firmware: arm_scmi: Add voltage domain management protocol support

SCMI v3.0 introduces voltage domain protocol which provides commands to:
 - Discover the voltage levels supported by a domain
 - Get the configuration and voltage level of a domain
 - Set the configuration and voltage level of a domain

Let us add support for the same.

Link: https://lore.kernel.org/r/20201119191051.46363-2-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Cristian Marussi 2020-11-19 19:10:47 +00:00 committed by Sudeep Holla
parent 0f80fcec08
commit 2add5cacff
5 changed files with 448 additions and 1 deletions

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@ -4,7 +4,7 @@ scmi-driver-y = driver.o notify.o
scmi-transport-y = shmem.o
scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o
scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o
scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \
$(scmi-transport-y)
obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o

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@ -169,6 +169,7 @@ DECLARE_SCMI_REGISTER_UNREGISTER(perf);
DECLARE_SCMI_REGISTER_UNREGISTER(power);
DECLARE_SCMI_REGISTER_UNREGISTER(reset);
DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
DECLARE_SCMI_REGISTER_UNREGISTER(system);
#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \

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@ -946,6 +946,7 @@ static int __init scmi_driver_init(void)
scmi_power_register();
scmi_reset_register();
scmi_sensors_register();
scmi_voltage_register();
scmi_system_register();
return platform_driver_register(&scmi_driver);
@ -961,6 +962,7 @@ static void __exit scmi_driver_exit(void)
scmi_power_unregister();
scmi_reset_unregister();
scmi_sensors_unregister();
scmi_voltage_unregister();
scmi_system_unregister();
platform_driver_unregister(&scmi_driver);

