1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * drivers/media/i2c/ad5820.c 4 * 5 * AD5820 DAC driver for camera voice coil focus. 6 * 7 * Copyright (C) 2008 Nokia Corporation 8 * Copyright (C) 2007 Texas Instruments 9 * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz> 10 * 11 * Contact: Tuukka Toivonen <tuukkat76@gmail.com> 12 * Sakari Ailus <sakari.ailus@iki.fi> 13 * 14 * Based on af_d88.c by Texas Instruments. 15 */ 16 17 #include <linux/errno.h> 18 #include <linux/i2c.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/regulator/consumer.h> 22 #include <linux/gpio/consumer.h> 23 24 #include <media/v4l2-ctrls.h> 25 #include <media/v4l2-device.h> 26 #include <media/v4l2-subdev.h> 27 28 /* Register definitions */ 29 #define AD5820_POWER_DOWN (1 << 15) 30 #define AD5820_DAC_SHIFT 4 31 #define AD5820_RAMP_MODE_LINEAR (0 << 3) 32 #define AD5820_RAMP_MODE_64_16 (1 << 3) 33 34 #define CODE_TO_RAMP_US(s) ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50) 35 #define RAMP_US_TO_CODE(c) fls(((c) + ((c)>>1)) / 50) 36 37 #define to_ad5820_device(sd) container_of(sd, struct ad5820_device, subdev) 38 39 struct ad5820_device { 40 struct v4l2_subdev subdev; 41 struct ad5820_platform_data *platform_data; 42 struct regulator *vana; 43 44 struct v4l2_ctrl_handler ctrls; 45 u32 focus_absolute; 46 u32 focus_ramp_time; 47 u32 focus_ramp_mode; 48 49 struct gpio_desc *enable_gpio; 50 51 struct mutex power_lock; 52 int power_count; 53 54 bool standby; 55 }; 56 57 static int ad5820_write(struct ad5820_device *coil, u16 data) 58 { 59 struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev); 60 struct i2c_msg msg; 61 __be16 be_data; 62 int r; 63 64 if (!client->adapter) 65 return -ENODEV; 66 67 be_data = cpu_to_be16(data); 68 msg.addr = client->addr; 69 msg.flags = 0; 70 msg.len = 2; 71 msg.buf = (u8 *)&be_data; 72 73 r = i2c_transfer(client->adapter, &msg, 1); 74 if (r < 0) { 75 dev_err(&client->dev, "write failed, error %d\n", r); 76 return r; 77 } 78 79 return 0; 80 } 81 82 /* 83 * Calculate status word and write it to the device based on current 84 * values of V4L2 controls. It is assumed that the stored V4L2 control 85 * values are properly limited and rounded. 86 */ 87 static int ad5820_update_hw(struct ad5820_device *coil) 88 { 89 u16 status; 90 91 status = RAMP_US_TO_CODE(coil->focus_ramp_time); 92 status |= coil->focus_ramp_mode 93 ? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR; 94 status |= coil->focus_absolute << AD5820_DAC_SHIFT; 95 96 if (coil->standby) 97 status |= AD5820_POWER_DOWN; 98 99 return ad5820_write(coil, status); 100 } 101 102 /* 103 * Power handling 104 */ 105 static int ad5820_power_off(struct ad5820_device *coil, bool standby) 106 { 107 int ret = 0, ret2; 108 109 /* 110 * Go to standby first as real power off my be denied by the hardware 111 * (single power line control for both coil and sensor). 