firmware: xilinx: Add sysfs support for feature config

Add support for sysfs interface for runtime features configuration.
 The user can configure the features at runtime. First, the user need
 to select the config id of the supported features and then the user
 can configure the parameters of the feature based on the config id.

Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ronak Jain <ronak.jain@xilinx.com>
Link: https://lore.kernel.org/r/20220209082709.32378-4-ronak.jain@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/xilinx/zynqmp.c

@@ -41,6 +41,16 @@ static DEFINE_HASHTABLE(pm_api_features_map, PM_API_FEATURE_CHECK_MAX_ORDER);
 
 static struct platform_device *em_dev;
 
+/**
+ * struct zynqmp_devinfo - Structure for Zynqmp device instance
+ * @dev:		Device Pointer
+ * @feature_conf_id:	Feature conf id
+ */
+struct zynqmp_devinfo {
+	struct device *dev;
+	u32 feature_conf_id;
+};
+
 /**
  * struct pm_api_feature_data - PM API Feature data
  * @pm_api_id:		PM API Id, used as key to index into hashmap
@@ -1451,6 +1461,78 @@ static DEVICE_ATTR_RW(pggs1);
 static DEVICE_ATTR_RW(pggs2);
 static DEVICE_ATTR_RW(pggs3);
 
+static ssize_t feature_config_id_show(struct device *device,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct zynqmp_devinfo *devinfo = dev_get_drvdata(device);
+
+	return sysfs_emit(buf, "%d\n", devinfo->feature_conf_id);
+}
+
+static ssize_t feature_config_id_store(struct device *device,
+				       struct device_attribute *attr,
+				       const char *buf, size_t count)
+{
+	u32 config_id;
+	int ret;
+	struct zynqmp_devinfo *devinfo = dev_get_drvdata(device);
+
+	if (!buf)
+		return -EINVAL;
+
+	ret = kstrtou32(buf, 10, &config_id);
+	if (ret)
+		return ret;
+
+	devinfo->feature_conf_id = config_id;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(feature_config_id);
+
+static ssize_t feature_config_value_show(struct device *device,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	int ret;
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	struct zynqmp_devinfo *devinfo = dev_get_drvdata(device);
+
+	ret = zynqmp_pm_get_feature_config(devinfo->feature_conf_id,
+					   ret_payload);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", ret_payload[1]);
+}
+
+static ssize_t feature_config_value_store(struct device *device,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	u32 value;
+	int ret;
+	struct zynqmp_devinfo *devinfo = dev_get_drvdata(device);
+
+	if (!buf)
+		return -EINVAL;
+
+	ret = kstrtou32(buf, 10, &value);
+	if (ret)
+		return ret;
+
+	ret = zynqmp_pm_set_feature_config(devinfo->feature_conf_id,
+					   value);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(feature_config_value);
+
 static struct attribute *zynqmp_firmware_attrs[] = {
 	&dev_attr_ggs0.attr,
 	&dev_attr_ggs1.attr,
@@ -1462,6 +1544,8 @@ static struct attribute *zynqmp_firmware_attrs[] = {
 	&dev_attr_pggs3.attr,
 	&dev_attr_shutdown_scope.attr,
 	&dev_attr_health_status.attr,
+	&dev_attr_feature_config_id.attr,
+	&dev_attr_feature_config_value.attr,
 	NULL,
 };
 
@@ -1471,6 +1555,7 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np;
+	struct zynqmp_devinfo *devinfo;
 	int ret;
 
 	np = of_find_compatible_node(NULL, NULL, "xlnx,zynqmp");
@@ -1487,6 +1572,14 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	devinfo = devm_kzalloc(dev, sizeof(*devinfo), GFP_KERNEL);
+	if (!devinfo)
+		return -ENOMEM;
+
+	devinfo->dev = dev;
+
+	platform_set_drvdata(pdev, devinfo);
+
 	/* Check PM API version number */
 	ret = zynqmp_pm_get_api_version(&pm_api_version);
 	if (ret)