soundwire: amd: implement function to extract slave information

Implement function to extract slaves information connected on the bus.
This information is required during machine select logic.
This function will be called from machine select logic code.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Link: https://msgid.link/r/20240129055147.1493853-5-Vijendar.Mukunda@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/soundwire/amd_init.c

@@ -142,6 +142,49 @@ void sdw_amd_exit(struct sdw_amd_ctx *ctx)
 }
 EXPORT_SYMBOL_NS(sdw_amd_exit, SOUNDWIRE_AMD_INIT);
 
+int sdw_amd_get_slave_info(struct sdw_amd_ctx *ctx)
+{
+	struct amd_sdw_manager *amd_manager;
+	struct sdw_bus *bus;
+	struct sdw_slave *slave;
+	struct list_head *node;
+	int index;
+	int i = 0;
+	int num_slaves = 0;
+
+	for (index = 0; index < ctx->count; index++) {
+		if (!(ctx->link_mask & BIT(index)))
+			continue;
+		amd_manager = dev_get_drvdata(&ctx->pdev[index]->dev);
+		if (!amd_manager)
+			return -ENODEV;
+		bus = &amd_manager->bus;
+		/* Calculate number of slaves */
+		list_for_each(node, &bus->slaves)
+			num_slaves++;
+	}
+
+	ctx->ids = kcalloc(num_slaves, sizeof(*ctx->ids), GFP_KERNEL);
+	if (!ctx->ids)
+		return -ENOMEM;
+	ctx->num_slaves = num_slaves;
+	for (index = 0; index < ctx->count; index++) {
+		if (!(ctx->link_mask & BIT(index)))
+			continue;
+		amd_manager = dev_get_drvdata(&ctx->pdev[index]->dev);
+		if (amd_manager) {
+			bus = &amd_manager->bus;
+			list_for_each_entry(slave, &bus->slaves, node) {
+				ctx->ids[i].id = slave->id;
+				ctx->ids[i].link_id = bus->link_id;
+				i++;
+			}
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS(sdw_amd_get_slave_info, SOUNDWIRE_AMD_INIT);
+
 MODULE_AUTHOR("Vijendar.Mukunda@amd.com");
 MODULE_DESCRIPTION("AMD SoundWire Init Library");
 MODULE_LICENSE("Dual BSD/GPL");

include/linux/soundwire/sdw_amd.h

@@ -170,5 +170,7 @@ int sdw_amd_probe(struct sdw_amd_res *res, struct sdw_amd_ctx **ctx);
 
 void sdw_amd_exit(struct sdw_amd_ctx *ctx);
 
+int sdw_amd_get_slave_info(struct sdw_amd_ctx *ctx);
+
 int amd_sdw_scan_controller(struct sdw_amd_acpi_info *info);
 #endif