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SubjectRe: [RFC PATCH 2/2] iio: light: Add support for LTR559 chip
On 31/03/15 11:37, Daniel Baluta wrote:
> 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@intel.com>
Looks good to me. Let us know when you've tested it ;)
Anyhow, one comment inline. It 'think' you can end up with a device probing
succesfully with no known name...

J
> ---
> 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;
Can name still be NULL? Needs a default value that makes sense.
> 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);
>



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