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56d4fe31af
MIPI Discovery And Configuration (DisCo) Specification for SoundWire
specifies properties to be implemented for SoundWire Masters and
Slaves. The DisCo spec doesn't mandate these properties. However,
SDW bus cannot work without knowing these values.
The helper functions read the Master and Slave properties.
Implementers of Master or Slave drivers can use any of the below
three mechanisms:
a) Use these APIs here as .read_prop() callback for Master
and Slave
b) Implement own methods and set those as .read_prop(), but invoke
APIs in this file for generic read and override the values with
platform specific data
c) Implement ones own methods which do not use anything provided
here
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>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
133 lines
3.4 KiB
C
133 lines
3.4 KiB
C
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
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// Copyright(c) 2015-17 Intel Corporation.
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#include <linux/acpi.h>
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#include <linux/mod_devicetable.h>
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#include <linux/soundwire/sdw.h>
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#include "bus.h"
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/**
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* sdw_add_bus_master() - add a bus Master instance
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* @bus: bus instance
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*
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* Initializes the bus instance, read properties and create child
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* devices.
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*/
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int sdw_add_bus_master(struct sdw_bus *bus)
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{
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int ret;
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if (!bus->dev) {
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pr_err("SoundWire bus has no device");
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return -ENODEV;
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}
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mutex_init(&bus->bus_lock);
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INIT_LIST_HEAD(&bus->slaves);
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if (bus->ops->read_prop) {
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ret = bus->ops->read_prop(bus);
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if (ret < 0) {
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dev_err(bus->dev, "Bus read properties failed:%d", ret);
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return ret;
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}
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}
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/*
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* Device numbers in SoundWire are 0 thru 15. Enumeration device
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* number (0), Broadcast device number (15), Group numbers (12 and
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* 13) and Master device number (14) are not used for assignment so
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* mask these and other higher bits.
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*/
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/* Set higher order bits */
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*bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
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/* Set enumuration device number and broadcast device number */
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set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
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set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
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/* Set group device numbers and master device number */
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set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
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set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
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set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
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/*
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* SDW is an enumerable bus, but devices can be powered off. So,
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* they won't be able to report as present.
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*
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* Create Slave devices based on Slaves described in
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* the respective firmware (ACPI/DT)
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*/
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if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
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ret = sdw_acpi_find_slaves(bus);
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else
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ret = -ENOTSUPP; /* No ACPI/DT so error out */
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if (ret) {
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dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL(sdw_add_bus_master);
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static int sdw_delete_slave(struct device *dev, void *data)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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struct sdw_bus *bus = slave->bus;
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mutex_lock(&bus->bus_lock);
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if (slave->dev_num) /* clear dev_num if assigned */
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clear_bit(slave->dev_num, bus->assigned);
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list_del_init(&slave->node);
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mutex_unlock(&bus->bus_lock);
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device_unregister(dev);
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return 0;
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}
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/**
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* sdw_delete_bus_master() - delete the bus master instance
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* @bus: bus to be deleted
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*
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* Remove the instance, delete the child devices.
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*/
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void sdw_delete_bus_master(struct sdw_bus *bus)
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{
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device_for_each_child(bus->dev, NULL, sdw_delete_slave);
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}
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EXPORT_SYMBOL(sdw_delete_bus_master);
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void sdw_extract_slave_id(struct sdw_bus *bus,
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u64 addr, struct sdw_slave_id *id)
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{
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dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr);
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/*
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* Spec definition
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* Register Bit Contents
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* DevId_0 [7:4] 47:44 sdw_version
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* DevId_0 [3:0] 43:40 unique_id
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* DevId_1 39:32 mfg_id [15:8]
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* DevId_2 31:24 mfg_id [7:0]
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* DevId_3 23:16 part_id [15:8]
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* DevId_4 15:08 part_id [7:0]
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* DevId_5 07:00 class_id
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*/
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id->sdw_version = (addr >> 44) & GENMASK(3, 0);
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id->unique_id = (addr >> 40) & GENMASK(3, 0);
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id->mfg_id = (addr >> 24) & GENMASK(15, 0);
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id->part_id = (addr >> 8) & GENMASK(15, 0);
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id->class_id = addr & GENMASK(7, 0);
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dev_dbg(bus->dev,
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"SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x",
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id->class_id, id->part_id, id->mfg_id,
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id->unique_id, id->sdw_version);
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}
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