[PATCH] i2c: xlp9xx: Add support for SMBAlert

[Manoj Iyer]

From: George Cherian <george.cherian at cavium.com>

Add support for SMBus alert mechanism to i2c-xlp9xx driver.
The second interrupt is parsed to use for SMBus alert.
The first interrupt is the i2c controller main interrupt.

BugLink: https://launchpad.net/bugs/1786981

Signed-off-by: Kamlakant Patel <kamlakant.patel at cavium.com>
Signed-off-by: George Cherian <george.cherian at cavium.com>
Reviewed-by: Jan Glauber <jglauber at cavium.com>
Signed-off-by: Wolfram Sang <wsa at the-dreams.de>
(cherry picked from commit 40f4e372cba8a6729c997c0bda1fa03adf7f956e)
Signed-off-by: Manoj Iyer <manoj.iyer at canonical.com>
---
 drivers/i2c/busses/i2c-xlp9xx.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c
index f2d224371c08..1f41a4f89c08 100644
--- a/drivers/i2c/busses/i2c-xlp9xx.c
+++ b/drivers/i2c/busses/i2c-xlp9xx.c
@@ -10,6 +10,7 @@
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -84,6 +85,8 @@ struct xlp9xx_i2c_dev {
 	struct device *dev;
 	struct i2c_adapter adapter;
 	struct completion msg_complete;
+	struct i2c_smbus_alert_setup alert_data;
+	struct i2c_client *ara;
 	int irq;
 	bool msg_read;
 	bool len_recv;
@@ -470,6 +473,19 @@ static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
 	return 0;
 }
 
+static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev *priv,
+				  struct platform_device *pdev)
+{
+	if (!priv->alert_data.irq)
+		return -EINVAL;
+
+	priv->ara = i2c_setup_smbus_alert(&priv->adapter, &priv->alert_data);
+	if (!priv->ara)
+		return -ENODEV;
+
+	return 0;
+}
+
 static int xlp9xx_i2c_probe(struct platform_device *pdev)
 {
 	struct xlp9xx_i2c_dev *priv;
@@ -490,6 +506,10 @@ static int xlp9xx_i2c_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "invalid irq!\n");
 		return priv->irq;
 	}
+	/* SMBAlert irq */
+	priv->alert_data.irq = platform_get_irq(pdev, 1);
+	if (priv->alert_data.irq <= 0)
+		priv->alert_data.irq = 0;
 
 	xlp9xx_i2c_get_frequency(pdev, priv);
 	xlp9xx_i2c_init(priv);
@@ -516,6 +536,10 @@ static int xlp9xx_i2c_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	err = xlp9xx_i2c_smbus_setup(priv, pdev);
+	if (err)
+		dev_dbg(&pdev->dev, "No active SMBus alert %d\n", err);
+
 	platform_set_drvdata(pdev, priv);
 	dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);
 
-- 
2.17.1