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/mod_devicetable.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/sysfs.h> 16 #include <linux/iio/events.h> 17 #include <linux/iio/consumer.h> /* To get our ADC channel */ 18 #include <linux/iio/types.h> /* To deal with our ADC channel */ 19 #include <linux/init.h> 20 #include <linux/leds.h> 21 #include <linux/platform_device.h> 22 #include <linux/property.h> 23 #include <linux/regulator/consumer.h> 24 #include <linux/gpio/consumer.h> 25 #include <linux/interrupt.h> 26 #include <linux/math64.h> 27 #include <linux/pm.h> 28 29 #define CM3605_PROX_CHANNEL 0 30 #define CM3605_ALS_CHANNEL 1 31 #define CM3605_AOUT_TYP_MAX_MV 1550 32 /* It should not go above 1.650V according to the data sheet */ 33 #define CM3605_AOUT_MAX_MV 1650 34 35 /** 36 * struct cm3605 - CM3605 state 37 * @dev: pointer to parent device 38 * @vdd: regulator controlling VDD 39 * @aset: sleep enable GPIO, high = sleep 40 * @aout: IIO ADC channel to convert the AOUT signal 41 * @als_max: maximum LUX detection (depends on RSET) 42 * @dir: proximity direction: start as FALLING 43 * @led: trigger for the infrared LED used by the proximity sensor 44 */ 45 struct cm3605 { 46 struct device *dev; 47 struct regulator *vdd; 48 struct gpio_desc *aset; 49 struct iio_channel *aout; 50 s32 als_max; 51 enum iio_event_direction dir; 52 struct led_trigger *led; 53 }; 54 55 static irqreturn_t cm3605_prox_irq(int irq, void *d) 56 { 57 struct iio_dev *indio_dev = d; 58 struct cm3605 *cm3605 = iio_priv(indio_dev); 59 u64 ev; 60 61 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL, 62 IIO_EV_TYPE_THRESH, cm3605->dir); 63 iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev)); 64 65 /* Invert the edge for each event */ 66 if (cm3605->dir == IIO_EV_DIR_RISING) 67 cm3605->dir = IIO_EV_DIR_FALLING; 68 else 69 cm3605->dir = IIO_EV_DIR_RISING; 70 71 return IRQ_HANDLED; 72 } 73 74 static int cm3605_get_lux(struct cm3605 *cm3605) 75 { 76 int ret, res; 77 s64 lux; 78 79 ret = iio_read_channel_processed(cm3605->aout, &res); 80 if (ret < 0) 81 return ret; 82 83 dev_dbg(cm3605->dev, "read %d mV from ADC\n", res); 84 85 /* 86 * AOUT has an offset of ~30mV then linear at dark 87 * then goes from 2.54 up to 650 LUX yielding 1.55V 88 * (1550 mV) so scale the returned value to this interval 89 * using simple linear interpolation. 90 */ 91 if (res < 30) 92 return 0; 93 if (res > CM3605_AOUT_MAX_MV) 94 dev_err(cm3605->dev, "device out of range\n"); 95 96 /* Remove bias */ 97 lux = res - 30; 98 99 /* Linear interpolation between 0 and ALS typ max */ 100 lux *= cm3605->als_max; 101 lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV); 102 103 return lux; 104 } 105 106 static int cm3605_read_raw(struct iio_dev *indio_dev, 107 struct iio_chan_spec const *chan, 108 int *val, int *val2, long mask) 109 { 110 struct cm3605 *cm3605 = iio_priv(indio_dev); 111 int ret; 112 113 switch (mask) { 114 case IIO_CHAN_INFO_RAW: 115 switch (chan->type) { 116 case IIO_LIGHT: 117 ret = cm3605_get_lux(cm3605); 118 if (ret < 0) 119 return ret; 120 *val = ret; 121 return IIO_VAL_INT; 122 default: 123 return -EINVAL; 124 } 125 default: 126 return -EINVAL; 127 } 128 } 129 130 static const struct iio_info cm3605_info = { 131 .read_raw = cm3605_read_raw, 132 }; 133 134 static const struct iio_event_spec cm3605_events[] = { 135 { 136 .type = IIO_EV_TYPE_THRESH, 137 .dir = IIO_EV_DIR_EITHER, 138 .mask_separate = BIT(IIO_EV_INFO_ENABLE), 139 }, 140 }; 141 142 static const struct iio_chan_spec cm3605_channels[] = { 143 { 144 .type = IIO_PROXIMITY, 145 .event_spec = cm3605_events, 146 .num_event_specs = ARRAY_SIZE(cm3605_events), 147 }, 148 { 149 .type = IIO_LIGHT, 150 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 151 .channel = CM3605_ALS_CHANNEL, 152 }, 153 }; 154 155 static int cm3605_probe(struct platform_device *pdev) 156 { 157 struct cm3605 *cm3605; 158 struct iio_dev *indio_dev; 159 struct device *dev = &pdev->dev; 160 enum iio_chan_type ch_type; 161 u32 rset; 162 int irq; 163 int ret; 164 165 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605)); 166 if (!indio_dev) 167 return -ENOMEM; 168 platform_set_drvdata(pdev, indio_dev); 169 170 cm3605 = iio_priv(indio_dev); 171 cm3605->dev = dev; 172 cm3605->dir = IIO_EV_DIR_FALLING; 173 174 ret = device_property_read_u32(dev, "capella,aset-resistance-ohms", &rset); 