1 files changed, 306 insertions, 54 deletions

diff --git a/drivers/iio/proximity/sx9500.c b/drivers/iio/proximity/sx9500.c
index c6cb7f927018..8db9d5bfecc3 100644
--- a/drivers/iio/proximity/sx9500.c
+++ b/drivers/iio/proximity/sx9500.c
@@ -19,6 +19,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/regmap.h>
 #include <linux/pm.h>
+#include <linux/delay.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
@@ -75,6 +76,7 @@
 #define SX9500_CONVDONE_IRQ		BIT(3)
 
 #define SX9500_PROXSTAT_SHIFT		4
+#define SX9500_COMPSTAT_MASK		GENMASK(3, 0)
 
 #define SX9500_NUM_CHANNELS		4
 
@@ -93,6 +95,9 @@ struct sx9500_data {
 	u16 *buffer;
 	/* Remember enabled channels and sample rate during suspend. */
 	unsigned int suspend_ctrl0;
+	struct completion completion;
+	int data_rdy_users, close_far_users;
+	int channel_users[SX9500_NUM_CHANNELS];
 };
 
 static const struct iio_event_spec sx9500_events[] = {
@@ -143,6 +148,10 @@ static const struct {
 	{2, 500000},
 };
 
+static const unsigned int sx9500_scan_period_table[] = {
+	30, 60, 90, 120, 150, 200, 300, 400,
+};
+
 static const struct regmap_range sx9500_writable_reg_ranges[] = {
 	regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
 	regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
@@ -195,7 +204,67 @@ static const struct regmap_config sx9500_regmap_config = {
 	.volatile_table = &sx9500_volatile_regs,
 };
 
-static int sx9500_read_proximity(struct sx9500_data *data,
+static int sx9500_inc_users(struct sx9500_data *data, int *counter,
+			    unsigned int reg, unsigned int bitmask)
+{
+	(*counter)++;
+	if (*counter != 1)
+		/* Bit is already active, nothing to do. */
+		return 0;
+
+	return regmap_update_bits(data->regmap, reg, bitmask, bitmask);
+}
+
+static int sx9500_dec_users(struct sx9500_data *data, int *counter,
+			    unsigned int reg, unsigned int bitmask)
+{
+	(*counter)--;
+	if (*counter != 0)
+		/* There are more users, do not deactivate. */
+		return 0;
+
+	return regmap_update_bits(data->regmap, reg, bitmask, 0);
+}
+
+static int sx9500_inc_chan_users(struct sx9500_data *data, int chan)
+{
+	return sx9500_inc_users(data, &data->channel_users[chan],
+				SX9500_REG_PROX_CTRL0, BIT(chan));
+}
+
+static int sx9500_dec_chan_users(struct sx9500_data *data, int chan)
+{
+	return sx9500_dec_users(data, &data->channel_users[chan],
+				SX9500_REG_PROX_CTRL0, BIT(chan));
+}
+
+static int sx9500_inc_data_rdy_users(struct sx9500_data *data)
+{
+	return sx9500_inc_users(data, &data->data_rdy_users,
+				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
+}
+
+static int sx9500_dec_data_rdy_users(struct sx9500_data *data)
+{
+	return sx9500_dec_users(data, &data->data_rdy_users,
+				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
+}
+
+static int sx9500_inc_close_far_users(struct sx9500_data *data)
+{
+	return sx9500_inc_users(data, &data->close_far_users,
+				SX9500_REG_IRQ_MSK,
+				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
+}
+
+static int sx9500_dec_close_far_users(struct sx9500_data *data)
+{
+	return sx9500_dec_users(data, &data->close_far_users,
+				SX9500_REG_IRQ_MSK,
+				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
+}
+
+static int sx9500_read_prox_data(struct sx9500_data *data,
 				 const struct iio_chan_spec *chan,
 				 int *val)
 {
@@ -215,6 +284,79 @@ static int sx9500_read_proximity(struct sx9500_data *data,
 	return IIO_VAL_INT;
 }
 
+/*
+ * If we have no interrupt support, we have to wait for a scan period
+ * after enabling a channel to get a result.
+ */
+static int sx9500_wait_for_sample(struct sx9500_data *data)
+{
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &val);
+	if (ret < 0)
+		return ret;
+
+	val = (val & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
+
+	msleep(sx9500_scan_period_table[val]);
+
+	return 0;
+}
+
+static int sx9500_read_proximity(struct sx9500_data *data,
+				 const struct iio_chan_spec *chan,
+				 int *val)
+{
+	int ret;
+
+	mutex_lock(&data->mutex);
+
+	ret = sx9500_inc_chan_users(data, chan->channel);
+	if (ret < 0)
+		goto out;
+
+	ret = sx9500_inc_data_rdy_users(data);
+	if (ret < 0)
+		goto out_dec_chan;
+
+	mutex_unlock(&data->mutex);
+
+	if (data->client->irq > 0)
+		ret = wait_for_completion_interruptible(&data->completion);
+	else
+		ret = sx9500_wait_for_sample(data);
+
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&data->mutex);
+
+	ret = sx9500_read_prox_data(data, chan, val);
+	if (ret < 0)
+		goto out;
+
+	ret = sx9500_dec_chan_users(data, chan->channel);
+	if (ret < 0)
+		goto out;
+
+	ret = sx9500_dec_data_rdy_users(data);
+	if (ret < 0)
+		goto out;
+
+	ret = IIO_VAL_INT;
+
+	goto out;
+
+out_dec_chan:
+	sx9500_dec_chan_users(data, chan->channel);
+out:
+	mutex_unlock(&data->mutex);
+	reinit_completion(&data->completion);
+
+	return ret;
+}
+
 static int sx9500_read_samp_freq(struct sx9500_data *data,
 				 int *val, int *val2)
 {
@@ -240,7 +382,6 @@ static int sx9500_read_raw(struct iio_dev *indio_dev,
 			   int *val, int *val2, long mask)
 {
 	struct sx9500_data *data = iio_priv(indio_dev);
-	int ret;
 
