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[PATCH v3 0/5] Support for max44000 Ambient and Infrared Proximity Sensor

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  [PATCH v3 0/5] Support for max44000 Ambient and Infrared Proximity Sensor Crestez Dan Leonard <leonard.crestez@intel.com> - 2016-04-18 16:40 +0200
    [PATCH v3 2/5] max44000: Initial support for proximity reading Crestez Dan Leonard <leonard.crestez@intel.com> - 2016-04-18 16:40 +0200
      Re: [PATCH v3 2/5] max44000: Initial support for proximity reading Jonathan Cameron <jic23@kernel.org> - 2016-04-24 11:30 +0200
    [PATCH v3 5/5] max44000: Initial triggered buffer support Crestez Dan Leonard <leonard.crestez@intel.com> - 2016-04-18 16:40 +0200
      Re: [PATCH v3 5/5] max44000: Initial triggered buffer support Jonathan Cameron <jic23@kernel.org> - 2016-04-24 11:30 +0200
    [PATCH v3 3/5] max44000: Support controlling LED current output Crestez Dan Leonard <leonard.crestez@intel.com> - 2016-04-18 16:40 +0200
      Re: [PATCH v3 3/5] max44000: Support controlling LED current output Jonathan Cameron <jic23@kernel.org> - 2016-04-24 11:30 +0200
    [PATCH v3 1/5] max44000: Initial support Crestez Dan Leonard <leonard.crestez@intel.com> - 2016-04-18 16:40 +0200
      Re: [PATCH v3 1/5] max44000: Initial support Jonathan Cameron <jic23@kernel.org> - 2016-04-24 11:20 +0200

#1381760 — [PATCH v3 0/5] Support for max44000 Ambient and Infrared Proximity Sensor

Changes since v2:
* Drop reg_defaults from regmap_config
* Use REGCACHE_RBTREE
* Implement readable/writable/volatile reg with switches
* Use test_bit when checking the scan mask
* Add _INT_TIME info_mask in patch 4 rather than 2
* Cleaner spacing in max44000_remove

Changes since v1:
* Remove max44000_data.client
* Maintain alphabetical order in kconfig/makefile
* Avoid pointless inlines
* Remove explicit CONFIG_OF because no special handling is done
* Set storagebits = 16 for proximity channel and avoid VLAs
* Expand MAX44000_REGMASK for readability/reviewability
* Clear irq bits at the end of the probe function
* Only write important bits on probe rather than everything

Crestez Dan Leonard (5):
  max44000: Initial support
  max44000: Initial support for proximity reading
  max44000: Support controlling LED current output
  max44000: Expose ambient sensor scaling
  max44000: Initial triggered buffer support

 drivers/iio/light/Kconfig    |  11 +
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/max44000.c | 637 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 649 insertions(+)
 create mode 100644 drivers/iio/light/max44000.c

-- 
2.5.5

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#1381763 — [PATCH v3 2/5] max44000: Initial support for proximity reading

The proximity sensor relies on sending pulses to an external IR led and
it is disabled by default on powerup. The driver will enable it with a
default power setting.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
---
 drivers/iio/light/max44000.c | 45 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index 5ed7934..dc63de2 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -59,6 +59,11 @@
  */
 #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
 
+/* REG_TX bits */
+#define MAX44000_LED_CURRENT_MASK	0xf
+#define MAX44000_LED_CURRENT_MAX	11
+#define MAX44000_LED_CURRENT_DEFAULT	6
+
 #define MAX44000_ALSDATA_OVERFLOW	0x4000
 
 struct max44000_data {
@@ -75,6 +80,11 @@ static const struct iio_chan_spec max44000_channels[] = {
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 	},
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+	},
 };
 
 static int max44000_read_alsval(struct max44000_data *data)
@@ -104,11 +114,23 @@ static int max44000_read_alsval(struct max44000_data *data)
 	return regval;
 }
 
+static int max44000_write_led_current_raw(struct max44000_data *data, int val)
+{
+	/* Maybe we should clamp the value instead? */
+	if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
+		return -ERANGE;
+	if (val >= 8)
+		val += 4;
+	return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
+				 MAX44000_LED_CURRENT_MASK, val);
+}
+
 static int max44000_read_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int *val, int *val2, long mask)
 {
 	struct max44000_data *data = iio_priv(indio_dev);
+	unsigned int regval;
 	int ret;
 
 	switch (mask) {
@@ -123,6 +145,15 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
 			*val = ret;
 			return IIO_VAL_INT;
 
+		case IIO_PROXIMITY:
+			mutex_lock(&data->lock);
+			ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
+			mutex_unlock(&data->lock);
+			if (ret < 0)
+				return ret;
+			*val = regval;
+			return IIO_VAL_INT;
+
 		default:
 			return -EINVAL;
 		}
@@ -266,8 +297,18 @@ static int max44000_probe(struct i2c_client *client,
 		return ret;
 	}
 