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@ -0,0 +1,380 @@
// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Voltage Protocol
*
* Copyright (C) 2020 ARM Ltd.
*/
#include <linux/scmi_protocol.h>
#include "common.h"
#define VOLTAGE_DOMS_NUM_MASK GENMASK(15, 0)
#define REMAINING_LEVELS_MASK GENMASK(31, 16)
#define RETURNED_LEVELS_MASK GENMASK(11, 0)
enum scmi_voltage_protocol_cmd {
VOLTAGE_DOMAIN_ATTRIBUTES = 0x3,
VOLTAGE_DESCRIBE_LEVELS = 0x4,
VOLTAGE_CONFIG_SET = 0x5,
VOLTAGE_CONFIG_GET = 0x6,
VOLTAGE_LEVEL_SET = 0x7,
VOLTAGE_LEVEL_GET = 0x8,
};
#define NUM_VOLTAGE_DOMAINS(x) ((u16)(FIELD_GET(VOLTAGE_DOMS_NUM_MASK, (x))))
struct scmi_msg_resp_domain_attributes {
__le32 attr;
u8 name[SCMI_MAX_STR_SIZE];
};
struct scmi_msg_cmd_describe_levels {
__le32 domain_id;
__le32 level_index;
};
struct scmi_msg_resp_describe_levels {
__le32 flags;
#define NUM_REMAINING_LEVELS(f) ((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
#define NUM_RETURNED_LEVELS(f) ((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
#define SUPPORTS_SEGMENTED_LEVELS(f) ((f) & BIT(12))
__le32 voltage[];
};
struct scmi_msg_cmd_config_set {
__le32 domain_id;
__le32 config;
};
struct scmi_msg_cmd_level_set {
__le32 domain_id;
__le32 flags;
__le32 voltage_level;
};
struct voltage_info {
unsigned int version;
unsigned int num_domains;
struct scmi_voltage_info *domains;
};
static int scmi_protocol_attributes_get(const struct scmi_handle *handle,
struct voltage_info *vinfo)
{
int ret;
struct scmi_xfer *t;
ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
SCMI_PROTOCOL_VOLTAGE, 0, sizeof(__le32), &t);
if (ret)
return ret;
ret = scmi_do_xfer(handle, t);
if (!ret)
vinfo->num_domains =
NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_init_voltage_levels(struct device *dev,
struct scmi_voltage_info *v,
u32 num_returned, u32 num_remaining,
bool segmented)
{
u32 num_levels;
num_levels = num_returned + num_remaining;
/*
* segmented levels entries are represented by a single triplet
* returned all in one go.
*/
if (!num_levels ||
(segmented && (num_remaining || num_returned != 3))) {
dev_err(dev,
"Invalid level descriptor(%d/%d/%d) for voltage dom %d\n",
num_levels, num_returned, num_remaining, v->id);
return -EINVAL;
}
v->levels_uv = devm_kcalloc(dev, num_levels, sizeof(u32), GFP_KERNEL);
if (!v->levels_uv)
return -ENOMEM;
v->num_levels = num_levels;
v->segmented = segmented;
return 0;
}
static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
struct voltage_info *vinfo)
{
int ret, dom;
struct scmi_xfer *td, *tl;
struct device *dev = handle->dev;
struct scmi_msg_resp_domain_attributes *resp_dom;
struct scmi_msg_resp_describe_levels *resp_levels;
ret = scmi_xfer_get_init(handle, VOLTAGE_DOMAIN_ATTRIBUTES,
SCMI_PROTOCOL_VOLTAGE, sizeof(__le32),
sizeof(*resp_dom), &td);
if (ret)
return ret;
resp_dom = td->rx.buf;
ret = scmi_xfer_get_init(handle, VOLTAGE_DESCRIBE_LEVELS,
SCMI_PROTOCOL_VOLTAGE, sizeof(__le64), 0, &tl);
if (ret)
goto outd;
resp_levels = tl->rx.buf;
for (dom = 0; dom < vinfo->num_domains; dom++) {
u32 desc_index = 0;
u16 num_returned = 0, num_remaining = 0;
struct scmi_msg_cmd_describe_levels *cmd;
struct scmi_voltage_info *v;
/* Retrieve domain attributes at first ... */
put_unaligned_le32(dom, td->tx.buf);
ret = scmi_do_xfer(handle, td);
/* Skip domain on comms error */
if (ret)
continue;
v = vinfo->domains + dom;
v->id = dom;
v->attributes = le32_to_cpu(resp_dom->attr);
strlcpy(v->name, resp_dom->name, SCMI_MAX_STR_SIZE);
cmd = tl->tx.buf;
/* ...then retrieve domain levels descriptions */
do {
u32 flags;
int cnt;
cmd->domain_id = cpu_to_le32(v->id);
cmd->level_index = desc_index;
ret = scmi_do_xfer(handle, tl);
if (ret)
break;
flags = le32_to_cpu(resp_levels->flags);
num_returned = NUM_RETURNED_LEVELS(flags);
num_remaining = NUM_REMAINING_LEVELS(flags);
/* Allocate space for num_levels if not already done */
if (!v->num_levels) {
ret = scmi_init_voltage_levels(dev, v,
num_returned,
num_remaining,
SUPPORTS_SEGMENTED_LEVELS(flags));
if (ret)
break;
}
if (desc_index + num_returned > v->num_levels) {
dev_err(handle->dev,
"No. of voltage levels can't exceed %d\n",
v->num_levels);
ret = -EINVAL;
break;
}
for (cnt = 0; cnt < num_returned; cnt++) {
