[PATCH v2 4/4] iio: light: ltr501: Add support for the LTR-659PS-01 proximity sensor

[Svyatoslav Ryhel <clamor95@gmail.com>]

Add support for the Lite-On LTR-659PS-01 proximity sensor. This device is
nearly identical to the LTR-559ALS-01, but omits all elements related to
ambient light sensing.

Add a no_als_support flag, similar to how no_irq_support is used, to
isolate ALS register access for the LTR-659PS-01, since ALS registers are
marked as reserved and interactions with them are discouraged.

The ltr501_trigger_handler relied on the scan index to identify channels.
This approach is fragile regarding channel status flags and can break if
the index is not strictly set. Switch to checking the channel type
instead.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/iio/light/ltr501.c | 73 +++++++++++++++++++++++++++++++-------
 1 file changed, 61 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
index d5ce6468a229b..e7762115df913 100644
--- a/drivers/iio/light/ltr501.c
+++ b/drivers/iio/light/ltr501.c
@@ -151,6 +151,7 @@ struct ltr501_chip_info {
 	u8 als_gain_mask;
 	u8 als_gain_shift;
 	bool no_irq_support;
+	bool no_als_support;
 	struct iio_chan_spec const *channels;
 	const int no_channels;
 };
@@ -192,6 +193,11 @@ static bool ltr501_has_irq_support(const struct ltr501_chip_info *info)
 	return !info->no_irq_support;
 }
 
+static bool ltr501_has_als_support(const struct ltr501_chip_info *info)
+{
+	return !info->no_als_support;
+}
+
 static int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
 					   int len, int val, int val2)
 {
@@ -656,6 +662,29 @@ static const struct iio_chan_spec ltr301_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
+static const struct iio_chan_spec ltr659_channels[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.address = LTR501_PS_DATA,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
+						BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 11,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+		.event_spec = ltr501_pxs_event_spec,
+		.num_event_specs = ARRAY_SIZE(ltr501_pxs_event_spec),
+		.ext_info = ltr501_ext_info,
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
 static int ltr501_read_info_raw(struct ltr501_data *data,
 				struct iio_chan_spec const *chan,
 				int *val)
@@ -1230,13 +1259,24 @@ static const struct ltr501_chip_info ltr559_chip_info_tbl = {
 	.no_channels = ARRAY_SIZE(ltr501_channels),
 };
 
+static const struct ltr501_chip_info ltr659_chip_info_tbl = {
+	.partid = 0x09,
+	.ps_gain = ltr559_ps_gain_tbl,
+	.ps_gain_tbl_size = ARRAY_SIZE(ltr559_ps_gain_tbl),
+	.no_als_support = true,
+	.channels = ltr659_channels,
+	.no_channels = ARRAY_SIZE(ltr659_channels),
+};
+
 static int ltr501_write_contr(struct ltr501_data *data, u8 als_val, u8 ps_val)
 {
 	int ret;
 
-	ret = regmap_write(data->regmap, LTR501_ALS_CONTR, als_val);
-	if (ret < 0)
-		return ret;
+	if (ltr501_has_als_support(data->chip_info)) {
+		ret = regmap_write(data->regmap, LTR501_ALS_CONTR, als_val);
+		if (ret < 0)
+			return ret;
+	}
 
 	return regmap_write(data->regmap, LTR501_PS_CONTR, ps_val);
 }
@@ -1251,16 +1291,21 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 		aligned_s64 ts;
 	} scan = { };
 	__le16 als_buf[2];
+	unsigned int i;
 	u8 mask = 0;
 	int j = 0;
 	int ret, psdata;
 
 	/* figure out which data needs to be ready */
-	if (test_bit(0, indio_dev->active_scan_mask) ||
-	    test_bit(1, indio_dev->active_scan_mask))
-		mask |= LTR501_STATUS_ALS_RDY;
-	if (test_bit(2, indio_dev->active_scan_mask))
-		mask |= LTR501_STATUS_PS_RDY;
+	for_each_set_bit(i, indio_dev->active_scan_mask, indio_dev->num_channels) {
+		const struct iio_chan_spec *chan = &indio_dev->channels[i];
+
+		if (chan->type == IIO_INTENSITY)
+			mask |= LTR501_STATUS_ALS_RDY;
+
+		if (chan->type == IIO_PROXIMITY)
+			mask |= LTR501_STATUS_PS_RDY;
+	}
 
 	ret = ltr501_drdy(data, mask);
 	if (ret < 0)
@@ -1328,11 +1373,13 @@ static int ltr501_init(struct ltr501_data *data)
 {
 	int ret, status;
 
-	ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
-	if (ret < 0)
-		return ret;
+	if (ltr501_has_als_support(data->chip_info)) {
+		ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
+		if (ret < 0)
+			return ret;
 
-	data->als_contr = status | data->chip_info->als_mode_active;
+		data->als_contr = status | data->chip_info->als_mode_active;
+	}
 
 	ret = regmap_read(data->regmap, LTR501_PS_CONTR, &status);
 	if (ret < 0)
@@ -1569,6 +1616,7 @@ static const struct i2c_device_id ltr501_id[] = {
 	{ .name = "ltr329", .driver_data = (kernel_ulong_t)&ltr329_chip_info_tbl },
 	{ .name = "ltr501", .driver_data = (kernel_ulong_t)&ltr501_chip_info_tbl },
 	{ .name = "ltr559", .driver_data = (kernel_ulong_t)&ltr559_chip_info_tbl },
+	{ .name = "ltr659", .driver_data = (kernel_ulong_t)&ltr659_chip_info_tbl },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ltr501_id);
@@ -1579,6 +1627,7 @@ static const struct of_device_id ltr501_of_match[] = {
 	{ .compatible = "liteon,ltr329", .data = &ltr329_chip_info_tbl },
 	{ .compatible = "liteon,ltr501", .data = &ltr501_chip_info_tbl },
 	{ .compatible = "liteon,ltr559", .data = &ltr559_chip_info_tbl },
+	{ .compatible = "liteon,ltr659", .data = &ltr659_chip_info_tbl },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ltr501_of_match);
-- 
2.53.0