[PATCH v2 2/3] hwmon: (lm90) add support to handle IRQ.

[Wei Ni <wni-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

When the temperature exceed the limit range value,
the driver can handle the interrupt.

Signed-off-by: Wei Ni <wni-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/hwmon/lm90.c |   77 +++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 64 insertions(+), 13 deletions(-)

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 2cb7f8e..88ff362 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -89,6 +89,7 @@
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
+#include <linux/interrupt.h>
 
 /*
  * Addresses to scan
@@ -179,6 +180,19 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
 
+/* LM90 status */
+#define LM90_LTHRM	(1 << 0)	/* local THERM limit tripped */
+#define LM90_RTHRM	(1 << 1)	/* remote THERM limit tripped */
+#define LM90_OPEN	(1 << 2)	/* remote is an open circuit */
+#define LM90_RLOW	(1 << 3)	/* remote low temp limit tripped */
+#define LM90_RHIGH	(1 << 4)	/* remote high temp limit tripped */
+#define LM90_LLOW	(1 << 5)	/* local low temp limit tripped */
+#define LM90_LHIGH	(1 << 6)	/* local high temp limit tripped */
+#define LM90_BUSY	(1 << 7)	/* ADC is converting */
+
+#define MAX6696_RLOW	(1 << 3)	/* remote2 low temp limit tripped */
+#define MAX6696_RHIGH	(1 << 4)	/* remote2 high temp limit tripped */
+
 /*
  * Driver data (common to all clients)
  */
@@ -1423,6 +1437,43 @@ static void lm90_init_client(struct i2c_client *client)
 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
 }
 
+static void lm90_alarm_status(struct i2c_client *client,
+			      u8 alarms, u8 alarms_max6696)
+{
+	if (alarms & (LM90_LLOW | LM90_LHIGH | LM90_LTHRM))
+		dev_warn(&client->dev,
+			 "temp%d out of range, please check!\n", 1);
+	if (alarms & (LM90_RLOW | LM90_RHIGH | LM90_RTHRM))
+		dev_warn(&client->dev,
+			 "temp%d out of range, please check!\n", 2);
+	if (alarms & LM90_OPEN)
+		dev_warn(&client->dev,
+			 "temp%d diode open, please check!\n", 2);
+
+	if (alarms_max6696 & (MAX6696_RLOW | MAX6696_RHIGH))
+		dev_warn(&client->dev,
+			 "temp%d out of range, please check!\n", 3);
+}
+
+static irqreturn_t lm90_irq_thread(int irq, void *dev_id)
+{
+	struct lm90_data *data = dev_id;
+	struct i2c_client *client = to_i2c_client(data->hwmon_dev->parent);
+	u8 alarms, alarms_max6696 = 0;
+
+	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
+
+	if (data->kind == max6696)
+		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms_max6696);
+
+	if ((alarms & 0x7f) == 0 && (alarms_max6696 & 0xfe) == 0) {
+		return IRQ_NONE;
+	} else {
+		lm90_alarm_status(client, alarms, alarms_max6696);
+		return IRQ_HANDLED;
+	}
+}
+
 static int lm90_probe(struct i2c_client *client,
 		      const struct i2c_device_id *id)
 {
@@ -1499,6 +1550,18 @@ static int lm90_probe(struct i2c_client *client,
 		goto exit_remove_files;
 	}
 
+	if (client->irq >= 0) {
+		dev_dbg(dev, "lm90 IRQ: %d\n", client->irq);
+		err = devm_request_threaded_irq(dev, client->irq,
+						NULL, lm90_irq_thread,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"lm90", data);
+		if (err < 0) {
+			dev_err(dev, "cannot request interrupt\n");
+			goto exit_remove_files;
+		}
+	}
+
 	return 0;
 
 exit_remove_files:
@@ -1532,19 +1595,7 @@ static void lm90_alert(struct i2c_client *client, unsigned int flag)
 	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
 		dev_info(&client->dev, "Everything OK\n");
 	} else {
-		if (alarms & 0x61)
-			dev_warn(&client->dev,
-				 "temp%d out of range, please check!\n", 1);
-		if (alarms & 0x1a)
-			dev_warn(&client->dev,
-				 "temp%d out of range, please check!\n", 2);
-		if (alarms & 0x04)
-			dev_warn(&client->dev,
-				 "temp%d diode open, please check!\n", 2);
-
-		if (alarms2 & 0x18)
-			dev_warn(&client->dev,
-				 "temp%d out of range, please check!\n", 3);
+		lm90_alarm_status(client, alarms, alarms2);
 
 		/*
 		 * Disable ALERT# output, because these chips don't implement
-- 
1.7.9.5