> This adds a driver for the Capella Microsystems CM3605 Ambient
> Light Sensor and proximity sensor. This is a pretty simple entirely
> analog device that is interfaced with the target system using
> the POUT (proximity out) and AOUT (ambient light out) signals.
nitpicking below
> The POUT signal is a simple high/low signal that indicates whether
> an object is in proximity, most typically used to detect a face
> in front of a mobile device. The signal requires that an infrared
> LED is mounted next to the device, making IR light reflect off
> the object in proximity and triggering the POUT signal. We grab
> a GPIO pin to handle the POUT signal as an interrupt line and
> register this as an event channel for the sensor.
>
> Since the proximity sensor requires an IR LED, we add a LED trigger
> named "cm3605" so that the infrared LED can just associate with
> this trigger to be sure it is always on when the proximity sensor
> needs it.
>
> The AOUT is an analog voltage between 0 and 1550 mV that indicate
> the LUX value in the ambient light: this is orthogonal to the
> proximity sensor functionality. Since this analog voltage needs
> to be converted into a digital value, the driver grabs an IIO
> channel named "aout" associated with the device.
>
> This patch created a combined ALS and proximity sensor driver.
> The former supports raw reads of the LUX value and the latter
> will generate proximity events.
>
> To integrate this properly with Linux we also add a supply
> regulator for the VDD pin (driving both functions) and add device
> tree bindings to define the RSET resistor that in turn configures
> the luminosity range of the ALS sensor.
>
> Since the sensor needs to be on more or less constantly, we
> restrict the power management to system suspend/resume: we
> disable the IR LED and disable the regulator for VDD on suspend
> and take them back up on resume.
>
> Tests:
> cd /sys/bus/iio/devices/iio:device1
> cat in_illuminance_raw
> 304
> (hold hand over sensor)
> cat in_illuminance_raw
> 17
> iio_event_monitor cm3605
> Found IIO device with name cm3605 with device number 1
> (hold hand over sensor)
> Event: time: 2444842301447, type: proximity, channel: 0,
> evtype: thresh, direction: falling
> (remove hand over sensor)
> Event: time: 2445583440706, type: proximity, channel: 0,
> evtype: thresh, direction: rising
>
> Cc: Capella Microsystems <capellamicro@xxxxxxxxx>
> Cc: Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> drivers/iio/light/Kconfig | 10 ++
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/cm3605.c | 327 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 338 insertions(+)
> create mode 100644 drivers/iio/light/cm3605.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index ba2e64d7ee58..d816ea958cc1 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -115,6 +115,16 @@ config CM3323
> To compile this driver as a module, choose M here: the module will
> be called cm3323.
>
> +config CM3605
> + tristate "Capella CM3605 ambient light and proximity sensor"
> + depends on OF
> + help
> + Say Y here if you want to build a driver for Capella CM3605
> + ambient light and short range proximity sensor.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called cm3605.
> +
> config CM36651
> depends on I2C
> tristate "CM36651 driver"
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index c5768df87a17..eff0fcc9e930 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_BH1780) += bh1780.o
> obj-$(CONFIG_CM32181) += cm32181.o
> obj-$(CONFIG_CM3232) += cm3232.o
> obj-$(CONFIG_CM3323) += cm3323.o
> +obj-$(CONFIG_CM3605) += cm3605.o
> obj-$(CONFIG_CM36651) += cm36651.o
> obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
> obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
> diff --git a/drivers/iio/light/cm3605.c b/drivers/iio/light/cm3605.c
> new file mode 100644
> index 000000000000..ec9e59688cd8
> --- /dev/null
> +++ b/drivers/iio/light/cm3605.c
> @@ -0,0 +1,327 @@
> +/*
> + * CM3605 Ambient Light and Proximity Sensor
> + *
> + * Copyright (C) 2016 Linaro Ltd.
> + * Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
> + *
> + * 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: maximun LUX detection (depends on RSET)
maximum
> + * @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,
> + .channel = CM3605_PROX_CHANNEL,
.channel is not needed I think since not indexed
> + .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", &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_disable_aset;
need to unregister LED trigger?
> + dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
> + cm3605->als_max);
> +
> + return 0;
> +
> +out_disable_aset:
> + gpiod_set_value_cansleep(cm3605->aset, 1);
> +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);
should be unregistered in reverse order...
> + 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@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
> +MODULE_LICENSE("GPL");
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
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