xref: /openbmc/linux/drivers/media/i2c/dw9714.c (revision b78412b8)
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 acts as the minimum granularity of lens movement.
25  * Keep this value power of 2, so the control steps can be
26  * uniformly adjusted for gradual lens movement, with desired
27  * number of control steps.
28  */
29 #define DW9714_CTRL_STEPS	16
30 #define DW9714_CTRL_DELAY_US	1000
31 /*
32  * S[3:2] = 0x00, codes per step for "Linear Slope Control"
33  * S[1:0] = 0x00, step period
34  */
35 #define DW9714_DEFAULT_S 0x0
36 #define DW9714_VAL(data, s) ((data) << 4 | (s))
37 
38 /* dw9714 device structure */
39 struct dw9714_device {
40 	struct i2c_client *client;
41 	struct v4l2_ctrl_handler ctrls_vcm;
42 	struct v4l2_subdev sd;
43 	u16 current_val;
44 };
45 
46 static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl *ctrl)
47 {
48 	return container_of(ctrl->handler, struct dw9714_device, ctrls_vcm);
49 }
50 
51 static inline struct dw9714_device *sd_to_dw9714_vcm(struct v4l2_subdev *subdev)
52 {
53 	return container_of(subdev, struct dw9714_device, sd);
54 }
55 
56 static int dw9714_i2c_write(struct i2c_client *client, u16 data)
57 {
58 	int ret;
59 	u16 val = cpu_to_be16(data);
60 
61 	ret = i2c_master_send(client, (const char *)&val, sizeof(val));
62 	if (ret != sizeof(val)) {
63 		dev_err(&client->dev, "I2C write fail\n");
64 		return -EIO;
65 	}
66 	return 0;
67 }
68 
69 static int dw9714_t_focus_vcm(struct dw9714_device *dw9714_dev, u16 val)
70 {
71 	struct i2c_client *client = dw9714_dev->client;
72 
73 	dw9714_dev->current_val = val;
74 
75 	return dw9714_i2c_write(client, DW9714_VAL(val, DW9714_DEFAULT_S));
76 }
77 
78 static int dw9714_set_ctrl(struct v4l2_ctrl *ctrl)
79 {
80 	struct dw9714_device *dev_vcm = to_dw9714_vcm(ctrl);
81 
82 	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
83 		return dw9714_t_focus_vcm(dev_vcm, ctrl->val);
84 
85 	return -EINVAL;
86 }
87 
88 static const struct v4l2_ctrl_ops dw9714_vcm_ctrl_ops = {
89 	.s_ctrl = dw9714_set_ctrl,
90 };
91 
92 static int dw9714_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
93 {
94 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
95 	struct device *dev = &dw9714_dev->client->dev;
96 	int rval;
97 
98 	rval = pm_runtime_get_sync(dev);
99 	if (rval < 0) {
100 		pm_runtime_put_noidle(dev);
101 		return rval;
102 	}
103 
104 	return 0;
105 }
106 
107 static int dw9714_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
108 {
109 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
110 	struct device *dev = &dw9714_dev->client->dev;
111 
112 	pm_runtime_put(dev);
113 
114 	return 0;
115 }
116 
117 static const struct v4l2_subdev_internal_ops dw9714_int_ops = {
118 	.open = dw9714_open,
119 	.close = dw9714_close,
120 };
121 
122 static const struct v4l2_subdev_ops dw9714_ops = { };
123 
124 static void dw9714_subdev_cleanup(struct dw9714_device *dw9714_dev)
125 {
126 	v4l2_async_unregister_subdev(&dw9714_dev->sd);
127 	v4l2_ctrl_handler_free(&dw9714_dev->ctrls_vcm);
128 	media_entity_cleanup(&dw9714_dev->sd.entity);
129 }
130 
131 static int dw9714_init_controls(struct dw9714_device *dev_vcm)
132 {
133 	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
134 	const struct v4l2_ctrl_ops *ops = &dw9714_vcm_ctrl_ops;
135 	struct i2c_client *client = dev_vcm->client;
136 
137 	v4l2_ctrl_handler_init(hdl, 1);
138 
139 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
140 			  0, DW9714_MAX_FOCUS_POS, DW9714_CTRL_STEPS, 0);
141 
142 	if (hdl->error)
143 		dev_err(&client->dev, "%s fail error: 0x%x\n",
144 			__func__, hdl->error);
145 	dev_vcm->sd.ctrl_handler = hdl;
146 	return hdl->error;
147 }
148 
149 static int dw9714_probe(struct i2c_client *client)
150 {
151 	struct dw9714_device *dw9714_dev;
152 	int rval;
153 
154 	dw9714_dev = devm_kzalloc(&client->dev, sizeof(*dw9714_dev),
155 				  GFP_KERNEL);
156 	if (dw9714_dev == NULL)
157 		return -ENOMEM;
158 
159 	dw9714_dev->client = client;
160 
161 	v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
