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Subject[PATCH 3/3] iio: add APDS9300 ambilent light sensor driver
Date
From: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>

This patch adds IIO driver for APDS9300 ambient light sensor (ALS).
http://www.avagotech.com/docs/AV02-1077EN

The driver allows to read raw data from ADC registers or calculate
lux value. It also can handle threshold interrupt.

Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
---
.../devicetree/bindings/iio/light/apds9300.txt | 22 +
drivers/iio/light/Kconfig | 10 +
drivers/iio/light/Makefile | 1 +
drivers/iio/light/apds9300.c | 517 ++++++++++++++++++++
4 files changed, 550 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/light/apds9300.txt
create mode 100644 drivers/iio/light/apds9300.c

diff --git a/Documentation/devicetree/bindings/iio/light/apds9300.txt b/Documentation/devicetree/bindings/iio/light/apds9300.txt
new file mode 100644
index 0000000..d6f66c7
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/light/apds9300.txt
@@ -0,0 +1,22 @@
+* Avago APDS9300 ambient light sensor
+
+http://www.avagotech.com/docs/AV02-1077EN
+
+Required properties:
+
+ - compatible : should be "avago,apds9300"
+ - reg : the I2C address of the sensor
+
+Optional properties:
+
+ - interrupt-parent : should be the phandle for the interrupt controller
+ - interrupts : interrupt mapping for GPIO IRQ
+
+Example:
+
+apds9300@39 {
+ compatible = "avago,apds9300";
+ reg = <0x39>;
+ interrupt-parent = <&gpio2>;
+ interrupts = <29 8>;
+};
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 5ef1a39..fb6af1b 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -15,6 +15,16 @@ config ADJD_S311
This driver can also be built as a module. If so, the module
will be called adjd_s311.

+config APDS9300
+ tristate "APDS9300 ambient light sensor"
+ depends on I2C
+ help
+ Say Y here if you want to build a driver for the Avago APDS9300
+ ambient light sensor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called apds9300.
+
config SENSORS_LM3533
tristate "LM3533 ambient light sensor"
depends on MFD_LM3533
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 040d9c7..da58e12 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_ADJD_S311) += adjd_s311.o
obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
obj-$(CONFIG_SENSORS_TSL2563) += tsl2563.o
obj-$(CONFIG_VCNL4000) += vcnl4000.o
+obj-$(CONFIG_APDS9300) += apds9300.o
obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
diff --git a/drivers/iio/light/apds9300.c b/drivers/iio/light/apds9300.c
new file mode 100644
index 0000000..c06a59e
--- /dev/null
+++ b/drivers/iio/light/apds9300.c
@@ -0,0 +1,517 @@
+/*
+ * apds9300.c - IIO driver for Avago APDS9300 ambient light sensor
+ *
+ * Copyright 2013 Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pm.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+#define ALS_DRV_NAME "apds9300"
+#define ALS_IRQ_NAME "apds9300_event"
+
+/* Command register bits */
+#define ALS_CMD BIT(7) /* Select command register. Must write as 1 */
+#define ALS_WORD BIT(5) /* I2C write/read: if 1 word, if 0 byte */
+#define ALS_CLEAR BIT(6) /* Interrupt clear. Clears pending interrupt */
+
+/* Register set */
+#define ALS_CONTROL 0x00 /* Control of basic functions */
+#define ALS_THRESHLOWLOW 0x02 /* Low byte of low interrupt threshold */
+#define ALS_THRESHHIGHLOW 0x04 /* Low byte of high interrupt threshold */
+#define ALS_INTERRUPT 0x06 /* Interrupt control */
