staging: iio: add driver for isl29028

Intersil's ISL29028 is concurrent Ambient Light and
Proximity Sensor device.
Add driver to access the light and IR intensity and
proximity value via iio interface.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/light/Kconfig

@@ -14,6 +14,16 @@ config SENSORS_ISL29018
          in lux, proximity infrared sensing and normal infrared sensing.
          Data from sensor is accessible via sysfs.
 
+config SENSORS_ISL29028
+	tristate "Intersil ISL29028 Concurrent Light and Proximity Sensor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	 Provides driver for the Intersil's ISL29028 device.
+	 This driver supports the sysfs interface to get the ALS, IR intensity,
+	 Proximity value via iio. The ISL29028 provides the concurrent sensing
+	 of ambient light and proximity.
+
 config SENSORS_TSL2563
 	tristate "TAOS TSL2560, TSL2561, TSL2562 and TSL2563 ambient light sensors"
 	depends on I2C

drivers/staging/iio/light/Makefile

@@ -4,4 +4,5 @@
 
 obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
 obj-$(CONFIG_SENSORS_ISL29018)	+= isl29018.o
+obj-$(CONFIG_SENSORS_ISL29028)	+= isl29028.o
 obj-$(CONFIG_TSL2583)	+= tsl2583.o

drivers/staging/iio/light/isl29028.c

@@ -0,0 +1,563 @@
+/*
+ * IIO driver for the light sensor ISL29028.
+ * ISL29028 is Concurrent Ambient Light and Proximity Sensor
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include "../iio.h"
+#include "../sysfs.h"
+
+#define CONVERSION_TIME_MS		100
+
+#define ISL29028_REG_CONFIGURE		0x01
+
+#define CONFIGURE_ALS_IR_MODE_ALS	0
+#define CONFIGURE_ALS_IR_MODE_IR	BIT(0)
+#define CONFIGURE_ALS_IR_MODE_MASK	BIT(0)
+
+#define CONFIGURE_ALS_RANGE_LOW_LUX	0
+#define CONFIGURE_ALS_RANGE_HIGH_LUX	BIT(1)
+#define CONFIGURE_ALS_RANGE_MASK	BIT(1)
+
+#define CONFIGURE_ALS_DIS		0
+#define CONFIGURE_ALS_EN		BIT(2)
+#define CONFIGURE_ALS_EN_MASK		BIT(2)
+
+#define CONFIGURE_PROX_DRIVE		BIT(3)
+
+#define CONFIGURE_PROX_SLP_SH		4
+#define CONFIGURE_PROX_SLP_MASK		(7 << CONFIGURE_PROX_SLP_SH)
+
+#define CONFIGURE_PROX_EN		BIT(7)
+#define CONFIGURE_PROX_EN_MASK		BIT(7)
+
+#define ISL29028_REG_INTERRUPT		0x02
+
+#define ISL29028_REG_PROX_DATA		0x08
+#define ISL29028_REG_ALSIR_L		0x09
+#define ISL29028_REG_ALSIR_U		0x0A
+
+#define ISL29028_REG_TEST1_MODE		0x0E
+#define ISL29028_REG_TEST2_MODE		0x0F
+
+#define ISL29028_NUM_REGS		(ISL29028_REG_TEST2_MODE + 1)
+
+enum als_ir_mode {
+	MODE_NONE = 0,
+	MODE_ALS,
+	MODE_IR
+};
+
+struct isl29028_chip {
+	struct device		*dev;
+	struct mutex		lock;
+	struct regmap		*regmap;
+
+	unsigned int		prox_sampling;
+	bool			enable_prox;
+
+	int			lux_scale;
+	int			als_ir_mode;
+};
+
+static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
+			unsigned int sampling)
+{
+	static unsigned int prox_period[] = {800, 400, 200, 100, 75, 50, 12, 0};
+	int sel;
+	unsigned int period = DIV_ROUND_UP(1000, sampling);
+
+	for (sel = 0; sel < ARRAY_SIZE(prox_period); ++sel) {
+		if (period >= prox_period[sel])
+			break;
+	}
+	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_PROX_SLP_MASK, sel << CONFIGURE_PROX_SLP_SH);
+}
+
+static int isl29028_enable_proximity(struct isl29028_chip *chip, bool enable)
+{
+	int ret;
+	int val = 0;
+
+	if (enable)
+		val = CONFIGURE_PROX_EN;
+	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_PROX_EN_MASK, val);
+	if (ret < 0)
+		return ret;
+
+	/* Wait for conversion to be complete for first sample */
+	mdelay(DIV_ROUND_UP(1000, chip->prox_sampling));
+	return 0;
+}
+
