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