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authorSagar Dharia <sdharia@codeaurora.org>2017-12-11 23:42:57 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-19 11:01:02 +0100
commit3648e78ec701843ff8fab461071ba05067274f26 (patch)
tree6ed541fbe39a922cf46fce73479b2cce768261d8 /drivers/slimbus
parent2df7296603399cbad9522ce111ea0c5270153990 (diff)
slimbus: Add SLIMbus bus type
SLIMbus (Serial Low Power Interchip Media Bus) is a specification developed by MIPI (Mobile Industry Processor Interface) alliance. SLIMbus is a 2-wire implementation, which is used to communicate with peripheral components like audio-codec. SLIMbus uses Time-Division-Multiplexing to accommodate multiple data channels, and control channel. Control channel has messages to do device-enumeration, messages to send/receive control-data to/from SLIMbus devices, messages for port/channel management, and messages to do bandwidth allocation. The framework supports multiple instances of the bus (1 controller per bus), and multiple slave devices per controller. This patch adds support to basic silmbus core which includes support to SLIMbus type, slimbus device registeration and some basic data structures. Signed-off-by: Sagar Dharia <sdharia@codeaurora.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviwed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/slimbus')
-rw-r--r--drivers/slimbus/Kconfig17
-rw-r--r--drivers/slimbus/Makefile6
-rw-r--r--drivers/slimbus/core.c108
3 files changed, 131 insertions, 0 deletions
diff --git a/drivers/slimbus/Kconfig b/drivers/slimbus/Kconfig
new file mode 100644
index 000000000000..9b6bb84d66ed
--- /dev/null
+++ b/drivers/slimbus/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# SLIMbus driver configuration
+#
+menuconfig SLIMBUS
+ tristate "SLIMbus support"
+ help
+ SLIMbus is standard interface between System-on-Chip and audio codec,
+ and other peripheral components in typical embedded systems.
+
+ If unsure, choose N.
+
+if SLIMBUS
+
+# SLIMbus controllers
+
+endif
diff --git a/drivers/slimbus/Makefile b/drivers/slimbus/Makefile
new file mode 100644
index 000000000000..506ff17d6346
--- /dev/null
+++ b/drivers/slimbus/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for kernel SLIMbus framework.
+#
+obj-$(CONFIG_SLIMBUS) += slimbus.o
+slimbus-y := core.o
diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c
new file mode 100644
index 000000000000..02f5075a9309
--- /dev/null
+++ b/drivers/slimbus/core.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011-2017, The Linux Foundation
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/slimbus.h>
+
+static const struct slim_device_id *slim_match(const struct slim_device_id *id,
+ const struct slim_device *sbdev)
+{
+ while (id->manf_id != 0 || id->prod_code != 0) {
+ if (id->manf_id == sbdev->e_addr.manf_id &&
+ id->prod_code == sbdev->e_addr.prod_code)
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
+static int slim_device_match(struct device *dev, struct device_driver *drv)
+{
+ struct slim_device *sbdev = to_slim_device(dev);
+ struct slim_driver *sbdrv = to_slim_driver(drv);
+
+ return !!slim_match(sbdrv->id_table, sbdev);
+}
+
+static int slim_device_probe(struct device *dev)
+{
+ struct slim_device *sbdev = to_slim_device(dev);
+ struct slim_driver *sbdrv = to_slim_driver(dev->driver);
+
+ return sbdrv->probe(sbdev);
+}
+
+static int slim_device_remove(struct device *dev)
+{
+ struct slim_device *sbdev = to_slim_device(dev);
+ struct slim_driver *sbdrv;
+
+ if (dev->driver) {
+ sbdrv = to_slim_driver(dev->driver);
+ if (sbdrv->remove)
+ sbdrv->remove(sbdev);
+ }
+
+ return 0;
+}
+
+struct bus_type slimbus_bus = {
+ .name = "slimbus",
+ .match = slim_device_match,
+ .probe = slim_device_probe,
+ .remove = slim_device_remove,
+};
+EXPORT_SYMBOL_GPL(slimbus_bus);
+
+/*
+ * __slim_driver_register() - Client driver registration with SLIMbus
+ *
+ * @drv:Client driver to be associated with client-device.
+ * @owner: owning module/driver
+ *
+ * This API will register the client driver with the SLIMbus
+ * It is called from the driver's module-init function.
+ */
+int __slim_driver_register(struct slim_driver *drv, struct module *owner)
+{
+ /* ID table and probe are mandatory */
+ if (!drv->id_table || !drv->probe)
+ return -EINVAL;
+
+ drv->driver.bus = &slimbus_bus;
+ drv->driver.owner = owner;
+
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__slim_driver_register);
+
+/*
+ * slim_driver_unregister() - Undo effect of slim_driver_register
+ *
+ * @drv: Client driver to be unregistered
+ */
+void slim_driver_unregister(struct slim_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(slim_driver_unregister);
+
+static void __exit slimbus_exit(void)
+{
+ bus_unregister(&slimbus_bus);
+}
+module_exit(slimbus_exit);
+
+static int __init slimbus_init(void)
+{
+ return bus_register(&slimbus_bus);
+}
+postcore_initcall(slimbus_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SLIMbus core");