1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CM3605 Ambient Light and Proximity Sensor 4 * 5 * Copyright (C) 2016 Linaro Ltd. 6 * Author: Linus Walleij <linus.walleij@linaro.org> 7 * 8 * This hardware was found in the very first Nexus One handset from Google/HTC 9 * and an early endavour into mobile light and proximity sensors. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/iio/iio.h> 14 #include <linux/iio/sysfs.h> 15 #include <linux/iio/events.h> 16 #include <linux/iio/consumer.h> /* To get our ADC channel */ 17 #include <linux/iio/types.h> /* To deal with our ADC channel */ 18 #include <linux/init.h> 19 #include <linux/leds.h> 20 #include <linux/platform_device.h> 21 #include <linux/of.h> 22 #include <linux/regulator/consumer.h> 23 #include <linux/gpio/consumer.h> 24 #include <linux/interrupt.h> 25 #include <linux/math64.h> 26 #include <linux/pm.h> 27 28 #define CM3605_PROX_CHANNEL 0 29 #define CM3605_ALS_CHANNEL 1 30 #define CM3605_AOUT_TYP_MAX_MV 1550 31 /* It should not go above 1.650V according to the data sheet */ 32 #define CM3605_AOUT_MAX_MV 1650 33 34 /** 35 * struct cm3605 - CM3605 state 36 * @dev: pointer to parent device 37 * @vdd: regulator controlling VDD 38 * @aset: sleep enable GPIO, high = sleep 39 * @aout: IIO ADC channel to convert the AOUT signal 40 * @als_max: maximum LUX detection (depends on RSET) 41 * @dir: proximity direction: start as FALLING 42 * @led: trigger for the infrared LED used by the proximity sensor 43 */ 44 struct cm3605 { 45 struct device *dev; 46 struct regulator *vdd; 47 struct gpio_desc *aset; 48 struct iio_channel *aout; 49 s32 als_max; 50 enum iio_event_direction dir; 51 struct led_trigger *led; 52 }; 53 54 static irqreturn_t cm3605_prox_irq(int irq, void *d) 55 { 56 struct iio_dev *indio_dev = d; 57 struct cm3605 *cm3605 = iio_priv(indio_dev); 58 u64 ev; 59 60 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL, 61 IIO_EV_TYPE_THRESH, cm3605->dir); 62 iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev)); 63 64 /* Invert the edge for each event */ 65 if (cm3605->dir == IIO_EV_DIR_RISING) 66 cm3605->dir = IIO_EV_DIR_FALLING; 67 else 68 cm3605->dir = IIO_EV_DIR_RISING; 69 70 return IRQ_HANDLED; 71 } 72 73 static int cm3605_get_lux(struct cm3605 *cm3605) 74 { 75 int ret, res; 76 s64 lux; 77 78 ret = iio_read_channel_processed(cm3605->aout, &res); 79 if (ret < 0) 80 return ret; 81 82 dev_dbg(cm3605->dev, "read %d mV from ADC\n", res); 83 84 /* 85 * AOUT has an offset of ~30mV then linear at dark 86 * then goes from 2.54 up to 650 LUX yielding 1.55V 87 * (1550 mV) so scale the returned value to this interval 88 * using simple linear interpolation. 89 */ 90 if (res < 30) 91 return 0; 92 if (res > CM3605_AOUT_MAX_MV) 93 dev_err(cm3605->dev, "device out of range\n"); 94 95 /* Remove bias */ 96 lux = res - 30; 97 98 /* Linear interpolation between 0 and ALS typ max */ 99 lux *= cm3605->als_max; 100 lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV); 101 102 return lux; 103 } 104 105 static int cm3605_read_raw(struct iio_dev *indio_dev, 106 struct iio_chan_spec const *chan, 107 int *val, int *val2, long mask) 108 { 109 struct cm3605 *cm3605 = iio_priv(indio_dev); 110 int ret; 111 112 switch (mask) { 113 case IIO_CHAN_INFO_RAW: 114 switch (chan->type) { 115 case IIO_LIGHT: 116 ret = cm3605_get_lux(cm3605); 117 if (ret < 0) 118 return ret; 119 *val = ret; 120 return IIO_VAL_INT; 121 default: 122 return -EINVAL; 123 } 124 default: 125 return -EINVAL; 126 } 127 } 128 129 static const struct iio_info cm3605_info = { 130 .read_raw = cm3605_read_raw, 131 }; 132 133 static const struct iio_event_spec cm3605_events[] = { 134 { 135 .type = IIO_EV_TYPE_THRESH, 136 .dir = IIO_EV_DIR_EITHER, 137 .mask_separate = BIT(IIO_EV_INFO_ENABLE), 138 }, 139 }; 140 141 static const struct iio_chan_spec cm3605_channels[] = { 142 { 143 .type = IIO_PROXIMITY, 144 .event_spec = cm3605_events, 145 .num_event_specs = ARRAY_SIZE(cm3605_events), 146 }, 147 { 148 .type = IIO_LIGHT, 149 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 150 .channel = CM3605_ALS_CHANNEL, 151 }, 152 }; 153 154 static int cm3605_probe(struct platform_device *pdev) 155 { 156 struct cm3605 *cm3605; 157 struct iio_dev *indio_dev; 158 struct device *dev = &pdev->dev; 159 struct device_node *np = dev->of_node; 160 enum iio_chan_type ch_type; 161 u32 rset; 162 int ret; 163 164 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605)); 165 if (!indio_dev) 166 return -ENOMEM; 167 platform_set_drvdata(pdev, indio_dev); 168 169 