-	/* Reset CFG bits to ALS-only mode and no interrupts */
-	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
+	/*
+	 * By default the LED pulse used for the proximity sensor is disabled.
+	 * Set a middle value so that we get some sort of valid data by default.
+	 */
+	ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to write init config: %d\n", ret);
+		return ret;
+	}
+
+	/* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
+	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
 	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to write init config: %d\n", ret);
-- 
2.5.5

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#1385785 — Re: [PATCH v3 2/5] max44000: Initial support for proximity reading

On 18/04/16 15:31, Crestez Dan Leonard wrote:
> The proximity sensor relies on sending pulses to an external IR led and
> it is disabled by default on powerup. The driver will enable it with a
> default power setting.
> 
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Applied.
> ---
>  drivers/iio/light/max44000.c | 45 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index 5ed7934..dc63de2 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -59,6 +59,11 @@
>   */
>  #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
>  
> +/* REG_TX bits */
> +#define MAX44000_LED_CURRENT_MASK	0xf
> +#define MAX44000_LED_CURRENT_MAX	11
> +#define MAX44000_LED_CURRENT_DEFAULT	6
> +
>  #define MAX44000_ALSDATA_OVERFLOW	0x4000
>  
>  struct max44000_data {
> @@ -75,6 +80,11 @@ static const struct iio_chan_spec max44000_channels[] = {
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
>  	},
> +	{
> +		.type = IIO_PROXIMITY,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> +	},
>  };
>  
>  static int max44000_read_alsval(struct max44000_data *data)
> @@ -104,11 +114,23 @@ static int max44000_read_alsval(struct max44000_data *data)
>  	return regval;
>  }
>  
> +static int max44000_write_led_current_raw(struct max44000_data *data, int val)
> +{
> +	/* Maybe we should clamp the value instead? */
> +	if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
> +		return -ERANGE;
> +	if (val >= 8)
> +		val += 4;
> +	return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
> +				 MAX44000_LED_CURRENT_MASK, val);
> +}
> +
>  static int max44000_read_raw(struct iio_dev *indio_dev,
>  			     struct iio_chan_spec const *chan,
>  			     int *val, int *val2, long mask)
>  {
>  	struct max44000_data *data = iio_priv(indio_dev);
> +	unsigned int regval;
>  	int ret;
>  
>  	switch (mask) {
> @@ -123,6 +145,15 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
>  			*val = ret;
>  			return IIO_VAL_INT;
>  
> +		case IIO_PROXIMITY:
> +			mutex_lock(&data->lock);
> +			ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
> +			mutex_unlock(&data->lock);
> +			if (ret < 0)
> +				return ret;
> +			*val = regval;
> +			return IIO_VAL_INT;
> +
>  		default:
>  			return -EINVAL;
>  		}
> @@ -266,8 +297,18 @@ static int max44000_probe(struct i2c_client *client,
>  		return ret;
>  	}
>  
> -	/* Reset CFG bits to ALS-only mode and no interrupts */
> -	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
> +	/*
> +	 * By default the LED pulse used for the proximity sensor is disabled.
> +	 * Set a middle value so that we get some sort of valid data by default.
> +	 */
> +	ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to write init config: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
> +	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
>  	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
>  	if (ret < 0) {
>  		dev_err(&client->dev, "failed to write init config: %d\n", ret);
> 

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#1381764 — [PATCH v3 5/5] max44000: Initial triggered buffer support

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
---
 drivers/iio/light/max44000.c | 62 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index c58bb78..b83d47d 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -19,6 +19,9 @@
 #include <linux/util_macros.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/acpi.h>
 
 #define MAX44000_DRV_NAME		"max44000"
@@ -125,24 +128,41 @@ static const char max44000_scale_avail_str[] =
 	"0.5 "
 	 "4";
 
+#define MAX44000_SCAN_INDEX_ALS 0
+#define MAX44000_SCAN_INDEX_PRX 1
+
 static const struct iio_chan_spec max44000_channels[] = {
 	{
 		.type = IIO_LIGHT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
 					    BIT(IIO_CHAN_INFO_INT_TIME),
+		.scan_index = MAX44000_SCAN_INDEX_ALS,
+		.scan_type = {
+			.sign		= 'u',
+			.realbits	= 14,
+			.storagebits	= 16,
+		}
 	},
 	{
 		.type = IIO_PROXIMITY,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = MAX44000_SCAN_INDEX_PRX,
+		.scan_type = {
+			.sign		= 'u',
+			.realbits	= 8,
+			.storagebits	= 16,
+		}
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
 	{
 		.type = IIO_CURRENT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE),
 		.extend_name = "led",
 		.output = 1,
+		.scan_index = -1,
 	},
 };
 
@@ -467,6 +487,41 @@ static const struct regmap_config max44000_regmap_config = {
 	.cache_type	= REGCACHE_RBTREE,
 };
 