 	switch (chan->type) {
 	case IIO_PROXIMITY:
@@ -248,10 +389,7 @@ static int sx9500_read_raw(struct iio_dev *indio_dev,
 		case IIO_CHAN_INFO_RAW:
 			if (iio_buffer_enabled(indio_dev))
 				return -EBUSY;
-			mutex_lock(&data->mutex);
-			ret = sx9500_read_proximity(data, chan, val);
-			mutex_unlock(&data->mutex);
-			return ret;
+			return sx9500_read_proximity(data, chan, val);
 		case IIO_CHAN_INFO_SAMP_FREQ:
 			return sx9500_read_samp_freq(data, val, val2);
 		default:
@@ -322,28 +460,16 @@ static irqreturn_t sx9500_irq_handler(int irq, void *private)
 	return IRQ_WAKE_THREAD;
 }
 
-static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
+static void sx9500_push_events(struct iio_dev *indio_dev)
 {
-	struct iio_dev *indio_dev = private;
-	struct sx9500_data *data = iio_priv(indio_dev);
 	int ret;
 	unsigned int val, chan;
-
-	mutex_lock(&data->mutex);
-
-	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
-	if (ret < 0) {
-		dev_err(&data->client->dev, "i2c transfer error in irq\n");
-		goto out;
-	}
-
-	if (!(val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ)))
-		goto out;
+	struct sx9500_data *data = iio_priv(indio_dev);
 
 	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
 	if (ret < 0) {
 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
-		goto out;
+		return;
 	}
 
 	val >>= SX9500_PROXSTAT_SHIFT;
@@ -358,15 +484,34 @@ static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
 			/* No change on this channel. */
 			continue;
 
-		dir = new_prox ? IIO_EV_DIR_FALLING :
-			IIO_EV_DIR_RISING;
-		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY,
-					  chan,
-					  IIO_EV_TYPE_THRESH,
-					  dir);
+		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
+		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
+					  IIO_EV_TYPE_THRESH, dir);
 		iio_push_event(indio_dev, ev, iio_get_time_ns());
 		data->prox_stat[chan] = new_prox;
 	}
+}
+
+static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+	unsigned int val;
+
+	mutex_lock(&data->mutex);
+
+	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "i2c transfer error in irq\n");
+		goto out;
+	}
+
+	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
+		sx9500_push_events(indio_dev);
+
+	if (val & SX9500_CONVDONE_IRQ)
+		complete_all(&data->completion);
 
 out:
 	mutex_unlock(&data->mutex);
@@ -395,9 +540,7 @@ static int sx9500_write_event_config(struct iio_dev *indio_dev,
 				     int state)
 {
 	struct sx9500_data *data = iio_priv(indio_dev);
-	int ret, i;
-	bool any_active = false;
-	unsigned int irqmask;
+	int ret;
 
 	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
 	    dir != IIO_EV_DIR_EITHER)
@@ -405,24 +548,32 @@ static int sx9500_write_event_config(struct iio_dev *indio_dev,
 
 	mutex_lock(&data->mutex);
 
-	data->event_enabled[chan->channel] = state;
+	if (state == 1) {
+		ret = sx9500_inc_chan_users(data, chan->channel);
+		if (ret < 0)
+			goto out_unlock;
+		ret = sx9500_inc_close_far_users(data);
+		if (ret < 0)
+			goto out_undo_chan;
+	} else {
+		ret = sx9500_dec_chan_users(data, chan->channel);
+		if (ret < 0)
+			goto out_unlock;
+		ret = sx9500_dec_close_far_users(data);
+		if (ret < 0)
+			goto out_undo_chan;
+	}
 
-	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
-		if (data->event_enabled[i]) {
-			any_active = true;
-			break;
-		}
+	data->event_enabled[chan->channel] = state;
+	goto out_unlock;
 
-	irqmask = SX9500_CLOSE_IRQ | SX9500_FAR_IRQ;
-	if (any_active)
-		ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
-					 irqmask, irqmask);
+out_undo_chan:
+	if (state == 1)
+		sx9500_dec_chan_users(data, chan->channel);
 	else
-		ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
-					 irqmask, 0);
-
+		sx9500_inc_chan_users(data, chan->channel);
+out_unlock:
 	mutex_unlock(&data->mutex);
-
 	return ret;
 }
 
