Add value normalization of alsa control values

Add functions that allows to normalize values that are requested
to be sent with an alsa set control call (using alsacore).

Change-Id: I5046a66d807c9b9b6751e036a47303ceddc0c16a
Signed-off-by: Jonathan Aillet <jonathan.aillet@iot.bzh>

1 files changed, 161 insertions, 0 deletions

diff --git a/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c b/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c
new file mode 100644
index 0000000..f749521
--- /dev/null
+++ b/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author Jonathan Aillet <jonathan.aillet@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include <limits.h>
+#include <math.h>
+
+#include <wrap-json.h>
+
+#include "4a-hal-controllers-value-handler.h"
+#include "4a-hal-controllers-alsacore-link.h"
+
+/*******************************************************************************
+ *		Simple conversion value to/from percentage functions	       *
+ ******************************************************************************/
+
+int HalCtlsConvertValueToPercentage(double val, double min, double max)
+{
+	double range;
+
+	range = max - min;
+	if(range <= 0)
+		return -INT_MAX;
+
+	val -= min;
+
+	return (int) round(val / range * 100);
+}
+
+int HalCtlsConvertPercentageToValue(int percentage, int min, int max)
+{
+	int range;
+
+	range = max - min;
+	if(range <= 0)
+		return -INT_MAX;
+
+	return (int) round((double) percentage * (double) range * 0.01 + (double) min);
+}
+
+/*******************************************************************************
+ *		Convert json object from percentage to value	 	       *
+ ******************************************************************************/
+
+int HalCtlsNormalizeJsonValues(AFB_ApiT apiHandle, struct CtlHalAlsaCtlProperties *alsaCtlProperties, json_object *toConvertJ, json_object ** ConvertedJ)
+{
+	int err = 0, idx, count, initialValue, convertedValue;
+
+	json_object *toConvertObjectJ, *convertedValueJ, *convertedArrayJ;
+
+	switch(json_object_get_type(toConvertJ)) {
+		case json_type_array:
+			count = json_object_array_length(toConvertJ);
+			break;
+
+		case json_type_null:
+		case json_type_object:
+			count = 0;
+			AFB_ApiWarning(apiHandle, "%s: can't normalize json values :\n-- %s", __func__, json_object_get_string(toConvertJ));
+			*ConvertedJ = json_object_get(toConvertJ);
+			return -1;
+
+		default:
+			count = 1;
+			break;
+	}
+
+	convertedArrayJ = json_object_new_array();
+
+	for(idx = 0; idx < count; idx++) {
+		if(count > 1)
+			toConvertObjectJ = json_object_array_get_idx(toConvertJ, idx);
+		else
+			toConvertObjectJ = toConvertJ;
+
+		switch(alsaCtlProperties->type) {
+			case SND_CTL_ELEM_TYPE_INTEGER:
+			case SND_CTL_ELEM_TYPE_INTEGER64:
+				if(! json_object_is_type(toConvertObjectJ, json_type_int)) {
+					err += -10*idx;
+					AFB_ApiWarning(apiHandle,
+						"%s: Try normalize an integer control but value sent in json is not an integer : '%s'",
+						__func__,
+						json_object_get_string(toConvertObjectJ));
+					convertedValueJ = toConvertObjectJ;
+					break;
+				}
+
+				initialValue = json_object_get_int(toConvertObjectJ);
+				convertedValue = HalCtlsConvertPercentageToValue(initialValue, alsaCtlProperties->minval, alsaCtlProperties->maxval);
+				if(convertedValue == -INT_MAX) {
+					AFB_ApiWarning(apiHandle,
+						"%s: Can't normalize %i (using min %i et max %i), value set to 0",
+						__func__,
+						initialValue,
+						alsaCtlProperties->minval,
+						alsaCtlProperties->maxval);
+					convertedValue = 0;
+				}
+
+				if(alsaCtlProperties->step) {
+					// Round value to the nearest step
+					convertedValue = (int) round((double) convertedValue / (double) alsaCtlProperties->step);
+					convertedValue *= alsaCtlProperties->step;
+				}
+
+				convertedValueJ = json_object_new_int(convertedValue);
+				break;
+
+			case SND_CTL_ELEM_TYPE_BOOLEAN:
+				if(! (json_object_is_type(toConvertObjectJ, json_type_int) ||
+				      json_object_is_type(toConvertObjectJ, json_type_boolean))) {
+					err += -1000*idx;
+					AFB_ApiWarning(apiHandle,
+						"%s: Try normalize a boolean control but value sent in json is not a boolean/integer : '%s'",
+						__func__,
+						json_object_get_string(toConvertObjectJ));
+					convertedValueJ = toConvertObjectJ;
+					break;
+				}
+
+				initialValue = json_object_get_int(toConvertObjectJ);
+				convertedValueJ = json_object_new_int(initialValue ? 1 : 0);
+				break;
+
+			default:
+				AFB_ApiWarning(apiHandle,
+					       "%s: Normalization not handle for the alsa control type %i, sending back the object as it was '%s'",
+					       __func__,
+					       (int) alsaCtlProperties->type,
+					       json_object_get_string(toConvertJ));
+				convertedValueJ = toConvertObjectJ;
+				break;
+		}
+
+		json_object_array_put_idx(convertedArrayJ, idx, convertedValueJ);
+	}
+
+	*ConvertedJ = convertedArrayJ;
+
+	return 0;
+}
\ No newline at end of file