+#define ALS_DATA0LOW 0x0c /* Low byte of ADC channel 0 */
+#define ALS_DATA1LOW 0x0e /* Low byte of ADC channel 1 */
+
+/* Power on/off value for ALS_CONTROL register */
+#define ALS_POWER_ON 0x03
+#define ALS_POWER_OFF 0x00
+
+/* Interrupts */
+#define ALS_INTR_ENABLE 0x10
+/* Interrupt Persist Function: Any value outside of threshold range */
+#define ALS_THRESH_INTR 0x01
+
+#define ALS_THRESH_MAX 0xffff /* Max threshold value */
+
+struct als_data {
+ struct i2c_client *client;
+ struct mutex mutex;
+ int power_state;
+ int thresh_low;
+ int thresh_hi;
+ int intr_en;
+};
+
+/* Lux calculation */
+
+/* Calculated values 1000 * (CH1/CH0)^1.4 for CH1/CH0 from 0 to 0.52 */
+static const u16 lux_ratio[] = {
+ 0, 2, 4, 7, 11, 15, 19, 24, 29, 34, 40, 45, 51, 57, 64, 70, 77, 84, 91,
+ 98, 105, 112, 120, 128, 136, 144, 152, 160, 168, 177, 185, 194, 203,
+ 212, 221, 230, 239, 249, 258, 268, 277, 287, 297, 307, 317, 327, 337,
+ 347, 358, 368, 379, 390, 400,
+};
+
+static unsigned long als_calculate_lux(u16 ch0, u16 ch1)
+{
+ unsigned long lux, tmp;
+
+ /* avoid division by zero */
+ if (ch0 == 0)
+ return 0;
+
+ tmp = DIV_ROUND_UP(ch1 * 100, ch0);
+ if (tmp <= 52) {
+ /*
+ * Variable tmp64 need to avoid overflow of this part of lux
+ * calculation formula.
+ */
+ lux = 3150 * ch0 - (unsigned long)DIV_ROUND_UP_ULL(ch0
+ * lux_ratio[tmp] * 5930ull, 1000);
+ } else if (tmp <= 65) {
+ lux = 2290 * ch0 - 2910 * ch1;
+ } else if (tmp <= 80) {
+ lux = 1570 * ch0 - 1800 * ch1;
+ } else if (tmp <= 130) {
+ lux = 338 * ch0 - 260 * ch1;
+ } else {
+ lux = 0;
+ }
+
+ return lux / 100000;
+}
+
+/* I2C I/O operations */
+
+static int als_set_power_state(struct als_data *data, int state)
+{
+ int ret;
+ u8 cmd;
+
+ cmd = state ? ALS_POWER_ON : ALS_POWER_OFF;
+ ret = i2c_smbus_write_byte_data(data->client,
+ ALS_CONTROL | ALS_CMD, cmd);
+ if (!ret)
+ data->power_state = state;
+ else
+ dev_err(&data->client->dev,
+ "failed to set power state %d\n", state);
+
+ return ret;
+}
+
+static int als_get_adc_val(struct als_data *data, int adc_number)
+{
+ int ret;
+ u8 flags = ALS_CMD | ALS_WORD;
+
+ if (!data->power_state)
+ return -EBUSY;
+
+ /* Select ADC0 or ADC1 data register */
+ flags |= adc_number ? ALS_DATA1LOW : ALS_DATA0LOW;
+
+ ret = i2c_smbus_read_word_data(data->client, flags);
+ if (ret < 0)
+ dev_err(&data->client->dev,
+ "failed to read ADC%d value\n", adc_number);
+
+ return ret;
+}
+
+static int als_set_thresh_low(struct als_data *data, int value)
+{
+ int ret;
+
+ if (!data->power_state)
+ return -EBUSY;
+
+ if (value > ALS_THRESH_MAX || value > data->thresh_hi)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_word_data(data->client,
+ ALS_THRESHLOWLOW | ALS_CMD | ALS_WORD, value);
+ if (!ret)
+ data->thresh_low = value;
+ else
+ dev_err(&data->client->dev,
+ "failed to set thresh_low\n");
+
+ return ret;
+}
+
+static int als_set_thresh_hi(struct als_data *data, int value)
+{
+ int ret;
+
+ if (!data->power_state)
+ return -EBUSY;
+
+ if (value > ALS_THRESH_MAX || value < data->thresh_low)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_word_data(data->client,
+ ALS_THRESHHIGHLOW | ALS_CMD | ALS_WORD, value);
+ if (!ret)
+ data->thresh_hi = value;
+ else
+ dev_err(&data->client->dev,
+ "failed to set thresh_hi\n");
+
+ return ret;
+}
+
+static int als_set_intr_state(struct als_data *data, int state)
+{
+ int ret;
+ u8 cmd;
+
+ if (!data->power_state)
+ return -EBUSY;
+
+ cmd = state ? ALS_INTR_ENABLE | ALS_THRESH_INTR : 0x00;