s32 val;
val =
(s32)le32_to_cpu(resp_levels->voltage[cnt]);
v->levels_uv[desc_index + cnt] = val;
if (val < 0)
v->negative_volts_allowed = true;
}
desc_index += num_returned;
scmi_reset_rx_to_maxsz(handle, tl);
/* check both to avoid infinite loop due to buggy fw */
} while (num_returned && num_remaining);
if (ret) {
v->num_levels = 0;
devm_kfree(dev, v->levels_uv);
}
scmi_reset_rx_to_maxsz(handle, td);
}
scmi_xfer_put(handle, tl);
outd:
scmi_xfer_put(handle, td);
return ret;
}
static int __scmi_voltage_get_u32(const struct scmi_handle *handle,
u8 cmd_id, u32 domain_id, u32 *value)
{
int ret;
struct scmi_xfer *t;
struct voltage_info *vinfo = handle->voltage_priv;
if (domain_id >= vinfo->num_domains)
return -EINVAL;
ret = scmi_xfer_get_init(handle, cmd_id,
SCMI_PROTOCOL_VOLTAGE,
sizeof(__le32), 0, &t);
if (ret)
return ret;
put_unaligned_le32(domain_id, t->tx.buf);
ret = scmi_do_xfer(handle, t);
if (!ret)
*value = get_unaligned_le32(t->rx.buf);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_voltage_config_set(const struct scmi_handle *handle,
u32 domain_id, u32 config)
{
int ret;
struct scmi_xfer *t;
struct voltage_info *vinfo = handle->voltage_priv;
struct scmi_msg_cmd_config_set *cmd;
if (domain_id >= vinfo->num_domains)
return -EINVAL;
ret = scmi_xfer_get_init(handle, VOLTAGE_CONFIG_SET,
SCMI_PROTOCOL_VOLTAGE,
sizeof(*cmd), 0, &t);
if (ret)
return ret;
cmd = t->tx.buf;
cmd->domain_id = cpu_to_le32(domain_id);
cmd->config = cpu_to_le32(config & GENMASK(3, 0));
ret = scmi_do_xfer(handle, t);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_voltage_config_get(const struct scmi_handle *handle,
u32 domain_id, u32 *config)
{
return __scmi_voltage_get_u32(handle, VOLTAGE_CONFIG_GET,
domain_id, config);
}
static int scmi_voltage_level_set(const struct scmi_handle *handle,
u32 domain_id, u32 flags, s32 volt_uV)
{
int ret;
struct scmi_xfer *t;
struct voltage_info *vinfo = handle->voltage_priv;
struct scmi_msg_cmd_level_set *cmd;
if (domain_id >= vinfo->num_domains)
return -EINVAL;
ret = scmi_xfer_get_init(handle, VOLTAGE_LEVEL_SET,
SCMI_PROTOCOL_VOLTAGE,
sizeof(*cmd), 0, &t);
if (ret)
return ret;
cmd = t->tx.buf;
cmd->domain_id = cpu_to_le32(domain_id);
cmd->flags = cpu_to_le32(flags);
cmd->voltage_level = cpu_to_le32(volt_uV);
ret = scmi_do_xfer(handle, t);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_voltage_level_get(const struct scmi_handle *handle,
u32 domain_id, s32 *volt_uV)
{
return __scmi_voltage_get_u32(handle, VOLTAGE_LEVEL_GET,
domain_id, (u32 *)volt_uV);
}
static const struct scmi_voltage_info * __must_check
scmi_voltage_info_get(const struct scmi_handle *handle, u32 domain_id)
{
struct voltage_info *vinfo = handle->voltage_priv;
if (domain_id >= vinfo->num_domains ||
!vinfo->domains[domain_id].num_levels)
return NULL;
return vinfo->domains + domain_id;
}
static int scmi_voltage_domains_num_get(const struct scmi_handle *handle)
{
struct voltage_info *vinfo = handle->voltage_priv;
return vinfo->num_domains;
}
static struct scmi_voltage_ops voltage_ops = {
.num_domains_get = scmi_voltage_domains_num_get,
.info_get = scmi_voltage_info_get,
.config_set = scmi_voltage_config_set,
.config_get = scmi_voltage_config_get,
.level_set = scmi_voltage_level_set,
.level_get = scmi_voltage_level_get,
};
static int scmi_voltage_protocol_init(struct scmi_handle *handle)
{
int ret;
u32 version;
struct voltage_info *vinfo;
ret = scmi_version_get(handle, SCMI_PROTOCOL_VOLTAGE, &version);
if (ret)
return ret;
dev_dbg(handle->dev, "Voltage Version %d.%d\n",
PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
vinfo = devm_kzalloc(handle->dev, sizeof(*vinfo), GFP_KERNEL);
if (!vinfo)
return -ENOMEM;
vinfo->version = version;
ret = scmi_protocol_attributes_get(handle, vinfo);
if (ret)
return ret;
if (vinfo->num_domains) {
vinfo->domains = devm_kcalloc(handle->dev, vinfo->num_domains,
sizeof(*vinfo->domains),
GFP_KERNEL);
if (!vinfo->domains)
return -ENOMEM;
ret = scmi_voltage_descriptors_get(handle, vinfo);
if (ret)
return ret;
} else {
dev_warn(handle->dev, "No Voltage domains found.\n");
}
handle->voltage_ops = &voltage_ops;
handle->voltage_priv = vinfo;
return 0;
}
DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_VOLTAGE, voltage)

