1 /* 2 * drivers/media/i2c/ad5820.c 3 * 4 * AD5820 DAC driver for camera voice coil focus. 5 * 6 * Copyright (C) 2008 Nokia Corporation 7 * Copyright (C) 2007 Texas Instruments 8 * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz> 9 * 10 * Contact: Tuukka Toivonen <tuukkat76@gmail.com> 11 * Sakari Ailus <sakari.ailus@iki.fi> 12 * 13 * Based on af_d88.c by Texas Instruments. 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License 17 * version 2 as published by the Free Software Foundation. 18 * 19 * This program is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 */ 24 25 #include <linux/errno.h> 26 #include <linux/i2c.h> 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/regulator/consumer.h> 30 31 #include <media/v4l2-ctrls.h> 32 #include <media/v4l2-device.h> 33 #include <media/v4l2-subdev.h> 34 35 #define AD5820_NAME "ad5820" 36 37 /* Register definitions */ 38 #define AD5820_POWER_DOWN (1 << 15) 39 #define AD5820_DAC_SHIFT 4 40 #define AD5820_RAMP_MODE_LINEAR (0 << 3) 41 #define AD5820_RAMP_MODE_64_16 (1 << 3) 42 43 #define CODE_TO_RAMP_US(s) ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50) 44 #define RAMP_US_TO_CODE(c) fls(((c) + ((c)>>1)) / 50) 45 46 #define to_ad5820_device(sd) container_of(sd, struct ad5820_device, subdev) 47 48 struct ad5820_device { 49 struct v4l2_subdev subdev; 50 struct ad5820_platform_data *platform_data; 51 struct regulator *vana; 52 53 struct v4l2_ctrl_handler ctrls; 54 u32 focus_absolute; 55 u32 focus_ramp_time; 56 u32 focus_ramp_mode; 57 58 struct mutex power_lock; 59 int power_count; 60 61 bool standby; 62 }; 63 64 static int ad5820_write(struct ad5820_device *coil, u16 data) 65 { 66 struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev); 67 struct i2c_msg msg; 68 __be16 be_data; 69 int r; 70 71 if (!client->adapter) 72 return -ENODEV; 73 74 be_data = cpu_to_be16(data); 75 msg.addr = client->addr; 76 msg.flags = 0; 77 msg.len = 2; 78 msg.buf = (u8 *)&be_data; 79 80 r = i2c_transfer(client->adapter, &msg, 1); 81 if (r < 0) { 82 dev_err(&client->dev, "write failed, error %d\n", r); 83 return r; 84 } 85 86 return 0; 87 } 88 89 /* 90 * Calculate status word and write it to the device based on current 91 * values of V4L2 controls. It is assumed that the stored V4L2 control 92 * values are properly limited and rounded. 93 */ 94 static int ad5820_update_hw(struct ad5820_device *coil) 95 { 96 u16 status; 97 98 status = RAMP_US_TO_CODE(coil->focus_ramp_time); 99 status |= coil->focus_ramp_mode 100 ? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR; 101 status |= coil->focus_absolute << AD5820_DAC_SHIFT; 102 103 if (coil->standby) 104 status |= AD5820_POWER_DOWN; 105 106 return ad5820_write(coil, status); 107 } 108 109 /* 110 * Power handling 111 */ 112 static int ad5820_power_off(struct ad5820_device *coil, bool standby) 113 { 114 int ret = 0, ret2; 115 116 /* 117 * Go to standby first as real power off my be denied by the hardware 118 * (single power line control for both coil and sensor). 119 */ 120 if (standby) { 121 coil->standby = true; 122 ret = ad5820_update_hw(coil); 123 } 124 125 ret2 = regulator_disable(coil->vana); 126 if (ret) 127 return ret; 128 return ret2; 129 } 130 131 static int ad5820_power_on(struct ad5820_device *coil, bool restore) 132 { 133 int ret; 134 135 ret = regulator_enable(coil->vana); 136 if (ret < 0) 137 return ret; 138 139 if (restore) { 140 /* Restore the hardware settings. */ 141 coil->standby = false; 142 ret = ad5820_update_hw(coil); 143 if (ret) 144 goto fail; 145 } 146 return 0; 147 148 fail: 149 coil->standby = true; 150 regulator_disable(coil->vana); 151 152 return ret; 153 } 154 155 /* 156 * V4L2 controls 157 */ 158 static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl) 159 { 160 struct ad5820_device *coil = 161 container_of(ctrl->handler, struct ad5820_device, ctrls); 162 163 switch (ctrl->id) { 164 case V4L2_CID_FOCUS_ABSOLUTE: 165 coil->focus_absolute = ctrl->val; 166 return ad5820_update_hw(coil); 167 } 168 169 return 0; 170 } 171 172 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = { 173 .s_ctrl = ad5820_set_ctrl, 174 }; 175 176 177 static int ad5820_init_controls(struct ad5820_device *coil) 178 { 179 v4l2_ctrl_handler_init(&coil->ctrls, 1); 180 181 /* 182 * V4L2_CID_FOCUS_ABSOLUTE 183 * 184 * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is 185 * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA] 186 * for focus position, because it is meaningless for user. Meaningful 187 * would be to use focus distance or even its inverse, but since the 188 * driver doesn't have sufficiently knowledge to do the conversion, we 189 * will just use abstract codes here. In any case, smaller value = focus 190 * position farther from camera. The default zero value means focus at 191 * infinity, and also least current consumption. 