soundwire: Add Master registration (7c3cd189) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/soundwire/Makefile

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		@@ -3,5 +3,5 @@
		#

		#Bus Objs
		soundwire-bus-objs := bus_type.o
		soundwire-bus-objs := bus_type.o bus.o slave.o
		obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o

drivers/soundwire/bus.c

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		// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
		// Copyright(c) 2015-17 Intel Corporation.

		#include <linux/acpi.h>
		#include <linux/mod_devicetable.h>
		#include <linux/soundwire/sdw.h>
		#include "bus.h"

		/**
		* sdw_add_bus_master() - add a bus Master instance
		* @bus: bus instance
		*
		* Initializes the bus instance, read properties and create child
		* devices.
		*/
		int sdw_add_bus_master(struct sdw_bus *bus)
		{
		int ret;

		if (!bus->dev) {
		pr_err("SoundWire bus has no device");
		return -ENODEV;
		}

		mutex_init(&bus->bus_lock);
		INIT_LIST_HEAD(&bus->slaves);

		/*
		* Device numbers in SoundWire are 0 thru 15. Enumeration device
		* number (0), Broadcast device number (15), Group numbers (12 and
		* 13) and Master device number (14) are not used for assignment so
		* mask these and other higher bits.
		*/

		/* Set higher order bits */
		*bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);

		/* Set enumuration device number and broadcast device number */
		set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
		set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);

		/* Set group device numbers and master device number */
		set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
		set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
		set_bit(SDW_MASTER_DEV_NUM, bus->assigned);

		/*
		* SDW is an enumerable bus, but devices can be powered off. So,
		* they won't be able to report as present.
		*
		* Create Slave devices based on Slaves described in
		* the respective firmware (ACPI/DT)
		*/
		if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
		ret = sdw_acpi_find_slaves(bus);
		else
		ret = -ENOTSUPP; /* No ACPI/DT so error out */

		if (ret) {
		dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
		return ret;
		}

		return 0;
		}
		EXPORT_SYMBOL(sdw_add_bus_master);

		static int sdw_delete_slave(struct device dev, void data)
		{
		struct sdw_slave *slave = dev_to_sdw_dev(dev);
		struct sdw_bus *bus = slave->bus;

		mutex_lock(&bus->bus_lock);

		if (slave->dev_num) /* clear dev_num if assigned */
		clear_bit(slave->dev_num, bus->assigned);

		list_del_init(&slave->node);
		mutex_unlock(&bus->bus_lock);

		device_unregister(dev);
		return 0;
		}

		/**
		* sdw_delete_bus_master() - delete the bus master instance
		* @bus: bus to be deleted
		*
		* Remove the instance, delete the child devices.
		*/
		void sdw_delete_bus_master(struct sdw_bus *bus)
		{
		device_for_each_child(bus->dev, NULL, sdw_delete_slave);
		}
		EXPORT_SYMBOL(sdw_delete_bus_master);

		void sdw_extract_slave_id(struct sdw_bus *bus,
		u64 addr, struct sdw_slave_id *id)
		{
		dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr);

		/*
		* Spec definition
		* Register Bit Contents
		* DevId_0 [7:4] 47:44 sdw_version
		* DevId_0 [3:0] 43:40 unique_id
		* DevId_1 39:32 mfg_id [15:8]
		* DevId_2 31:24 mfg_id [7:0]
		* DevId_3 23:16 part_id [15:8]
		* DevId_4 15:08 part_id [7:0]
		* DevId_5 07:00 class_id
		*/
		id->sdw_version = (addr >> 44) & GENMASK(3, 0);
		id->unique_id = (addr >> 40) & GENMASK(3, 0);
		id->mfg_id = (addr >> 24) & GENMASK(15, 0);
		id->part_id = (addr >> 8) & GENMASK(15, 0);
		id->class_id = addr & GENMASK(7, 0);

		dev_dbg(bus->dev,
		"SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x",
		id->class_id, id->part_id, id->mfg_id,
		id->unique_id, id->sdw_version);

		}

drivers/soundwire/bus.h

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		// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
		// Copyright(c) 2015-17 Intel Corporation.

