bus: mhi: Update Makefile to used Kconfig flags

Makefile was always suggesting to build subdirectories regardless of
Kconfig. Use the Kconfig flags as intended.

Signed-off-by: Carl Vanderlip <quic_carlv@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://lore.kernel.org/r/20221207192613.2098614-1-quic_carlv@quicinc.com
[mani: fixed the subject prefix]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

bus: mhi: ep: Add support for registering MHI endpoint controllers

This commit adds support for registering MHI endpoint controller drivers
with the MHI endpoint stack. MHI endpoint controller drivers manage
the interaction with the host machines (such as x86). They are also the
MHI endpoint bus master in charge of managing the physical link between
the host and endpoint device. Eventhough the MHI spec is bus agnostic,
the current implementation is entirely based on PCIe bus.

The endpoint controller driver encloses all information about the
underlying physical bus like PCIe. The registration process involves
parsing the channel configuration and allocating an MHI EP device.

Channels used in the endpoint stack follows the perspective of the MHI
host stack. i.e.,

UL - From host to endpoint
DL - From endpoint to host

Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220405135754.6622-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus: mhi: ep: Add support for registering MHI endpoint controllers

This commit adds support for registering MHI endpoint controller drivers
with the MHI endpoint stack. MHI endpoint controller drivers manage
the interaction with the host machines (such as x86). They are also the
MHI endpoint bus master in charge of managing the physical link between
the host and endpoint device. Eventhough the MHI spec is bus agnostic,
the current implementation is entirely based on PCIe bus.

The endpoint controller driver encloses all information about the
underlying physical bus like PCIe. The registration process involves
parsing the channel configuration and allocating an MHI EP device.

Channels used in the endpoint stack follows the perspective of the MHI
host stack. i.e.,

UL - From host to endpoint
DL - From endpoint to host

Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

bus: mhi: Move host MHI code to "host" directory

In preparation of the endpoint MHI support, let's move the host MHI code
to its own "host" directory and adjust the toplevel MHI Kconfig & Makefile.

While at it, let's also move the "pci_generic" driver to "host" directory
as it is a host MHI controller driver.

Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220301160308.107452-5-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus: mhi: Add MHI PCI support for WWAN modems

This is a generic MHI-over-PCI controller driver for MHI only devices
such as QCOM modems. For now it supports registering of Qualcomm SDX55
based PCIe modules. The MHI channels have been extracted from mhi
downstream driver.

This driver is for MHI-only devices which have all functionalities
exposed through MHI channels and accessed by the corresponding MHI
device drivers (no out-of-band communication).

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[mani: fixed up the Makefile rule]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

bus: mhi: core: Add support for registering MHI controllers

This commit adds support for registering MHI controller drivers with
the MHI stack. MHI controller drivers manages the interaction with the
MHI client devices such as the external modems and WiFi chipsets. They
are also the MHI bus master in charge of managing the physical link
between the host and client device.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/987

Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[jhugo: added static config for controllers and fixed several bugs]
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
[mani: removed DT dependency, splitted and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200220095854.4804-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>