[v4,1/5] firmware: scmi: voltage regulator

Message ID 20210308213810.29535-1-etienne.carriere@linaro.org
State Accepted
Commit 1f213ee4dbf249933c29d5f62fd53ec4754ab4aa
Headers show
Series
  • [v4,1/5] firmware: scmi: voltage regulator
Related show

Commit Message

Etienne Carriere March 8, 2021, 9:38 p.m.
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://github.com/torvalds/linux/commit/0f80fcec08e9c50b8d2992cf26495673765ebaba
Link: [2] https://github.com/torvalds/linux/commit/2add5cacff3531e54c50b0832128299faa9f0563
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

---
Changes in v4:
- define a device for SCMI voltage protocol that binds the SCMI regulators
  as suggested by Patrick.
- removed Simon and Jaehoon tags since changes.

Changes in v3:
- applied review tags

Changes in v2:
- no change
---
 doc/device-tree-bindings/arm/arm,scmi.txt |  34 ++++
 drivers/firmware/scmi/scmi_agent-uclass.c |  10 ++
 drivers/power/regulator/Kconfig           |   8 +
 drivers/power/regulator/Makefile          |   1 +
 drivers/power/regulator/scmi_regulator.c  | 195 ++++++++++++++++++++++
 include/scmi_protocols.h                  | 113 +++++++++++++
 6 files changed, 361 insertions(+)
 create mode 100644 drivers/power/regulator/scmi_regulator.c

-- 
2.17.1

Comments

Jaehoon Chung March 9, 2021, 10:42 p.m. | #1
On 3/9/21 6:38 AM, 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=4762535a-18f96b93-4763d815-0cc47a336fae-3c00cacbc555f86e&q=1&e=d232145a-df26-46c6-b2ed-fd2b665c4b71&u=https%3A%2F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F0f80fcec08e9c50b8d2992cf26495673765ebaba

> Link: [2] https://protect2.fireeye.com/v1/url?k=3da6e589-623ddd40-3da76ec6-0cc47a336fae-8f68d44282000af5&q=1&e=d232145a-df26-46c6-b2ed-fd2b665c4b71&u=https%3A%2F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F2add5cacff3531e54c50b0832128299faa9f0563

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


Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>


Best Regards,
Jaehoon Chung

> ---

> Changes in v4:

> - define a device for SCMI voltage protocol that binds the SCMI regulators

>   as suggested by Patrick.

> - removed Simon and Jaehoon tags since changes.

> 

> Changes in v3:

> - applied review tags

> 

> Changes in v2:

> - no change

> ---

>  doc/device-tree-bindings/arm/arm,scmi.txt |  34 ++++

>  drivers/firmware/scmi/scmi_agent-uclass.c |  10 ++

>  drivers/power/regulator/Kconfig           |   8 +

>  drivers/power/regulator/Makefile          |   1 +

>  drivers/power/regulator/scmi_regulator.c  | 195 ++++++++++++++++++++++

>  include/scmi_protocols.h                  | 113 +++++++++++++

>  6 files changed, 361 insertions(+)

>  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..f13e46c36 100644

> --- a/drivers/firmware/scmi/scmi_agent-uclass.c

> +++ b/drivers/firmware/scmi/scmi_agent-uclass.c

> @@ -79,6 +79,16 @@ 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)) {

> +				node = ofnode_find_subnode(node, "regulators");

> +				if (!ofnode_valid(node)) {

> +					dev_err(dev, "no regulators node\n");

> +					return -ENXIO;

> +				}

> +				drv = DM_DRIVER_GET(scmi_voltage_domain);

> +			}

> +			break;

>  		default:

>  			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..b3142bf4e

> --- /dev/null

> +++ b/drivers/power/regulator/scmi_regulator.c

> @@ -0,0 +1,195 @@

> +// 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 <dm/device-internal.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->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->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->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->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->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_regulator) = {

> +	.name = "scmi_regulator",

> +	.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),

> +};

> +

> +static int scmi_regulator_bind(struct udevice *dev)

> +{

> +	struct driver *drv;

> +	ofnode node;

> +	int ret;

> +

> +	drv = DM_DRIVER_GET(scmi_regulator);

> +

> +	ofnode_for_each_subnode(node, dev_ofnode(dev)) {

> +		ret = device_bind(dev, drv, ofnode_get_name(node),

> +				  NULL, node, NULL);

> +		if (ret)

> +			return ret;

> +	}

> +

> +	return 0;

> +}

> +

> +U_BOOT_DRIVER(scmi_voltage_domain) = {

> +	.name = "scmi_voltage_domain",

> +	.id = UCLASS_NOP,

> +	.bind = scmi_regulator_bind,

> +};

> 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 */

>
Tom Rini April 13, 2021, 2:28 p.m. | #2
On Mon, Mar 08, 2021 at 10:38:06PM +0100, 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://github.com/torvalds/linux/commit/0f80fcec08e9c50b8d2992cf26495673765ebaba

> Link: [2] https://github.com/torvalds/linux/commit/2add5cacff3531e54c50b0832128299faa9f0563

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

> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>


Applied to u-boot/master, thanks!

-- 
Tom

Patch

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..f13e46c36 100644
--- a/drivers/firmware/scmi/scmi_agent-uclass.c
+++ b/drivers/firmware/scmi/scmi_agent-uclass.c
@@ -79,6 +79,16 @@  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)) {
+				node = ofnode_find_subnode(node, "regulators");
+				if (!ofnode_valid(node)) {
+					dev_err(dev, "no regulators node\n");
+					return -ENXIO;
+				}
+				drv = DM_DRIVER_GET(scmi_voltage_domain);
+			}
+			break;
 		default:
 			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..b3142bf4e
--- /dev/null
+++ b/drivers/power/regulator/scmi_regulator.c
@@ -0,0 +1,195 @@ 
+// 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 <dm/device-internal.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->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->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->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->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->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_regulator) = {
+	.name = "scmi_regulator",
+	.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),
+};
+
+static int scmi_regulator_bind(struct udevice *dev)
+{
+	struct driver *drv;
+	ofnode node;
+	int ret;
+
+	drv = DM_DRIVER_GET(scmi_regulator);
+
+	ofnode_for_each_subnode(node, dev_ofnode(dev)) {
+		ret = device_bind(dev, drv, ofnode_get_name(node),
+				  NULL, node, NULL);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+U_BOOT_DRIVER(scmi_voltage_domain) = {
+	.name = "scmi_voltage_domain",
+	.id = UCLASS_NOP,
+	.bind = scmi_regulator_bind,
+};
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 */