+static irqreturn_t max44000_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct max44000_data *data = iio_priv(indio_dev);
+	u16 buf[8]; /* 2x u16 + padding + 8 bytes timestamp */
+	int index = 0;
+	unsigned int regval;
+	int ret;
+
+	mutex_lock(&data->lock);
+	if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {
+		ret = max44000_read_alsval(data);
+		if (ret < 0)
+			goto out_unlock;
+		buf[index++] = ret;
+	}
+	if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {
+		ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
+		if (ret < 0)
+			goto out_unlock;
+		buf[index] = regval;
+	}
+	mutex_unlock(&data->lock);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+
+out_unlock:
+	mutex_unlock(&data->lock);
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
 static int max44000_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
@@ -532,6 +587,12 @@ static int max44000_probe(struct i2c_client *client,
 		return ret;
 	}
 
+	ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		return ret;
+	}
+
 	return iio_device_register(indio_dev);
 }
 
@@ -540,6 +601,7 @@ static int max44000_remove(struct i2c_client *client)
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
 
 	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
 
 	return 0;
 }
-- 
2.5.5

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#1385788 — Re: [PATCH v3 5/5] max44000: Initial triggered buffer support

On 18/04/16 15:31, Crestez Dan Leonard wrote:
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
>  drivers/iio/light/max44000.c | 62 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 62 insertions(+)
> 
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index c58bb78..b83d47d 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -19,6 +19,9 @@
>  #include <linux/util_macros.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>  #include <linux/acpi.h>
>  
>  #define MAX44000_DRV_NAME		"max44000"
> @@ -125,24 +128,41 @@ static const char max44000_scale_avail_str[] =
>  	"0.5 "
>  	 "4";
>  
> +#define MAX44000_SCAN_INDEX_ALS 0
> +#define MAX44000_SCAN_INDEX_PRX 1
> +
>  static const struct iio_chan_spec max44000_channels[] = {
>  	{
>  		.type = IIO_LIGHT,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
>  					    BIT(IIO_CHAN_INFO_INT_TIME),
> +		.scan_index = MAX44000_SCAN_INDEX_ALS,
> +		.scan_type = {
> +			.sign		= 'u',
> +			.realbits	= 14,
> +			.storagebits	= 16,
> +		}
>  	},
>  	{
>  		.type = IIO_PROXIMITY,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> +		.scan_index = MAX44000_SCAN_INDEX_PRX,
> +		.scan_type = {
> +			.sign		= 'u',
> +			.realbits	= 8,
> +			.storagebits	= 16,
> +		}
>  	},
> +	IIO_CHAN_SOFT_TIMESTAMP(2),
>  	{
>  		.type = IIO_CURRENT,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>  				      BIT(IIO_CHAN_INFO_SCALE),
>  		.extend_name = "led",
>  		.output = 1,
> +		.scan_index = -1,
>  	},
>  };
>  
> @@ -467,6 +487,41 @@ static const struct regmap_config max44000_regmap_config = {
>  	.cache_type	= REGCACHE_RBTREE,
>  };
>  
> +static irqreturn_t max44000_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct max44000_data *data = iio_priv(indio_dev);
> +	u16 buf[8]; /* 2x u16 + padding + 8 bytes timestamp */
> +	int index = 0;
> +	unsigned int regval;
> +	int ret;
> +
> +	mutex_lock(&data->lock);
> +	if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {
> +		ret = max44000_read_alsval(data);
> +		if (ret < 0)
> +			goto out_unlock;
> +		buf[index++] = ret;
> +	}
> +	if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {
> +		ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
> +		if (ret < 0)
> +			goto out_unlock;
> +		buf[index] = regval;
> +	}
> +	mutex_unlock(&data->lock);
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +
> +out_unlock:
> +	mutex_unlock(&data->lock);
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +}
> +
>  static int max44000_probe(struct i2c_client *client,
>  			  const struct i2c_device_id *id)
>  {
> @@ -532,6 +587,12 @@ static int max44000_probe(struct i2c_client *client,
>  		return ret;
>  	}
>  
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +		return ret;
> +	}
> +
>  	return iio_device_register(indio_dev);
>  }
>  
> @@ -540,6 +601,7 @@ static int max44000_remove(struct i2c_client *client)
>  	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>  
>  	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
>  
>  	return 0;
>  }
> 

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#1381765 — [PATCH v3 3/5] max44000: Support controlling LED current output

This is exposed as an output channel with "led" as an extend_name.

Other sensors also have support for controlling an external LED. It's
not clear that simply exposing an undecorated output channel is the
correct approach.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
---
 drivers/iio/light/max44000.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index dc63de2..0ccd110 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -85,6 +85,13 @@ static const struct iio_chan_spec max44000_channels[] = {
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 	},
+	{
+		.type = IIO_CURRENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.extend_name = "led",
+		.output = 1,
+	},
 };
 
 static int max44000_read_alsval(struct max44000_data *data)
@@ -125,6 +132,20 @@ static int max44000_write_led_current_raw(struct max44000_data *data, int val)
 				 MAX44000_LED_CURRENT_MASK, val);
 }
 
