1 files changed, 349 insertions, 14 deletions

diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index 7a3eef5d5e75..f1bb0976273d 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -6,39 +6,123 @@
  * Author: <andrew.hepp@ahepp.dev>
  */
 
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/math.h>
+#include <linux/minmax.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 
+#include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 
 /* MCP9600 registers */
 #define MCP9600_HOT_JUNCTION 0x0
 #define MCP9600_COLD_JUNCTION 0x2
+#define MCP9600_STATUS			0x4
+#define MCP9600_STATUS_ALERT(x)		BIT(x)
+#define MCP9600_ALERT_CFG1		0x8
+#define MCP9600_ALERT_CFG(x)		(MCP9600_ALERT_CFG1 + (x - 1))
+#define MCP9600_ALERT_CFG_ENABLE	BIT(0)
+#define MCP9600_ALERT_CFG_ACTIVE_HIGH	BIT(2)
+#define MCP9600_ALERT_CFG_FALLING	BIT(3)
+#define MCP9600_ALERT_CFG_COLD_JUNCTION	BIT(4)
+#define MCP9600_ALERT_HYSTERESIS1	0xc
+#define MCP9600_ALERT_HYSTERESIS(x)	(MCP9600_ALERT_HYSTERESIS1 + (x - 1))
+#define MCP9600_ALERT_LIMIT1		0x10
+#define MCP9600_ALERT_LIMIT(x)		(MCP9600_ALERT_LIMIT1 + (x - 1))
+#define MCP9600_ALERT_LIMIT_MASK	GENMASK(15, 2)
 #define MCP9600_DEVICE_ID 0x20
 
 /* MCP9600 device id value */
 #define MCP9600_DEVICE_ID_MCP9600 0x40
 
-static const struct iio_chan_spec mcp9600_channels[] = {
+#define MCP9600_ALERT_COUNT		4
+
+#define MCP9600_MIN_TEMP_HOT_JUNCTION_MICRO	-200000000
+#define MCP9600_MAX_TEMP_HOT_JUNCTION_MICRO	1800000000
+
+#define MCP9600_MIN_TEMP_COLD_JUNCTION_MICRO	-40000000
+#define MCP9600_MAX_TEMP_COLD_JUNCTION_MICRO	125000000
+
+enum mcp9600_alert {
+	MCP9600_ALERT1,
+	MCP9600_ALERT2,
+	MCP9600_ALERT3,
+	MCP9600_ALERT4
+};
+
+static const char * const mcp9600_alert_name[MCP9600_ALERT_COUNT] = {
+	[MCP9600_ALERT1] = "alert1",
+	[MCP9600_ALERT2] = "alert2",
+	[MCP9600_ALERT3] = "alert3",
+	[MCP9600_ALERT4] = "alert4",
+};
+
+static const struct iio_event_spec mcp9600_events[] = {
 	{
-		.type = IIO_TEMP,
-		.address = MCP9600_HOT_JUNCTION,
-		.info_mask_separate =
-			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+				 BIT(IIO_EV_INFO_VALUE) |
+				 BIT(IIO_EV_INFO_HYSTERESIS),
 	},
 	{
-		.type = IIO_TEMP,
-		.address = MCP9600_COLD_JUNCTION,
-		.channel2 = IIO_MOD_TEMP_AMBIENT,
-		.modified = 1,
-		.info_mask_separate =
-			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+				 BIT(IIO_EV_INFO_VALUE) |
+				 BIT(IIO_EV_INFO_HYSTERESIS),
 	},
 };
 