175 if (ret) { 176 dev_info(dev, "no RSET specified, assuming 100K\n"); 177 rset = 100000; 178 } 179 switch (rset) { 180 case 50000: 181 cm3605->als_max = 650; 182 break; 183 case 100000: 184 cm3605->als_max = 300; 185 break; 186 case 300000: 187 cm3605->als_max = 100; 188 break; 189 case 600000: 190 cm3605->als_max = 50; 191 break; 192 default: 193 dev_info(dev, "non-standard resistance\n"); 194 return -EINVAL; 195 } 196 197 cm3605->aout = devm_iio_channel_get(dev, "aout"); 198 if (IS_ERR(cm3605->aout)) { 199 ret = PTR_ERR(cm3605->aout); 200 ret = (ret == -ENODEV) ? -EPROBE_DEFER : ret; 201 return dev_err_probe(dev, ret, "failed to get AOUT ADC channel\n"); 202 } 203 ret = iio_get_channel_type(cm3605->aout, &ch_type); 204 if (ret < 0) 205 return ret; 206 if (ch_type != IIO_VOLTAGE) { 207 dev_err(dev, "wrong type of IIO channel specified for AOUT\n"); 208 return -EINVAL; 209 } 210 211 cm3605->vdd = devm_regulator_get(dev, "vdd"); 212 if (IS_ERR(cm3605->vdd)) 213 return dev_err_probe(dev, PTR_ERR(cm3605->vdd), 214 "failed to get VDD regulator\n"); 215 216 ret = regulator_enable(cm3605->vdd); 217 if (ret) { 218 dev_err(dev, "failed to enable VDD regulator\n"); 219 return ret; 220 } 221 222 cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH); 223 if (IS_ERR(cm3605->aset)) { 224 ret = dev_err_probe(dev, PTR_ERR(cm3605->aset), "no ASET GPIO\n"); 225 goto out_disable_vdd; 226 } 227 228 irq = platform_get_irq(pdev, 0); 229 if (irq < 0) { 230 ret = irq; 231 goto out_disable_aset; 232 } 233 234 ret = devm_request_threaded_irq(dev, irq, cm3605_prox_irq, 235 NULL, 0, "cm3605", indio_dev); 236 if (ret) { 237 dev_err(dev, "unable to request IRQ\n"); 238 goto out_disable_aset; 239 } 240 241 /* Just name the trigger the same as the driver */ 242 led_trigger_register_simple("cm3605", &cm3605->led); 243 led_trigger_event(cm3605->led, LED_FULL); 244 245 indio_dev->info = &cm3605_info; 246 indio_dev->name = "cm3605"; 247 indio_dev->channels = cm3605_channels; 248 indio_dev->num_channels = ARRAY_SIZE(cm3605_channels); 249 indio_dev->modes = INDIO_DIRECT_MODE; 250 251 ret = iio_device_register(indio_dev); 252 if (ret) 253 goto out_remove_trigger; 254 dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n", 255 cm3605->als_max); 256 257 return 0; 258 259 out_remove_trigger: 260 led_trigger_event(cm3605->led, LED_OFF); 261 led_trigger_unregister_simple(cm3605->led); 262 out_disable_aset: 263 gpiod_set_value_cansleep(cm3605->aset, 0); 264 out_disable_vdd: 265 regulator_disable(cm3605->vdd); 266 return ret; 267 } 268 269 static int cm3605_remove(struct platform_device *pdev) 270 { 271 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 272 struct cm3605 *cm3605 = iio_priv(indio_dev); 273 274 led_trigger_event(cm3605->led, LED_OFF); 275 led_trigger_unregister_simple(cm3605->led); 276 gpiod_set_value_cansleep(cm3605->aset, 0); 277 iio_device_unregister(indio_dev); 278 regulator_disable(cm3605->vdd); 279 280 return 0; 281 } 282 283 static int cm3605_pm_suspend(struct device *dev) 284 { 285 struct iio_dev *indio_dev = dev_get_drvdata(dev); 286 struct cm3605 *cm3605 = iio_priv(indio_dev); 287 288 led_trigger_event(cm3605->led, LED_OFF); 289 regulator_disable(cm3605->vdd); 290 291 return 0; 292 } 293 294 static int cm3605_pm_resume(struct device *dev) 295 { 296 struct iio_dev *indio_dev = dev_get_drvdata(dev); 297 struct cm3605 *cm3605 = iio_priv(indio_dev); 298 int ret; 299 300 ret = regulator_enable(cm3605->vdd); 301 if (ret) 302 dev_err(dev, "failed to enable regulator in resume path\n"); 303 led_trigger_event(cm3605->led, LED_FULL); 304 305 return 0; 306 } 307 static DEFINE_SIMPLE_DEV_PM_OPS(cm3605_dev_pm_ops, cm3605_pm_suspend, 308 cm3605_pm_resume); 309 310 static const struct of_device_id cm3605_of_match[] = { 311 {.compatible = "capella,cm3605"}, 312 { }, 313 }; 314 MODULE_DEVICE_TABLE(of, cm3605_of_match); 315 316 static struct platform_driver cm3605_driver = { 317 .driver = { 318 .name = "cm3605", 319 .of_match_table = cm3605_of_match, 320 .pm = pm_sleep_ptr(&cm3605_dev_pm_ops), 321 }, 322 .probe = cm3605_probe, 323 .remove = cm3605_remove, 324 }; 325 module_platform_driver(cm3605_driver); 326 327 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 328 MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver"); 329 MODULE_LICENSE("GPL"); 330