9 files changed, 385 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-mei b/Documentation/ABI/testing/sysfs-bus-mei
new file mode 100644
index 000000000000..2066f0bbd453
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-mei
@@ -0,0 +1,7 @@
+What:		/sys/bus/mei/devices/.../modalias
+Date:		March 2013
+KernelVersion:	3.10
+Contact:	Samuel Ortiz <sameo@linux.intel.com>
+		linux-mei@linux.intel.com
+Description:	Stores the same MODALIAS value emitted by uevent
+		Format: mei:<mei device name>
diff --git a/Documentation/misc-devices/mei/mei-client-bus.txt b/Documentation/misc-devices/mei/mei-client-bus.txt
new file mode 100644
index 000000000000..9dc5ebf94eb1
--- /dev/null
+++ b/Documentation/misc-devices/mei/mei-client-bus.txt
@@ -0,0 +1,135 @@
+Intel(R) Management Engine (ME) Client bus API
+===============================================
+
+
+Rationale
+=========
+MEI misc character device is useful for dedicated applications to send and receive
+data to the many FW appliance found in Intel's ME from the user space.
+However for some of the ME functionalities it make sense to leverage existing software
+stack and expose them through existing kernel subsystems.
+
+In order to plug seamlessly into the kernel device driver model we add kernel virtual
+bus abstraction on top of the MEI driver. This allows implementing linux kernel drivers
+for the various MEI features as a stand alone entities found in their respective subsystem.
+Existing device drivers can even potentially be re-used by adding an MEI CL bus layer to
+the existing code.
+
+
+MEI CL bus API
+===========
+A driver implementation for an MEI Client is very similar to existing bus
+based device drivers. The driver registers itself as an MEI CL bus driver through
+the mei_cl_driver structure:
+
+struct mei_cl_driver {
+	struct device_driver driver;
+	const char *name;
+
+	const struct mei_cl_device_id *id_table;
+
+	int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id);
+	int (*remove)(struct mei_cl_device *dev);
+};
+
+struct mei_cl_id {
+	char name[MEI_NAME_SIZE];
+	kernel_ulong_t driver_info;
+};
+
+The mei_cl_id structure allows the driver to bind itself against a device name.
+
+To actually register a driver on the ME Client bus one must call the mei_cl_add_driver()
+API. This is typically called at module init time.
+
+Once registered on the ME Client bus, a driver will typically try to do some I/O on
+this bus and this should be done through the mei_cl_send() and mei_cl_recv()
+routines. The latter is synchronous (blocks and sleeps until data shows up).
+In order for drivers to be notified of pending events waiting for them (e.g.
+an Rx event) they can register an event handler through the
+mei_cl_register_event_cb() routine. Currently only the MEI_EVENT_RX event
+will trigger an event handler call and the driver implementation is supposed
+to call mei_recv() from the event handler in order to fetch the pending
+received buffers.
+
+
+Example
+=======
+As a theoretical example let's pretend the ME comes with a "contact" NFC IP.
+The driver init and exit routines for this device would look like:
+
+#define CONTACT_DRIVER_NAME "contact"
+
+static struct mei_cl_device_id contact_mei_cl_tbl[] = {
+	{ CONTACT_DRIVER_NAME, },
+
+	/* required last entry */
+	{ }
+};
+MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl);
+
+static struct mei_cl_driver contact_driver = {
+       .id_table = contact_mei_tbl,
+       .name = CONTACT_DRIVER_NAME,
+
+       .probe = contact_probe,
+       .remove = contact_remove,
+};
+
+static int contact_init(void)
+{
+	int r;
+
+	r = mei_cl_driver_register(&contact_driver);
+	if (r) {
+		pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n");
+		return r;
+	}
+
+	return 0;
+}
+
+static void __exit contact_exit(void)
+{
+	mei_cl_driver_unregister(&contact_driver);
+}
+
+module_init(contact_init);
+module_exit(contact_exit);
+
+And the driver's simplified probe routine would look like that:
+
+int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id)
+{
+	struct contact_driver *contact;
+
+	[...]
+	mei_cl_register_event_cb(dev, contact_event_cb, contact);
+
+	return 0;
+ }
+
+In the probe routine the driver basically registers an ME bus event handler
+which is as close as it can get to registering a threaded IRQ handler.
+The handler implementation will typically call some I/O routine depending on
+the pending events:
+
+#define MAX_NFC_PAYLOAD 128
+
+static void contact_event_cb(struct mei_cl_device *dev, u32 events,
+			     void *context)
+{
+	struct contact_driver *contact = context;
+
+	if (events & BIT(MEI_EVENT_RX)) {
+		u8 payload[MAX_NFC_PAYLOAD];
+		int payload_size;
+
+		payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD);
+		if (payload_size <= 0)
+			return;
+
+		/* Hook to the NFC subsystem */
+		nfc_hci_recv_frame(contact->hdev, payload, payload_size);
+	}
+}
diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile
index 2c336d087749..1b29f7ccac49 100644
--- a/drivers/misc/mei/Makefile
+++ b/drivers/misc/mei/Makefile
@@ -10,6 +10,7 @@ mei-objs += client.o
 mei-objs += main.o
 mei-objs += amthif.o
 mei-objs += wd.o
+mei-objs += bus.o
 
