1 files changed, 356 insertions, 1 deletions

diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
index d6e926de955e..d2fdc7581fe0 100644
--- a/drivers/iio/accel/adxl372.c
+++ b/drivers/iio/accel/adxl372.c
@@ -6,12 +6,19 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 /* ADXL372 registers definition */
 #define ADXL372_DEVID			0x00
@@ -123,6 +130,9 @@
 #define ADXL372_INT1_MAP_LOW_MSK		BIT(7)
 #define ADXL372_INT1_MAP_LOW_MODE(x)		(((x) & 0x1) << 7)
 
+/* The ADXL372 includes a deep, 512 sample FIFO buffer */
+#define ADXL372_FIFO_SIZE			512
+
 /*
  * At +/- 200g with 12-bit resolution, scale is computed as:
  * (200 + 200) * 9.81 / (2^12 - 1) = 0.958241
@@ -170,6 +180,43 @@ static const unsigned int adxl372_th_reg_high_addr[3] = {
 	[ADXL372_INACTIVITY] = ADXL372_X_THRESH_INACT_H,
 };
 
+enum adxl372_fifo_format {
+	ADXL372_XYZ_FIFO,
+	ADXL372_X_FIFO,
+	ADXL372_Y_FIFO,
+	ADXL372_XY_FIFO,
+	ADXL372_Z_FIFO,
+	ADXL372_XZ_FIFO,
+	ADXL372_YZ_FIFO,
+	ADXL372_XYZ_PEAK_FIFO,
+};
+
+enum adxl372_fifo_mode {
+	ADXL372_FIFO_BYPASSED,
+	ADXL372_FIFO_STREAMED,
+	ADXL372_FIFO_TRIGGERED,
+	ADXL372_FIFO_OLD_SAVED
+};
+
+static const int adxl372_samp_freq_tbl[5] = {
+	400, 800, 1600, 3200, 6400,
+};
+
+struct adxl372_axis_lookup {
+	unsigned int bits;
+	enum adxl372_fifo_format fifo_format;
+};
+
+static const struct adxl372_axis_lookup adxl372_axis_lookup_table[] = {
+	{ BIT(0), ADXL372_X_FIFO },
+	{ BIT(1), ADXL372_Y_FIFO },
+	{ BIT(2), ADXL372_Z_FIFO },
+	{ BIT(0) | BIT(1), ADXL372_XY_FIFO },
+	{ BIT(0) | BIT(2), ADXL372_XZ_FIFO },
+	{ BIT(1) | BIT(2), ADXL372_YZ_FIFO },
+	{ BIT(0) | BIT(1) | BIT(2), ADXL372_XYZ_FIFO },
+};
+
 #define ADXL372_ACCEL_CHANNEL(index, reg, axis) {			\
 	.type = IIO_ACCEL,						\
 	.address = reg,							\
@@ -177,6 +224,13 @@ static const unsigned int adxl372_th_reg_high_addr[3] = {
 	.channel2 = IIO_MOD_##axis,					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.scan_index = index,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 12,						\
+		.storagebits = 16,					\
+		.shift = 4,						\
+	},								\
 }
 
 static const struct iio_chan_spec adxl372_channels[] = {
@@ -188,12 +242,29 @@ static const struct iio_chan_spec adxl372_channels[] = {
 struct adxl372_state {
 	struct spi_device		*spi;
 	struct regmap			*regmap;
+	struct iio_trigger		*dready_trig;
+	enum adxl372_fifo_mode		fifo_mode;
+	enum adxl372_fifo_format	fifo_format;
 	enum adxl372_op_mode		op_mode;
 	enum adxl372_act_proc_mode	act_proc_mode;
 	enum adxl372_odr		odr;
 	enum adxl372_bandwidth		bw;
 	u32				act_time_ms;
 	u32				inact_time_ms;
+	u8				fifo_set_size;
+	u8				int1_bitmask;
+	u8				int2_bitmask;
+	u16				watermark;
+	__be16				fifo_buf[ADXL372_FIFO_SIZE];
+};
+
+static const unsigned long adxl372_channel_masks[] = {
+	BIT(0), BIT(1), BIT(2),
+	BIT(0) | BIT(1),
+	BIT(0) | BIT(2),
+	BIT(1) | BIT(2),
+	BIT(0) | BIT(1) | BIT(2),
+	0
 };
 
 static int adxl372_read_axis(struct adxl372_state *st, u8 addr)
@@ -359,6 +430,112 @@ static int adxl372_set_inactivity_time_ms(struct adxl372_state *st,
 	return ret;
 }
 
