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soundwire: Add Master registration 

A Master adds a SoundWire bus instance which scans the firmware
provided for device description.

In this patch we scan ACPI namespaces and create SoundWire
Slave devices based on ACPI description

Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Vinod Koul 2017-12-14 11:19:34 +05:30 committed by Greg Kroah-Hartman
parent 9251345dca
commit 7c3cd189b8
5 changed files with 276 additions and 1 deletions
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2
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

124
drivers/soundwire/bus.c 100644
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@ -0,0 +1,124 @@
// 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);
}

19
drivers/soundwire/bus.h 100644
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@ -0,0 +1,19 @@
// 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 */

114
drivers/soundwire/slave.c 100644
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@ -0,0 +1,114 @@
// 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

18
include/linux/soundwire/sdw.h
View File

@ -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 */