[PATCH v4 6/7] iio: light: ltr501: Add ltr329 driver support

From: Esben Haabendal

Date: Mon Aug 10 2026 - 03:12:37 EST


This adds support for the LTR-329ALS-01 chip, which is similar to
LTR-303ALS-01, except for interrupt, which LTR-329ALS-01 chip does not
have.

Reviewed-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Acked-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Signed-off-by: Esben Haabendal <esben@xxxxxxxxxx>
---
drivers/iio/light/ltr501.c | 48 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
index b36bd10a0262..cd5ff00ef5e2 100644
--- a/drivers/iio/light/ltr501.c
+++ b/drivers/iio/light/ltr501.c
@@ -9,6 +9,7 @@
* TODO: IR LED characteristics
*/

+#include <linux/array_size.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
@@ -94,6 +95,7 @@ enum {
ltr559,
ltr301,
ltr303,
+ ltr329,
};

struct ltr501_gain {
@@ -140,6 +142,7 @@ struct ltr501_chip_info {
u8 als_mode_active;
u8 als_gain_mask;
u8 als_gain_shift;
+ bool no_irq_support;
struct iio_chan_spec const *channels;
const int no_channels;
const struct iio_info *info;
@@ -178,6 +181,11 @@ static const struct ltr501_samp_table ltr501_ps_samp_table[] = {
{500000, 2000000}
};

+static bool ltr501_has_irq_support(const struct ltr501_chip_info *info)
+{
+ return !info->no_irq_support;
+}
+
static int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
int len, int val, int val2)
{
@@ -821,6 +829,9 @@ static int __ltr501_write_raw(struct iio_dev *indio_dev,
if (ret < 0)
return ret;

+ if (!ltr501_has_irq_support(info))
+ return ret;
+
/* update persistence count when changing frequency */
ret = ltr501_write_intr_prst(data, chan->type,
0, data->als_period);
@@ -840,6 +851,9 @@ static int __ltr501_write_raw(struct iio_dev *indio_dev,
if (ret < 0)
return ret;

+ if (!ltr501_has_irq_support(info))
+ return ret;
+
/* update persistence count when changing frequency */
ret = ltr501_write_intr_prst(data, chan->type,
0, data->ps_period);
@@ -1257,6 +1271,18 @@ static const struct ltr501_chip_info ltr501_chip_info_tbl[] = {
.channels = ltr301_channels,
.no_channels = ARRAY_SIZE(ltr301_channels),
},
+ [ltr329] = {
+ .partid = 0x0A,
+ .als_gain = ltr559_als_gain_tbl,
+ .als_gain_tbl_size = ARRAY_SIZE(ltr559_als_gain_tbl),
+ .als_mode_active = BIT(0),
+ .als_gain_mask = BIT(2) | BIT(3) | BIT(4),
+ .als_gain_shift = 2,
+ .no_irq_support = true,
+ .info_no_irq = &ltr301_info_no_irq,
+ .channels = ltr301_channels,
+ .no_channels = ARRAY_SIZE(ltr301_channels),
+ },
};

static int ltr501_write_contr(struct ltr501_data *data, u8 als_val, u8 ps_val)
@@ -1369,13 +1395,15 @@ static int ltr501_init(struct ltr501_data *data)

data->ps_contr = status | LTR501_CONTR_ACTIVE;

- ret = ltr501_read_intr_prst(data, IIO_INTENSITY, &data->als_period);
- if (ret < 0)
- return ret;
+ if (ltr501_has_irq_support(data->chip_info)) {
+ ret = ltr501_read_intr_prst(data, IIO_INTENSITY, &data->als_period);
+ if (ret < 0)
+ return ret;

- ret = ltr501_read_intr_prst(data, IIO_PROXIMITY, &data->ps_period);
- if (ret < 0)
- return ret;
+ ret = ltr501_read_intr_prst(data, IIO_PROXIMITY, &data->ps_period);
+ if (ret < 0)
+ return ret;
+ }

return ltr501_write_contr(data, data->als_contr, data->ps_contr);
}
@@ -1531,6 +1559,12 @@ static int ltr501_probe(struct i2c_client *client)
return ret;

if (client->irq > 0) {
+ if (!ltr501_has_irq_support(data->chip_info)) {
+ ret = dev_err_probe(&client->dev, -EINVAL,
+ "chip does not support irq\n");
+ goto powerdown_on_error;
+ }
+
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, ltr501_interrupt_handler,
IRQF_TRIGGER_FALLING |
@@ -1601,6 +1635,7 @@ static const struct i2c_device_id ltr501_id[] = {
{ .name = "ltr559", .driver_data = ltr559 },
{ .name = "ltr301", .driver_data = ltr301 },
{ .name = "ltr303", .driver_data = ltr303 },
+ { .name = "ltr329", .driver_data = ltr329 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ltr501_id);
@@ -1610,6 +1645,7 @@ static const struct of_device_id ltr501_of_match[] = {
{ .compatible = "liteon,ltr559", },
{ .compatible = "liteon,ltr301", },
{ .compatible = "liteon,ltr303", },
+ { .compatible = "liteon,ltr329", },
{ }
};
MODULE_DEVICE_TABLE(of, ltr501_of_match);

--
2.55.0