+static int adxl372_set_interrupts(struct adxl372_state *st,
+				  unsigned char int1_bitmask,
+				  unsigned char int2_bitmask)
+{
+	int ret;
+
+	ret = regmap_write(st->regmap, ADXL372_INT1_MAP, int1_bitmask);
+	if (ret < 0)
+		return ret;
+
+	return regmap_write(st->regmap, ADXL372_INT2_MAP, int2_bitmask);
+}
+
+static int adxl372_configure_fifo(struct adxl372_state *st)
+{
+	unsigned int fifo_samples, fifo_ctl;
+	int ret;
+
+	/* FIFO must be configured while in standby mode */
+	ret = adxl372_set_op_mode(st, ADXL372_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	fifo_samples = st->watermark & 0xFF;
+	fifo_ctl = ADXL372_FIFO_CTL_FORMAT_MODE(st->fifo_format) |
+		   ADXL372_FIFO_CTL_MODE_MODE(st->fifo_mode) |
+		   ADXL372_FIFO_CTL_SAMPLES_MODE(st->watermark);
+
+	ret = regmap_write(st->regmap, ADXL372_FIFO_SAMPLES, fifo_samples);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(st->regmap, ADXL372_FIFO_CTL, fifo_ctl);
+	if (ret < 0)
+		return ret;
+
+	return adxl372_set_op_mode(st, ADXL372_FULL_BW_MEASUREMENT);
+}
+
+static int adxl372_get_status(struct adxl372_state *st,
+			      u8 *status1, u8 *status2,
+			      u16 *fifo_entries)
+{
+	__be32 buf;
+	u32 val;
+	int ret;
+
+	/* STATUS1, STATUS2, FIFO_ENTRIES2 and FIFO_ENTRIES are adjacent regs */
+	ret = regmap_bulk_read(st->regmap, ADXL372_STATUS_1,
+			       &buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	val = be32_to_cpu(buf);
+
+	*status1 = (val >> 24) & 0x0F;
+	*status2 = (val >> 16) & 0x0F;
+	/*
+	 * FIFO_ENTRIES contains the least significant byte, and FIFO_ENTRIES2
+	 * contains the two most significant bits
+	 */
+	*fifo_entries = val & 0x3FF;
+
+	return ret;
+}
+
+static irqreturn_t adxl372_trigger_handler(int irq, void  *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct adxl372_state *st = iio_priv(indio_dev);
+	u8 status1, status2;
+	u16 fifo_entries;
+	int i, ret;
+
+	ret = adxl372_get_status(st, &status1, &status2, &fifo_entries);
+	if (ret < 0)
+		goto err;
+
+	if (st->fifo_mode != ADXL372_FIFO_BYPASSED &&
+	    ADXL372_STATUS_1_FIFO_FULL(status1)) {
+		/*
+		 * When reading data from multiple axes from the FIFO,
+		 * to ensure that data is not overwritten and stored out
+		 * of order at least one sample set must be left in the
+		 * FIFO after every read.
+		 */
+		fifo_entries -= st->fifo_set_size;
+
+		/* Read data from the FIFO */
+		ret = regmap_noinc_read(st->regmap, ADXL372_FIFO_DATA,
+					st->fifo_buf,
+					fifo_entries * sizeof(u16));
+		if (ret < 0)
+			goto err;
+
+		/* Each sample is 2 bytes */
+		for (i = 0; i < fifo_entries * sizeof(u16);
+		     i += st->fifo_set_size * sizeof(u16))
+			iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
+	}
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
 static int adxl372_setup(struct adxl372_state *st)
 {
 	unsigned int regval;
@@ -438,7 +615,12 @@ static int adxl372_read_raw(struct iio_dev *indio_dev,
 
