On 2/19/21 10:33 PM, Etienne Carriere wrote:
> Implement voltage regulators interfaced by the SCMI voltage domain
> protocol. The DT bindings are defined in the Linux kernel since
> SCMI voltage domain and regulators patches [1] and [2] integration
> in v5.11-rc7.
>
> Link: [1]
> https://protect2.fireeye.com/v1/url?k=472c44bf-18b77dae-472dcff0-0cc47a31cdbc-c857593954d155c5&q=1&e=117141f8-c98a-4b9c-83e8-c7bbf1ffbd72&u=https%3A%2F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F0f80fcec08e9c50b8d2992cf26495673765ebaba
> Link: [2]
> https://protect2.fireeye.com/v1/url?k=8c3fa7e5-d3a49ef4-8c3e2caa-0cc47a31cdbc-5d6f0aa01e7bcbb1&q=1&e=117141f8-c98a-4b9c-83e8-c7bbf1ffbd72&u=https%3A%2F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F2add5cacff3531e54c50b0832128299faa9f0563
>
> Signed-off-by: Etienne Carriere <etienne.carri...@linaro.org>
Reviewed-by: Jaehoon Chung <jh80.ch...@samsung.com>
Best Regards,
Jaehoon Chung
> ---
> Changes in v2:
> - no change
> ---
> doc/device-tree-bindings/arm/arm,scmi.txt | 34 +++++
> drivers/firmware/scmi/scmi_agent-uclass.c | 35 ++++-
> drivers/power/regulator/Kconfig | 8 +
> drivers/power/regulator/Makefile | 1 +
> drivers/power/regulator/scmi_regulator.c | 170 ++++++++++++++++++++++
> include/scmi_protocols.h | 113 ++++++++++++++
> 6 files changed, 359 insertions(+), 2 deletions(-)
> create mode 100644 drivers/power/regulator/scmi_regulator.c
>
> diff --git a/doc/device-tree-bindings/arm/arm,scmi.txt
> b/doc/device-tree-bindings/arm/arm,scmi.txt
> index 1f293ea24..a76124f4a 100644
> --- a/doc/device-tree-bindings/arm/arm,scmi.txt
> +++ b/doc/device-tree-bindings/arm/arm,scmi.txt
> @@ -62,6 +62,20 @@ Required properties:
> - #power-domain-cells : Should be 1. Contains the device or the power
> domain ID value used by SCMI commands.
>
> +Regulator bindings for the SCMI Regulator based on SCMI Message Protocol
> +------------------------------------------------------------
> +An SCMI Regulator is permanently bound to a well defined SCMI Voltage Domain,
> +and should be always positioned as a root regulator.
> +It does not support any current operation.
> +
> +SCMI Regulators are grouped under a 'regulators' node which in turn is a
> child
> +of the SCMI Voltage protocol node inside the desired SCMI instance node.
> +
> +This binding uses the common regulator binding[6].
> +
> +Required properties:
> + - reg : shall identify an existent SCMI Voltage Domain.
> +
> Sensor bindings for the sensors based on SCMI Message Protocol
> --------------------------------------------------------------
> SCMI provides an API to access the various sensors on the SoC.
> @@ -105,6 +119,7 @@ Required sub-node properties:
> [3] Documentation/devicetree/bindings/thermal/thermal.txt
> [4] Documentation/devicetree/bindings/sram/sram.yaml
> [5] Documentation/devicetree/bindings/reset/reset.txt
> +[6] Documentation/devicetree/bindings/regulator/regulator.yaml
>
> Example:
>
> @@ -169,6 +184,25 @@ firmware {
> reg = <0x16>;
> #reset-cells = <1>;
> };
> +
> + scmi_voltage: protocol@17 {
> + reg = <0x17>;
> +
> + regulators {
> + regulator_devX: regulator@0 {
> + reg = <0x0>;
> + regulator-max-microvolt = <3300000>;
> + };
> +
> + regulator_devY: regulator@9 {
> + reg = <0x9>;
> + regulator-min-microvolt = <500000>;
> + regulator-max-microvolt = <4200000>;
> + };
> +
> + ...