112 */ 113 if (standby) { 114 coil->standby = true; 115 ret = ad5820_update_hw(coil); 116 } 117 118 gpiod_set_value_cansleep(coil->enable_gpio, 0); 119 120 ret2 = regulator_disable(coil->vana); 121 if (ret) 122 return ret; 123 return ret2; 124 } 125 126 static int ad5820_power_on(struct ad5820_device *coil, bool restore) 127 { 128 int ret; 129 130 ret = regulator_enable(coil->vana); 131 if (ret < 0) 132 return ret; 133 134 gpiod_set_value_cansleep(coil->enable_gpio, 1); 135 136 if (restore) { 137 /* Restore the hardware settings. */ 138 coil->standby = false; 139 ret = ad5820_update_hw(coil); 140 if (ret) 141 goto fail; 142 } 143 return 0; 144 145 fail: 146 gpiod_set_value_cansleep(coil->enable_gpio, 0); 147 coil->standby = true; 148 regulator_disable(coil->vana); 149 150 return ret; 151 } 152 153 /* 154 * V4L2 controls 155 */ 156 static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl) 157 { 158 struct ad5820_device *coil = 159 container_of(ctrl->handler, struct ad5820_device, ctrls); 160 161 switch (ctrl->id) { 162 case V4L2_CID_FOCUS_ABSOLUTE: 163 coil->focus_absolute = ctrl->val; 164 return ad5820_update_hw(coil); 165 } 166 167 return 0; 168 } 169 170 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = { 171 .s_ctrl = ad5820_set_ctrl, 172 }; 173 174 175 static int ad5820_init_controls(struct ad5820_device *coil) 176 { 177 v4l2_ctrl_handler_init(&coil->ctrls, 1); 178 179 /* 180 * V4L2_CID_FOCUS_ABSOLUTE 181 * 182 * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is 183 * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA] 184 * for focus position, because it is meaningless for user. Meaningful 185 * would be to use focus distance or even its inverse, but since the 186 * driver doesn't have sufficiently knowledge to do the conversion, we 187 * will just use abstract codes here. In any case, smaller value = focus 188 * position farther from camera. The default zero value means focus at 189 * infinity, and also least current consumption. 190 */ 191 v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops, 192 V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0); 193 194 if (coil->ctrls.error) 195 return coil->ctrls.error; 196 197 coil->focus_absolute = 0; 198 coil->focus_ramp_time = 0; 199 coil->focus_ramp_mode = 0; 200 201 coil->subdev.ctrl_handler = &coil->ctrls; 202 203 return 0; 204 } 205 206 /* 207 * V4L2 subdev operations 208 */ 209 static int ad5820_registered(struct v4l2_subdev *subdev) 210 { 211 struct ad5820_device *coil = to_ad5820_device(subdev); 212 213 return ad5820_init_controls(coil); 214 } 215 216 static int 217 ad5820_set_power(struct v4l2_subdev *subdev, int on) 218 { 219 struct ad5820_device *coil = to_ad5820_device(subdev); 220 int ret = 0; 221 222 mutex_lock(&coil->power_lock); 223 224 /* 225 * If the power count is modified from 0 to != 0 or from != 0 to 0, 226 * update the power state. 227 */ 228 if (coil->power_count == !on) { 229 ret = on ? ad5820_power_on(coil, true) : 230 ad5820_power_off(coil, true); 231 if (ret < 0) 232 goto done; 233 } 234 235 /* Update the power count. */ 236 coil->power_count += on ? 1 : -1; 237 WARN_ON(coil->power_count < 0); 238 239 done: 240 mutex_unlock(&coil->power_lock); 241 return ret; 242 } 243 244 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) 245 { 246 return ad5820_set_power(sd, 1); 247 } 248 249 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) 250 { 251 return ad5820_set_power(sd, 0); 252 } 253 254 static const struct v4l2_subdev_core_ops ad5820_core_ops = { 255 .s_power = ad5820_set_power, 256 }; 257 258 static const struct v4l2_subdev_ops ad5820_ops = { 259 .core = &ad5820_core_ops, 260 }; 261 262 static const struct v4l2_subdev_internal_ops