[PATCH v2 1/3] powerpc/powernv: convert codes returned by OPAL calls

["Cédric Le Goater" <clg@fr.ibm.com>]

OPAL has its own list of return codes. The patch provides a translation
of such codes in errnos for the opal_sensor_read call.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
---
 arch/powerpc/platforms/powernv/opal-sensor.c |   37 ++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

Index: linux.git/arch/powerpc/platforms/powernv/opal-sensor.c
===================================================================
--- linux.git.orig/arch/powerpc/platforms/powernv/opal-sensor.c
+++ linux.git/arch/powerpc/platforms/powernv/opal-sensor.c
@@ -26,6 +26,38 @@
 
 static DEFINE_MUTEX(opal_sensor_mutex);
 
+
+/*
+ * opal_sensor_read() return codes
+ *
+ * OPAL_PARAMETER - invalid sensor handler
+ * OPAL_UNSUPPORTED - plateform does not support reading sensors.
+ *
+ *     in case of communication with the FSP on IBM systems
+ *
+ * OPAL_ASYNC_COMPLETION - a request was sent and an async completion will
+ *	be triggered with the @token argument
+ * OPAL_PARTIAL - the request completed but the data returned is invalid
+ * OPAL_BUSY_EVENT - a previous request is still pending
+ * OPAL_NO_MEM - allocation failed
+ * OPAL_INTERNAL_ERROR - communication failure with the FSP
+ * OPAL_HARDWARE - FSP is not available
+ */
+static int convert_opal_code(int ret)
+{
+	switch (ret) {
+	case OPAL_SUCCESS:		return 0;
+	case OPAL_PARAMETER:		return -EINVAL;
+	case OPAL_UNSUPPORTED:		return -ENOSYS;
+	case OPAL_ASYNC_COMPLETION:	return -EAGAIN;
+	case OPAL_BUSY_EVENT:		return -EBUSY;
+	case OPAL_NO_MEM:		return -ENOMEM;
+	case OPAL_HARDWARE:		return -ENOENT;
+	case OPAL_INTERNAL_ERROR:	return -EIO;
+	default:			return -EIO;
+	}
+}
+
 /*
  * This will return sensor information to driver based on the requested sensor
  * handle. A handle is an opaque id for the powernv, read by the driver from the
@@ -46,8 +78,10 @@ int opal_get_sensor_data(u32 sensor_hndl
 
 	mutex_lock(&opal_sensor_mutex);
 	ret = opal_sensor_read(sensor_hndl, token, &data);
-	if (ret != OPAL_ASYNC_COMPLETION)
+	if (ret != OPAL_ASYNC_COMPLETION) {
+		ret = convert_opal_code(ret);
 		goto out_token;
+	}
 
 	ret = opal_async_wait_response(token, &msg);
 	if (ret) {
@@ -58,6 +92,7 @@ int opal_get_sensor_data(u32 sensor_hndl
 
 	*sensor_data = be32_to_cpu(data);
 	ret = be64_to_cpu(msg.params[1]);
+	ret = convert_opal_code(ret);
 
 out_token:
 	mutex_unlock(&opal_sensor_mutex);