162 	dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
163 	dw9714_dev->sd.internal_ops = &dw9714_int_ops;
164 
165 	rval = dw9714_init_controls(dw9714_dev);
166 	if (rval)
167 		goto err_cleanup;
168 
169 	rval = media_entity_pads_init(&dw9714_dev->sd.entity, 0, NULL);
170 	if (rval < 0)
171 		goto err_cleanup;
172 
173 	dw9714_dev->sd.entity.function = MEDIA_ENT_F_LENS;
174 
175 	rval = v4l2_async_register_subdev(&dw9714_dev->sd);
176 	if (rval < 0)
177 		goto err_cleanup;
178 
179 	pm_runtime_set_active(&client->dev);
180 	pm_runtime_enable(&client->dev);
181 
182 	return 0;
183 
184 err_cleanup:
185 	dw9714_subdev_cleanup(dw9714_dev);
186 	dev_err(&client->dev, "Probe failed: %d\n", rval);
187 	return rval;
188 }
189 
190 static int dw9714_remove(struct i2c_client *client)
191 {
192 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
193 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
194 
195 	pm_runtime_disable(&client->dev);
196 	dw9714_subdev_cleanup(dw9714_dev);
197 
198 	return 0;
199 }
200 
201 /*
202  * This function sets the vcm position, so it consumes least current
203  * The lens position is gradually moved in units of DW9714_CTRL_STEPS,
204  * to make the movements smoothly.
205  */
206 static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
207 {
208 	struct i2c_client *client = to_i2c_client(dev);
209 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
210 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
211 	int ret, val;
212 
213 	for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1);
214 	     val >= 0; val -= DW9714_CTRL_STEPS) {
215 		ret = dw9714_i2c_write(client,
216 				       DW9714_VAL(val, DW9714_DEFAULT_S));
217 		if (ret)
218 			dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
219 		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
220 	}
221 	return 0;
222 }
223 
224 /*
225  * This function sets the vcm position to the value set by the user
226  * through v4l2_ctrl_ops s_ctrl handler
227  * The lens position is gradually moved in units of DW9714_CTRL_STEPS,
228  * to make the movements smoothly.
229  */
230 static int  __maybe_unused dw9714_vcm_resume(struct device *dev)
231 {
232 	struct i2c_client *client = to_i2c_client(dev);
233 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
234 	struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
235 	int ret, val;
236 
237 	for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
238 	     val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
239 	     val += DW9714_CTRL_STEPS) {
240 		ret = dw9714_i2c_write(client,
241 				       DW9714_VAL(val, DW9714_DEFAULT_S));
242 		if (ret)
243 			dev_err_ratelimited(dev, "%s I2C failure: %d",
244 						__func__, ret);
245 		usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
246 	}
247 
248 	return 0;
249 }
250 
251 static const struct i2c_device_id dw9714_id_table[] = {
252 	{ DW9714_NAME, 0 },
253 	{ { 0 } }
254 };
255 MODULE_DEVICE_TABLE(i2c, dw9714_id_table);
256 
257 static const struct of_device_id dw9714_of_table[] = {
258 	{ .compatible = "dongwoon,dw9714" },
259 	{ { 0 } }
260 };
261 MODULE_DEVICE_TABLE(of, dw9714_of_table);
262 
263 static const struct dev_pm_ops dw9714_pm_ops = {
264 	SET_SYSTEM_SLEEP_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_resume)
265 	SET_RUNTIME_PM_OPS(dw9714_vcm_suspend, dw9714_vcm_resume, NULL)
266 };
267 
268 static struct i2c_driver dw9714_i2c_driver = {
269 	.driver = {
270 		.name = DW9714_NAME,
271 		.pm = &dw9714_pm_ops,
272 		.of_match_table = dw9714_of_table,
273 	},
274 	.probe_new = dw9714_probe,
275 	.remove = dw9714_remove,
276 	.id_table = dw9714_id_table,
277 };
278 
279 module_i2c_driver(dw9714_i2c_driver);
280 
281 MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
282 MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
283 MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
284 MODULE_AUTHOR("Jouni Ukkonen <jouni.ukkonen@intel.com>");
285 MODULE_AUTHOR("Tommi Franttila <tommi.franttila@intel.com>");
286 MODULE_DESCRIPTION("DW9714 VCM driver");
287 MODULE_LICENSE("GPL v2");
288