soc: qcom: Introduce QMI encoder/decoder

Add the helper library for encoding and decoding QMI encoded messages.
The implementation is taken from lib/qmi_encdec.c of the Qualcomm kernel
(msm-3.18).

Modifications has been made to the public API, source buffers has been
made const and the debug-logging part was omitted, for now.

Acked-by: Chris Lew <[email protected]>
Tested-by: Chris Lew <[email protected]>
Tested-by: Srinivas Kandagatla <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

Author: andersson

drivers/soc/qcom/Kconfig

@@ -35,6 +35,15 @@ config QCOM_PM
 	  modes. It interface with various system drivers to put the cores in
 	  low power modes.
 
+config QCOM_QMI_HELPERS
+	tristate
+	depends on ARCH_QCOM
+	help
+	  Helper library for handling QMI encoded messages.  QMI encoded
+	  messages are used in communication between the majority of QRTR
+	  clients and this helpers provide the common functionality needed for
+	  doing this from a kernel driver.
+
 config QCOM_RMTFS_MEM
 	tristate "Qualcomm Remote Filesystem memory driver"
 	depends on ARCH_QCOM

drivers/soc/qcom/Makefile

@@ -3,6 +3,8 @@ obj-$(CONFIG_QCOM_GLINK_SSR) +=	glink_ssr.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
+obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
+qmi_helpers-y	+= qmi_encdec.o
 obj-$(CONFIG_QCOM_RMTFS_MEM)	+= rmtfs_mem.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o