+static int max44000_read_led_current_raw(struct max44000_data *data)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
+	if (ret < 0)
+		return ret;
+	regval &= MAX44000_LED_CURRENT_MASK;
+	if (regval >= 8)
+		regval -= 4;
+	return regval;
+}
+
 static int max44000_read_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int *val, int *val2, long mask)
@@ -154,12 +175,26 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
 			*val = regval;
 			return IIO_VAL_INT;
 
+		case IIO_CURRENT:
+			mutex_lock(&data->lock);
+			ret = max44000_read_led_current_raw(data);
+			mutex_unlock(&data->lock);
+			if (ret < 0)
+				return ret;
+			*val = ret;
+			return IIO_VAL_INT;
+
 		default:
 			return -EINVAL;
 		}
 
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
+		case IIO_CURRENT:
+			/* Output register is in 10s of miliamps */
+			*val = 10;
+			return IIO_VAL_INT;
+
 		case IIO_LIGHT:
 			*val = 1;
 			*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
@@ -174,9 +209,27 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static int max44000_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct max44000_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
+		mutex_lock(&data->lock);
+		ret = max44000_write_led_current_raw(data, val);
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
 static const struct iio_info max44000_info = {
 	.driver_module		= THIS_MODULE,
 	.read_raw		= max44000_read_raw,
+	.write_raw		= max44000_write_raw,
 };
 
 static bool max44000_readable_reg(struct device *dev, unsigned int reg)
-- 
2.5.5

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#1385786 — Re: [PATCH v3 3/5] max44000: Support controlling LED current output

On 18/04/16 15:31, Crestez Dan Leonard wrote:
> This is exposed as an output channel with "led" as an extend_name.
> 
> Other sensors also have support for controlling an external LED. It's
> not clear that simply exposing an undecorated output channel is thee
> correct approach.
> 
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
While I suspect we will sometime have a better solution for this common problem,
it won't be a problem to maintain this interface as well

Applied
> ---
>  drivers/iio/light/max44000.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index dc63de2..0ccd110 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -85,6 +85,13 @@ static const struct iio_chan_spec max44000_channels[] = {
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
>  	},
> +	{
> +		.type = IIO_CURRENT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE),
> +		.extend_name = "led",
> +		.output = 1,
> +	},
>  };
>  
>  static int max44000_read_alsval(struct max44000_data *data)
> @@ -125,6 +132,20 @@ static int max44000_write_led_current_raw(struct max44000_data *data, int val)
>  				 MAX44000_LED_CURRENT_MASK, val);
>  }
>  
> +static int max44000_read_led_current_raw(struct max44000_data *data)
> +{
> +	unsigned int regval;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
> +	if (ret < 0)
> +		return ret;
> +	regval &= MAX44000_LED_CURRENT_MASK;
> +	if (regval >= 8)
> +		regval -= 4;
> +	return regval;
> +}
> +
>  static int max44000_read_raw(struct iio_dev *indio_dev,
>  			     struct iio_chan_spec const *chan,
>  			     int *val, int *val2, long mask)
> @@ -154,12 +175,26 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
>  			*val = regval;
>  			return IIO_VAL_INT;
>  
> +		case IIO_CURRENT:
> +			mutex_lock(&data->lock);
> +			ret = max44000_read_led_current_raw(data);
> +			mutex_unlock(&data->lock);
> +			if (ret < 0)
> +				return ret;
> +			*val = ret;
> +			return IIO_VAL_INT;
> +
>  		default:
>  			return -EINVAL;
>  		}
>  
>  	case IIO_CHAN_INFO_SCALE:
>  		switch (chan->type) {
> +		case IIO_CURRENT:
> +			/* Output register is in 10s of miliamps */
> +			*val = 10;
> +			return IIO_VAL_INT;
> +
>  		case IIO_LIGHT:
>  			*val = 1;
>  			*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
> @@ -174,9 +209,27 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int max44000_write_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int val, int val2, long mask)
> +{
> +	struct max44000_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
> +		mutex_lock(&data->lock);
> +		ret = max44000_write_led_current_raw(data, val);
> +		mutex_unlock(&data->lock);
> +		return ret;
> +	}
> +
> +	return -EINVAL;
> +}
> +
>  static const struct iio_info max44000_info = {
>  	.driver_module		= THIS_MODULE,
>  	.read_raw		= max44000_read_raw,
> +	.write_raw		= max44000_write_raw,
>  };
>  
>  static bool max44000_readable_reg(struct device *dev, unsigned int reg)
> 

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#1381770 — [PATCH v3 1/5] max44000: Initial support

This just adds support for reporting illuminance with default settings.

Important default registers are written on probe because the device
otherwise lacks a reset function.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
---
 drivers/iio/light/Kconfig    |  11 ++
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/max44000.c | 324 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 336 insertions(+)
 create mode 100644 drivers/iio/light/max44000.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 5ee1d45..d146c2c 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -234,6 +234,17 @@ config LTR501
 	 This driver can also be built as a module.  If so, the module
          will be called ltr501.
 