192 */ 193 v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops, 194 V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0); 195 196 if (coil->ctrls.error) 197 return coil->ctrls.error; 198 199 coil->focus_absolute = 0; 200 coil->focus_ramp_time = 0; 201 coil->focus_ramp_mode = 0; 202 203 coil->subdev.ctrl_handler = &coil->ctrls; 204 205 return 0; 206 } 207 208 /* 209 * V4L2 subdev operations 210 */ 211 static int ad5820_registered(struct v4l2_subdev *subdev) 212 { 213 struct ad5820_device *coil = to_ad5820_device(subdev); 214 215 return ad5820_init_controls(coil); 216 } 217 218 static int 219 ad5820_set_power(struct v4l2_subdev *subdev, int on) 220 { 221 struct ad5820_device *coil = to_ad5820_device(subdev); 222 int ret = 0; 223 224 mutex_lock(&coil->power_lock); 225 226 /* 227 * If the power count is modified from 0 to != 0 or from != 0 to 0, 228 * update the power state. 229 */ 230 if (coil->power_count == !on) { 231 ret = on ? ad5820_power_on(coil, true) : 232 ad5820_power_off(coil, true); 233 if (ret < 0) 234 goto done; 235 } 236 237 /* Update the power count. */ 238 coil->power_count += on ? 1 : -1; 239 WARN_ON(coil->power_count < 0); 240 241 done: 242 mutex_unlock(&coil->power_lock); 243 return ret; 244 } 245 246 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) 247 { 248 return ad5820_set_power(sd, 1); 249 } 250 251 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) 252 { 253 return ad5820_set_power(sd, 0); 254 } 255 256 static const struct v4l2_subdev_core_ops ad5820_core_ops = { 257 .s_power = ad5820_set_power, 258 }; 259 260 static const struct v4l2_subdev_ops ad5820_ops = { 261 .core = &ad5820_core_ops, 262 }; 263 264 static const struct v4l2_subdev_internal_ops ad5820_internal_ops = { 265 .registered = ad5820_registered, 266 .open = ad5820_open, 267 .close = ad5820_close, 268 }; 269 270 /* 271 * I2C driver 272 */ 273 static int __maybe_unused ad5820_suspend(struct device *dev) 274 { 275 struct i2c_client *client = container_of(dev, struct i2c_client, dev); 276 struct v4l2_subdev *subdev = i2c_get_clientdata(client); 277 struct ad5820_device *coil = to_ad5820_device(subdev); 278 279 if (!coil->power_count) 280 return 0; 281 282 return ad5820_power_off(coil, false); 283 } 284 285 static int __maybe_unused ad5820_resume(struct device *dev) 286 { 287 struct i2c_client *client = container_of(dev, struct i2c_client, dev); 288 struct v4l2_subdev *subdev = i2c_get_clientdata(client); 289 struct ad5820_device *coil = to_ad5820_device(subdev); 290 291 if (!coil->power_count) 292 return 0; 293 294 return ad5820_power_on(coil, true); 295 } 296 297 static int ad5820_probe(struct i2c_client *client, 298 const struct i2c_device_id *devid) 299 { 300 struct ad5820_device *coil; 301 int ret; 302 303 coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL); 304 if (!coil) 305 return -ENOMEM; 306 307 coil->vana = devm_regulator_get(&client->dev, "VANA"); 308 if (IS_ERR(coil->vana)) { 309 ret = PTR_ERR(coil->vana); 310 if (ret != -EPROBE_DEFER) 311 dev_err(&client->dev, "could not get regulator for vana\n"); 312 return ret; 313 } 314 315 mutex_init(&coil->power_lock); 316 317 v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops); 318 coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; 319 coil->subdev.internal_ops = &ad5820_internal_ops; 320 strcpy(coil->subdev.name, "ad5820 focus"); 321 322 ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL); 323 if (ret < 0) 324 goto cleanup2; 325 326 ret = v4l2_async_register_subdev(&coil->subdev); 327 if (ret < 0) 328 goto cleanup; 329 330 return ret; 331 332 cleanup2: 333 mutex_destroy(&coil->power_lock); 334 cleanup: 335 media_entity_cleanup(&coil->subdev.entity); 336 return ret; 337 } 338 339 static int ad5820_remove(struct i2c_client *client) 340 { 341 struct v4l2_subdev *subdev = i2c_get_clientdata(client); 342 struct ad5820_device *coil = to_ad5820_device(subdev); 343 344 v4l2_device_unregister_subdev(&coil->subdev); 345 v4l2_ctrl_handler_free(&coil->ctrls); 346 media_entity_cleanup(&coil->subdev.entity); 347 mutex_destroy(&coil->power_lock); 348 return 0; 349 } 350 351 static const struct i2c_device_id ad5820_id_table[] = { 352 { AD5820_NAME, 0 }, 353 { } 354 }; 355 MODULE_DEVICE_TABLE(i2c, ad5820_id_table); 356 357 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume); 358 359 static struct i2c_driver ad5820_i2c_driver = { 360 .driver = { 361 .name = AD5820_NAME, 362 .pm = &ad5820_pm, 363 }, 364 .probe = ad5820_probe, 365 .remove = ad5820_remove, 366 .id_table = ad5820_id_table, 367 }; 368 369 module_i2c_driver(ad5820_i2c_driver); 370 371 MODULE_AUTHOR("Tuukka Toivonen"); 372 MODULE_DESCRIPTION("AD5820 camera lens driver"); 373 MODULE_LICENSE("GPL"); 374