diff options
Diffstat (limited to 'drivers/iio/light/cm3605.c')
| -rw-r--r-- | drivers/iio/light/cm3605.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/iio/light/cm3605.c b/drivers/iio/light/cm3605.c new file mode 100644 index 000000000000..2d96543db1ef --- /dev/null +++ b/drivers/iio/light/cm3605.c @@ -0,0 +1,330 @@ +/* + * CM3605 Ambient Light and Proximity Sensor + * + * Copyright (C) 2016 Linaro Ltd. + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * This hardware was found in the very first Nexus One handset from Google/HTC + * and an early endavour into mobile light and proximity sensors. + */ + +#include <linux/module.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/events.h> +#include <linux/iio/consumer.h> /* To get our ADC channel */ +#include <linux/iio/types.h> /* To deal with our ADC channel */ +#include <linux/init.h> +#include <linux/leds.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/regulator/consumer.h> +#include <linux/gpio/consumer.h> +#include <linux/interrupt.h> +#include <linux/math64.h> +#include <linux/pm.h> + +#define CM3605_PROX_CHANNEL 0 +#define CM3605_ALS_CHANNEL 1 +#define CM3605_AOUT_TYP_MAX_MV 1550 +/* It should not go above 1.650V according to the data sheet */ +#define CM3605_AOUT_MAX_MV 1650 + +/** + * struct cm3605 - CM3605 state + * @dev: pointer to parent device + * @vdd: regulator controlling VDD + * @aset: sleep enable GPIO, high = sleep + * @aout: IIO ADC channel to convert the AOUT signal + * @als_max: maximum LUX detection (depends on RSET) + * @dir: proximity direction: start as FALLING + * @led: trigger for the infrared LED used by the proximity sensor + */ +struct cm3605 { + struct device *dev; + struct regulator *vdd; + struct gpio_desc *aset; + struct iio_channel *aout; + s32 als_max; + enum iio_event_direction dir; + struct led_trigger *led; +}; + +static irqreturn_t cm3605_prox_irq(int irq, void *d) +{ + struct iio_dev *indio_dev = d; + struct cm3605 *cm3605 = iio_priv(indio_dev); + u64 ev; + + ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL, + IIO_EV_TYPE_THRESH, cm3605->dir); + iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev)); + + /* Invert the edge for each event */ + if (cm3605->dir == IIO_EV_DIR_RISING) + cm3605->dir = IIO_EV_DIR_FALLING; + else + cm3605->dir = IIO_EV_DIR_RISING; + + return IRQ_HANDLED; +} + +static int cm3605_get_lux(struct cm3605 *cm3605) +{ + int ret, res; + s64 lux; + + ret = iio_read_channel_processed(cm3605->aout, &res); + if (ret < 0) + return ret; + + dev_dbg(cm3605->dev, "read %d mV from ADC\n", res); + + /* + * AOUT has an offset of ~30mV then linear at dark + * then goes from 2.54 up to 650 LUX yielding 1.55V + * (1550 mV) so scale the returned value to this interval + * using simple linear interpolation. + */ + if (res < 30) + return 0; + if (res > CM3605_AOUT_MAX_MV) + dev_err(cm3605->dev, "device out of range\n"); + + /* Remove bias */ + lux = res - 30; + + /* Linear interpolation between 0 and ALS typ max */ + lux *= cm3605->als_max; + lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV); + + return lux; +} + +static int cm3605_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct cm3605 *cm3605 = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_LIGHT: + ret = cm3605_get_lux(cm3605); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static const struct iio_info cm3605_info = { + .driver_module = THIS_MODULE, + .read_raw = cm3605_read_raw, +}; + +static const struct iio_event_spec cm3605_events[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_EITHER, + .mask_separate = BIT(IIO_EV_INFO_ENABLE), + }, +}; + +static const struct iio_chan_spec cm3605_channels[] = { + { + .type = IIO_PROXIMITY, + .event_spec = cm3605_events, + .num_event_specs = ARRAY_SIZE(cm3605_events), + }, + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .channel = CM3605_ALS_CHANNEL, + }, +}; + +static int cm3605_probe(struct platform_device *pdev) +{ + struct cm3605 *cm3605; + struct iio_dev *indio_dev; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + enum iio_chan_type ch_type; + u32 rset; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605)); + if (!indio_dev) + return -ENOMEM; + platform_set_drvdata(pdev, indio_dev); + + cm3605 = iio_priv(indio_dev); + cm3605->dev = dev; + cm3605->dir = IIO_EV_DIR_FALLING; + + ret = of_property_read_u32(np, "capella,aset-resistance-ohms", &rset); + if (ret) { + dev_info(dev, "no RSET specified, assuming 100K\n"); + rset = 100000; + } + switch (rset) { + case 50000: + cm3605->als_max = 650; + break; + case 100000: + cm3605->als_max = 300; + break; + case 300000: + cm3605->als_max = 100; + break; + case 600000: + cm3605->als_max = 50; + break; + default: + dev_info(dev, "non-standard resistance\n"); + return -EINVAL; + } + + cm3605->aout = devm_iio_channel_get(dev, "aout"); + if (IS_ERR(cm3605->aout)) { + if (PTR_ERR(cm3605->aout) == -ENODEV) { + dev_err(dev, "no ADC, deferring...\n"); + return -EPROBE_DEFER; + } + dev_err(dev, "failed to get AOUT ADC channel\n"); + return PTR_ERR(cm3605->aout); + } + ret = iio_get_channel_type(cm3605->aout, &ch_type); + if (ret < 0) + return ret; + if (ch_type != IIO_VOLTAGE) { + dev_err(dev, "wrong type of IIO channel specified for AOUT\n"); + return -EINVAL; + } + + cm3605->vdd = devm_regulator_get(dev, "vdd"); + if (IS_ERR(cm3605->vdd)) { + dev_err(dev, "failed to get VDD regulator\n"); + return PTR_ERR(cm3605->vdd); + } + ret = regulator_enable(cm3605->vdd); + if (ret) { + dev_err(dev, "failed to enable VDD regulator\n"); + return ret; + } + + cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH); + if (IS_ERR(cm3605->aset)) { + dev_err(dev, "no ASET GPIO\n"); + ret = PTR_ERR(cm3605->aset); + goto out_disable_vdd; + } + + ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0), + cm3605_prox_irq, NULL, 0, "cm3605", indio_dev); + if (ret) { + dev_err(dev, "unable to request IRQ\n"); + goto out_disable_aset; + } + + /* Just name the trigger the same as the driver */ + led_trigger_register_simple("cm3605", &cm3605->led); + led_trigger_event(cm3605->led, LED_FULL); + + indio_dev->dev.parent = dev; + indio_dev->info = &cm3605_info; + indio_dev->name = "cm3605"; + indio_dev->channels = cm3605_channels; + indio_dev->num_channels = ARRAY_SIZE(cm3605_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = iio_device_register(indio_dev); + if (ret) + goto out_remove_trigger; + dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n", + cm3605->als_max); + + return 0; + +out_remove_trigger: + led_trigger_event(cm3605->led, LED_OFF); + led_trigger_unregister_simple(cm3605->led); +out_disable_aset: + gpiod_set_value_cansleep(cm3605->aset, 0); +out_disable_vdd: + regulator_disable(cm3605->vdd); + return ret; +} + +static int cm3605_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct cm3605 *cm3605 = iio_priv(indio_dev); + + led_trigger_event(cm3605->led, LED_OFF); + led_trigger_unregister_simple(cm3605->led); + gpiod_set_value_cansleep(cm3605->aset, 0); + iio_device_unregister(indio_dev); + regulator_disable(cm3605->vdd); + + return 0; +} + +static int cm3605_pm_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct cm3605 *cm3605 = iio_priv(indio_dev); + + led_trigger_event(cm3605->led, LED_OFF); + regulator_disable(cm3605->vdd); + + return 0; +} + +static int cm3605_pm_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct cm3605 *cm3605 = iio_priv(indio_dev); + int ret; + + ret = regulator_enable(cm3605->vdd); + if (ret) + dev_err(dev, "failed to enable regulator in resume path\n"); + led_trigger_event(cm3605->led, LED_FULL); + + return 0; +} + +static const struct dev_pm_ops cm3605_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(cm3605_pm_suspend, + cm3605_pm_resume) +}; + +static const struct of_device_id cm3605_of_match[] = { + {.compatible = "capella,cm3605"}, + { }, +}; +MODULE_DEVICE_TABLE(of, cm3605_of_match); + +static struct platform_driver cm3605_driver = { + .driver = { + .name = "cm3605", + .of_match_table = cm3605_of_match, + .pm = &cm3605_dev_pm_ops, + }, + .probe = cm3605_probe, + .remove = cm3605_remove, +}; +module_platform_driver(cm3605_driver); + +MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); +MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver"); +MODULE_LICENSE("GPL"); |