[RFC PATCH 7/9] soundwire: add initial definitions for sdw_master_device

From: Pierre-Louis Bossart
Date: Mon Sep 16 2019 - 17:24:14 EST


Since we want an explicit support for the SoundWire Master device, add
the definitions, following the Grey Bus example.

Open: do we need to set a variable when dealing with the master uevent?

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
drivers/soundwire/Makefile | 2 +-
drivers/soundwire/bus_type.c | 16 +++---
drivers/soundwire/master.c | 78 ++++++++++++++++++++++++++++++
include/linux/soundwire/sdw.h | 35 ++++++++++++++
include/linux/soundwire/sdw_type.h | 9 ++++
5 files changed, 133 insertions(+), 7 deletions(-)
create mode 100644 drivers/soundwire/master.c

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index 563894e5ecaf..89b29819dd3a 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_type.c b/drivers/soundwire/bus_type.c
index 5df095f4e12f..cf33f63773f0 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -49,21 +49,25 @@ int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)

static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
{
+ struct sdw_master_device *md;
struct sdw_slave *slave;
char modalias[32];

- if (is_sdw_slave(dev)) {
+ if (is_sdw_md(dev)) {
+ md = to_sdw_master_device(dev);
+ /* TODO: do we need to call add_uevent_var() ? */
+ } else if (is_sdw_slave(dev)) {
slave = to_sdw_slave_device(dev);
+
+ sdw_slave_modalias(slave, modalias, sizeof(modalias));
+
+ if (add_uevent_var(env, "MODALIAS=%s", modalias))
+ return -ENOMEM;
} else {
dev_warn(dev, "uevent for unknown Soundwire type\n");
return -EINVAL;
}

- sdw_slave_modalias(slave, modalias, sizeof(modalias));
-
- if (add_uevent_var(env, "MODALIAS=%s", modalias))
- return -ENOMEM;
-
return 0;
}

diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c
new file mode 100644
index 000000000000..d9d09759b9c3
--- /dev/null
+++ b/drivers/soundwire/master.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2019 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 ssize_t bus_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sdw_master_device *md = to_sdw_master_device(dev);
+
+ return sprintf(buf, "%d\n", md->link_id);
+}
+static DEVICE_ATTR_RO(bus_id);
+
+static struct attribute *bus_attrs[] = {
+ &dev_attr_bus_id.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(bus);
+
+static void sdw_md_release(struct device *dev)
+{
+ struct sdw_master_device *md = to_sdw_master_device(dev);
+
+ kfree(md);
+}
+
+struct device_type sdw_md_type = {
+ .name = "soundwire_master",
+ .release = sdw_md_release,
+};
+
+struct sdw_master_device *sdw_md_add(struct sdw_md_driver *driver,
+ struct device *parent,
+ struct fwnode_handle *fwnode,
+ int link_id)
+{
+ struct sdw_master_device *md;
+ int ret;
+
+ if (!driver->probe) {
+ dev_err(parent, "mandatory probe callback missing\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ md = kzalloc(sizeof(*md), GFP_KERNEL);
+ if (!md)
+ return ERR_PTR(-ENOMEM);
+
+ md->link_id = link_id;
+
+ md->driver = driver;
+
+ md->dev.parent = parent;
+ md->dev.fwnode = fwnode;
+ md->dev.bus = &sdw_bus_type;
+ md->dev.type = &sdw_md_type;
+ md->dev.groups = bus_groups;
+ md->dev.dma_mask = md->dev.parent->dma_mask;
+ dev_set_name(&md->dev, "sdw-master-%d", md->link_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);
+ }
+
+ return md;
+}
+EXPORT_SYMBOL(sdw_md_add);
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index f004de91ce24..6289924b0336 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -564,6 +564,16 @@ struct sdw_slave {
#define to_sdw_slave_device(d) \
container_of(d, struct sdw_slave, dev)

+struct sdw_master_device {
+ struct device dev;
+ int link_id;
+ struct sdw_md_driver *driver;
+ void *pdata; /* core does not touch */
+};
+
+#define to_sdw_master_device(d) \
+ container_of(d, struct sdw_master_device, dev)
+
struct sdw_driver {
const char *name;

@@ -578,6 +588,26 @@ struct sdw_driver {
struct device_driver driver;
};

+struct sdw_md_driver {
+ /* initializations and allocations */
+ int (*probe)(struct sdw_master_device *md, void *link_ctx);
+ /* hardware enablement, all clock/power dependencies are available */
+ int (*startup)(struct sdw_master_device *md);
+ /* hardware disabled */
+ int (*shutdown)(struct sdw_master_device *md);
+ /* free all resources */
+ int (*remove)(struct sdw_master_device *md);
+ /*
+ * enable/disable driver control while in clock-stop mode,
+ * typically in always-on/D0ix modes. When the driver yields
+ * control, another entity in the system (typically firmware
+ * running on an always-on microprocessor) is responsible to
+ * tracking Slave-initiated wakes
+ */
+ int (*autonomous_clock_stop_enable)(struct sdw_master_device *md,
+ bool state);
+};
+
#define SDW_SLAVE_ENTRY(_mfg_id, _part_id, _drv_data) \
{ .mfg_id = (_mfg_id), .part_id = (_part_id), \
.driver_data = (unsigned long)(_drv_data) }
@@ -767,6 +797,11 @@ struct sdw_bus {
int sdw_add_bus_master(struct sdw_bus *bus);
void sdw_delete_bus_master(struct sdw_bus *bus);

+struct sdw_master_device *sdw_md_add(struct sdw_md_driver *driver,
+ struct device *parent,
+ struct fwnode_handle *fwnode,
+ int link_id);
+
/**
* sdw_port_config: Master or Slave Port configuration
*
diff --git a/include/linux/soundwire/sdw_type.h b/include/linux/soundwire/sdw_type.h
index c681b3426478..463d6d018d56 100644
--- a/include/linux/soundwire/sdw_type.h
+++ b/include/linux/soundwire/sdw_type.h
@@ -6,15 +6,24 @@

extern struct bus_type sdw_bus_type;
extern struct device_type sdw_slave_type;
+extern struct device_type sdw_md_type;

static inline int is_sdw_slave(const struct device *dev)
{
return dev->type == &sdw_slave_type;
}

+static inline int is_sdw_md(const struct device *dev)
+{
+ return dev->type == &sdw_md_type;
+}
+
#define to_sdw_slave_driver(_drv) \
container_of(_drv, struct sdw_driver, driver)

+#define to_sdw_md_driver(_drv) \
+ container_of(_drv, struct sdw_md_driver, driver)
+
#define sdw_register_slave_driver(drv) \
__sdw_register_slave_driver(drv, THIS_MODULE)

--
2.20.1