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path: root/drivers/iio/light/cm3605.c
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Diffstat (limited to 'drivers/iio/light/cm3605.c')
-rw-r--r--drivers/iio/light/cm3605.c330
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");