[RFC PATCH 2/2] iio: light: Add support for LTR559 chip

From: Daniel Baluta
Date: Tue Mar 31 2015 - 06:37:59 EST

This device is register compatible with LTR501, with a minor difference for
ALS control register as showed below:

ALS Control register for LTR501:

7 6 5 4 3 2 1 0
+------+------+------+------+------+------+------+------+
| | | | |
| Reserved | Gain | SW | ALS Mode |
| | | Reset| |
+------+------+------+------+------+------+------+------+

ALS Control register for LTR559:

7 6 5 4 3 2 1 0
+------+------+------+------+------+------+------+------+
| | | | |
| Reserved | Gain | SW | ALS |
| | | Reset| Mode |
+------+------+------+------+------+------+------+------+

We handle this difference by introducing ltr501_chip_info.

Datasheet for LTR559 is at:
http://optoelectronics.liteon.com/upload/download/DS86-2013-0003/S_110_LTR-559ALS-01_DS_V1.pdf

Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
drivers/iio/light/ltr501.c | 196 +++++++++++++++++++++++++++++++++++++--------
1 file changed, 163 insertions(+), 33 deletions(-)

diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
index 883855a..5939cda 100644
--- a/drivers/iio/light/ltr501.c
+++ b/drivers/iio/light/ltr501.c
@@ -45,12 +45,89 @@

#define LTR501_PS_DATA_MASK 0x7ff

+#define LTR501_RESERVED_GAIN -1
+
+enum {
+ ltr501 = 0,
+ ltr559,
+};
+
+struct ltr501_gain {
+ int scale;
+ int uscale;
+};
+
+static struct ltr501_gain ltr501_als_gain_tbl[] = {
+ {1, 0},
+ {0, 5000},
+};
+
+static struct ltr501_gain ltr559_als_gain_tbl[] = {
+ {1, 0},
+ {0, 500000},
+ {0, 250000},
+ {0, 125000},
+ {LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
+ {LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
+ {0, 20000},
+ {0, 10000},
+};
+
+static struct ltr501_gain ltr501_ps_gain_tbl[] = {
+ {1, 0},
+ {0, 250000},
+ {0, 125000},
+ {0, 62500},
+};
+
+static struct ltr501_gain ltr559_ps_gain_tbl[] = {
+ {0, 62500}, /* x16 gain */
+ {0, 31250}, /* x32 gain */
+ {0, 15625}, /* bits X1 are for x64 gain */
+ {0, 15624},
+};
+
+struct ltr501_chip_info {
+ u8 chip_id;
+ struct ltr501_gain *als_gain;
+ int als_gain_tbl_size;
+ struct ltr501_gain *ps_gain;
+ int ps_gain_tbl_size;
+ u8 als_mode_active;
+ u8 als_gain_mask;
+ u8 als_gain_shift;
+};
+
struct ltr501_data {
struct i2c_client *client;
struct mutex lock_als, lock_ps;
+ struct ltr501_chip_info *chip_info;
u8 als_contr, ps_contr;
};

+static struct ltr501_chip_info ltr501_chip_info_tbl[] = {
+ [ltr501] = {
+ .chip_id = 0x08,
+ .als_gain = ltr501_als_gain_tbl,
+ .als_gain_tbl_size = ARRAY_SIZE(ltr501_als_gain_tbl),
+ .ps_gain = ltr501_ps_gain_tbl,
+ .ps_gain_tbl_size = ARRAY_SIZE(ltr501_ps_gain_tbl),
+ .als_mode_active = BIT(0) | BIT(1),
+ .als_gain_mask = BIT(3),
+ .als_gain_shift = 3,
+ },
+ [ltr559] = {
+ .chip_id = 0x09,
+ .als_gain = ltr559_als_gain_tbl,
+ .als_gain_tbl_size = ARRAY_SIZE(ltr559_als_gain_tbl),
+ .ps_gain = ltr559_ps_gain_tbl,
+ .ps_gain_tbl_size = ARRAY_SIZE(ltr559_ps_gain_tbl),
+ .als_mode_active = BIT(1),
+ .als_gain_mask = BIT(2) | BIT(3) | BIT(4),
+ .als_gain_shift = 2,
+ },
+};
+
static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
{
int tries = 100;
@@ -125,10 +202,6 @@ static const struct iio_chan_spec ltr501_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(3),
};

-static const int ltr501_ps_gain[4][2] = {
- {1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
-};
-
static int ltr501_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
@@ -166,20 +239,16 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_INTENSITY:
- if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
- *val = 0;
- *val2 = 5000;
- return IIO_VAL_INT_PLUS_MICRO;
- } else {
- *val = 1;
- *val2 = 0;
- return IIO_VAL_INT;
- }
+ i = (data->als_contr & data->chip_info->als_gain_mask) >>
+ data->chip_info->als_gain_shift;
+ *val = data->chip_info->als_gain[i].scale;
+ *val2 = data->chip_info->als_gain[i].uscale;
+ return IIO_VAL_INT_PLUS_MICRO;
case IIO_PROXIMITY:
i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
LTR501_CONTR_PS_GAIN_SHIFT;
- *val = ltr501_ps_gain[i][0];
- *val2 = ltr501_ps_gain[i][1];
+ *val = data->chip_info->ps_gain[i].scale;
+ *val2 = data->chip_info->ps_gain[i].uscale;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
@@ -188,12 +257,13 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
return -EINVAL;
}

