Hi,
On 4/7/23 12:18, Oleksii Moisieiev wrote:
This RFC patch series is intended to introduce the potential generic driver for
pin controls over SCMI protocol, provided in the latest beta version of DEN0056 [0].
On ARM-based systems, a separate Cortex-M based System Control Processor (SCP)
provides control on pins, as well as with power, clocks, reset controllers. In this case,
kernel should use one of the possible transports, described in [0] to access SCP and
control clocks/power-domains etc. This driver is using SMC transport to communicate with SCP via
SCMI protocol and access to the Pin Control Subsystem.
The provided driver consists of 2 parts:
- firmware/arm_scmi/pinctrl.c - the SCMI pinctrl protocol inmplementation
responsible for the communication with SCP firmware.
- drivers/pinctrl/pinctrl-scmi.c - pinctrl driver, which is using pinctrl
protocol implementation to access all necessary data.
Configuration:
The scmi-pinctrl driver can be configured using DT bindings.
For example:
/ {
cpu_scp_shm: scp-shmem@0x53FF0000 {
compatible = "arm,scmi-shmem";
reg = <0x0 0x53FF0000 0x0 0x1000>;
};
firmware {
scmi {
compatible = "arm,scmi-smc";
arm,smc-id = <0x82000002>;
shmem = <&cpu_scp_shm>;
#address-cells = <1>;
#size-cells = <0>;
scmi_pinctrl: protocol@19 {
reg = <0x18>;
#pinctrl-cells = <0>;
i2c2_pins: i2c2 {
groups = "i2c2_a";
function = "i2c2";
};
};
};
};
};
Spec itself has as the part of pinctrl also gpio support.
Here the example there is no gpio-cells property that's why I am curious if you
plan to also add it here.
Thanks,
Michal
