From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
In the existing SoundWire code, Master Devices are not explicitly
represented - only SoundWire Slave Devices are exposed (the use of
capital letters follows the SoundWire specification conventions).
With the existing code, the bus is handled without using a proper device,
and bus->dev typically points to a platform device. The right thing to
do as discussed in multiple reviews is use a device for each bus.
The sdw_master_device addition is done with minimal internal plumbing
and not exposed externally. The existing API based on
sdw_bus_master_add() and sdw_bus_master_delete() will deal with the
sdw_master_device life cycle, which minimizes changes to existing
drivers.
Note that the Intel code will be modified in follow-up patches (no
impact on any platform since the connection with ASoC is not supported
upstream so far).
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/Makefile | 2 +-
drivers/soundwire/bus.c | 14 ++++--
drivers/soundwire/bus.h | 3 ++
drivers/soundwire/intel.c | 1 -
drivers/soundwire/master.c | 81 +++++++++++++++++++++++++++++++++++
drivers/soundwire/qcom.c | 1 -
include/linux/soundwire/sdw.h | 17 +++++++-
7 files changed, 112 insertions(+), 7 deletions(-)
create mode 100644 drivers/soundwire/master.c
diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index e2cdff990e9f..7319918e0aec 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -4,7 +4,7 @@
#
#Bus Objs
-soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
+soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o
obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
ifdef CONFIG_DEBUG_FS
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 2d24f183061d..c31a1c2788a9 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -37,14 +37,21 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
struct sdw_master_prop *prop = NULL;
int ret;
- if (!bus->dev) {
- pr_err("SoundWire bus has no device\n");
+ if (!parent) {
+ pr_err("SoundWire parent device is not set\n");
return -ENODEV;
}
ret = sdw_get_id(bus);
if (ret) {
- dev_err(bus->dev, "Failed to get bus id\n");
+ dev_err(parent, "Failed to get bus id\n");
+ return ret;
+ }
+
+ ret = sdw_master_device_add(bus, parent, fwnode);
+ if (ret) {
+ dev_err(parent, "Failed to add master device at link %d\n",
+ bus->link_id);
return ret;
}
@@ -161,6 +168,7 @@ static int sdw_delete_slave(struct device *dev, void *data)
void sdw_bus_master_delete(struct sdw_bus *bus)
{
device_for_each_child(bus->dev, NULL, sdw_delete_slave);
+ sdw_master_device_del(bus);
sdw_bus_debugfs_exit(bus);
ida_free(&sdw_ida, bus->id);
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
index 204204a26db8..93ab0234a491 100644
--- a/drivers/soundwire/bus.h
+++ b/drivers/soundwire/bus.h
@@ -19,6 +19,9 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus)
int sdw_of_find_slaves(struct sdw_bus *bus);
void sdw_extract_slave_id(struct sdw_bus *bus,
u64 addr, struct sdw_slave_id *id);
+int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
+ struct fwnode_handle *fwnode);
+int sdw_master_device_del(struct sdw_bus *bus);
#ifdef CONFIG_DEBUG_FS
void sdw_bus_debugfs_init(struct sdw_bus *bus);
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 210459390046..3562f2106e30 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1099,7 +1099,6 @@ static int intel_probe(struct platform_device *pdev)
sdw->cdns.registers = sdw->link_res->registers;
sdw->cdns.instance = sdw->instance;
sdw->cdns.msg_count = 0;
- sdw->cdns.bus.dev = &pdev->dev;
sdw->cdns.bus.link_id = pdev->id;
sdw_cdns_probe(&sdw->cdns);
diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c
new file mode 100644
index 000000000000..6be0a027def7
--- /dev/null
+++ b/drivers/soundwire/master.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright(c) 2019-2020 Intel Corporation.
+
+#include <linux/device.h>
+#include <linux/acpi.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include "bus.h"
+
+static void sdw_master_device_release(struct device *dev)
+{
+ struct sdw_master_device *md = dev_to_sdw_master_device(dev);
+
+ kfree(md);
+}
+
+struct device_type sdw_master_type = {
+ .name = "soundwire_master",
+ .release = sdw_master_device_release,
+};
+
+/**
+ * sdw_master_device_add() - create a Linux Master Device representation.
+ * @bus: SDW bus instance
+ * @parent: parent device
+ * @fwnode: firmware node handle
+ */
+int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
+ struct fwnode_handle *fwnode)
+{
+ struct sdw_master_device *md;
+ int ret;
+
+ if (!parent)
+ return -EINVAL;
+
+ md = kzalloc(sizeof(*md), GFP_KERNEL);
+ if (!md)
+ return -ENOMEM;
+
+ md->dev.bus = &sdw_bus_type;
+ md->dev.type = &sdw_master_type;
+ md->dev.parent = parent;
+ md->dev.of_node = parent->of_node;
+ md->dev.fwnode = fwnode;
+ md->dev.dma_mask = parent->dma_mask;
+
+ dev_set_name(&md->dev, "sdw-master-%d", bus->id);
+
+ ret = device_register(&md->dev);
+ if (ret) {
+ dev_err(parent, "Failed to add master: ret %d\n", ret);
+ /*
+ * On err, don't free but drop ref as this will be freed
+ * when release method is invoked.
+ */
+ put_device(&md->dev);
+ goto device_register_err;
+ }
+
+ /* add shortcuts to improve code readability/compactness */
+ md->bus = bus;
+ bus->dev = &md->dev;
+ bus->md = md;
+
+device_register_err:
+ return ret;
+}
+
+/**
+ * sdw_master_device_del() - delete a Linux Master Device representation.
+ * @bus: bus handle
+ *
+ * This function is the dual of sdw_master_device_add()
+ */
+int sdw_master_device_del(struct sdw_bus *bus)
+{
+ device_unregister(bus->dev);
+
+ return 0;
+}
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 401811d6627e..1c335ab1cd3f 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -784,7 +784,6 @@ static int qcom_swrm_probe(struct platform_device *pdev)
mutex_init(&ctrl->port_lock);
INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq);
- ctrl->bus.dev = dev;
ctrl->bus.ops = &qcom_swrm_ops;
ctrl->bus.port_ops = &qcom_swrm_port_ops;
ctrl->bus.compute_params = &qcom_swrm_compute_params;
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index a32cb26f1815..7658d9698dd5 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -632,6 +632,19 @@ struct sdw_slave {
#define dev_to_sdw_dev(_dev) container_of(_dev, struct sdw_slave, dev)
+/**
+ * struct sdw_master_device - SoundWire 'Master Device' representation
+ * @dev: Linux device for this Master
+ * @bus: Bus handle shortcut
+ */
+struct sdw_master_device {
+ struct device dev;
+ struct sdw_bus *bus;
+};
+
+#define dev_to_sdw_master_device(d) \
+ container_of(d, struct sdw_master_device, dev)
+
struct sdw_driver {
const char *name;
@@ -787,7 +800,8 @@ struct sdw_master_ops {
/**
* struct sdw_bus - SoundWire bus
- * @dev: Master linux device
+ * @dev: Shortcut to &bus->md->dev to avoid changing the entire code.
+ * @md: Master device
* @link_id: Link id number, can be 0 to N, unique for each Master
* @id: bus system-wide unique id
* @slaves: list of Slaves on this bus
@@ -813,6 +827,7 @@ struct sdw_master_ops {
*/
struct sdw_bus {
struct device *dev;
+ struct sdw_master_device *md;
unsigned int link_id;
int id;
struct list_head slaves;
--
2.17.1
