soundwire: Add Master registration
authorVinod Koul <vinod.koul@intel.com>
Thu, 14 Dec 2017 05:49:34 +0000 (11:19 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 19 Dec 2017 10:14:56 +0000 (11:14 +0100)
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>
drivers/soundwire/Makefile
drivers/soundwire/bus.c [new file with mode: 0644]
drivers/soundwire/bus.h [new file with mode: 0644]
drivers/soundwire/slave.c [new file with mode: 0644]
include/linux/soundwire/sdw.h

index d1281de..c875e43 100644 (file)
@@ -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 (file)
index 0000000..bc72c3d
--- /dev/null
@@ -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);
+
+}
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
new file mode 100644 (file)
index 0000000..a549218
--- /dev/null
@@ -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 (file)
index 0000000..ac103bd
--- /dev/null
@@ -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
index 869d704..3bfa7f1 100644 (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 */