714_dev;
157 	int rval;
158 
159 	dw9714_dev = devm_kzalloc(&client->dev, sizeof(*dw9714_dev),
160 				  GFP_KERNEL);
161 	if (dw9714_dev == NULL)
162 		return -ENOMEM;
163 
164 	dw9714_dev->client = client;
165 
166 	v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
167 	dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
168 	dw9714_dev->sd.internal_ops = &dw9714_int_ops;
169 
170 	rval = dw9714_init_controls(dw9714_dev);
171 	if (rval)
172 		goto err_cleanup;
173 
174 	rval = media_entity_pads_init(&dw9714_dev->sd.entity, 0, NULL);
175 	if (rval < 0)
176 		goto err_cleanup;
177 
178 	dw9714_dev->sd.entity.function = MEDIA_ENT_F_LENS;
179 
180 	rval = v4l2_async_register_subdev(&dw9714_dev->sd);
181 	if (rval < 0)
182 		goto err_cleanup;
183 
184 	pm_runtime_set_active(&client->dev);
185 	pm_runtime_enable(&client->dev);
186 
187 	return 0;
188 
189 err_cleanup:
190 	dw9714_subdev_cleanup(dw9714_dev);
191 	dev_err(&client->dev, "Probe failed: %d\n", rval);
192 	return rval;
193 }
194 
195 static int dw9714_remove(struct i2c_client *client)
196 {
197 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
198 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
199 
200 	pm_runtime_disable(&client->dev);
201 	dw9714_subdev_cleanup(dw9714_dev);
202 
203 	return 0;
204 }
205 
206 /*
207  * This function sets the vcm position, so it consumes least current
208  * The lens position is gradually moved in units of DW9714_CTRL_STEPS,
209  * to make the movements smoothly.
210  */
211 static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
212 {
213 	struct i2c_client *client = to_i2c_client(dev);
214 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
215 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
216 	int ret, val;
217 
218 	for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1);
219 	     val >= 0; val -= DW9714_CTRL_STEPS) {
220 		ret = dw9714_i2c_write(client,
221 				       DW9714_VAL(val, DW9714_DEFAULT_S));
222 		if (ret)
223 			dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
224 		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
225 	}
226 	return 0;
227 }
228 
229 /*
230  * This function sets the vcm position to the value set by the user
231  * through v4l2_ctrl_ops s_ctrl handler
232  * The lens position is gradually moved in units of DW9714_CTRL_STEPS,
233  * to make the movements smoothly.
234  */
235 static int  __maybe_unused dw9714_vcm_resume(struct device *dev)
236 {
237 	struct i2c_client *client = to_i2c_client(dev);
238 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
239 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
240 	int ret, val;
241 
242 	for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
243 	     val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
244 	     val += DW9714_CTRL_STEPS) {
245 		ret = dw9714_i2c_write(client,
246 				       DW9714_VAL(val, DW9714_DEFAULT_S));
247 		if (ret)
248 			dev_err_ratelimited(dev, "%s I2C failure: %d",
249 						__func__, ret);
250 		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
251 	}
252 
253 	return 0;
254 }
255 
256 static const struct i2c_device_id dw9714_id_table[] = {
257 	{ DW9714_NAME, 0 },
258 	{ { 0 } }
259 };
260 MODULE_DEVICE_TABLE(i2c, dw9714_id_table);
261 
262 static const struct of_device_id dw9714_of_table[] = {
263 	{ .compatible = "dongwoon,dw9714" },
264 	{ { 0 } }
265 };
266 MODULE_DEVICE_TABLE(of, dw9714_of_table);
267 
268 static const struct dev_pm_ops dw9714_pm_ops = {
269 	SET_SYSTEM_SLEEP_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_resume)
270 	SET_RUNTIME_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_resume, NULL)
271 };
272 
273 static struct i2c_driver dw9714_i2c_driver = {
274 	.driver = {
275 		.name = DW9714_NAME,
276 		.pm = &dw9714_pm_ops,
277 		.of_match_table = dw9714_of_table,
278 	},
279 	.probe_new = dw9714_probe,
280 	.remove = dw9714_remove,
281 	.id_table = dw9714_id_table,
282 };
283 
284 module_i2c_driver(dw9714_i2c_driver);
285 
286 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
287 MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
288 MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
289 MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@intel.com>");
290 MODULE_AUTHOR("Tommi Franttila <tommi.franttila@intel.com>");
291 MODULE_DESCRIPTION("DW9714 VCM driver");
292 MODULE_LICENSE("GPL v2");
293