xref: /openbmc/linux/drivers/media/i2c/dw9807-vcm.c (revision da1d9caf)
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/iopoll.h>
8 #include <linux/module.h>
9 #include <linux/pm_runtime.h>
10 #include <media/v4l2-ctrls.h>
11 #include <media/v4l2-device.h>
12 
13 #define DW9807_MAX_FOCUS_POS	1023
14 /*
15  * This sets the minimum granularity for the focus positions.
16  * A value of 1 gives maximum accuracy for a desired focus position.
17  */
18 #define DW9807_FOCUS_STEPS	1
19 /*
20  * This acts as the minimum granularity of lens movement.
21  * Keep this value power of 2, so the control steps can be
22  * uniformly adjusted for gradual lens movement, with desired
23  * number of control steps.
24  */
25 #define DW9807_CTRL_STEPS	16
26 #define DW9807_CTRL_DELAY_US	1000
27 
28 #define DW9807_CTL_ADDR		0x02
29 /*
30  * DW9807 separates two registers to control the VCM position.
31  * One for MSB value, another is LSB value.
32  */
33 #define DW9807_MSB_ADDR		0x03
34 #define DW9807_LSB_ADDR		0x04
35 #define DW9807_STATUS_ADDR	0x05
36 #define DW9807_MODE_ADDR	0x06
37 #define DW9807_RESONANCE_ADDR	0x07
38 
39 #define MAX_RETRY		10
40 
41 struct dw9807_device {
42 	struct v4l2_ctrl_handler ctrls_vcm;
43 	struct v4l2_subdev sd;
44 	u16 current_val;
45 };
46 
47 static inline struct dw9807_device *sd_to_dw9807_vcm(
48 					struct v4l2_subdev *subdev)
49 {
50 	return container_of(subdev, struct dw9807_device, sd);
51 }
52 
53 static int dw9807_i2c_check(struct i2c_client *client)
54 {
55 	const char status_addr = DW9807_STATUS_ADDR;
56 	char status_result;
57 	int ret;
58 
59 	ret = i2c_master_send(client, &status_addr, sizeof(status_addr));
60 	if (ret < 0) {
61 		dev_err(&client->dev, "I2C write STATUS address fail ret = %d\n",
62 			ret);
63 		return ret;
64 	}
65 
66 	ret = i2c_master_recv(client, &status_result, sizeof(status_result));
67 	if (ret < 0) {
68 		dev_err(&client->dev, "I2C read STATUS value fail ret = %d\n",
69 			ret);
70 		return ret;
71 	}
72 
73 	return status_result;
74 }
75 
76 static int dw9807_set_dac(struct i2c_client *client, u16 data)
77 {
78 	const char tx_data[3] = {
79 		DW9807_MSB_ADDR, ((data >> 8) & 0x03), (data & 0xff)
80 	};
81 	int val, ret;
82 
83 	/*
84 	 * According to the datasheet, need to check the bus status before we
85 	 * write VCM position. This ensure that we really write the value
86 	 * into the register
87 	 */
88 	ret = readx_poll_timeout(dw9807_i2c_check, client, val, val <= 0,
89 			DW9807_CTRL_DELAY_US, MAX_RETRY * DW9807_CTRL_DELAY_US);
90 
91 	if (ret || val < 0) {
92 		if (ret) {
93 			dev_warn(&client->dev,
94 				"Cannot do the write operation because VCM is busy\n");
95 		}
96 
97 		return ret ? -EBUSY : val;
98 	}
99 
100 	/* Write VCM position to registers */
101 	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
102 	if (ret < 0) {
103 		dev_err(&client->dev,
104 			"I2C write MSB fail ret=%d\n", ret);
105 
106 		return ret;
107 	}
108 
109 	return 0;
110 }
111 
112 static int dw9807_set_ctrl(struct v4l2_ctrl *ctrl)
113 {
114 	struct dw9807_device *dev_vcm = container_of(ctrl->handler,
115 		struct dw9807_device, ctrls_vcm);
116 
117 	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE) {
118 		struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd);
119 
120 		dev_vcm->current_val = ctrl->val;
121 		return dw9807_set_dac(client, ctrl->val);
122 	}
123 
124 	return -EINVAL;
125 }
126 
127 static const struct v4l2_ctrl_ops dw9807_vcm_ctrl_ops = {
128 	.s_ctrl = dw9807_set_ctrl,
129 };
130 
131 static int dw9807_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
132 {
133 	return pm_runtime_resume_and_get(sd->dev);
134 }
135 
136 static int dw9807_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
137 {
138 	pm_runtime_put(sd->dev);
139 
140 	return 0;
141 }
142 
143 static const struct v4l2_subdev_internal_ops dw9807_int_ops = {
144 	.open = dw9807_open,
145 	.close = dw9807_close,
146 };
147 
148 static const struct v4l2_subdev_ops dw9807_ops = { };
149 
150 static void dw9807_subdev_cleanup(struct dw9807_device *dw9807_dev)
151 {
152 	v4l2_async_unregister_subdev(&dw9807_dev->sd);
153 	v4l2_ctrl_handler_free(&dw9807_dev->ctrls_vcm);
154 	media_entity_cleanup(&dw9807_dev->sd.entity);
155 }
156 
157 static int dw9807_init_controls(struct dw9807_device *dev_vcm)
158 {
159 	struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm;
160 	const struct v4l2_ctrl_ops *ops = &dw9807_vcm_ctrl_ops;
161 	struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd);
162 
163 	v4l2_ctrl_handler_init(hdl, 1);
164 
165 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE,
166 			  0, DW9807_MAX_FOCUS_POS, DW9807_FOCUS_STEPS, 0);
167 
168 	dev_vcm->sd.ctrl_handler = hdl;
169 	if (hdl->error) {
