Commit 7ceaa40b authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Vinod Koul
Browse files

soundwire: bus_type: add sdw_master_device support 



In the existing SoundWire code, Master Devices are not explicitly
represented - only SoundWire Slave Devices are exposed (the use of
capital letters follows the SoundWire specification conventions).

With the existing code, the bus is handled without using a proper device,
and bus->dev typically points to a platform device. The right thing to
do as discussed in multiple reviews is use a device for each bus.

The sdw_master_device addition is done with minimal internal plumbing
and not exposed externally. The existing API based on
sdw_bus_master_add() and sdw_bus_master_delete() will deal with the
sdw_master_device life cycle, which minimizes changes to existing
drivers.

Note that the Intel code will be modified in follow-up patches (no
impact on any platform since the connection with ASoC is not supported
upstream so far).

Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: default avatarBard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: default avatarJaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-5-yung-chuan.liao@linux.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent dbb50c7a

drivers/soundwire/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
#



#Bus Objs

soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o

soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o

obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o



ifdef CONFIG_DEBUG_FS

drivers/soundwire/bus.c

+11 −3
Original line number Diff line number Diff line
@@ -37,14 +37,21 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent, 
	struct sdw_master_prop *prop = NULL;

	int ret;



	if (!bus->dev) {

		pr_err("SoundWire bus has no device\n");

	if (!parent) {

		pr_err("SoundWire parent device is not set\n");

		return -ENODEV;

	}



	ret = sdw_get_id(bus);

	if (ret) {

		dev_err(bus->dev, "Failed to get bus id\n");

		dev_err(parent, "Failed to get bus id\n");

		return ret;

	}



	ret = sdw_master_device_add(bus, parent, fwnode);

	if (ret) {

		dev_err(parent, "Failed to add master device at link %d\n",

			bus->link_id);

		return ret;

	}
@@ -161,6 +168,7 @@ static int sdw_delete_slave(struct device *dev, void *data) 
void sdw_bus_master_delete(struct sdw_bus *bus)

{

	device_for_each_child(bus->dev, NULL, sdw_delete_slave);

	sdw_master_device_del(bus);



	sdw_bus_debugfs_exit(bus);

	ida_free(&sdw_ida, bus->id);

drivers/soundwire/bus.h

+3 −0
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus) 
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);

int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,

			  struct fwnode_handle *fwnode);

int sdw_master_device_del(struct sdw_bus *bus);



#ifdef CONFIG_DEBUG_FS

void sdw_bus_debugfs_init(struct sdw_bus *bus);

drivers/soundwire/intel.c

+0 −1
Original line number Diff line number Diff line
@@ -1099,7 +1099,6 @@ static int intel_probe(struct platform_device *pdev) 
	sdw->cdns.registers = sdw->link_res->registers;

	sdw->cdns.instance = sdw->instance;

	sdw->cdns.msg_count = 0;

	sdw->cdns.bus.dev = &pdev->dev;

	sdw->cdns.bus.link_id = pdev->id;



	sdw_cdns_probe(&sdw->cdns);

drivers/soundwire/master.c

0 → 100644
+81 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

// Copyright(c) 2019-2020 Intel Corporation.



#include <linux/device.h>

#include <linux/acpi.h>

#include <linux/soundwire/sdw.h>

#include <linux/soundwire/sdw_type.h>

#include "bus.h"



static void sdw_master_device_release(struct device *dev)

{

	struct sdw_master_device *md = dev_to_sdw_master_device(dev);



	kfree(md);

}



struct device_type sdw_master_type = {

	.name =		"soundwire_master",

	.release =	sdw_master_device_release,

};



/**

 * sdw_master_device_add() - create a Linux Master Device representation.

 * @bus: SDW bus instance

 * @parent: parent device

 * @fwnode: firmware node handle

 */

int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,

			  struct fwnode_handle *fwnode)

{

	struct sdw_master_device *md;

	int ret;



	if (!parent)

		return -EINVAL;



	md = kzalloc(sizeof(*md), GFP_KERNEL);

	if (!md)

		return -ENOMEM;



	md->dev.bus = &sdw_bus_type;

	md->dev.type = &sdw_master_type;

	md->dev.parent = parent;

	md->dev.of_node = parent->of_node;

	md->dev.fwnode = fwnode;

	md->dev.dma_mask = parent->dma_mask;



	dev_set_name(&md->dev, "sdw-master-%d", bus->id);



	ret = device_register(&md->dev);

	if (ret) {

		dev_err(parent, "Failed to add master: ret %d\n", ret);

		/*

		 * On err, don't free but drop ref as this will be freed

		 * when release method is invoked.

		 */

		put_device(&md->dev);

		goto device_register_err;

	}



	/* add shortcuts to improve code readability/compactness */

	md->bus = bus;

	bus->dev = &md->dev;

	bus->md = md;



device_register_err:

	return ret;

}



/**

 * sdw_master_device_del() - delete a Linux Master Device representation.

 * @bus: bus handle

 *

 * This function is the dual of sdw_master_device_add()

 */

int sdw_master_device_del(struct sdw_bus *bus)

{

	device_unregister(bus->dev);



	return 0;

}

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