+#define MCP9600_CHANNELS(hj_num_ev, hj_ev_spec_off, cj_num_ev, cj_ev_spec_off) \
+	{								       \
+		{							       \
+			.type = IIO_TEMP,				       \
+			.address = MCP9600_HOT_JUNCTION,		       \
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	       \
+					      BIT(IIO_CHAN_INFO_SCALE),	       \
+			.event_spec = &mcp9600_events[hj_ev_spec_off],	       \
+			.num_event_specs = hj_num_ev,			       \
+		},							       \
+		{							       \
+			.type = IIO_TEMP,				       \
+			.address = MCP9600_COLD_JUNCTION,		       \
+			.channel2 = IIO_MOD_TEMP_AMBIENT,		       \
+			.modified = 1,					       \
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	       \
+					      BIT(IIO_CHAN_INFO_SCALE),	       \
+			.event_spec = &mcp9600_events[cj_ev_spec_off],	       \
+			.num_event_specs = cj_num_ev,			       \
+		},							       \
+	}
+
+static const struct iio_chan_spec mcp9600_channels[][2] = {
+	MCP9600_CHANNELS(0, 0, 0, 0), /* Alerts: - - - - */
+	MCP9600_CHANNELS(1, 0, 0, 0), /* Alerts: 1 - - - */
+	MCP9600_CHANNELS(1, 1, 0, 0), /* Alerts: - 2 - - */
+	MCP9600_CHANNELS(2, 0, 0, 0), /* Alerts: 1 2 - - */
+	MCP9600_CHANNELS(0, 0, 1, 0), /* Alerts: - - 3 - */
+	MCP9600_CHANNELS(1, 0, 1, 0), /* Alerts: 1 - 3 - */
+	MCP9600_CHANNELS(1, 1, 1, 0), /* Alerts: - 2 3 - */
+	MCP9600_CHANNELS(2, 0, 1, 0), /* Alerts: 1 2 3 - */
+	MCP9600_CHANNELS(0, 0, 1, 1), /* Alerts: - - - 4 */
+	MCP9600_CHANNELS(1, 0, 1, 1), /* Alerts: 1 - - 4 */
+	MCP9600_CHANNELS(1, 1, 1, 1), /* Alerts: - 2 - 4 */
+	MCP9600_CHANNELS(2, 0, 1, 1), /* Alerts: 1 2 - 4 */
+	MCP9600_CHANNELS(0, 0, 2, 0), /* Alerts: - - 3 4 */
+	MCP9600_CHANNELS(1, 0, 2, 0), /* Alerts: 1 - 3 4 */
+	MCP9600_CHANNELS(1, 1, 2, 0), /* Alerts: - 2 3 4 */
+	MCP9600_CHANNELS(2, 0, 2, 0), /* Alerts: 1 2 3 4 */
+};
+
 struct mcp9600_data {
 	struct i2c_client *client;
 };
@@ -80,15 +164,261 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static int mcp9600_get_alert_index(int channel2, enum iio_event_direction dir)
+{
+	if (channel2 == IIO_MOD_TEMP_AMBIENT) {
+		if (dir == IIO_EV_DIR_RISING)
+			return MCP9600_ALERT3;
+		else
+			return MCP9600_ALERT4;
+	} else {
+		if (dir == IIO_EV_DIR_RISING)
+			return MCP9600_ALERT1;
+		else
+			return MCP9600_ALERT2;
+	}
+}
+
+static int mcp9600_read_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir)
+{
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	int i, ret;
+
+	i = mcp9600_get_alert_index(chan->channel2, dir);
+	ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
+	if (ret < 0)
+		return ret;
+
+	return FIELD_GET(MCP9600_ALERT_CFG_ENABLE, ret);
+}
+
+static int mcp9600_write_event_config(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir,
+				      int state)
+{
