[PATCH v2 0/6] firmware: arm_scmi: Add SCMI v3.2 pincontrol protocol basic support

[Peng Fan (OSS)]

This patchset is a rework from Oleksii's RFC v5 patchset
https://lore.kernel.org/all/cover.1698353854.git.oleksii_moisieiev@epam.com/

This patchset introduces some changes based on RFC v5:
- introduce helper get_max_msg_size
- support compatible string
- iterate the id_table
- Support multiple configs in one command
- Added i.MX support
- Patch 5 firmware: arm_scmi: Add SCMI v3.2 pincontrol protocol basic support
  is almost same as RFCv5 expect multiple configs support.
- Patch 4 the dt-bindings includes compatible string to support i.MX
- Rebased on 2023-12-15 linux-next/master

If any comments from RFC v5 are missed, I am sorry in advance.

This PINCTRL Protocol is following Version 3.2 SCMI Spec Beta release.

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. So implement the driver to support such cases.

The i.MX95 Example as below:

Configuration:
The scmi-pinctrl driver can be configured using DT bindings.
For example:
/ {
	sram0: sram at 445b1000 {
		compatible = "mmio-sram";
		reg = <0x0 0x445b1000 0x0 0x400>;

		#address-cells = <1>;
		#size-cells = <1>;
		ranges = <0x0 0x0 0x445b1000 0x400>;

		scmi_buf0: scmi-sram-section at 0 {
			compatible = "arm,scmi-shmem";
			reg = <0x0 0x80>;
		};

		scmi_buf1: scmi-sram-section at 80 {
			compatible = "arm,scmi-shmem";
			reg = <0x80 0x80>;
		};
	};

	firmware {
		scmi {
			compatible = "arm,scmi";
			mboxes = <&mu2 5 0>, <&mu2 3 0>, <&mu2 3 1>;
			shmem = <&scmi_buf0>, <&scmi_buf1>;
			#address-cells = <1>;
			#size-cells = <0>;

			scmi_iomuxc: protocol at 19 {
				compatible = "fsl,imx95-scmi-pinctrl";
				reg = <0x19>;
			};
		};
	};
};

&scmi_iomuxc {
	pinctrl_tpm3: tpm3grp {
		fsl,pins = <
			IMX95_PAD_GPIO_IO12__TPM3_CH2		0x51e
		>;
	};
};

This patchset has been tested on i.MX95-19x19-EVK board.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
Changes in v2:
 Added comments, and added R-b for Patch 1
 Moved the compatile string and i.MX patch to the end, marked NOT APPLY
 Patchset based on lore.kernel.org/all/20231221151129.325749-1-cristian.marussi at arm.com/
 Addressed the binding doc issue, dropped i.MX content.
 For the firmware pinctrl scmi driver, addressed the comments from Cristian
 For the pinctrl scmi driver, addressed comments from Cristian

 For the i.MX95 OEM stuff, I not have good idea, expect using compatbile
 string. Maybe the firmware public an protocol attribute to indicate it is 
 VENDOR stuff or NXP use a new protocol id, not 0x19. But I think
 current pinctrl-scmi.c not able to support OEM config, should we extend
 it with some method? Anyway if patch 1-4 is good enough, they could
 be picked up first.

 Since I am only able to test the patch on i.MX95 which not support
 geneirc pinconf, only OEM configs are tested in my side.

---
Oleksii Moisieiev (1):
      firmware: arm_scmi: Add SCMI v3.2 pincontrol protocol basic support

Peng Fan (5):
      firmware: arm_scmi: introduce helper get_max_msg_size
      dt-bindings: firmware: arm,scmi: support pinctrl protocol
      pinctrl: Implementation of the generic scmi-pinctrl driver
      [NOT APPLY]firmware: scmi: support compatible string
      [NOT APPLY] pinctrl: scmi: implement pinctrl_scmi_imx_dt_node_to_map

 .../devicetree/bindings/firmware/arm,scmi.yaml     |  50 ++
 MAINTAINERS                                        |   7 +
 drivers/firmware/arm_scmi/Makefile                 |   1 +
 drivers/firmware/arm_scmi/bus.c                    |  39 +-
 drivers/firmware/arm_scmi/common.h                 |   2 +-
 drivers/firmware/arm_scmi/driver.c                 |  32 +-
 drivers/firmware/arm_scmi/pinctrl.c                | 930 +++++++++++++++++++++
 drivers/firmware/arm_scmi/protocols.h              |   3 +
 drivers/pinctrl/Kconfig                            |  11 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/pinctrl-scmi-imx.c                 | 117 +++
 drivers/pinctrl/pinctrl-scmi.c                     | 540 ++++++++++++
 drivers/pinctrl/pinctrl-scmi.h                     |  12 +
 include/linux/scmi_protocol.h                      |  75 ++
 14 files changed, 1806 insertions(+), 14 deletions(-)
---
base-commit: 8f266a167d1f0ca34668f05cd8c01bd245c8698b
change-id: 20231215-pinctrl-scmi-4c5b0374f4c6

Best regards,
-- 
Peng Fan <peng.fan at nxp.com>