170 		dev_err(&client->dev, "%s fail error: 0x%x\n",
171 			__func__, hdl->error);
172 		return hdl->error;
173 	}
174 
175 	return 0;
176 }
177 
178 static int dw9807_probe(struct i2c_client *client)
179 {
180 	struct dw9807_device *dw9807_dev;
181 	int rval;
182 
183 	dw9807_dev = devm_kzalloc(&client->dev, sizeof(*dw9807_dev),
184 				  GFP_KERNEL);
185 	if (dw9807_dev == NULL)
186 		return -ENOMEM;
187 
188 	v4l2_i2c_subdev_init(&dw9807_dev->sd, client, &dw9807_ops);
189 	dw9807_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
190 	dw9807_dev->sd.internal_ops = &dw9807_int_ops;
191 
192 	rval = dw9807_init_controls(dw9807_dev);
193 	if (rval)
194 		goto err_cleanup;
195 
196 	rval = media_entity_pads_init(&dw9807_dev->sd.entity, 0, NULL);
197 	if (rval < 0)
198 		goto err_cleanup;
199 
200 	dw9807_dev->sd.entity.function = MEDIA_ENT_F_LENS;
201 
202 	rval = v4l2_async_register_subdev(&dw9807_dev->sd);
203 	if (rval < 0)
204 		goto err_cleanup;
205 
206 	pm_runtime_set_active(&client->dev);
207 	pm_runtime_enable(&client->dev);
208 	pm_runtime_idle(&client->dev);
209 
210 	return 0;
211 
212 err_cleanup:
213 	v4l2_ctrl_handler_free(&dw9807_dev->ctrls_vcm);
214 	media_entity_cleanup(&dw9807_dev->sd.entity);
215 
216 	return rval;
217 }
218 
219 static int dw9807_remove(struct i2c_client *client)
220 {
221 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
222 	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
223 
224 	pm_runtime_disable(&client->dev);
225 
226 	dw9807_subdev_cleanup(dw9807_dev);
227 
228 	return 0;
229 }
230 
231 /*
232  * This function sets the vcm position, so it consumes least current
233  * The lens position is gradually moved in units of DW9807_CTRL_STEPS,
234  * to make the movements smoothly.
235  */
236 static int __maybe_unused dw9807_vcm_suspend(struct device *dev)
237 {
238 	struct i2c_client *client = to_i2c_client(dev);
239 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
240 	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
241 	const char tx_data[2] = { DW9807_CTL_ADDR, 0x01 };
242 	int ret, val;
243 
244 	for (val = dw9807_dev->current_val & ~(DW9807_CTRL_STEPS - 1);
245 	     val >= 0; val -= DW9807_CTRL_STEPS) {
246 		ret = dw9807_set_dac(client, val);
247 		if (ret)
248 			dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
249 		usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10);
250 	}
251 
252 	/* Power down */
253 	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
254 	if (ret < 0) {
255 		dev_err(&client->dev, "I2C write CTL fail ret = %d\n", ret);
256 		return ret;
257 	}
258 
259 	return 0;
260 }
261 
262 /*
263  * This function sets the vcm position to the value set by the user
264  * through v4l2_ctrl_ops s_ctrl handler
265  * The lens position is gradually moved in units of DW9807_CTRL_STEPS,
266  * to make the movements smoothly.
267  */
268 static int  __maybe_unused dw9807_vcm_resume(struct device *dev)
269 {
270 	struct i2c_client *client = to_i2c_client(dev);
271 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
272 	struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd);
273 	const char tx_data[2] = { DW9807_CTL_ADDR, 0x00 };
274 	int ret, val;
275 
276 	/* Power on */
277 	ret = i2c_master_send(client, tx_data, sizeof(tx_data));
278 	if (ret < 0) {
279 		dev_err(&client->dev, "I2C write CTL fail ret = %d\n", ret);
280 		return ret;
281 	}
282 
283 	for (val = dw9807_dev->current_val % DW9807_CTRL_STEPS;
284 	     val < dw9807_dev->current_val + DW9807_CTRL_STEPS - 1;
285 	     val += DW9807_CTRL_STEPS) {
286 		ret = dw9807_set_dac(client, val);
287 		if (ret)
288 			dev_err_ratelimited(dev, "%s I2C failure: %d",
289 						__func__, ret);
290 		usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10);
291 	}
292 
293 	return 0;
294 }
295 
296 static const struct of_device_id dw9807_of_table[] = {
297 	{ .compatible = "dongwoon,dw9807-vcm" },
298 	/* Compatibility for older firmware, NEVER USE THIS IN FIRMWARE! */
299 	{ .compatible = "dongwoon,dw9807" },
300 	{ /* sentinel */ }
301 };
302 MODULE_DEVICE_TABLE(of, dw9807_of_table);
303 
304 static const struct dev_pm_ops dw9807_pm_ops = {
305 	SET_SYSTEM_SLEEP_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume)
306 	SET_RUNTIME_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume, NULL)
307 };
308 
309 static struct i2c_driver dw9807_i2c_driver = {
310 	.driver = {
311 		.name = "dw9807",
312 		.pm = &dw9807_pm_ops,
313 		.of_match_table = dw9807_of_table,
314 	},
315 	.probe_new = dw9807_probe,
316 	.remove = dw9807_remove,
317 };
318 
319 module_i2c_driver(dw9807_i2c_driver);
320 
321 MODULE_AUTHOR("Chiang, Alan");
322 MODULE_DESCRIPTION("DW9807 VCM driver");
323 MODULE_LICENSE("GPL v2");
324