+ ret = i2c_smbus_write_byte_data(data->client,
+ ALS_INTERRUPT | ALS_CMD, cmd);
+ if (!ret)
+ data->intr_en = state;
+ else
+ dev_err(&data->client->dev,
+ "failed to set interrupt state %d\n", state);
+
+ return ret;
+}
+
+static void als_clear_intr(struct als_data *data)
+{
+ int ret;
+
+ ret = i2c_smbus_write_byte(data->client, ALS_CLEAR | ALS_CMD);
+ if (ret < 0)
+ dev_err(&data->client->dev,
+ "failed to clear interrupt\n");
+}
+
+static int als_chip_init(struct als_data *data)
+{
+ int ret;
+
+ /* Need to set power off to ensure that the chip is off */
+ ret = als_set_power_state(data, 0);
+ if (ret < 0)
+ goto err;
+ /*
+ * Probe the chip. To do so we try to power up the device and then to
+ * read back the 0x03 code
+ */
+ ret = als_set_power_state(data, 1);
+ if (ret < 0)
+ goto err;
+ ret = i2c_smbus_read_byte_data(data->client, ALS_CONTROL | ALS_CMD);
+ if (ret != ALS_POWER_ON) {
+ ret = -ENODEV;
+ goto err;
+ }
+ /*
+ * Disable interrupt to ensure thai it is doesn't enable
+ * i.e. after device soft reset
+ */
+ ret = als_set_intr_state(data, 0);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+
+err:
+ dev_err(&data->client->dev, "failed to init the chip\n");
+ return ret;
+}
+
+/* Industrial I/O data and functions */
+
+static int als_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val, int *val2,
+ long mask)
+{
+ int ch0, ch1, ret = -EINVAL;
+ struct als_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->mutex);
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_PROCESSED:
+ switch (chan->type) {
+ case IIO_LIGHT:
+ ch0 = als_get_adc_val(data, 0);
+ if (ch0 < 0) {
+ ret = ch0;
+ break;
+ }
+ ch1 = als_get_adc_val(data, 1);
+ if (ch1 < 0) {
+ ret = ch1;
+ break;
+ }
+ *val = als_calculate_lux(ch0, ch1);
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_INTENSITY:
+ ret = als_get_adc_val(data, chan->channel);
+ if (ret < 0)
+ break;
+ *val = ret;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int als_read_thresh(struct iio_dev *indio_dev, u64 event_code, int *val)
+{
+ struct als_data *data = iio_priv(indio_dev);
+
+ switch (IIO_EVENT_CODE_EXTRACT_DIR(event_code)) {
+ case IIO_EV_DIR_RISING:
+ *val = data->thresh_hi;
+ break;
+ case IIO_EV_DIR_FALLING:
+ *val = data->thresh_low;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int als_write_thresh(struct iio_dev *indio_dev, u64 event_code, int val)
+{
+ struct als_data *data = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&data->mutex);
+ if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_RISING)
+ ret = als_set_thresh_hi(data, val);
+ else
+ ret = als_set_thresh_low(data, val);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int als_read_interrupt_config(struct iio_dev *indio_dev,
+ u64 event_code)
+{
+ struct als_data *data = iio_priv(indio_dev);
+ return data->intr_en;
+}
+
+static int als_write_interrupt_config(struct iio_dev *indio_dev,
+ u64 event_code, int state)
+{
+ struct als_data *data = iio_priv(indio_dev);
+ int ret = 0;
+
+ mutex_lock(&data->mutex);
+ ret = als_set_intr_state(data, state);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static const struct iio_info als_info_no_irq = {
+ .driver_module = THIS_MODULE,
+ .read_raw = &als_read_raw,
+};
+
+static const struct iio_info als_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = als_read_raw,
+ .read_event_value = &als_read_thresh,
+ .write_event_value = &als_write_thresh,
