stm class: Factor out default framing protocol

The STP framing pattern that the stm class implicitly applies to the
data payload is, in fact, a protocol. This patch moves the relevant code
out of the stm core into its own driver module.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig
index 723e2d90083d..262e7891fb97 100644
--- a/drivers/hwtracing/stm/Kconfig
+++ b/drivers/hwtracing/stm/Kconfig
@@ -11,6 +11,21 @@ config STM
 
 if STM
 
+config STM_PROTO_BASIC
+	tristate "Basic STM framing protocol driver"
+	default CONFIG_STM
+	help
+	  This is a simple framing protocol for sending data over STM
+	  devices. This was the protocol that the STM framework used
+	  exclusively until the MIPI SyS-T support was added. Use this
+	  driver for compatibility with your existing STM setup.
+
+	  The receiving side only needs to be able to decode the MIPI
+	  STP protocol in order to extract the data.
+
+	  If you want to be able to use the basic protocol or want the
+	  backwards compatibility for your existing setup, say Y.
+
 config STM_DUMMY
 	tristate "Dummy STM driver"
 	help