> + };
> + };
> };
> };
>
> diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c
> b/drivers/firmware/scmi/scmi_agent-uclass.c
> index 516e690ac..03d236426 100644
> --- a/drivers/firmware/scmi/scmi_agent-uclass.c
> +++ b/drivers/firmware/scmi/scmi_agent-uclass.c
> @@ -50,6 +50,29 @@ int scmi_to_linux_errno(s32 scmi_code)
> return -EPROTO;
> }
>
> +static int regulator_devices_bind(struct udevice *dev, struct driver *drv,
> + ofnode protocol_node)
> +{
> + ofnode regulators_node;
> + ofnode node;
> + int ret;
> +
> + regulators_node = ofnode_find_subnode(protocol_node, "regulators");
> + if (!ofnode_valid(regulators_node)) {
> + dev_err(dev, "regulators subnode not found\n");
> + return -ENXIO;
> + }
> +
> + ofnode_for_each_subnode(node, regulators_node) {
> + ret = device_bind(dev, drv, ofnode_get_name(node), NULL, node,
> + NULL);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> /*
> * SCMI agent devices binds devices of various uclasses depeding on
> * the FDT description. scmi_bind_protocol() is a generic bind sequence
> @@ -79,6 +102,10 @@ static int scmi_bind_protocols(struct udevice *dev)
> if (IS_ENABLED(CONFIG_RESET_SCMI))
> drv = DM_DRIVER_GET(scmi_reset_domain);
> break;
> + case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
> + if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI))
> + drv = DM_DRIVER_GET(scmi_voltage_domain);
> + break;
> default:
> break;
> }
> @@ -89,8 +116,12 @@ static int scmi_bind_protocols(struct udevice *dev)
> continue;
> }
>
> - ret = device_bind(dev, drv, ofnode_get_name(node), NULL, node,
> - NULL);
> + if (protocol_id == SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN)
> + ret = regulator_devices_bind(dev, drv, node);
> + else
> + ret = device_bind(dev, drv, ofnode_get_name(node),
> + NULL, node, NULL);
> +
> if (ret)
> break;
> }
> diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
> index fbbea18c7..5d6180229 100644
> --- a/drivers/power/regulator/Kconfig
> +++ b/drivers/power/regulator/Kconfig
> @@ -353,3 +353,11 @@ config DM_REGULATOR_TPS65941
> TPS65941 series of PMICs have 5 single phase BUCKs that can also
> be configured in multi phase modes & 4 LDOs. The driver implements
> get/set api for value and enable.
> +
> +config DM_REGULATOR_SCMI
> + bool "Enable driver for SCMI voltage domain regulators"
> + depends on DM_REGULATOR
> + select SCMI_AGENT
> + help
> + Enable this option if you want to support regulators exposed
> through
> + the SCMI voltage domain protocol by a SCMI server.
> diff --git a/drivers/power/regulator/Makefile
> b/drivers/power/regulator/Makefile
> index 9d58112dc..b2f5972ea 100644
> --- a/drivers/power/regulator/Makefile
> +++ b/drivers/power/regulator/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o
> obj-$(CONFIG_DM_REGULATOR_TPS62360) += tps62360_regulator.o
> obj-$(CONFIG_$(SPL_)DM_REGULATOR_STPMIC1) += stpmic1.o
> obj-$(CONFIG_DM_REGULATOR_TPS65941) += tps65941_regulator.o
> +obj-$(CONFIG_DM_REGULATOR_SCMI) += scmi_regulator.o
> diff --git a/drivers/power/regulator/scmi_regulator.c
> b/drivers/power/regulator/scmi_regulator.c
> new file mode 100644
> index 000000000..072a978a8
> --- /dev/null
> +++ b/drivers/power/regulator/scmi_regulator.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020-2021 Linaro Limited
> + */
> +#include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <scmi_agent.h>
> +#include <scmi_protocols.h>
> +#include <asm/types.h>
> +#include <dm/device.h>
> +#include <dm/device_compat.h>
> +#include <linux/kernel.h>
> +#include <power/regulator.h>
> +
> +/**
> + * struct scmi_regulator_platdata - Platform data for a scmi voltage domain
> regulator
> + * @domain_id: ID representing the regulator for the related SCMI agent
> + */