-static int ltr501_get_ps_gain_index(int val, int val2)
+static int ltr501_get_gain_index(struct ltr501_gain *gain, int size,
+ int val, int val2)
{
int i;

- for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
- if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
+ for (i = 0; i < size; i++)
+ if (val == gain[i].scale && val2 == gain[i].uscale)
return i;

return -1;
@@ -204,6 +274,7 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct ltr501_data *data = iio_priv(indio_dev);
+ struct ltr501_chip_info *info = data->chip_info;
int i;

if (iio_buffer_enabled(indio_dev))
@@ -213,17 +284,20 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_INTENSITY:
- if (val == 0 && val2 == 5000)
- data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;
- else if (val == 1 && val2 == 0)
- data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
- else
+ i = ltr501_get_gain_index(info->als_gain,
+ info->als_gain_tbl_size,
+ val, val2);
+ if (i < 0)
return -EINVAL;
+ data->als_contr &= ~info->als_gain_mask;
+ data->als_contr |= i << info->als_gain_shift;
return i2c_smbus_write_byte_data(data->client,
LTR501_ALS_CONTR,
data->als_contr);
case IIO_PROXIMITY:
- i = ltr501_get_ps_gain_index(val, val2);
+ i = ltr501_get_gain_index(info->ps_gain,
+ info->ps_gain_tbl_size,
+ val, val2);
if (i < 0)
return -EINVAL;
data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
@@ -238,12 +312,58 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
return -EINVAL;
}

-static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
-static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
+static ssize_t ltr501_show_proximity_scale_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ltr501_data *data = iio_priv(dev_to_iio_dev(dev));
+ struct ltr501_chip_info *info = data->chip_info;
+ ssize_t len = 0;
+ int i;
+
+ for (i = 0; i < info->ps_gain_tbl_size; i++) {
+ if (info->ps_gain[i].scale == LTR501_RESERVED_GAIN)
+ continue;
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
+ info->ps_gain[i].scale,
+ info->ps_gain[i].uscale);
+ }
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static ssize_t ltr501_show_intensity_scale_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ltr501_data *data = iio_priv(dev_to_iio_dev(dev));
+ struct ltr501_chip_info *info = data->chip_info;
+ ssize_t len = 0;
+ int i;
+
+ for (i = 0; i < info->als_gain_tbl_size; i++) {
+ if (info->als_gain[i].scale == LTR501_RESERVED_GAIN)
+ continue;
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
+ info->als_gain[i].scale,
+ info->als_gain[i].uscale);
+ }
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(in_proximity_scale_available, S_IRUGO,
+ ltr501_show_proximity_scale_avail, NULL, 0);
+static IIO_DEVICE_ATTR(in_intensity_scale_available, S_IRUGO,
+ ltr501_show_intensity_scale_avail, NULL, 0);

static struct attribute *ltr501_attributes[] = {
- &iio_const_attr_in_proximity_scale_available.dev_attr.attr,
- &iio_const_attr_in_intensity_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_proximity_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_intensity_scale_available.dev_attr.attr,
NULL
};

@@ -326,7 +446,7 @@ static int ltr501_init(struct ltr501_data *data)
ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
if (ret < 0)
return ret;
- data->als_contr = ret | LTR501_CONTR_ACTIVE;
+ data->als_contr = ret | data->chip_info->als_mode_active;

ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
if (ret < 0)
@@ -342,6 +462,8 @@ static int ltr501_probe(struct i2c_client *client,
{
struct ltr501_data *data;
struct iio_dev *indio_dev;
+ const char *name = NULL;
+ int chip_id = 0;
int ret;

indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
@@ -354,17 +476,24 @@ static int ltr501_probe(struct i2c_client *client,
mutex_init(&data->lock_als);
mutex_init(&data->lock_ps);

+ if (id) {
+ name = id->name;
+ chip_id = id->driver_data;
+ }
+
+ data->chip_info = &ltr501_chip_info_tbl[chip_id];
+
ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
if (ret < 0)
return ret;
- if ((ret >> 4) != 0x8)
+ if ((ret >> 4) != data->chip_info->chip_id)
return -ENODEV;

indio_dev->dev.parent = &client->dev;
indio_dev->info = &ltr501_info;
indio_dev->channels = ltr501_channels;
indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
- indio_dev->name = LTR501_DRV_NAME;
+ indio_dev->name = name;
indio_dev->modes = INDIO_DIRECT_MODE;

ret = ltr501_init(data);
@@ -390,7 +519,7 @@ error_unreg_buffer:
static int ltr501_powerdown(struct ltr501_data *data)
{
return ltr501_write_contr(data->client,
- data->als_contr & ~LTR501_CONTR_ACTIVE,
+ data->als_contr & ~data->chip_info->als_mode_active,
data->ps_contr & ~LTR501_CONTR_ACTIVE);
}

@@ -426,7 +555,8 @@ static int ltr501_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);

static const struct i2c_device_id ltr501_id[] = {
- { "ltr501", 0 },
+ { "ltr501", ltr501},
+ { "ltr559", ltr559},
{ }
};
MODULE_DEVICE_TABLE(i2c, ltr501_id);
--
1.9.1

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