+static int isl29028_set_als_scale(struct isl29028_chip *chip, int lux_scale)
+{
+	int val = (lux_scale == 2000) ? CONFIGURE_ALS_RANGE_HIGH_LUX :
+					CONFIGURE_ALS_RANGE_LOW_LUX;
+
+	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+		CONFIGURE_ALS_RANGE_MASK, val);
+}
+
+static int isl29028_set_als_ir_mode(struct isl29028_chip *chip,
+	enum als_ir_mode mode)
+{
+	int ret = 0;
+
+	switch (mode) {
+	case MODE_ALS:
+		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_ALS);
+		if (ret < 0)
+			return ret;
+
+		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_ALS_RANGE_MASK, CONFIGURE_ALS_RANGE_HIGH_LUX);
+		break;
+
+	case MODE_IR:
+		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_ALS_IR_MODE_MASK, CONFIGURE_ALS_IR_MODE_IR);
+		break;
+
+	case MODE_NONE:
+		return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_DIS);
+	}
+
+	if (ret < 0)
+		return ret;
+
+	/* Enable the ALS/IR */
+	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+			CONFIGURE_ALS_EN_MASK, CONFIGURE_ALS_EN);
+	if (ret < 0)
+		return ret;
+
+	/* Need to wait for conversion time if ALS/IR mode enabled */
+	mdelay(CONVERSION_TIME_MS);
+	return 0;
+}
+
+static int isl29028_read_als_ir(struct isl29028_chip *chip, int *als_ir)
+{
+	unsigned int lsb;
+	unsigned int msb;
+	int ret;
+
+	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_L, &lsb);
+	if (ret < 0) {
+		dev_err(chip->dev,
+			"Error in reading register ALSIR_L err %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_U, &msb);
+	if (ret < 0) {
+		dev_err(chip->dev,
+			"Error in reading register ALSIR_U err %d\n", ret);
+		return ret;
+	}
+
+	*als_ir = ((msb & 0xF) << 8) | (lsb & 0xFF);
+	return 0;
+}
+
+static int isl29028_read_proxim(struct isl29028_chip *chip, int *prox)
+{
+	unsigned int data;
+	int ret;
+
+	ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
+	if (ret < 0) {
+		dev_err(chip->dev, "Error in reading register %d, error %d\n",
+				ISL29028_REG_PROX_DATA, ret);
+		return ret;
+	}
+	*prox = data;
+	return 0;
+}
+
+static int isl29028_proxim_get(struct isl29028_chip *chip, int *prox_data)
+{
+	int ret;
+
+	if (!chip->enable_prox) {
+		ret = isl29028_enable_proximity(chip, true);
+		if (ret < 0)
+			return ret;
+		chip->enable_prox = true;
+	}
+	return isl29028_read_proxim(chip, prox_data);
+}
+
+static int isl29028_als_get(struct isl29028_chip *chip, int *als_data)
+{
+	int ret;
+	int als_ir_data;
+
+	if (chip->als_ir_mode != MODE_ALS) {
+		ret = isl29028_set_als_ir_mode(chip, MODE_ALS);
+		if (ret < 0) {
+			dev_err(chip->dev,
+				"Error in enabling ALS mode err %d\n", ret);
+			return ret;
+		}
+		chip->als_ir_mode = MODE_ALS;
+	}
+
+	ret = isl29028_read_als_ir(chip, &als_ir_data);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * convert als data count to lux.
+	 * if lux_scale = 125,  lux = count * 0.031
+	 * if lux_scale = 2000, lux = count * 0.49
+	 */
+	if (chip->lux_scale == 125)
+		als_ir_data = (als_ir_data * 31) / 1000;
+	else
+		als_ir_data = (als_ir_data * 49) / 100;
+
+	*als_data = als_ir_data;
+	return 0;
+}
+
+static int isl29028_ir_get(struct isl29028_chip *chip, int *ir_data)
+{
+	int ret;
+
+	if (chip->als_ir_mode != MODE_IR) {
+		ret = isl29028_set_als_ir_mode(chip, MODE_IR);
+		if (ret < 0) {
+			dev_err(chip->dev,
+				"Error in enabling IR mode err %d\n", ret);
+			return ret;
+		}
+		chip->als_ir_mode = MODE_IR;
+	}
+	return isl29028_read_als_ir(chip, ir_data);
+}
+
+/* Channel IO */
+static int isl29028_write_raw(struct iio_dev *indio_dev,