cm3605 = iio_priv(indio_dev); 170 cm3605->dev = dev; 171 cm3605->dir = IIO_EV_DIR_FALLING; 172 173 ret = of_property_read_u32(np, "capella,aset-resistance-ohms", &rset); 174 if (ret) { 175 dev_info(dev, "no RSET specified, assuming 100K\n"); 176 rset = 100000; 177 } 178 switch (rset) { 179 case 50000: 180 cm3605->als_max = 650; 181 break; 182 case 100000: 183 cm3605->als_max = 300; 184 break; 185 case 300000: 186 cm3605->als_max = 100; 187 break; 188 case 600000: 189 cm3605->als_max = 50; 190 break; 191 default: 192 dev_info(dev, "non-standard resistance\n"); 193 return -EINVAL; 194 } 195 196 cm3605->aout = devm_iio_channel_get(dev, "aout"); 197 if (IS_ERR(cm3605->aout)) { 198 if (PTR_ERR(cm3605->aout) == -ENODEV) { 199 dev_err(dev, "no ADC, deferring...\n"); 200 return -EPROBE_DEFER; 201 } 202 dev_err(dev, "failed to get AOUT ADC channel\n"); 203 return PTR_ERR(cm3605->aout); 204 } 205 ret = iio_get_channel_type(cm3605->aout, &ch_type); 206 if (ret < 0) 207 return ret; 208 if (ch_type != IIO_VOLTAGE) { 209 dev_err(dev, "wrong type of IIO channel specified for AOUT\n"); 210 return -EINVAL; 211 } 212 213 cm3605->vdd = devm_regulator_get(dev, "vdd"); 214 if (IS_ERR(cm3605->vdd)) { 215 dev_err(dev, "failed to get VDD regulator\n"); 216 return PTR_ERR(cm3605->vdd); 217 } 218 ret = regulator_enable(cm3605->vdd); 219 if (ret) { 220 dev_err(dev, "failed to enable VDD regulator\n"); 221 return ret; 222 } 223 224 cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH); 225 if (IS_ERR(cm3605->aset)) { 226 dev_err(dev, "no ASET GPIO\n"); 227 ret = PTR_ERR(cm3605->aset); 228 goto out_disable_vdd; 229 } 230 231 ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0), 232 cm3605_prox_irq, NULL, 0, "cm3605", indio_dev); 233 if (ret) { 234 dev_err(dev, "unable to request IRQ\n"); 235 goto out_disable_aset; 236 } 237 238 /* Just name the trigger the same as the driver */ 239 led_trigger_register_simple("cm3605", &cm3605->led); 240 led_trigger_event(cm3605->led, LED_FULL); 241 242 indio_dev->dev.parent = dev; 243 indio_dev->info = &cm3605_info; 244 indio_dev->name = "cm3605"; 245 indio_dev->channels = cm3605_channels; 246 indio_dev->num_channels = ARRAY_SIZE(cm3605_channels); 247 indio_dev->modes = INDIO_DIRECT_MODE; 248 249 ret = iio_device_register(indio_dev); 250 if (ret) 251 goto out_remove_trigger; 252 dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n", 253 cm3605->als_max); 254 255 return 0; 256 257 out_remove_trigger: 258 led_trigger_event(cm3605->led, LED_OFF); 259 led_trigger_unregister_simple(cm3605->led); 260 out_disable_aset: 261 gpiod_set_value_cansleep(cm3605->aset, 0); 262 out_disable_vdd: 263 regulator_disable(cm3605->vdd); 264 return ret; 265 } 266 267 static int cm3605_remove(struct platform_device *pdev) 268 { 269 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 270 struct cm3605 *cm3605 = iio_priv(indio_dev); 271 272 led_trigger_event(cm3605->led, LED_OFF); 273 led_trigger_unregister_simple(cm3605->led); 274 gpiod_set_value_cansleep(cm3605->aset, 0); 275 iio_device_unregister(indio_dev); 276 regulator_disable(cm3605->vdd); 277 278 return 0; 279 } 280 281 static int __maybe_unused cm3605_pm_suspend(struct device *dev) 282 { 283 struct iio_dev *indio_dev = dev_get_drvdata(dev); 284 struct cm3605 *cm3605 = iio_priv(indio_dev); 285 286 led_trigger_event(cm3605->led, LED_OFF); 287 regulator_disable(cm3605->vdd); 288 289 return 0; 290 } 291 292 static int __maybe_unused cm3605_pm_resume(struct device *dev) 293 { 294 struct iio_dev *indio_dev = dev_get_drvdata(dev); 295 struct cm3605 *cm3605 = iio_priv(indio_dev); 296 int ret; 297 298 ret = regulator_enable(cm3605->vdd); 299 if (ret) 300 dev_err(dev, "failed to enable regulator in resume path\n"); 301 led_trigger_event(cm3605->led, LED_FULL); 302 303 return 0; 304 } 305 306 static const struct dev_pm_ops cm3605_dev_pm_ops = { 307 SET_SYSTEM_SLEEP_PM_OPS(cm3605_pm_suspend, 308 cm3605_pm_resume) 309 }; 310 311 static const struct of_device_id cm3605_of_match[] = { 312 {.compatible = "capella,cm3605"}, 313 { }, 314 }; 315 MODULE_DEVICE_TABLE(of, cm3605_of_match); 316 317 static struct platform_driver cm3605_driver = { 318 .driver = { 319 .name = "cm3605", 320 .of_match_table = cm3605_of_match, 321 .pm = &cm3605_dev_pm_ops, 322 }, 323 .probe = cm3605_probe, 324 .remove = cm3605_remove, 325 }; 326 module_platform_driver(cm3605_driver); 327 328 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 329 MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver"); 330 MODULE_LICENSE("GPL"); 331