+ .read_event_config = &als_read_interrupt_config,
+ .write_event_config = &als_write_interrupt_config,
+};
+
+static const struct iio_chan_spec als_channels[] = {
+ {
+ .type = IIO_LIGHT,
+ .channel = 0,
+ .indexed = true,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ }, {
+ .type = IIO_INTENSITY,
+ .channel = 0,
+ .indexed = true,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .event_mask = (IIO_EV_BIT(IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING) |
+ IIO_EV_BIT(IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING)),
+ }, {
+ .type = IIO_INTENSITY,
+ .channel = 1,
+ .indexed = true,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ },
+};
+
+static irqreturn_t als_interrupt_handler(int irq, void *private)
+{
+ struct iio_dev *dev_info = private;
+ struct als_data *data = iio_priv(dev_info);
+
+ iio_push_event(dev_info,
+ IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_EITHER),
+ iio_get_time_ns());
+
+ als_clear_intr(data);
+
+ return IRQ_HANDLED;
+}
+
+static int als_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct als_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ ret = als_chip_init(data);
+ if (ret < 0)
+ goto err;
+
+ mutex_init(&data->mutex);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->channels = als_channels;
+ indio_dev->num_channels = ARRAY_SIZE(als_channels);
+ indio_dev->name = ALS_DRV_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ if (client->irq)
+ indio_dev->info = &als_info;
+ else
+ indio_dev->info = &als_info_no_irq;
+
+ if (client->irq) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, als_interrupt_handler,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ ALS_IRQ_NAME, indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "irq request error %d\n", -ret);
+ goto err;
+ }
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+
+err:
+ /* Ensure that power off in case of error */
+ als_set_power_state(data, 0);
+ return ret;
+}
+
+static int als_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct als_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ /* Ensure that power off and interrupts are disabled */
+ als_set_intr_state(data, 0);
+ als_set_power_state(data, 0);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int als_suspend(struct device *dev)
+{
+ struct als_data *data = i2c_get_clientdata(to_i2c_client(dev));
+ int ret;
+
+ mutex_lock(&data->mutex);
+ ret = als_set_power_state(data, 0);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int als_resume(struct device *dev)
+{
+ struct als_data *data = i2c_get_clientdata(to_i2c_client(dev));
+ int ret;
+
+ mutex_lock(&data->mutex);
+ ret = als_set_power_state(data, 1);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(als_pm_ops, als_suspend, als_resume);
+#define ALS_PM_OPS (&als_pm_ops)
+#else
+#define ALS_PM_OPS NULL
+#endif
+
+static struct i2c_device_id als_id[] = {
+ { ALS_DRV_NAME, 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, als_id);
+
+static struct i2c_driver als_driver = {
+ .driver = {
+ .name = ALS_DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = ALS_PM_OPS,
+ },
+ .probe = als_probe,
+ .remove = als_remove,
+ .id_table = als_id,
+};
+
+module_i2c_driver(als_driver);
+
+MODULE_AUTHOR("Kravchenko Oleksandr <o.v.kravchenko@globallogic.com>");
+MODULE_AUTHOR("GlobalLogic inc.");
+MODULE_DESCRIPTION("APDS9300 ambient light photo sensor driver");
+MODULE_LICENSE("GPL");
--
1.7.9.5


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