+	     struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	struct isl29028_chip *chip = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&chip->lock);
+	switch (chan->type) {
+	case IIO_PROXIMITY:
+		if (mask != IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT) {
+			dev_err(chip->dev,
+				"proximity: mask value 0x%08lx not supported\n",
+				mask);
+			break;
+		}
+		if (val < 1 || val > 100) {
+			dev_err(chip->dev,
+				"Samp_freq %d is not in range[1:100]\n", val);
+			break;
+		}
+		ret = isl29028_set_proxim_sampling(chip, val);
+		if (ret < 0) {
+			dev_err(chip->dev,
+				"Setting proximity samp_freq fail, err %d\n",
+				ret);
+			break;
+		}
+		chip->prox_sampling = val;
+		break;
+
+	case IIO_LIGHT:
+		if (mask != IIO_CHAN_INFO_SCALE_SEPARATE_BIT) {
+			dev_err(chip->dev,
+				"light: mask value 0x%08lx not supported\n",
+				mask);
+			break;
+		}
+		if ((val != 125) && (val != 2000)) {
+			dev_err(chip->dev,
+				"lux scale %d is invalid [125, 2000]\n", val);
+			break;
+		}
+		ret = isl29028_set_als_scale(chip, val);
+		if (ret < 0) {
+			dev_err(chip->dev,
+				"Setting lux scale fail with error %d\n", ret);
+			break;
+		}
+		chip->lux_scale = val;
+		break;
+
+	default:
+		dev_err(chip->dev, "Unsupported channel type\n");
+		break;
+	}
+	mutex_unlock(&chip->lock);
+	return ret;
+}
+
+static int isl29028_read_raw(struct iio_dev *indio_dev,
+	     struct iio_chan_spec const *chan, int *val, int *val2, long mask)
+{
+	struct isl29028_chip *chip = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&chip->lock);
+	switch (mask) {
+	case 0:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			ret = isl29028_als_get(chip, val);
+			break;
+		case IIO_INTENSITY:
+			ret = isl29028_ir_get(chip, val);
+			break;
+		case IIO_PROXIMITY:
+			ret = isl29028_proxim_get(chip, val);
+			break;
+		default:
+			break;
+		}
+		if (ret < 0)
+			break;
+		ret = IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT:
+		if (chan->type != IIO_PROXIMITY)
+			break;
+		*val = chip->prox_sampling;
+		ret = IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_SCALE_SEPARATE_BIT:
+		if (chan->type != IIO_LIGHT)
+			break;
+		*val = chip->lux_scale;
+		ret = IIO_VAL_INT;
+		break;
+
+	default:
+		dev_err(chip->dev, "mask value 0x%08lx not supported\n", mask);
+		break;
+	}
+	mutex_unlock(&chip->lock);
+	return ret;
+}
+
+static IIO_CONST_ATTR(in_proximity_sampling_frequency_available,
+				"1, 3, 5, 10, 13, 20, 83, 100");
+static IIO_CONST_ATTR(in_illuminance_scale_available, "125, 2000");
+
+#define ISL29028_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
+#define ISL29028_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
+static struct attribute *isl29028_attributes[] = {
+	ISL29028_CONST_ATTR(in_proximity_sampling_frequency_available),
+	ISL29028_CONST_ATTR(in_illuminance_scale_available),
+	NULL,
+};
+
+static const struct attribute_group isl29108_group = {
+	.attrs = isl29028_attributes,
+};
+
+static const struct iio_chan_spec isl29028_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.processed_val = 1,
+		.info_mask = IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
+	}, {
+		.type = IIO_INTENSITY,
+	}, {
+		.type = IIO_PROXIMITY,
+		.info_mask = IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT,
+	}
+};
+
+static const struct iio_info isl29028_info = {
+	.attrs = &isl29108_group,
+	.driver_module = THIS_MODULE,
+	.read_raw = &isl29028_read_raw,
+	.write_raw = &isl29028_write_raw,
+};
+
