[PATCH v3 1/4] firmware: arm_scmi: Add Voltage Domain Support
Etienne Carriere
etienne.carriere at linaro.org
Wed Oct 28 10:29:57 EDT 2020
Hi Cristian,
Some remaining minor comments see below.
FYI I've successfully tested this series (the 4 patches).
Regards,
Etienne
On Mon, 26 Oct 2020 at 21:32, Cristian Marussi <cristian.marussi at arm.com> wrote:
>
> Add SCMI Voltage Domain protocol support.
>
> Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
> ---
> v2 --> v3
> - restrict segmented voltage domain descriptors to one triplet
> - removed unneeded inline
> - free allocated resources for invalid voltage domain
> - added __must_check to info_get voltage operations
> - added a few comments
> - removed fixed size typing from struct voltage_info
>
> v1 --> v2
> - fix voltage levels query loop to reload full cmd description
> between iterations as reported by Etienne Carriere
> - ensure rx buffer is properly sized calli scmi_reset_rx_to_maxsz
> between transfers
> ---
> drivers/firmware/arm_scmi/Makefile | 2 +-
> drivers/firmware/arm_scmi/common.h | 1 +
> drivers/firmware/arm_scmi/driver.c | 2 +
> drivers/firmware/arm_scmi/voltage.c | 398 ++++++++++++++++++++++++++++
> include/linux/scmi_protocol.h | 64 +++++
> 5 files changed, 466 insertions(+), 1 deletion(-)
> create mode 100644 drivers/firmware/arm_scmi/voltage.c
>
> diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
> index bc0d54f8e861..6a2ef63306d6 100644
> --- a/drivers/firmware/arm_scmi/Makefile
> +++ b/drivers/firmware/arm_scmi/Makefile
> @@ -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
> diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
> index 65063fa948d4..c0fb45e7c3e8 100644
> --- a/drivers/firmware/arm_scmi/common.h
> +++ b/drivers/firmware/arm_scmi/common.h
> @@ -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) \
> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> index 3dfd8b6a0ebf..ada35e63feae 100644
> --- a/drivers/firmware/arm_scmi/driver.c
> +++ b/drivers/firmware/arm_scmi/driver.c
> @@ -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);
> diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c
> new file mode 100644
> index 000000000000..2c5a3c8b8649
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/voltage.c
> @@ -0,0 +1,398 @@
> +// 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,
> +};
> +
> +struct scmi_msg_resp_protocol_attributes {
> + __le32 attr;
> +#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 {
> + u32 version;
> + u16 num_domains;
Could be an unsigned int.
> + 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;
> + struct scmi_msg_resp_protocol_attributes *resp;
> +
> + ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
> + SCMI_PROTOCOL_VOLTAGE, 0, sizeof(*resp), &t);
> + if (ret)
> + return ret;
> +
> + resp = t->rx.buf;
> + ret = scmi_do_xfer(handle, t);
> + if (!ret)
> + vinfo->num_domains =
> + NUM_VOLTAGE_DOMAINS(le32_to_cpu(resp->attr));
> +
> + scmi_xfer_put(handle, t);
> + return ret;
> +}
> +
> +static inline int scmi_init_voltage_levels(struct device *dev,
Should remove this inline attribute.
> + struct scmi_voltage_info *v,
> + u32 flags, u32 num_returned,
> + u32 num_remaining)
> +{
> + bool segmented;
> + u32 num_levels;
> +
> + segmented = SUPPORTS_SEGMENTED_LEVELS(flags);
> + 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 = devm_kzalloc(dev, sizeof(*v), GFP_KERNEL);
> + if (!v) {
> + ret = -ENOMEM;
> + break;
> + }
> +
> + 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, flags,
> + num_returned,
> + num_remaining);
> + 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);
> +
> + /*
> + * Bail out only on memory errors, just skip domain and free
> + * on any other error.
> + */
> + if (!ret) {
> + vinfo->domains[dom] = v;
> + } else if (ret != -ENOMEM) {
> + devm_kfree(dev, v->levels_uv);
> + devm_kfree(dev, v);
> + } else {
> + break;
> + }
> +
> + 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)
> + 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)
> diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> index 9cd312a1ff92..181fdebc2793 100644
> --- a/include/linux/scmi_protocol.h
> +++ b/include/linux/scmi_protocol.h
> @@ -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;
> +#define SCMI_VOLTAGE_SEGMENT_LOW 0
> +#define SCMI_VOLTAGE_SEGMENT_HIGH 1
> +#define SCMI_VOLTAGE_SEGMENT_STEP 2
Maybe move these macros before 'int *level_us;' as these are indices
in that array.
> + bool negative_volts_allowed;
> + unsigned int attributes;
> + char name[SCMI_MAX_STR_SIZE];
> + unsigned int num_levels;
> + 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 {
> --
> 2.17.1
>
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