Commit a2e48458 authored by Srinivas Kandagatla's avatar Srinivas Kandagatla Committed by Vinod Koul
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soundwire: core: add device tree support for slave devices 



This patch adds support to parsing device tree based
SoundWire slave devices.

Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190829163514.11221-3-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent dd4689e2

drivers/soundwire/bus.c

+2 −0
Original line number Diff line number Diff line
@@ -79,6 +79,8 @@ int sdw_add_bus_master(struct sdw_bus *bus) 
	 */

	if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))

		ret = sdw_acpi_find_slaves(bus);

	else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)

		ret = sdw_of_find_slaves(bus);

	else

		ret = -ENOTSUPP; /* No ACPI/DT so error out */

drivers/soundwire/bus.h

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus) 
}

#endif



int sdw_of_find_slaves(struct sdw_bus *bus);

void sdw_extract_slave_id(struct sdw_bus *bus,

			  u64 addr, struct sdw_slave_id *id);

drivers/soundwire/slave.c

+52 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
// Copyright(c) 2015-17 Intel Corporation.



#include <linux/acpi.h>

#include <linux/of.h>

#include <linux/soundwire/sdw.h>

#include <linux/soundwire/sdw_type.h>

#include "bus.h"
@@ -35,6 +36,7 @@ static int sdw_slave_add(struct sdw_bus *bus, 


	slave->dev.release = sdw_slave_release;

	slave->dev.bus = &sdw_bus_type;

	slave->dev.of_node = of_node_get(to_of_node(fwnode));

	slave->bus = bus;

	slave->status = SDW_SLAVE_UNATTACHED;

	slave->dev_num = 0;
@@ -113,3 +115,53 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus) 
}



#endif



/*

 * sdw_of_find_slaves() - Find Slave devices in master device tree node

 * @bus: SDW bus instance

 *

 * Scans Master DT node for SDW child Slave devices and registers it.

 */

int sdw_of_find_slaves(struct sdw_bus *bus)

{

	struct device *dev = bus->dev;

	struct device_node *node;



	for_each_child_of_node(bus->dev->of_node, node) {

		int link_id, sdw_version, ret, len;

		const char *compat = NULL;

		struct sdw_slave_id id;

		const __be32 *addr;



		compat = of_get_property(node, "compatible", NULL);

		if (!compat)

			continue;



		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,

			     &id.mfg_id, &id.part_id, &id.class_id);



		if (ret != 4) {

			dev_err(dev, "Invalid compatible string found %s\n",

				compat);

			continue;

		}



		addr = of_get_property(node, "reg", &len);

		if (!addr || (len < 2 * sizeof(u32))) {

			dev_err(dev, "Invalid Link and Instance ID\n");

			continue;

		}



		link_id = be32_to_cpup(addr++);

		id.unique_id = be32_to_cpup(addr);

		id.sdw_version = sdw_version;



		/* Check for link_id match */

		if (link_id != bus->link_id)

			continue;



		sdw_slave_add(bus, &id, of_fwnode_handle(node));

	}



	return 0;

}