 obj-$(CONFIG_INTEL_MEI_ME) += mei-me.o
 mei-me-objs := pci-me.o
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
new file mode 100644
index 000000000000..78c876af2676
--- /dev/null
+++ b/drivers/misc/mei/bus.c
@@ -0,0 +1,172 @@
+/*
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2012-2013, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/mei_cl_bus.h>
+
+#include "mei_dev.h"
+
+#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
+#define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
+
+static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
+{
+	struct mei_cl_device *device = to_mei_cl_device(dev);
+	struct mei_cl_driver *driver = to_mei_cl_driver(drv);
+	const struct mei_cl_device_id *id;
+
+	if (!device)
+		return 0;
+
+	if (!driver || !driver->id_table)
+		return 0;
+
+	id = driver->id_table;
+
+	while (id->name[0]) {
+		if (!strcmp(dev_name(dev), id->name))
+			return 1;
+
+		id++;
+	}
+
+	return 0;
+}
+
+static int mei_cl_device_probe(struct device *dev)
+{
+	struct mei_cl_device *device = to_mei_cl_device(dev);
+	struct mei_cl_driver *driver;
+	struct mei_cl_device_id id;
+
+	if (!device)
+		return 0;
+
+	driver = to_mei_cl_driver(dev->driver);
+	if (!driver || !driver->probe)
+		return -ENODEV;
+
+	dev_dbg(dev, "Device probe\n");
+
+	strncpy(id.name, dev_name(dev), MEI_CL_NAME_SIZE);
+
+	return driver->probe(device, &id);
+}
+
+static int mei_cl_device_remove(struct device *dev)
+{
+	struct mei_cl_device *device = to_mei_cl_device(dev);
+	struct mei_cl_driver *driver;
+
+	if (!device || !dev->driver)
+		return 0;
+
+	driver = to_mei_cl_driver(dev->driver);
+	if (!driver->remove) {
+		dev->driver = NULL;
+
+		return 0;
+	}
+
+	return driver->remove(device);
+}
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "mei:%s\n", dev_name(dev));
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+
+static struct device_attribute mei_cl_dev_attrs[] = {
+	__ATTR_RO(modalias),
+	__ATTR_NULL,
+};
+
+static int mei_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	if (add_uevent_var(env, "MODALIAS=mei:%s", dev_name(dev)))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static struct bus_type mei_cl_bus_type = {
+	.name		= "mei",
+	.dev_attrs	= mei_cl_dev_attrs,
+	.match		= mei_cl_device_match,
+	.probe		= mei_cl_device_probe,
+	.remove		= mei_cl_device_remove,
+	.uevent		= mei_cl_uevent,
+};
+
+static void mei_cl_dev_release(struct device *dev)
+{
+	kfree(to_mei_cl_device(dev));
+}
+
+static struct device_type mei_cl_device_type = {
+	.release	= mei_cl_dev_release,
+};
+
+struct mei_cl_device *mei_cl_add_device(struct mei_device *mei_device,
+				  uuid_le uuid, char *name)
+{
+	struct mei_cl_device *device;
+	int status;
+
+	device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
+	if (!device)
+		return NULL;
+
+	device->dev.parent = &mei_device->pdev->dev;
+	device->dev.bus = &mei_cl_bus_type;
+	device->dev.type = &mei_cl_device_type;
+
+	dev_set_name(&device->dev, "%s", name);
+
+	status = device_register(&device->dev);
+	if (status)
+		goto out_err;
+
+	dev_dbg(&device->dev, "client %s registered\n", name);
+
+	return device;
+
+out_err:
+	dev_err(device->dev.parent, "Failed to register MEI client\n");
+
+	kfree(device);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(mei_cl_add_device);
+
+void mei_cl_remove_device(struct mei_cl_device *device)
+{
+	device_unregister(&device->dev);
+}
+EXPORT_SYMBOL_GPL(mei_cl_remove_device);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index b5d66076de3d..7abb705ddf3f 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -21,6 +21,7 @@
 #include <linux/watchdog.h>
 #include <linux/poll.h>
 #include <linux/mei.h>
+#include <linux/mei_cl_bus.h>
 