 	switch (info) {
 	case IIO_CHAN_INFO_RAW:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
 		ret = adxl372_read_axis(st, chan->address);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 
@@ -454,16 +636,153 @@ static int adxl372_read_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static ssize_t adxl372_get_fifo_enabled(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adxl372_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->fifo_mode);
+}
+
+static ssize_t adxl372_get_fifo_watermark(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adxl372_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->watermark);
+}
+
+static IIO_CONST_ATTR(hwfifo_watermark_min, "1");
+static IIO_CONST_ATTR(hwfifo_watermark_max,
+		      __stringify(ADXL372_FIFO_SIZE));
+static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
+		       adxl372_get_fifo_watermark, NULL, 0);
+static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
+		       adxl372_get_fifo_enabled, NULL, 0);
+
+static const struct attribute *adxl372_fifo_attributes[] = {
+	&iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
+	&iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
+	&iio_dev_attr_hwfifo_watermark.dev_attr.attr,
+	&iio_dev_attr_hwfifo_enabled.dev_attr.attr,
+	NULL,
+};
+
+static int adxl372_set_watermark(struct iio_dev *indio_dev, unsigned int val)
+{
+	struct adxl372_state *st  = iio_priv(indio_dev);
+
+	if (val > ADXL372_FIFO_SIZE)
+		val = ADXL372_FIFO_SIZE;
+
+	st->watermark = val;
+
+	return 0;
+}
+
+static int adxl372_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct adxl372_state *st = iio_priv(indio_dev);
+	unsigned int mask;
+	int i, ret;
+
+	ret = adxl372_set_interrupts(st, ADXL372_INT1_MAP_FIFO_FULL_MSK, 0);
+	if (ret < 0)
+		return ret;
+
+	mask = *indio_dev->active_scan_mask;
+
+	for (i = 0; i < ARRAY_SIZE(adxl372_axis_lookup_table); i++) {
+		if (mask == adxl372_axis_lookup_table[i].bits)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(adxl372_axis_lookup_table))
+		return -EINVAL;
+
+	st->fifo_format = adxl372_axis_lookup_table[i].fifo_format;
+	st->fifo_set_size = bitmap_weight(indio_dev->active_scan_mask,
+					  indio_dev->masklength);
+	/*
+	 * The 512 FIFO samples can be allotted in several ways, such as:
+	 * 170 sample sets of concurrent 3-axis data
+	 * 256 sample sets of concurrent 2-axis data (user selectable)
+	 * 512 sample sets of single-axis data
+	 */
+	if ((st->watermark * st->fifo_set_size) > ADXL372_FIFO_SIZE)
+		st->watermark = (ADXL372_FIFO_SIZE  / st->fifo_set_size);
+
+	st->fifo_mode = ADXL372_FIFO_STREAMED;
+
+	ret = adxl372_configure_fifo(st);
+	if (ret < 0) {
+		st->fifo_mode = ADXL372_FIFO_BYPASSED;
+		adxl372_set_interrupts(st, 0, 0);
+		return ret;
+	}
+
+	return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int adxl372_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct adxl372_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	adxl372_set_interrupts(st, 0, 0);
+	st->fifo_mode = ADXL372_FIFO_BYPASSED;
+	adxl372_configure_fifo(st);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops adxl372_buffer_ops = {
+	.postenable = adxl372_buffer_postenable,
+	.predisable = adxl372_buffer_predisable,
+};
+
+static int adxl372_dready_trig_set_state(struct iio_trigger *trig,
+					 bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct adxl372_state *st = iio_priv(indio_dev);
+	unsigned long int mask = 0;
+
+	if (state)
+		mask = ADXL372_INT1_MAP_FIFO_FULL_MSK;
+
+	return adxl372_set_interrupts(st, mask, 0);
+}
+
+static const struct iio_trigger_ops adxl372_trigger_ops = {
+	.set_trigger_state = adxl372_dready_trig_set_state,
+};
+
 static const struct iio_info adxl372_info = {
 	.read_raw = adxl372_read_raw,
 	.debugfs_reg_access = &adxl372_reg_access,
+	.hwfifo_set_watermark = adxl372_set_watermark,
 };
 
+static bool adxl372_readable_noinc_reg(struct device *dev, unsigned int reg)
+{
+	return (reg == ADXL372_FIFO_DATA);
+}
+
 static const struct regmap_config adxl372_spi_regmap_config = {
 	.reg_bits = 7,
 	.pad_bits = 1,
 	.val_bits = 8,
 	.read_flag_mask = BIT(0),
+	.readable_noinc_reg = adxl372_readable_noinc_reg,
 };
 
 static int adxl372_probe(struct spi_device *spi)
@@ -490,10 +809,11 @@ static int adxl372_probe(struct spi_device *spi)
 
 	indio_dev->channels = adxl372_channels;
 	indio_dev->num_channels = ARRAY_SIZE(adxl372_channels);
+	indio_dev->available_scan_masks = adxl372_channel_masks;
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->info = &adxl372_info;
-	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 
 	ret = adxl372_setup(st);
 	if (ret < 0) {
@@ -501,6 +821,41 @@ static int adxl372_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	ret = devm_iio_triggered_buffer_setup(&st->spi->dev,
+					      indio_dev, NULL,
+					      adxl372_trigger_handler,
+					      &adxl372_buffer_ops);
+	if (ret < 0)
+		return ret;
+
+	iio_buffer_set_attrs(indio_dev->buffer, adxl372_fifo_attributes);
+
+	if (st->spi->irq) {
+		st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev,
+							 "%s-dev%d",
+							 indio_dev->name,
+							 indio_dev->id);
+		if (st->dready_trig == NULL)
+			return -ENOMEM;
+
+		st->dready_trig->ops = &adxl372_trigger_ops;
+		st->dready_trig->dev.parent = &st->spi->dev;
+		iio_trigger_set_drvdata(st->dready_trig, indio_dev);
+		ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig);
+		if (ret < 0)
+			return ret;
+
+		indio_dev->trig = iio_trigger_get(st->dready_trig);
+
+		ret = devm_request_threaded_irq(&st->spi->dev, st->spi->irq,
+					iio_trigger_generic_data_rdy_poll,
+					NULL,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					indio_dev->name, st->dready_trig);
+		if (ret < 0)
+			return ret;
+	}
+
 	return devm_iio_device_register(&st->spi->dev, indio_dev);
 }