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
sd_to_dw9807_vcm(struct v4l2_subdev * subdev)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
dw9807_i2c_check(struct i2c_client * client)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
dw9807_set_dac(struct i2c_client * client,u16 data)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
dw9807_set_ctrl(struct v4l2_ctrl * ctrl)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
dw9807_open(struct v4l2_subdev * sd,struct v4l2_subdev_fh * fh)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
dw9807_close(struct v4l2_subdev * sd,struct v4l2_subdev_fh * fh)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
dw9807_subdev_cleanup(struct dw9807_device * dw9807_dev)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
dw9807_init_controls(struct dw9807_device * dev_vcm)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
dw9807_probe(struct i2c_client * client)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
dw9807_remove(struct i2c_client * client)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 */
dw9807_vcm_suspend(struct device * dev)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 */
dw9807_vcm_resume(struct device * dev)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 { /* sentinel */ }
299 };
300 MODULE_DEVICE_TABLE(of, dw9807_of_table);
301
302 static const struct dev_pm_ops dw9807_pm_ops = {
303 SET_SYSTEM_SLEEP_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume)
304 SET_RUNTIME_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume, NULL)
305 };
306
307 static struct i2c_driver dw9807_i2c_driver = {
308 .driver = {
309 .name = "dw9807",
310 .pm = &dw9807_pm_ops,
311 .of_match_table = dw9807_of_table,
312 },
313 .probe_new = dw9807_probe,
314 .remove = dw9807_remove,
315 };
316
317 module_i2c_driver(dw9807_i2c_driver);
318
319 MODULE_AUTHOR("Chiang, Alan");
320 MODULE_DESCRIPTION("DW9807 VCM driver");
321 MODULE_LICENSE("GPL v2");
322