> +struct scmi_regulator_platdata {
> + u32 domain_id;
> +};
> +
> +static int scmi_voltd_set_enable(struct udevice *dev, bool enable)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + struct scmi_voltd_config_set_in in = {
> + .domain_id = pdata->domain_id,
> + .config = enable ? SCMI_VOLTD_CONFIG_ON : SCMI_VOLTD_CONFIG_OFF,
> + };
> + struct scmi_voltd_config_set_out out;
> + struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN,
> + SCMI_VOLTAGE_DOMAIN_CONFIG_SET,
> + in, out);
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev->parent, &msg);
> + if (ret)
> + return ret;
> +
> + ret = scmi_to_linux_errno(out.status);
> + if (ret)
> + return ret;
> +
> + return ret;
> +}
> +
> +static int scmi_voltd_get_enable(struct udevice *dev)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + struct scmi_voltd_config_get_in in = {
> + .domain_id = pdata->domain_id,
> + };
> + struct scmi_voltd_config_get_out out;
> + struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN,
> + SCMI_VOLTAGE_DOMAIN_CONFIG_GET,
> + in, out);
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev->parent, &msg);
> + if (ret < 0)
> + return ret;
> +
> + ret = scmi_to_linux_errno(out.status);
> + if (ret < 0)
> + return ret;
> +
> + return out.config == SCMI_VOLTD_CONFIG_ON;
> +}
> +
> +static int scmi_voltd_set_voltage_level(struct udevice *dev, int uV)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + struct scmi_voltd_level_set_in in = {
> + .domain_id = pdata->domain_id,
> + .voltage_level = uV,
> + };
> + struct scmi_voltd_level_set_out out;
> + struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN,
> + SCMI_VOLTAGE_DOMAIN_LEVEL_SET,
> + in, out);
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev->parent, &msg);
> + if (ret < 0)
> + return ret;
> +
> + return scmi_to_linux_errno(out.status);
> +}
> +
> +static int scmi_voltd_get_voltage_level(struct udevice *dev)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + struct scmi_voltd_level_get_in in = {
> + .domain_id = pdata->domain_id,
> + };
> + struct scmi_voltd_level_get_out out;
> + struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN,
> + SCMI_VOLTAGE_DOMAIN_LEVEL_GET,
> + in, out);
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev->parent, &msg);
> + if (ret < 0)
> + return ret;
> +
> + ret = scmi_to_linux_errno(out.status);
> + if (ret < 0)
> + return ret;
> +
> + return out.voltage_level;
> +}
> +
> +static int scmi_regulator_of_to_plat(struct udevice *dev)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + fdt_addr_t reg;
> +
> + reg = dev_read_addr(dev);
> + if (reg == FDT_ADDR_T_NONE)
> + return -EINVAL;
> +
> + pdata->domain_id = (u32)reg;
> +
> + return 0;
> +}
> +
> +static int scmi_regulator_probe(struct udevice *dev)
> +{
> + struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
> + struct scmi_voltd_attr_in in = { 0 };
> + struct scmi_voltd_attr_out out = { 0 };
> + struct scmi_msg scmi_msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN,
> + .message_id = SCMI_VOLTAGE_DOMAIN_ATTRIBUTES,
> + .in_msg = (u8 *)&in,
> + .in_msg_sz = sizeof(in),
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int ret;
> +
> + /* Check voltage domain is known from SCMI server */
> + in.domain_id = pdata->domain_id;
> +
> + ret = devm_scmi_process_msg(dev->parent, &scmi_msg);
> + if (ret) {
> + dev_err(dev, "Failed to query voltage domain %u: %d\n",
> + pdata->domain_id, ret);
> + return -ENXIO;
> + }
> +
> + return 0;
> +}
> +
> +static const struct dm_regulator_ops scmi_voltd_ops = {
> + .get_value = scmi_voltd_get_voltage_level,
> + .set_value = scmi_voltd_set_voltage_level,
> + .get_enable = scmi_voltd_get_enable,
> + .set_enable = scmi_voltd_set_enable,
> +};
> +
> +U_BOOT_DRIVER(scmi_voltage_domain) = {