+config MAX44000
+	tristate "MAX44000 Ambient and Infrared Proximity Sensor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	 Say Y here if you want to build support for Maxim Integrated's
+	 MAX44000 ambient and infrared proximity sensor device.
+
+	 To compile this driver as a module, choose M here:
+	 the module will be called max44000.
+
 config OPT3001
 	tristate "Texas Instruments OPT3001 Light Sensor"
 	depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 4aeee2b..6e640cf 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_ISL29125)		+= isl29125.o
 obj-$(CONFIG_JSA1212)		+= jsa1212.o
 obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
 obj-$(CONFIG_LTR501)		+= ltr501.o
+obj-$(CONFIG_MAX44000)		+= max44000.o
 obj-$(CONFIG_OPT3001)		+= opt3001.o
 obj-$(CONFIG_PA12203001)	+= pa12203001.o
 obj-$(CONFIG_RPR0521)		+= rpr0521.o
diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
new file mode 100644
index 0000000..5ed7934
--- /dev/null
+++ b/drivers/iio/light/max44000.c
@@ -0,0 +1,324 @@
+/*
+ * MAX44000 Ambient and Infrared Proximity Sensor
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * 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.
+ *
+ * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
+ *
+ * 7-bit I2C slave address 0x4a
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/util_macros.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/acpi.h>
+
+#define MAX44000_DRV_NAME		"max44000"
+
+/* Registers in datasheet order */
+#define MAX44000_REG_STATUS		0x00
+#define MAX44000_REG_CFG_MAIN		0x01
+#define MAX44000_REG_CFG_RX		0x02
+#define MAX44000_REG_CFG_TX		0x03
+#define MAX44000_REG_ALS_DATA_HI	0x04
+#define MAX44000_REG_ALS_DATA_LO	0x05
+#define MAX44000_REG_PRX_DATA		0x16
+#define MAX44000_REG_ALS_UPTHR_HI	0x06
+#define MAX44000_REG_ALS_UPTHR_LO	0x07
+#define MAX44000_REG_ALS_LOTHR_HI	0x08
+#define MAX44000_REG_ALS_LOTHR_LO	0x09
+#define MAX44000_REG_PST		0x0a
+#define MAX44000_REG_PRX_IND		0x0b
+#define MAX44000_REG_PRX_THR		0x0c
+#define MAX44000_REG_TRIM_GAIN_GREEN	0x0f
+#define MAX44000_REG_TRIM_GAIN_IR	0x10
+
+/* REG_CFG bits */
+#define MAX44000_CFG_ALSINTE            0x01
+#define MAX44000_CFG_PRXINTE            0x02
+#define MAX44000_CFG_MASK               0x1c
+#define MAX44000_CFG_MODE_SHUTDOWN      0x00
+#define MAX44000_CFG_MODE_ALS_GIR       0x04
+#define MAX44000_CFG_MODE_ALS_G         0x08
+#define MAX44000_CFG_MODE_ALS_IR        0x0c
+#define MAX44000_CFG_MODE_ALS_PRX       0x10
+#define MAX44000_CFG_MODE_PRX           0x14
+#define MAX44000_CFG_TRIM               0x20
+
+/*
+ * Upper 4 bits are not documented but start as 1 on powerup
+ * Setting them to 0 causes proximity to misbehave so set them to 1
+ */
+#define MAX44000_REG_CFG_RX_DEFAULT 0xf0
+
+#define MAX44000_ALSDATA_OVERFLOW	0x4000
+
+struct max44000_data {
+	struct mutex lock;
+	struct regmap *regmap;
+};
+
+/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
+#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
+
+static const struct iio_chan_spec max44000_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static int max44000_read_alsval(struct max44000_data *data)
+{
+	u16 regval;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
+			       &regval, sizeof(regval));
+	if (ret < 0)
+		return ret;
+
+	regval = be16_to_cpu(regval);
+
+	/*
+	 * Overflow is explained on datasheet page 17.
+	 *
+	 * It's a warning that either the G or IR channel has become saturated
+	 * and that the value in the register is likely incorrect.
+	 *
+	 * The recommendation is to change the scale (ALSPGA).
+	 * The driver just returns the max representable value.
+	 */
+	if (regval & MAX44000_ALSDATA_OVERFLOW)
+		return 0x3FFF;
+
+	return regval;
+}
+
+static int max44000_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct max44000_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			mutex_lock(&data->lock);
+			ret = max44000_read_alsval(data);
+			mutex_unlock(&data->lock);
+			if (ret < 0)
+				return ret;
+			*val = ret;
+			return IIO_VAL_INT;
+
+		default:
+			return -EINVAL;
+		}
+
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			*val = 1;
+			*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
+			return IIO_VAL_FRACTIONAL_LOG2;