 #include "hw.h"
 #include "hw-me-regs.h"
@@ -262,6 +263,31 @@ struct mei_hw_ops {
 		     unsigned char *buf, unsigned long len);
 };
 
+/* MEI bus API*/
+struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
+				  uuid_le uuid, char *name);
+void mei_cl_remove_device(struct mei_cl_device *device);
+
+/**
+ * struct mei_cl_device - MEI device handle
+ * An mei_cl_device pointer is returned from mei_add_device()
+ * and links MEI bus clients to their actual ME host client pointer.
+ * Drivers for MEI devices will get an mei_cl_device pointer
+ * when being probed and shall use it for doing ME bus I/O.
+ *
+ * @dev: linux driver model device pointer
+ * @uuid: me client uuid
+ * @cl: mei client
+ * @priv_data: client private data
+ */
+struct mei_cl_device {
+	struct device dev;
+
+	struct mei_cl *cl;
+
+	void *priv_data;
+};
+
 /**
  * struct mei_device -  MEI private device struct
 
diff --git a/include/linux/mei_cl_bus.h b/include/linux/mei_cl_bus.h
new file mode 100644
index 000000000000..4e7351de7eca
--- /dev/null
+++ b/include/linux/mei_cl_bus.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_MEI_CL_BUS_H
+#define _LINUX_MEI_CL_BUS_H
+
+#include <linux/device.h>
+#include <linux/uuid.h>
+
+struct mei_cl_device;
+
+struct mei_cl_driver {
+	struct device_driver driver;
+	const char *name;
+
+	const struct mei_cl_device_id *id_table;
+
+	int (*probe)(struct mei_cl_device *dev,
+		     const struct mei_cl_device_id *id);
+	int (*remove)(struct mei_cl_device *dev);
+};
+
+#endif /* _LINUX_MEI_CL_BUS_H */
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 779cf7c4a3d1..b508016fb76d 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -9,6 +9,7 @@
 
 #ifdef __KERNEL__
 #include <linux/types.h>
+#include <linux/uuid.h>
 typedef unsigned long kernel_ulong_t;
 #endif
 
@@ -568,4 +569,12 @@ struct ipack_device_id {
 	__u32 device;			/* Device ID or IPACK_ANY_ID */
 };
 
+#define MEI_CL_MODULE_PREFIX "mei:"
+#define MEI_CL_NAME_SIZE 32
+
+struct mei_cl_device_id {
+	char name[MEI_CL_NAME_SIZE];
+	kernel_ulong_t driver_info;
+};
+
 #endif /* LINUX_MOD_DEVICETABLE_H */
diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index b45260bfeaa0..e66d4d258e1a 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -174,5 +174,8 @@ int main(void)
 	DEVID_FIELD(x86_cpu_id, model);
 	DEVID_FIELD(x86_cpu_id, vendor);
 
+	DEVID(mei_cl_device_id);
+	DEVID_FIELD(mei_cl_device_id, name);
+
 	return 0;
 }
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 771ac17f635d..45f9a3377dcd 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1133,6 +1133,18 @@ static int do_x86cpu_entry(const char *filename, void *symval,
 }
 ADD_TO_DEVTABLE("x86cpu", x86_cpu_id, do_x86cpu_entry);
 
+/* Looks like: mei:S */
+static int do_mei_entry(const char *filename, void *symval,
+			char *alias)
+{
+	DEF_FIELD_ADDR(symval, mei_cl_device_id, name);
+
+	sprintf(alias, MEI_CL_MODULE_PREFIX "%s", *name);
+
+	return 1;
+}
+ADD_TO_DEVTABLE("mei", mei_cl_device_id, do_mei_entry);
+
 /* Does namelen bytes of name exactly match the symbol? */
 static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 {