@@ -473,12 +624,16 @@ static int sx9500_set_trigger_state(struct iio_trigger *trig,
 
 	mutex_lock(&data->mutex);
 
-	ret = regmap_update_bits(data->regmap, SX9500_REG_IRQ_MSK,
-				 SX9500_CONVDONE_IRQ,
-				 state ? SX9500_CONVDONE_IRQ : 0);
-	if (ret == 0)
-		data->trigger_enabled = state;
+	if (state)
+		ret = sx9500_inc_data_rdy_users(data);
+	else
+		ret = sx9500_dec_data_rdy_users(data);
+	if (ret < 0)
+		goto out;
+
+	data->trigger_enabled = state;
 
+out:
 	mutex_unlock(&data->mutex);
 
 	return ret;
@@ -500,7 +655,7 @@ static irqreturn_t sx9500_trigger_handler(int irq, void *private)
 
 	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
-		ret = sx9500_read_proximity(data, &indio_dev->channels[bit],
+		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
 					    &val);
 		if (ret < 0)
 			goto out;
@@ -519,6 +674,62 @@ out:
 	return IRQ_HANDLED;
 }
 
+static int sx9500_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret, i;
+
+	mutex_lock(&data->mutex);
+
+	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
+		if (test_bit(i, indio_dev->active_scan_mask)) {
+			ret = sx9500_inc_chan_users(data, i);
+			if (ret)
+				break;
+		}
+
+	if (ret)
+		for (i = i - 1; i >= 0; i--)
+			if (test_bit(i, indio_dev->active_scan_mask))
+				sx9500_dec_chan_users(data, i);
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret, i;
+
+	iio_triggered_buffer_predisable(indio_dev);
+
+	mutex_lock(&data->mutex);
+
+	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
+		if (test_bit(i, indio_dev->active_scan_mask)) {
+			ret = sx9500_dec_chan_users(data, i);
+			if (ret)
+				break;
+		}
+
+	if (ret)
+		for (i = i - 1; i >= 0; i--)
+			if (test_bit(i, indio_dev->active_scan_mask))
+				sx9500_inc_chan_users(data, i);
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
+	.preenable = sx9500_buffer_preenable,
+	.postenable = iio_triggered_buffer_postenable,
+	.predisable = sx9500_buffer_predisable,
+};
+
 struct sx9500_reg_default {
 	u8 reg;
 	u8 def;
@@ -574,11 +785,44 @@ static const struct sx9500_reg_default sx9500_default_regs[] = {
 	},
 	{
 		.reg = SX9500_REG_PROX_CTRL0,
-		/* Scan period: 30ms, all sensors enabled. */
-		.def = 0x0f,
+		/* Scan period: 30ms, all sensors disabled. */
+		.def = 0x00,
 	},
 };
 
+/* Activate all channels and perform an initial compensation. */
+static int sx9500_init_compensation(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int i, ret;
+	unsigned int val;
+
+	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
+				 GENMASK(SX9500_NUM_CHANNELS, 0),
+				 GENMASK(SX9500_NUM_CHANNELS, 0));
+	if (ret < 0)
+		return ret;
+
+	for (i = 10; i >= 0; i--) {
+		usleep_range(10000, 20000);
+		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
+		if (ret < 0)
+			goto out;
+		if (!(val & SX9500_COMPSTAT_MASK))
+			break;
+	}
+
+	if (i < 0) {
+		dev_err(&data->client->dev, "initial compensation timed out");
+		ret = -ETIMEDOUT;
+	}
+
+out:
+	regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
+			   GENMASK(SX9500_NUM_CHANNELS, 0), 0);
+	return ret;
+}
+
 static int sx9500_init_device(struct iio_dev *indio_dev)
 {
 	struct sx9500_data *data = iio_priv(indio_dev);
@@ -606,6 +850,10 @@ static int sx9500_init_device(struct iio_dev *indio_dev)
 			return ret;
 	}
 
+	ret = sx9500_init_compensation(indio_dev);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }
 
@@ -649,6 +897,7 @@ static int sx9500_probe(struct i2c_client *client,
 	data = iio_priv(indio_dev);
 	data->client = client;
 	mutex_init(&data->mutex);
+	init_completion(&data->completion);
 	data->trigger_enabled = false;
 
 	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
@@ -668,7 +917,9 @@ static int sx9500_probe(struct i2c_client *client,
 	if (client->irq <= 0)
 		client->irq = sx9500_gpio_probe(client, data);
 
-	if (client->irq > 0) {
+	if (client->irq <= 0)
+		dev_warn(&client->dev, "no valid irq found\n");
+	else {
 		ret = devm_request_threaded_irq(&client->dev, client->irq,
 				sx9500_irq_handler, sx9500_irq_thread_handler,
 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
@@ -691,7 +942,8 @@ static int sx9500_probe(struct i2c_client *client,
 	}
 
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
-					 sx9500_trigger_handler, NULL);
+					 sx9500_trigger_handler,
+					 &sx9500_buffer_setup_ops);
 	if (ret < 0)
 		goto out_trigger_unregister;