+
+		default:
+			return -EINVAL;
+		}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info max44000_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= max44000_read_raw,
+};
+
+static bool max44000_readable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX44000_REG_STATUS:
+	case MAX44000_REG_CFG_MAIN:
+	case MAX44000_REG_CFG_RX:
+	case MAX44000_REG_CFG_TX:
+	case MAX44000_REG_ALS_DATA_HI:
+	case MAX44000_REG_ALS_DATA_LO:
+	case MAX44000_REG_PRX_DATA:
+	case MAX44000_REG_ALS_UPTHR_HI:
+	case MAX44000_REG_ALS_UPTHR_LO:
+	case MAX44000_REG_ALS_LOTHR_HI:
+	case MAX44000_REG_ALS_LOTHR_LO:
+	case MAX44000_REG_PST:
+	case MAX44000_REG_PRX_IND:
+	case MAX44000_REG_PRX_THR:
+	case MAX44000_REG_TRIM_GAIN_GREEN:
+	case MAX44000_REG_TRIM_GAIN_IR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX44000_REG_CFG_MAIN:
+	case MAX44000_REG_CFG_RX:
+	case MAX44000_REG_CFG_TX:
+	case MAX44000_REG_ALS_UPTHR_HI:
+	case MAX44000_REG_ALS_UPTHR_LO:
+	case MAX44000_REG_ALS_LOTHR_HI:
+	case MAX44000_REG_ALS_LOTHR_LO:
+	case MAX44000_REG_PST:
+	case MAX44000_REG_PRX_IND:
+	case MAX44000_REG_PRX_THR:
+	case MAX44000_REG_TRIM_GAIN_GREEN:
+	case MAX44000_REG_TRIM_GAIN_IR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX44000_REG_STATUS:
+	case MAX44000_REG_ALS_DATA_HI:
+	case MAX44000_REG_ALS_DATA_LO:
+	case MAX44000_REG_PRX_DATA:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool max44000_precious_reg(struct device *dev, unsigned int reg)
+{
+	return reg == MAX44000_REG_STATUS;
+}
+
+static const struct regmap_config max44000_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+
+	.max_register	= MAX44000_REG_PRX_DATA,
+	.readable_reg	= max44000_readable_reg,
+	.writeable_reg	= max44000_writeable_reg,
+	.volatile_reg	= max44000_volatile_reg,
+	.precious_reg	= max44000_precious_reg,
+
+	.use_single_rw	= 1,
+	.cache_type	= REGCACHE_RBTREE,
+};
+
+static int max44000_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct max44000_data *data;
+	struct iio_dev *indio_dev;
+	int ret, reg;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+	data = iio_priv(indio_dev);
+	data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&client->dev, "regmap_init failed!\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	i2c_set_clientdata(client, indio_dev);
+	mutex_init(&data->lock);
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &max44000_info;
+	indio_dev->name = MAX44000_DRV_NAME;
+	indio_dev->channels = max44000_channels;
+	indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
+
+	/*
+	 * The device doesn't have a reset function so we just clear some
+	 * important bits at probe time to ensure sane operation.
+	 *
+	 * Since we don't support interrupts/events the threshold values are
+	 * not important. We also don't touch trim values.
+	 */
+
+	/* Reset ALS scaling bits */
+	ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX, MAX44000_REG_CFG_RX_DEFAULT);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to write default CFG_RX: %d\n", ret);
+		return ret;
+	}
+
+	/* Reset CFG bits to ALS-only mode and no interrupts */
+	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
+	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to write init config: %d\n", ret);
+		return ret;
+	}
+
+	/* Read status at least once to clear any stale interrupt bits. */
+	ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to read init status: %d\n", ret);
+		return ret;
+	}
+
+	return iio_device_register(indio_dev);
+}
+
+static int max44000_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id max44000_id[] = {
+	{"max44000", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max44000_id);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id max44000_acpi_match[] = {
+	{"MAX44000", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
+#endif
+
+static struct i2c_driver max44000_driver = {
+	.driver = {
+		.name	= MAX44000_DRV_NAME,
+		.acpi_match_table = ACPI_PTR(max44000_acpi_match),
+	},
+	.probe		= max44000_probe,
+	.remove		= max44000_remove,
+	.id_table	= max44000_id,
+};
+
+module_i2c_driver(max44000_driver);
+
+MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
+MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
+MODULE_LICENSE("GPL v2");
-- 
2.5.5