ad5820_internal_ops = { 263 .registered = ad5820_registered, 264 .open = ad5820_open, 265 .close = ad5820_close, 266 }; 267 268 /* 269 * I2C driver 270 */ 271 static int __maybe_unused ad5820_suspend(struct device *dev) 272 { 273 struct v4l2_subdev *subdev = dev_get_drvdata(dev); 274 struct ad5820_device *coil = to_ad5820_device(subdev); 275 276 if (!coil->power_count) 277 return 0; 278 279 return ad5820_power_off(coil, false); 280 } 281 282 static int __maybe_unused ad5820_resume(struct device *dev) 283 { 284 struct v4l2_subdev *subdev = dev_get_drvdata(dev); 285 struct ad5820_device *coil = to_ad5820_device(subdev); 286 287 if (!coil->power_count) 288 return 0; 289 290 return ad5820_power_on(coil, true); 291 } 292 293 static int ad5820_probe(struct i2c_client *client) 294 { 295 struct ad5820_device *coil; 296 int ret; 297 298 coil = devm_kzalloc(&client->dev, sizeof(*coil), GFP_KERNEL); 299 if (!coil) 300 return -ENOMEM; 301 302 coil->vana = devm_regulator_get(&client->dev, "VANA"); 303 if (IS_ERR(coil->vana)) 304 return dev_err_probe(&client->dev, PTR_ERR(coil->vana), 305 "could not get regulator for vana\n"); 306 307 coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", 308 GPIOD_OUT_LOW); 309 if (IS_ERR(coil->enable_gpio)) 310 return dev_err_probe(&client->dev, PTR_ERR(coil->enable_gpio), 311 "could not get enable gpio\n"); 312 313 mutex_init(&coil->power_lock); 314 315 v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops); 316 coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; 317 coil->subdev.internal_ops = &ad5820_internal_ops; 318 coil->subdev.entity.function = MEDIA_ENT_F_LENS; 319 strscpy(coil->subdev.name, "ad5820 focus", sizeof(coil->subdev.name)); 320 321 ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL); 322 if (ret < 0) 323 goto clean_mutex; 324 325 ret = v4l2_async_register_subdev(&coil->subdev); 326 if (ret < 0) 327 goto clean_entity; 328 329 return ret; 330 331 clean_entity: 332 media_entity_cleanup(&coil->subdev.entity); 333 clean_mutex: 334 mutex_destroy(&coil->power_lock); 335 return ret; 336 } 337 338 static void ad5820_remove(struct i2c_client *client) 339 { 340 struct v4l2_subdev *subdev = i2c_get_clientdata(client); 341 struct ad5820_device *coil = to_ad5820_device(subdev); 342 343 v4l2_async_unregister_subdev(&coil->subdev); 344 v4l2_ctrl_handler_free(&coil->ctrls); 345 media_entity_cleanup(&coil->subdev.entity); 346 mutex_destroy(&coil->power_lock); 347 } 348 349 static const struct i2c_device_id ad5820_id_table[] = { 350 { "ad5820", 0 }, 351 { "ad5821", 0 }, 352 { } 353 }; 354 MODULE_DEVICE_TABLE(i2c, ad5820_id_table); 355 356 static const struct of_device_id ad5820_of_table[] = { 357 { .compatible = "adi,ad5820" }, 358 { .compatible = "adi,ad5821" }, 359 { } 360 }; 361 MODULE_DEVICE_TABLE(of, ad5820_of_table); 362 363 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume); 364 365 static struct i2c_driver ad5820_i2c_driver = { 366 .driver = { 367 .name = "ad5820", 368 .pm = &ad5820_pm, 369 .of_match_table = ad5820_of_table, 370 }, 371 .probe = ad5820_probe, 372 .remove = ad5820_remove, 373 .id_table = ad5820_id_table, 374 }; 375 376 module_i2c_driver(ad5820_i2c_driver); 377 378 MODULE_AUTHOR("Tuukka Toivonen"); 379 MODULE_DESCRIPTION("AD5820 camera lens driver"); 380 MODULE_LICENSE("GPL"); 381