		#ifndef __SDW_BUS_H
		#define __SDW_BUS_H

		#if IS_ENABLED(CONFIG_ACPI)
		int sdw_acpi_find_slaves(struct sdw_bus *bus);
		#else
		static inline int sdw_acpi_find_slaves(struct sdw_bus *bus)
		{
		return -ENOTSUPP;
		}
		#endif

		void sdw_extract_slave_id(struct sdw_bus *bus,
		u64 addr, struct sdw_slave_id *id);

		#endif /* __SDW_BUS_H */

drivers/soundwire/slave.c

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		// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
		// Copyright(c) 2015-17 Intel Corporation.

		#include <linux/acpi.h>
		#include <linux/soundwire/sdw.h>
		#include <linux/soundwire/sdw_type.h>
		#include "bus.h"

		static void sdw_slave_release(struct device *dev)
		{
		struct sdw_slave *slave = dev_to_sdw_dev(dev);

		kfree(slave);
		}

		static int sdw_slave_add(struct sdw_bus *bus,
		struct sdw_slave_id id, struct fwnode_handle fwnode)
		{
		struct sdw_slave *slave;
		int ret;

		slave = kzalloc(sizeof(*slave), GFP_KERNEL);
		if (!slave)
		return -ENOMEM;

		/* Initialize data structure */
		memcpy(&slave->id, id, sizeof(*id));
		slave->dev.parent = bus->dev;
		slave->dev.fwnode = fwnode;

		/* name shall be sdw:link:mfg:part:class:unique */
		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
		bus->link_id, id->mfg_id, id->part_id,
		id->class_id, id->unique_id);

		slave->dev.release = sdw_slave_release;
		slave->dev.bus = &sdw_bus_type;
		slave->bus = bus;
		slave->status = SDW_SLAVE_UNATTACHED;
		slave->dev_num = 0;

		mutex_lock(&bus->bus_lock);
		list_add_tail(&slave->node, &bus->slaves);
		mutex_unlock(&bus->bus_lock);

		ret = device_register(&slave->dev);
		if (ret) {
		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);

		/*
		* On err, don't free but drop ref as this will be freed
		* when release method is invoked.
		*/
		mutex_lock(&bus->bus_lock);
		list_del(&slave->node);
		mutex_unlock(&bus->bus_lock);
		put_device(&slave->dev);
		}

		return ret;
		}

		#if IS_ENABLED(CONFIG_ACPI)
		/*
		* sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
		* @bus: SDW bus instance
		*
		* Scans Master ACPI node for SDW child Slave devices and registers it.
		*/
		int sdw_acpi_find_slaves(struct sdw_bus *bus)
		{
		struct acpi_device adev, parent;

		parent = ACPI_COMPANION(bus->dev);
		if (!parent) {
		dev_err(bus->dev, "Can't find parent for acpi bind\n");
		return -ENODEV;
		}

		list_for_each_entry(adev, &parent->children, node) {
		unsigned long long addr;
		struct sdw_slave_id id;
		unsigned int link_id;
		acpi_status status;

		status = acpi_evaluate_integer(adev->handle,
		METHOD_NAME__ADR, NULL, &addr);

		if (ACPI_FAILURE(status)) {
		dev_err(bus->dev, "_ADR resolution failed: %x\n",
		status);
		return status;
		}

		/* Extract link id from ADR, Bit 51 to 48 (included) */
		link_id = (addr >> 48) & GENMASK(3, 0);

		/* Check for link_id match */
		if (link_id != bus->link_id)
		continue;

		sdw_extract_slave_id(bus, addr, &id);

		/*
		* don't error check for sdw_slave_add as we want to continue
		* adding Slaves
		*/
		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
		}

		return 0;
		}

		#endif

include/linux/soundwire/sdw.h

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		@@ -7,6 +7,21 @@
		struct sdw_bus;
		struct sdw_slave;

		/* SDW spec defines and enums, as defined by MIPI 1.1. Spec */

		/* SDW Broadcast Device Number */
		#define SDW_BROADCAST_DEV_NUM 15

		/* SDW Enumeration Device Number */
		#define SDW_ENUM_DEV_NUM 0

		/* SDW Group Device Numbers */
		#define SDW_GROUP12_DEV_NUM 12
		#define SDW_GROUP13_DEV_NUM 13

		/* SDW Master Device Number, not supported yet */
		#define SDW_MASTER_DEV_NUM 14

		#define SDW_MAX_DEVICES 11

		/**
		@@ -105,4 +120,7 @@ struct sdw_bus {
		struct mutex bus_lock;
		};

		int sdw_add_bus_master(struct sdw_bus *bus);
		void sdw_delete_bus_master(struct sdw_bus *bus);

		#endif /* __SOUNDWIRE_H */