[toc] | [prev] | [next] | [standalone]

#1385784 — Re: [PATCH v3 1/5] max44000: Initial support

On 18/04/16 15:31, Crestez Dan Leonard wrote:
> This just adds support for reporting illuminance with default settings.
> 
> Important default registers are written on probe because the device
> otherwise lacks a reset function.
> 
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Looks good to me - applied to the togreg branch of iio.git
initially pushed out as testing for the autobuilders to play with it.
I did fix up a couple of overly long lines though.  They weren't cases where
breaking them effected readability so checkpatch warnings should have been
fixed.  Otherwise I end up with patches for them a few days after I push
the tree out!  Easier to fix them now.

Jonathan
> ---
>  drivers/iio/light/Kconfig    |  11 ++
>  drivers/iio/light/Makefile   |   1 +
>  drivers/iio/light/max44000.c | 324 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 336 insertions(+)
>  create mode 100644 drivers/iio/light/max44000.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 5ee1d45..d146c2c 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -234,6 +234,17 @@ config LTR501
>  	 This driver can also be built as a module.  If so, the module
>           will be called ltr501.
>  
> +config MAX44000
> +	tristate "MAX44000 Ambient and Infrared Proximity Sensor"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	 Say Y here if you want to build support for Maxim Integrated's
> +	 MAX44000 ambient and infrared proximity sensor device.
> +
> +	 To compile this driver as a module, choose M here:
> +	 the module will be called max44000.
> +
>  config OPT3001
>  	tristate "Texas Instruments OPT3001 Light Sensor"
>  	depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 4aeee2b..6e640cf 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_ISL29125)		+= isl29125.o
>  obj-$(CONFIG_JSA1212)		+= jsa1212.o
>  obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
>  obj-$(CONFIG_LTR501)		+= ltr501.o
> +obj-$(CONFIG_MAX44000)		+= max44000.o
>  obj-$(CONFIG_OPT3001)		+= opt3001.o
>  obj-$(CONFIG_PA12203001)	+= pa12203001.o
>  obj-$(CONFIG_RPR0521)		+= rpr0521.o
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> new file mode 100644
> index 0000000..5ed7934
> --- /dev/null
> +++ b/drivers/iio/light/max44000.c
> @@ -0,0 +1,324 @@
> +/*
> + * MAX44000 Ambient and Infrared Proximity Sensor
> + *
> + * Copyright (c) 2016, Intel Corporation.
> + *
> + * 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.
> + *
> + * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
> + *
> + * 7-bit I2C slave address 0x4a
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/util_macros.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/acpi.h>
> +
> +#define MAX44000_DRV_NAME		"max44000"
> +
> +/* Registers in datasheet order */
> +#define MAX44000_REG_STATUS		0x00
> +#define MAX44000_REG_CFG_MAIN		0x01
> +#define MAX44000_REG_CFG_RX		0x02
> +#define MAX44000_REG_CFG_TX		0x03
> +#define MAX44000_REG_ALS_DATA_HI	0x04
> +#define MAX44000_REG_ALS_DATA_LO	0x05
> +#define MAX44000_REG_PRX_DATA		0x16
> +#define MAX44000_REG_ALS_UPTHR_HI	0x06
> +#define MAX44000_REG_ALS_UPTHR_LO	0x07
> +#define MAX44000_REG_ALS_LOTHR_HI	0x08
> +#define MAX44000_REG_ALS_LOTHR_LO	0x09
> +#define MAX44000_REG_PST		0x0a
> +#define MAX44000_REG_PRX_IND		0x0b
> +#define MAX44000_REG_PRX_THR		0x0c
> +#define MAX44000_REG_TRIM_GAIN_GREEN	0x0f
> +#define MAX44000_REG_TRIM_GAIN_IR	0x10
> +
> +/* REG_CFG bits */
> +#define MAX44000_CFG_ALSINTE            0x01
> +#define MAX44000_CFG_PRXINTE            0x02
> +#define MAX44000_CFG_MASK               0x1c
> +#define MAX44000_CFG_MODE_SHUTDOWN      0x00
> +#define MAX44000_CFG_MODE_ALS_GIR       0x04
> +#define MAX44000_CFG_MODE_ALS_G         0x08
> +#define MAX44000_CFG_MODE_ALS_IR        0x0c
> +#define MAX44000_CFG_MODE_ALS_PRX       0x10
> +#define MAX44000_CFG_MODE_PRX           0x14
> +#define MAX44000_CFG_TRIM               0x20
> +
> +/*
> + * Upper 4 bits are not documented but start as 1 on powerup
> + * Setting them to 0 causes proximity to misbehave so set them to 1
> + */
> +#define MAX44000_REG_CFG_RX_DEFAULT 0xf0
> +
> +#define MAX44000_ALSDATA_OVERFLOW	0x4000
> +
> +struct max44000_data {
> +	struct mutex lock;
> +	struct regmap *regmap;
> +};
> +
> +/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
> +#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
> +
> +static const struct iio_chan_spec max44000_channels[] = {
> +	{
> +		.type = IIO_LIGHT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> +	},
> +};
> +
> +static int max44000_read_alsval(struct max44000_data *data)
> +{
> +	u16 regval;
> +	int ret;
> +
> +	ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
> +			       &regval, sizeof(regval));
> +	if (ret < 0)
> +		return ret;
> +
> +	regval = be16_to_cpu(regval);
> +
> +	/*
> +	 * Overflow is explained on datasheet page 17.
> +	 *
> +	 * It's a warning that either the G or IR channel has become saturated
> +	 * and that the value in the register is likely incorrect.
> +	 *
> +	 * The recommendation is to change the scale (ALSPGA).
> +	 * The driver just returns the max representable value.