> + .name = "scmi_voltage_domain",
> + .id = UCLASS_REGULATOR,
> + .ops = &scmi_voltd_ops,
> + .probe = scmi_regulator_probe,
> + .of_to_plat = scmi_regulator_of_to_plat,
> + .plat_auto = sizeof(struct scmi_regulator_platdata),
> +};
> diff --git a/include/scmi_protocols.h b/include/scmi_protocols.h
> index ccab97c96..2db71697e 100644
> --- a/include/scmi_protocols.h
> +++ b/include/scmi_protocols.h
> @@ -23,6 +23,7 @@ enum scmi_std_protocol {
> SCMI_PROTOCOL_ID_CLOCK = 0x14,
> SCMI_PROTOCOL_ID_SENSOR = 0x15,
> SCMI_PROTOCOL_ID_RESET_DOMAIN = 0x16,
> + SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN = 0x17,
> };
>
> enum scmi_status_code {
> @@ -176,4 +177,116 @@ struct scmi_rd_reset_out {
> s32 status;
> };
>
> +/*
> + * SCMI Voltage Domain Protocol
> + */
> +
> +enum scmi_voltage_domain_message_id {
> + SCMI_VOLTAGE_DOMAIN_ATTRIBUTES = 0x3,
> + SCMI_VOLTAGE_DOMAIN_CONFIG_SET = 0x5,
> + SCMI_VOLTAGE_DOMAIN_CONFIG_GET = 0x6,
> + SCMI_VOLTAGE_DOMAIN_LEVEL_SET = 0x7,
> + SCMI_VOLTAGE_DOMAIN_LEVEL_GET = 0x8,
> +};
> +
> +#define SCMI_VOLTD_NAME_LEN 16
> +
> +#define SCMI_VOLTD_CONFIG_MASK GENMASK(3, 0)
> +#define SCMI_VOLTD_CONFIG_OFF 0
> +#define SCMI_VOLTD_CONFIG_ON 0x7
> +
> +/**
> + * struct scmi_voltd_attr_in - Payload for VOLTAGE_DOMAIN_ATTRIBUTES message
> + * @domain_id: SCMI voltage domain ID
> + */
> +struct scmi_voltd_attr_in {
> + u32 domain_id;
> +};
> +
> +/**
> + * struct scmi_voltd_attr_out - Payload for VOLTAGE_DOMAIN_ATTRIBUTES
> response
> + * @status: SCMI command status
> + * @attributes: Retrieved attributes of the voltage domain
> + * @name: Voltage domain name
> + */
> +struct scmi_voltd_attr_out {
> + s32 status;
> + u32 attributes;
> + char name[SCMI_VOLTD_NAME_LEN];
> +};
> +
> +/**
> + * struct scmi_voltd_config_set_in - Message payload for VOLTAGE_CONFIG_SET
> cmd
> + * @domain_id: SCMI voltage domain ID
> + * @config: Configuration data of the voltage domain
> + */
> +struct scmi_voltd_config_set_in {
> + u32 domain_id;
> + u32 config;
> +};
> +
> +/**
> + * struct scmi_voltd_config_set_out - Response for VOLTAGE_CONFIG_SET command
> + * @status: SCMI command status
> + */
> +struct scmi_voltd_config_set_out {
> + s32 status;
> +};
> +
> +/**
> + * struct scmi_voltd_config_get_in - Message payload for VOLTAGE_CONFIG_GET
> cmd
> + * @domain_id: SCMI voltage domain ID
> + */
> +struct scmi_voltd_config_get_in {
> + u32 domain_id;
> +};
> +
> +/**
> + * struct scmi_voltd_config_get_out - Response for VOLTAGE_CONFIG_GET command
> + * @status: SCMI command status
> + * @config: Configuration data of the voltage domain
> + */
> +struct scmi_voltd_config_get_out {
> + s32 status;
> + u32 config;
> +};
> +
> +/**
> + * struct scmi_voltd_level_set_in - Message payload for VOLTAGE_LEVEL_SET cmd
> + * @domain_id: SCMI voltage domain ID
> + * @flags: Parameter flags for configuring target level
> + * @voltage_level: Target voltage level in microvolts (uV)
> + */
> +struct scmi_voltd_level_set_in {
> + u32 domain_id;
> + u32 flags;
> + s32 voltage_level;
> +};
> +
> +/**
> + * struct scmi_voltd_level_set_out - Response for VOLTAGE_LEVEL_SET command
> + * @status: SCMI command status
> + */
> +struct scmi_voltd_level_set_out {
> + s32 status;
> +};
> +
> +/**
> + * struct scmi_voltd_level_get_in - Message payload for VOLTAGE_LEVEL_GET cmd
> + * @domain_id: SCMI voltage domain ID
> + */
> +struct scmi_voltd_level_get_in {
> + u32 domain_id;
> +};
> +
> +/**
> + * struct scmi_voltd_level_get_out - Response for VOLTAGE_LEVEL_GET command
> + * @status: SCMI command status
> + * @voltage_level: Voltage level in microvolts (uV)
> + */
> +struct scmi_voltd_level_get_out {
> + s32 status;
> + s32 voltage_level;
> +};
> +
> #endif /* _SCMI_PROTOCOLS_H */
>