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	int i, ret;
+
+	i = mcp9600_get_alert_index(chan->channel2, dir);
+	ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
+	if (ret < 0)
+		return ret;
+
+	if (state)
+		ret |= MCP9600_ALERT_CFG_ENABLE;
+	else
+		ret &= ~MCP9600_ALERT_CFG_ENABLE;
+
+	return i2c_smbus_write_byte_data(client, MCP9600_ALERT_CFG(i + 1), ret);
+}
+
+static int mcp9600_read_thresh(struct iio_dev *indio_dev,
+			       const struct iio_chan_spec *chan,
+			       enum iio_event_type type,
+			       enum iio_event_direction dir,
+			       enum iio_event_info info, int *val, int *val2)
+{
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	s32 ret;
+	int i;
+
+	i = mcp9600_get_alert_index(chan->channel2, dir);
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
+		if (ret < 0)
+			return ret;
+		/*
+		 * Temperature is stored in two’s complement format in
+		 * bits(15:2), LSB is 0.25 degree celsius.
+		 */
+		*val = sign_extend32(FIELD_GET(MCP9600_ALERT_LIMIT_MASK, ret), 13);
+		*val2 = 4;
+		return IIO_VAL_FRACTIONAL;
+	case IIO_EV_INFO_HYSTERESIS:
+		ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_HYSTERESIS(i + 1));
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mcp9600_write_thresh(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir,
+				enum iio_event_info info, int val, int val2)
+{
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	int s_val, i;
+	s16 thresh;
+	u8 hyst;
+
+	i = mcp9600_get_alert_index(chan->channel2, dir);
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		/* Scale value to include decimal part into calculations */
+		s_val = (val < 0) ? ((val * 1000000) - val2) :
+				    ((val * 1000000) + val2);
+		if (chan->channel2 == IIO_MOD_TEMP_AMBIENT) {
+			s_val = max(s_val, MCP9600_MIN_TEMP_COLD_JUNCTION_MICRO);
+			s_val = min(s_val, MCP9600_MAX_TEMP_COLD_JUNCTION_MICRO);
+		} else {
+			s_val = max(s_val, MCP9600_MIN_TEMP_HOT_JUNCTION_MICRO);
+			s_val = min(s_val, MCP9600_MAX_TEMP_HOT_JUNCTION_MICRO);
+		}
+
+		/*
+		 * Shift length 4 bits = 2(15:2) + 2(0.25 LSB), temperature is
+		 * stored in two’s complement format.
+		 */
+		thresh = (s16)(s_val / (1000000 >> 4));
+		return i2c_smbus_write_word_swapped(client,
+						    MCP9600_ALERT_LIMIT(i + 1),
+						    thresh);
+	case IIO_EV_INFO_HYSTERESIS:
+		hyst = min(abs(val), 255);
+		return i2c_smbus_write_byte_data(client,
+						 MCP9600_ALERT_HYSTERESIS(i + 1),
+						 hyst);
+	default:
+		return -EINVAL;
+	}
+}
+
 static const struct iio_info mcp9600_info = {
 	.read_raw = mcp9600_read_raw,
+	.read_event_config = mcp9600_read_event_config,
+	.write_event_config = mcp9600_write_event_config,
+	.read_event_value = mcp9600_read_thresh,
+	.write_event_value = mcp9600_write_thresh,
 };
 