> +	 */
> +	if (regval & MAX44000_ALSDATA_OVERFLOW)
> +		return 0x3FFF;
> +
> +	return regval;
> +}
> +
> +static int max44000_read_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int *val, int *val2, long mask)
> +{
> +	struct max44000_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			mutex_lock(&data->lock);
> +			ret = max44000_read_alsval(data);
> +			mutex_unlock(&data->lock);
> +			if (ret < 0)
> +				return ret;
> +			*val = ret;
> +			return IIO_VAL_INT;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			*val = 1;
> +			*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
> +			return IIO_VAL_FRACTIONAL_LOG2;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_info max44000_info = {
> +	.driver_module		= THIS_MODULE,
> +	.read_raw		= max44000_read_raw,
> +};
> +
> +static bool max44000_readable_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case MAX44000_REG_STATUS:
> +	case MAX44000_REG_CFG_MAIN:
> +	case MAX44000_REG_CFG_RX:
> +	case MAX44000_REG_CFG_TX:
> +	case MAX44000_REG_ALS_DATA_HI:
> +	case MAX44000_REG_ALS_DATA_LO:
> +	case MAX44000_REG_PRX_DATA:
> +	case MAX44000_REG_ALS_UPTHR_HI:
> +	case MAX44000_REG_ALS_UPTHR_LO:
> +	case MAX44000_REG_ALS_LOTHR_HI:
> +	case MAX44000_REG_ALS_LOTHR_LO:
> +	case MAX44000_REG_PST:
> +	case MAX44000_REG_PRX_IND:
> +	case MAX44000_REG_PRX_THR:
> +	case MAX44000_REG_TRIM_GAIN_GREEN:
> +	case MAX44000_REG_TRIM_GAIN_IR:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case MAX44000_REG_CFG_MAIN:
> +	case MAX44000_REG_CFG_RX:
> +	case MAX44000_REG_CFG_TX:
> +	case MAX44000_REG_ALS_UPTHR_HI:
> +	case MAX44000_REG_ALS_UPTHR_LO:
> +	case MAX44000_REG_ALS_LOTHR_HI:
> +	case MAX44000_REG_ALS_LOTHR_LO:
> +	case MAX44000_REG_PST:
> +	case MAX44000_REG_PRX_IND:
> +	case MAX44000_REG_PRX_THR:
> +	case MAX44000_REG_TRIM_GAIN_GREEN:
> +	case MAX44000_REG_TRIM_GAIN_IR:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case MAX44000_REG_STATUS:
> +	case MAX44000_REG_ALS_DATA_HI:
> +	case MAX44000_REG_ALS_DATA_LO:
> +	case MAX44000_REG_PRX_DATA:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static bool max44000_precious_reg(struct device *dev, unsigned int reg)
> +{
> +	return reg == MAX44000_REG_STATUS;
> +}
> +
> +static const struct regmap_config max44000_regmap_config = {
> +	.reg_bits	= 8,
> +	.val_bits	= 8,
> +
> +	.max_register	= MAX44000_REG_PRX_DATA,
> +	.readable_reg	= max44000_readable_reg,
> +	.writeable_reg	= max44000_writeable_reg,
> +	.volatile_reg	= max44000_volatile_reg,
> +	.precious_reg	= max44000_precious_reg,
> +
> +	.use_single_rw	= 1,
> +	.cache_type	= REGCACHE_RBTREE,
> +};
> +
> +static int max44000_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)
> +{
> +	struct max44000_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret, reg;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +	data = iio_priv(indio_dev);
> +	data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&client->dev, "regmap_init failed!\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	i2c_set_clientdata(client, indio_dev);
> +	mutex_init(&data->lock);
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &max44000_info;
> +	indio_dev->name = MAX44000_DRV_NAME;
> +	indio_dev->channels = max44000_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
> +
> +	/*
> +	 * The device doesn't have a reset function so we just clear some
> +	 * important bits at probe time to ensure sane operation.
> +	 *
> +	 * Since we don't support interrupts/events the threshold values are
> +	 * not important. We also don't touch trim values.
> +	 */
> +
> +	/* Reset ALS scaling bits */
> +	ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX, MAX44000_REG_CFG_RX_DEFAULT);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to write default CFG_RX: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Reset CFG bits to ALS-only mode and no interrupts */
> +	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
> +	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to write init config: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Read status at least once to clear any stale interrupt bits. */
> +	ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to read init status: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return iio_device_register(indio_dev);
> +}
> +
> +static int max44000_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id max44000_id[] = {
> +	{"max44000", 0},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, max44000_id);
> +
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id max44000_acpi_match[] = {
> +	{"MAX44000", 0},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
> +#endif
> +
> +static struct i2c_driver max44000_driver = {
> +	.driver = {
> +		.name	= MAX44000_DRV_NAME,
> +		.acpi_match_table = ACPI_PTR(max44000_acpi_match),
> +	},
> +	.probe		= max44000_probe,
> +	.remove		= max44000_remove,
> +	.id_table	= max44000_id,
> +};
> +
> +module_i2c_driver(max44000_driver);
> +
> +MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
> +MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
> +MODULE_LICENSE("GPL v2");
> 

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