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Subject[PATCH v5 03/15] soundwire: Add Master registration
Date
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>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---
drivers/soundwire/Makefile | 2 +-
drivers/soundwire/bus.c | 123 ++++++++++++++++++++++++++++++++++++++++++
drivers/soundwire/bus.h | 19 +++++++
drivers/soundwire/slave.c | 114 +++++++++++++++++++++++++++++++++++++++
include/linux/soundwire/sdw.h | 18 +++++++
5 files changed, 275 insertions(+), 1 deletion(-)
create mode 100644 drivers/soundwire/bus.c
create mode 100644 drivers/soundwire/bus.h
create mode 100644 drivers/soundwire/slave.c

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index d1281def7662..c875e434f8b3 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -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
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
new file mode 100644
index 000000000000..ae2f9e673871
--- /dev/null
+++ b/drivers/soundwire/bus.c
@@ -0,0 +1,123 @@
+// 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 | 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);
+
+}
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
new file mode 100644
index 000000000000..a54921825ce0
--- /dev/null
+++ b/drivers/soundwire/bus.h
@@ -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 */
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
new file mode 100644
index 000000000000..2b88396bec66
--- /dev/null
+++ b/drivers/soundwire/slave.c
@@ -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, it is from 51 to bits */
+ 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
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index 4a7503781602..39dddfd1857c 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -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

/**
@@ -108,4 +123,7 @@ 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 */
--
2.7.4
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