[Intel-gfx] [PATCH v8 18/35] misc/mei/hdcp: Client driver for HDCP application

[Ramalingam C]

ME FW is contributes a vital role in HDCP2.2 authentication.
HDCP2.2 driver needs to communicate to ME FW for each step of the
HDCP2.2 authentication.

ME FW prepare and HDCP2.2 authentication  parameters and encrypt them
as per spec. With such parameter Driver prepares HDCP2.2 auth messages
and communicate with HDCP2.2 sink.

Similarly HDCP2. sink's response is shared with ME FW for decrypt and
verification.

Once All the steps of HDCP2.2 authentications are complete on driver's
request ME FW will configure the port as authenticated and supply the
HDCP keys to the Gen HW for encryption.

Only after this stage HDCP2.2 driver can start the HDCP2.2 encryption
for a port.

ME FW is interfaced to kernel through MEI Bus Driver. To obtain the
HDCP2.2 services from the ME FW through MEI Bus driver MEI Client
Driver is developed.

With this change MEI_HDCP drivers selected by I915 by default.
In case if we want to exclude the mei_hdcp compilation, we need to
introduce a new config called HDCP2.2. Using such CONFIG var we could
control the compilation of the HDCP2.2 code in I915 and also the
compilation of the MEI_HDCP.

v2:
  hdcp files are moved to drivers/misc/mei/hdcp/ [Tomas]
v3:
  Squashed the Kbuild support [Tomas]
  UUID renamed and Module License is modified [Tomas]
  drv_data is set to null at remove [Tomas]
v4:
  Module name is changed to "MEI HDCP"
  I915 Selects the MEI_HDCP
v5:
  No changes.
v6:
  No changes.
v7:
  Remove redundant text from the License header
  Fix malformed licence
  Removed the drv_data resetting.
v8:
  No changes.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler at intel.com>
---
 drivers/misc/mei/Kconfig         |  7 ++++++
 drivers/misc/mei/Makefile        |  2 ++
 drivers/misc/mei/hdcp/Makefile   |  7 ++++++
 drivers/misc/mei/hdcp/mei_hdcp.c | 54 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 70 insertions(+)
 create mode 100644 drivers/misc/mei/hdcp/Makefile
 create mode 100644 drivers/misc/mei/hdcp/mei_hdcp.c

diff --git a/drivers/misc/mei/Kconfig b/drivers/misc/mei/Kconfig
index c49e1d2269af..9c518b7f0011 100644
--- a/drivers/misc/mei/Kconfig
+++ b/drivers/misc/mei/Kconfig
@@ -43,3 +43,10 @@ config INTEL_MEI_TXE
 
 	  Supported SoCs:
 	  Intel Bay Trail
+
+config INTEL_MEI_HDCP
+	tristate "Intel HDCP2.2 services of ME Interface"
+	select INTEL_MEI_ME
+	depends on DRM_I915
+	help
+	  MEI Support for HDCP2.2 Services on Intel SoCs.
diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile
index cd6825afa8e1..e64d1212fb85 100644
--- a/drivers/misc/mei/Makefile
+++ b/drivers/misc/mei/Makefile
@@ -23,3 +23,5 @@ mei-txe-objs += hw-txe.o
 
 mei-$(CONFIG_EVENT_TRACING) += mei-trace.o
 CFLAGS_mei-trace.o = -I$(src)
+
+obj-$(CONFIG_INTEL_MEI_HDCP) += hdcp/
diff --git a/drivers/misc/mei/hdcp/Makefile b/drivers/misc/mei/hdcp/Makefile
new file mode 100644
index 000000000000..c1a86dd9782b
--- /dev/null
+++ b/drivers/misc/mei/hdcp/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+#
+# Copyright (c) 2017-2018, Intel Corporation.
+#
+# Makefile - HDCP client driver for Intel MEI Bus Driver.
+
+obj-$(CONFIG_INTEL_MEI_HDCP) += mei_hdcp.o
diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
new file mode 100644
index 000000000000..d4067d17f382
--- /dev/null
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/*
+ * Copyright © 2017-2018 Intel Corporation
+ *
+ * Mei_hdcp.c: HDCP client driver for mei bus
+ *
+ * Authors:
+ * Ramalingam C <ramalingam.c at intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/mei_cl_bus.h>
+
+static int mei_hdcp_probe(struct mei_cl_device *cldev,
+			  const struct mei_cl_device_id *id)
+{
+	int ret;
+
+	ret = mei_cldev_enable(cldev);
+	if (ret < 0)
+		dev_err(&cldev->dev, "mei_cldev_enable Failed. %d\n", ret);
+
+	return ret;
+}
+
+static int mei_hdcp_remove(struct mei_cl_device *cldev)
+{
+	return mei_cldev_disable(cldev);
+}
+
+#define MEI_UUID_HDCP		UUID_LE(0xB638AB7E, 0x94E2, 0x4EA2, 0xA5, \
+					0x52, 0xD1, 0xC5, 0x4B, \
+					0x62, 0x7F, 0x04)
+
+static struct mei_cl_device_id mei_hdcp_tbl[] = {
+	{ .uuid = MEI_UUID_HDCP, .version = MEI_CL_VERSION_ANY },
+	{ }
+};
+MODULE_DEVICE_TABLE(mei, mei_hdcp_tbl);
+
+static struct mei_cl_driver mei_hdcp_driver = {
+	.id_table	= mei_hdcp_tbl,
+	.name		= KBUILD_MODNAME,
+	.probe		= mei_hdcp_probe,
+	.remove		= mei_hdcp_remove,
+};
+
+module_mei_cl_driver(mei_hdcp_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("MEI HDCP");
-- 
2.7.4