+static irqreturn_t mcp9600_alert_handler(void *private,
+					 enum mcp9600_alert alert,
+					 enum iio_modifier mod,
+					 enum iio_event_direction dir)
+{
+	struct iio_dev *indio_dev = private;
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, MCP9600_STATUS);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	if (!(ret & MCP9600_STATUS_ALERT(alert)))
+		return IRQ_NONE;
+
+	iio_push_event(indio_dev,
+		       IIO_MOD_EVENT_CODE(IIO_TEMP, 0, mod, IIO_EV_TYPE_THRESH,
+					  dir),
+		       iio_get_time_ns(indio_dev));
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mcp9600_alert1_handler(int irq, void *private)
+{
+	return mcp9600_alert_handler(private, MCP9600_ALERT1, IIO_NO_MOD,
+				     IIO_EV_DIR_RISING);
+}
+
+static irqreturn_t mcp9600_alert2_handler(int irq, void *private)
+{
+	return mcp9600_alert_handler(private, MCP9600_ALERT2, IIO_NO_MOD,
+				     IIO_EV_DIR_FALLING);
+}
+
+static irqreturn_t mcp9600_alert3_handler(int irq, void *private)
+{
+	return mcp9600_alert_handler(private, MCP9600_ALERT3,
+				     IIO_MOD_TEMP_AMBIENT, IIO_EV_DIR_RISING);
+}
+
+static irqreturn_t mcp9600_alert4_handler(int irq, void *private)
+{
+	return mcp9600_alert_handler(private, MCP9600_ALERT4,
+				     IIO_MOD_TEMP_AMBIENT, IIO_EV_DIR_FALLING);
+}
+
+static irqreturn_t (*mcp9600_alert_handler_func[MCP9600_ALERT_COUNT]) (int, void *) = {
+	mcp9600_alert1_handler,
+	mcp9600_alert2_handler,
+	mcp9600_alert3_handler,
+	mcp9600_alert4_handler,
+};
+
+static int mcp9600_probe_alerts(struct iio_dev *indio_dev)
+{
+	struct mcp9600_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	struct device *dev = &client->dev;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+	unsigned int irq_type;
+	int ret, irq, i;
+	u8 val, ch_sel;
+
+	/*
+	 * alert1: hot junction, rising temperature
+	 * alert2: hot junction, falling temperature
+	 * alert3: cold junction, rising temperature
+	 * alert4: cold junction, falling temperature
+	 */
+	ch_sel = 0;
+	for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
+		irq = fwnode_irq_get_byname(fwnode, mcp9600_alert_name[i]);
+		if (irq <= 0)
+			continue;
+
+		val = 0;
+		irq_type = irq_get_trigger_type(irq);
+		if (irq_type == IRQ_TYPE_EDGE_RISING)
+			val |= MCP9600_ALERT_CFG_ACTIVE_HIGH;
+
+		if (i == MCP9600_ALERT2 || i == MCP9600_ALERT4)
+			val |= MCP9600_ALERT_CFG_FALLING;
+
+		if (i == MCP9600_ALERT3 || i == MCP9600_ALERT4)
+			val |= MCP9600_ALERT_CFG_COLD_JUNCTION;
+
+		ret = i2c_smbus_write_byte_data(client,
+						MCP9600_ALERT_CFG(i + 1),
+						val);
+		if (ret < 0)
+			return ret;
+
+		ret = devm_request_threaded_irq(dev, irq, NULL,
+						mcp9600_alert_handler_func[i],
+						IRQF_ONESHOT, "mcp9600",
+						indio_dev);
+		if (ret)
+			return ret;
+
+		ch_sel |= BIT(i);
+	}
+
+	return ch_sel;
+}
+
 static int mcp9600_probe(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev;
 	struct mcp9600_data *data;
-	int ret;
+	int ret, ch_sel;
 
 	ret = i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID);
 	if (ret < 0)
@@ -104,11 +434,15 @@ static int mcp9600_probe(struct i2c_client *client)
 	data = iio_priv(indio_dev);
 	data->client = client;
 
+	ch_sel = mcp9600_probe_alerts(indio_dev);
+	if (ch_sel < 0)
+		return ch_sel;
+
 	indio_dev->info = &mcp9600_info;
 	indio_dev->name = "mcp9600";
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = mcp9600_channels;
-	indio_dev->num_channels = ARRAY_SIZE(mcp9600_channels);
+	indio_dev->channels = mcp9600_channels[ch_sel];
+	indio_dev->num_channels = ARRAY_SIZE(mcp9600_channels[ch_sel]);
 
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
@@ -135,6 +469,7 @@ static struct i2c_driver mcp9600_driver = {
 };
 module_i2c_driver(mcp9600_driver);
 
+MODULE_AUTHOR("Dimitri Fedrau <dima.fedrau@gmail.com>");
 MODULE_AUTHOR("Andrew Hepp <andrew.hepp@ahepp.dev>");
 MODULE_DESCRIPTION("Microchip MCP9600 thermocouple EMF converter driver");
 MODULE_LICENSE("GPL");