+static int isl29028_chip_init(struct isl29028_chip *chip)
+{
+	int ret;
+
+	chip->enable_prox  = false;
+	chip->prox_sampling = 20;
+	chip->lux_scale = 2000;
+	chip->als_ir_mode = MODE_NONE;
+
+	ret = regmap_write(chip->regmap, ISL29028_REG_TEST1_MODE, 0x0);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
+			__func__, ISL29028_REG_TEST1_MODE, ret);
+		return ret;
+	}
+	ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
+			__func__, ISL29028_REG_TEST2_MODE, ret);
+		return ret;
+	}
+
+	ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s(): write to reg %d failed, err = %d\n",
+			__func__, ISL29028_REG_CONFIGURE, ret);
+		return ret;
+	}
+
+	ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s(): setting the proximity, err = %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ret = isl29028_set_als_scale(chip, chip->lux_scale);
+	if (ret < 0)
+		dev_err(chip->dev, "%s(): setting als scale failed, err = %d\n",
+			__func__, ret);
+	return ret;
+}
+
+static bool is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ISL29028_REG_INTERRUPT:
+	case ISL29028_REG_PROX_DATA:
+	case ISL29028_REG_ALSIR_L:
+	case ISL29028_REG_ALSIR_U:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config isl29028_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_reg = is_volatile_reg,
+	.max_register = ISL29028_NUM_REGS - 1,
+	.num_reg_defaults_raw = ISL29028_NUM_REGS,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int __devinit isl29028_probe(struct i2c_client *client,
+	const struct i2c_device_id *id)
+{
+	struct isl29028_chip *chip;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = iio_allocate_device(sizeof(*chip));
+	if (!indio_dev) {
+		dev_err(&client->dev, "iio allocation fails\n");
+		return -ENOMEM;
+	}
+
+	chip = iio_priv(indio_dev);
+
+	i2c_set_clientdata(client, indio_dev);
+	chip->dev = &client->dev;
+	mutex_init(&chip->lock);
+
+	chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		ret = PTR_ERR(chip->regmap);
+		dev_err(chip->dev, "regmap initialization failed: %d\n", ret);
+		goto exit_iio_free;
+	}
+
+	ret = isl29028_chip_init(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "chip initialization failed: %d\n", ret);
+		goto exit_iio_free;
+	}
+
+	indio_dev->info = &isl29028_info;
+	indio_dev->channels = isl29028_channels;
+	indio_dev->num_channels = ARRAY_SIZE(isl29028_channels);
+	indio_dev->name = id->name;
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(chip->dev, "iio registration fails with error %d\n",
+			ret);
+		goto exit_iio_free;
+	}
+	return 0;
+
+exit_iio_free:
+	iio_free_device(indio_dev);
+	return ret;
+}
+
+static int __devexit isl29028_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+	iio_free_device(indio_dev);
+	return 0;
+}
+
+static const struct i2c_device_id isl29028_id[] = {
+	{"isl29028", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, isl29028_id);
+
+static const struct of_device_id isl29028_of_match[] = {
+	{ .compatible = "isl,isl29028", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, isl29028_of_match);
+
+static struct i2c_driver isl29028_driver = {
+	.class	= I2C_CLASS_HWMON,
+	.driver  = {
+		.name = "isl29028",
+		.owner = THIS_MODULE,
+		.of_match_table = isl29028_of_match,
+	},
+	.probe	 = isl29028_probe,
+	.remove  = __devexit_p(isl29028_remove),
+	.id_table = isl29028_id,
+};
+
+module_i2c_driver(isl29028_driver);
+
+MODULE_DESCRIPTION("ISL29028 Ambient Light and Proximity Sensor driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");