[PATCH v8 3/4] iio: light: veml6031x00: add support for triggered buffers

[Javier Carrasco <javier.carrasco.cruz@gmail.com>]

Add triggered buffer functionality for the two channels the device
provides (ALS and IR).

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 drivers/iio/light/Kconfig       |   2 +
 drivers/iio/light/veml6031x00.c | 113 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+)

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 02291abeff60..462fff1ddef2 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -745,6 +745,8 @@ config VEML6031X00
 	tristate "VEML6031X00 ambient light sensor series"
 	select REGMAP_I2C
 	select IIO_GTS_HELPER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	depends on I2C
 	help
 	  Say Y here if you want to build a driver for the Vishay VEML6031X00
diff --git a/drivers/iio/light/veml6031x00.c b/drivers/iio/light/veml6031x00.c
index f3772577a05d..3d5a27a0baae 100644
--- a/drivers/iio/light/veml6031x00.c
+++ b/drivers/iio/light/veml6031x00.c
@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
 #include <linux/limits.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -25,6 +26,8 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/iio-gts-helper.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 /* Device registers */
 #define VEML6031X00_REG_CONF0       0x00
@@ -42,6 +45,12 @@
 
 #define VEML6031X00_GAIN_SEL(pd_div4, gain) (((pd_div4) << 2) | (gain))
 
+enum veml6031x00_scan {
+	VEML6031X00_SCAN_ALS,
+	VEML6031X00_SCAN_IR,
+	VEML6031X00_SCAN_TIMESTAMP,
+};
+
 struct veml6031x00_rf {
 	struct regmap_field *gain;
 	struct regmap_field *it;
@@ -135,6 +144,13 @@ static const struct iio_chan_spec veml6031x00_channels[] = {
 				      BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_INT_TIME) |
 						BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = VEML6031X00_SCAN_ALS,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
 	},
 	{
 		.type = IIO_INTENSITY,
@@ -142,7 +158,15 @@ static const struct iio_chan_spec veml6031x00_channels[] = {
 		.modified = 1,
 		.channel2 = IIO_MOD_LIGHT_IR,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = VEML6031X00_SCAN_IR,
+		.scan_type = {
+			.format = IIO_SCAN_FORMAT_UNSIGNED_INT,
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(VEML6031X00_SCAN_TIMESTAMP),
 };
 
 static const struct regmap_range veml6031x00_readable_ranges[] = {
@@ -390,6 +414,10 @@ static int veml6031x00_single_read(struct iio_dev *iio, enum iio_chan_type type,
 		return -EINVAL;
 	}
 
+	IIO_DEV_ACQUIRE_DIRECT_MODE(iio, claim);
+	if (IIO_DEV_ACQUIRE_FAILED(claim))
+		return -EBUSY;
+
 	guard(mutex)(&data->scale_lock);
 
 	PM_RUNTIME_ACQUIRE_AUTOSUSPEND(regmap_get_device(data->regmap), pm);
@@ -453,6 +481,10 @@ static int veml6031x00_write_raw(struct iio_dev *iio,
 				 struct iio_chan_spec const *chan,
 				 int val, int val2, long mask)
 {
+	IIO_DEV_ACQUIRE_DIRECT_MODE(iio, claim);
+	if (IIO_DEV_ACQUIRE_FAILED(claim))
+		return -EBUSY;
+
 	switch (mask) {
 	case IIO_CHAN_INFO_INT_TIME:
 		return veml6031x00_set_it(iio, val, val2);
@@ -484,6 +516,80 @@ static const struct iio_info veml6031x00_info = {
 	.write_raw_get_fmt = veml6031x00_write_raw_get_fmt,
 };
 
+static int veml6031x00_buffer_preenable(struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret, it_usec;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	ret = veml6031x00_get_it(data, &it_usec);
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(dev);
+		return ret;
+	}
+
+	/*
+	 * Wait one integration period + 10% margin so the first triggered
+	 * read does not race with the sensor completing its first conversion
+	 * after power-on.
+	 */
+	fsleep(it_usec + (it_usec / 10));
+
+	return 0;
+}
+
+static int veml6031x00_buffer_postdisable(struct iio_dev *iio)
+{
+	struct veml6031x00_data *data = iio_priv(iio);
+
+	pm_runtime_put_autosuspend(regmap_get_device(data->regmap));
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops veml6031x00_buffer_setup_ops = {
+	.preenable = veml6031x00_buffer_preenable,
+	.postdisable = veml6031x00_buffer_postdisable,
+};
+
+static irqreturn_t veml6031x00_trig_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *iio = pf->indio_dev;
+	struct veml6031x00_data *data = iio_priv(iio);
+	struct regmap *map = data->regmap;
+	IIO_DECLARE_BUFFER_WITH_TS(__le16, scan, 2) = { };
+	unsigned int i;
+	int ch, ret;
+
+	if (test_bit(VEML6031X00_SCAN_ALS, iio->active_scan_mask) &&
+	    test_bit(VEML6031X00_SCAN_IR, iio->active_scan_mask)) {
+		ret = regmap_bulk_read(map, VEML6031X00_REG_ALS_L,
+				       scan, 2 * sizeof(*scan));
+		if (ret)
+			goto done;
+	} else {
+		i = 0;
+		iio_for_each_active_channel(iio, ch) {
+			ret = regmap_bulk_read(map, iio->channels[ch].address,
+					       &scan[i++], sizeof(*scan));
+			if (ret)
+				goto done;
+		}
+	}
+
+	iio_push_to_buffers_with_ts(iio, scan, sizeof(scan), pf->timestamp);
+
+done:
+	iio_trigger_notify_done(iio->trig);
+
+	return IRQ_HANDLED;
+}
+
 static int veml6031x00_validate_part_id(struct veml6031x00_data *data)
 {
 	struct regmap *map = data->regmap;
@@ -573,6 +679,13 @@ static int veml6031x00_probe(struct i2c_client *i2c)
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to init IIO GTS\n");
 
+	ret = devm_iio_triggered_buffer_setup(dev, iio,
+					      iio_pollfunc_store_time,
+					      veml6031x00_trig_handler,
+					      &veml6031x00_buffer_setup_ops);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register triggered buffer\n");
+
 	ret = devm_iio_device_register(dev, iio);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to register IIO device\n");

-- 
2.43.0