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@ -209,6 +209,64 @@ struct scmi_reset_ops {
int (*deassert)(const struct scmi_handle *handle, u32 domain);
};
/**
* struct scmi_voltage_info - describe one available SCMI Voltage Domain
*
* @id: the domain ID as advertised by the platform
* @segmented: defines the layout of the entries of array @levels_uv.
* - when True the entries are to be interpreted as triplets,
* each defining a segment representing a range of equally
* space voltages: <lowest_volts>, <highest_volt>, <step_uV>
* - when False the entries simply represent a single discrete
* supported voltage level
* @negative_volts_allowed: True if any of the entries of @levels_uv represent
* a negative voltage.
* @attributes: represents Voltage Domain advertised attributes
* @name: name assigned to the Voltage Domain by platform
* @num_levels: number of total entries in @levels_uv.
* @levels_uv: array of entries describing the available voltage levels for
* this domain.
*/
struct scmi_voltage_info {
unsigned int id;
bool segmented;
bool negative_volts_allowed;
unsigned int attributes;
char name[SCMI_MAX_STR_SIZE];
unsigned int num_levels;
#define SCMI_VOLTAGE_SEGMENT_LOW 0
#define SCMI_VOLTAGE_SEGMENT_HIGH 1
#define SCMI_VOLTAGE_SEGMENT_STEP 2
int *levels_uv;
};
/**
* struct scmi_voltage_ops - represents the various operations provided
* by SCMI Voltage Protocol
*
* @num_domains_get: get the count of voltage domains provided by SCMI
* @info_get: get the information of the specified domain
* @config_set: set the config for the specified domain
* @config_get: get the config of the specified domain
* @level_set: set the voltage level for the specified domain
* @level_get: get the voltage level of the specified domain
*/
struct scmi_voltage_ops {
int (*num_domains_get)(const struct scmi_handle *handle);
const struct scmi_voltage_info __must_check *(*info_get)
(const struct scmi_handle *handle, u32 domain_id);
int (*config_set)(const struct scmi_handle *handle, u32 domain_id,
u32 config);
#define SCMI_VOLTAGE_ARCH_STATE_OFF 0x0
#define SCMI_VOLTAGE_ARCH_STATE_ON 0x7
int (*config_get)(const struct scmi_handle *handle, u32 domain_id,
u32 *config);
int (*level_set)(const struct scmi_handle *handle, u32 domain_id,
u32 flags, s32 volt_uV);
int (*level_get)(const struct scmi_handle *handle, u32 domain_id,
s32 *volt_uV);
};
/**
* struct scmi_notify_ops - represents notifications' operations provided by
* SCMI core
@ -262,6 +320,7 @@ struct scmi_notify_ops {
* @clk_ops: pointer to set of clock protocol operations
* @sensor_ops: pointer to set of sensor protocol operations
* @reset_ops: pointer to set of reset protocol operations
* @voltage_ops: pointer to set of voltage protocol operations
* @notify_ops: pointer to set of notifications related operations
* @perf_priv: pointer to private data structure specific to performance
* protocol(for internal use only)
@ -273,6 +332,8 @@ struct scmi_notify_ops {
* protocol(for internal use only)
* @reset_priv: pointer to private data structure specific to reset
* protocol(for internal use only)
* @voltage_priv: pointer to private data structure specific to voltage
* protocol(for internal use only)
* @notify_priv: pointer to private data structure specific to notifications
* (for internal use only)
*/
@ -284,6 +345,7 @@ struct scmi_handle {
const struct scmi_power_ops *power_ops;
const struct scmi_sensor_ops *sensor_ops;
const struct scmi_reset_ops *reset_ops;
const struct scmi_voltage_ops *voltage_ops;
const struct scmi_notify_ops *notify_ops;
/* for protocol internal use */
void *perf_priv;
@ -291,6 +353,7 @@ struct scmi_handle {
void *power_priv;
void *sensor_priv;
void *reset_priv;
void *voltage_priv;
void *notify_priv;
void *system_priv;
};
@ -303,6 +366,7 @@ enum scmi_std_protocol {
SCMI_PROTOCOL_CLOCK = 0x14,
SCMI_PROTOCOL_SENSOR = 0x15,
SCMI_PROTOCOL_RESET = 0x16,
SCMI_PROTOCOL_VOLTAGE = 0x17,
};
enum scmi_system_events {