[PATCH 1/3] firmware: scmi: voltage regulator
Etienne Carriere
etienne.carriere at linaro.org
Thu Feb 18 13:54:42 CET 2021
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 at linaro.org>
---
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 at 17 {
+ reg = <0x17>;
+
+ regulators {
+ regulator_devX: regulator at 0 {
+ reg = <0x0>;
+ regulator-max-microvolt = <3300000>;
+ };
+
+ regulator_devY: regulator at 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 */
--
2.17.1
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