This driver adds the base support of pinctrl over SCMI.  The driver
does two main things.  First, it allows you to configure the initial
pin states.  Secondly, it's used a base to build a GPIO driver on
top of it.

To configure the states then add a pinmux config to the scmi_pinctrl
section:

        scmi_pinctrl: protocol@19 {
                reg = <0x19>;
                pinmux1: pinmux_test {
                        pinmux = <0 1 0xFFFFFFFF 18 1
                                  0 2 0xFFFFFFFF 18 1
                                  0 3 0xFFFFFFFF 18 1>;
                        function = "f_gpio1";
                        groups = "grp_1", "grp_3";
                };
        };

Under linux the pinctrl subsystem will parse the function and group
properties and use that to handle muxing.  However, under u-boot the
pin muxing is done using the "pinmux" property, which feeds raw SCMI
pinctrl PINCTRL_SETTINGS_CONFIGURE commands to the server.  The
numbers are: selector, identifier, function_id, config_type, and
config_value.  In the example above, it sets pins 1, 2, and 3 to 1.
The linux-kernel ignores this pinmux property.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>

Preparing to add i.MX LMM and CPU protocol driver, support probe SCMI
vendor ID 0x80(i.MX SCMI LMM ID) and 0x82(i.MX SCMI CPU ID). And use
Kconfig option to support conditional compilation.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Alice Guo <alice.guo@nxp.com>

Add conditional compilation for SCMI protocol support in scmi_get_protocol()
and scmi_add_protocol() based on corresponding Kconfig options. This ensures
that only the enabled protocols are compiled and accessed, and reducing binary
size.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Alice Guo <alice.guo@nxp.com>

This patch adds SCMI pin control protocol support to make the pin
controller driver based on SCMI, such as
drivers/pinctrl/nxp/pinctrl-imx-scmi.c, can be bound to the SCMI agent
device whose protocol id is 0x19.

Signed-off-by: Alice Guo <alice.guo@nxp.com>

U_BOOT_SCMI_PROTO_DRIVER macro is used to add a SCMI protocol driver to
scmi_proto_driver list. scmi_proto_driver_get() function can be used to
match a SCMI protocol id and its driver.

Signed-off-by: Alice Guo <alice.guo@nxp.com>

Add power domain driver based on SCMI power domain management protocol.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

SCMI base protocol is mandatory, and once SCMI node is found in a device
tree, the protocol handle (udevice) is unconditionally installed to
the agent. Then basic information will be retrieved from SCMI server via
the protocol and saved into the agent instance's local storage.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>

This framework allows SCMI protocols to be installed and bound to the agent
so that the agent can manage and utilize them later.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>

SCMI specification allows any protocol to have its own channel for
the transport. While the current SCMI driver may assign its channel
from a device tree, the core function, devm_scmi_process_msg(), doesn't
use a protocol's channel, but always use an agent's channel.

With this commit, devm_scmi_process_msg() tries to find and use
a protocol's channel. If it doesn't exist, use an agent's.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Adds resources for SCMI protocols to possibly use a dedicated SCMI
channel instead of the default channel allocated by the SCMI agent
during initialization. As per DT binding documentation, some SCMI
transports can define a specific SCMI communication channel for
given SCMI protocols. It allows SCMI protocols to pass messages
concurrently each other.

This change introduces new scmi agent uclass API function
devm_scmi_of_get_channel() for SCMI drivers probe sequences to get
a reference to the SCMI channel assigned to its related SCMI protocol.
The function queries the channel reference to its SCMI transport driver
through new scmi agent uclass operator .of_get_channel that uses Device
Tree information from related SCMI agent node.

Operator .of_get_channel returns a reference to the SCMI channel
assigned to SCMI protocol used by the caller device. SCMI transport
drivers that do not support multi-channel are not mandated to register
this operator. When so, API function devm_scmi_of_get_channel() returns
NULL and SCMI transport driver are expected to retrieve by their own
means the reference to the unique SCMI channel, for example using
platform data as these drivers currently do in U-Boot source tree.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>