// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface (SCMI) Sensor Protocol
 *
 * Copyright (C) 2018-2022 ARM Ltd.
 */

#define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt

#include <linux/bitfield.h>
#include <linux/module.h>
#include <linux/scmi_protocol.h>

#include "protocols.h"
#include "notify.h"

/* Updated only after ALL the mandatory features for that version are merged */
#define SCMI_PROTOCOL_SUPPORTED_VERSION         0x30001

#define SCMI_MAX_NUM_SENSOR_AXIS        63
#define SCMIv2_SENSOR_PROTOCOL          0x10000

enum scmi_sensor_protocol_cmd {
        SENSOR_DESCRIPTION_GET = 0x3,
        SENSOR_TRIP_POINT_NOTIFY = 0x4,
        SENSOR_TRIP_POINT_CONFIG = 0x5,
        SENSOR_READING_GET = 0x6,
        SENSOR_AXIS_DESCRIPTION_GET = 0x7,
        SENSOR_LIST_UPDATE_INTERVALS = 0x8,
        SENSOR_CONFIG_GET = 0x9,
        SENSOR_CONFIG_SET = 0xA,
        SENSOR_CONTINUOUS_UPDATE_NOTIFY = 0xB,
        SENSOR_NAME_GET = 0xC,
        SENSOR_AXIS_NAME_GET = 0xD,
};

struct scmi_msg_resp_sensor_attributes {
        __le16 num_sensors;
        u8 max_requests;
        u8 reserved;
        __le32 reg_addr_low;
        __le32 reg_addr_high;
        __le32 reg_size;
};

/* v3 attributes_low macros */
#define SUPPORTS_UPDATE_NOTIFY(x)       FIELD_GET(BIT(30), (x))
#define SENSOR_TSTAMP_EXP(x)            FIELD_GET(GENMASK(14, 10), (x))
#define SUPPORTS_TIMESTAMP(x)           FIELD_GET(BIT(9), (x))
#define SUPPORTS_EXTEND_ATTRS(x)        FIELD_GET(BIT(8), (x))

/* v2 attributes_high macros */
#define SENSOR_UPDATE_BASE(x)           FIELD_GET(GENMASK(31, 27), (x))
#define SENSOR_UPDATE_SCALE(x)          FIELD_GET(GENMASK(26, 22), (x))

/* v3 attributes_high macros */
#define SENSOR_AXIS_NUMBER(x)           FIELD_GET(GENMASK(21, 16), (x))
#define SUPPORTS_AXIS(x)                FIELD_GET(BIT(8), (x))

/* v3 resolution macros */
#define SENSOR_RES(x)                   FIELD_GET(GENMASK(26, 0), (x))
#define SENSOR_RES_EXP(x)               FIELD_GET(GENMASK(31, 27), (x))

struct scmi_msg_resp_attrs {
        __le32 min_range_low;
        __le32 min_range_high;
        __le32 max_range_low;
        __le32 max_range_high;
};

struct scmi_msg_sensor_description {
        __le32 desc_index;
};

struct scmi_msg_resp_sensor_description {
        __le16 num_returned;
        __le16 num_remaining;
        struct scmi_sensor_descriptor {
                __le32 id;
                __le32 attributes_low;
/* Common attributes_low macros */
#define SUPPORTS_ASYNC_READ(x)          FIELD_GET(BIT(31), (x))
#define SUPPORTS_EXTENDED_NAMES(x)      FIELD_GET(BIT(29), (x))
#define NUM_TRIP_POINTS(x)              FIELD_GET(GENMASK(7, 0), (x))
                __le32 attributes_high;
/* Common attributes_high macros */
#define SENSOR_SCALE(x)                 FIELD_GET(GENMASK(15, 11), (x))
#define SENSOR_SCALE_SIGN               BIT(4)
#define SENSOR_SCALE_EXTEND             GENMASK(31, 5)
#define SENSOR_TYPE(x)                  FIELD_GET(GENMASK(7, 0), (x))
                u8 name[SCMI_SHORT_NAME_MAX_SIZE];
                /* only for version > 2.0 */
                __le32 power;
                __le32 resolution;
                struct scmi_msg_resp_attrs scalar_attrs;
        } desc[];
};

/* Base scmi_sensor_descriptor size excluding extended attrs after name */
#define SCMI_MSG_RESP_SENS_DESCR_BASE_SZ        28

/* Sign extend to a full s32 */
#define S32_EXT(v)                                                      \
        ({                                                              \
                int __v = (v);                                          \
                                                                        \
                if (__v & SENSOR_SCALE_SIGN)                            \
                        __v |= SENSOR_SCALE_EXTEND;                     \
                __v;                                                    \
        })

struct scmi_msg_sensor_axis_description_get {
        __le32 id;
        __le32 axis_desc_index;
};

struct scmi_msg_resp_sensor_axis_description {
        __le32 num_axis_flags;
#define NUM_AXIS_RETURNED(x)            FIELD_GET(GENMASK(5, 0), (x))
#define NUM_AXIS_REMAINING(x)           FIELD_GET(GENMASK(31, 26), (x))
        struct scmi_axis_descriptor {
                __le32 id;
                __le32 attributes_low;
#define SUPPORTS_EXTENDED_AXIS_NAMES(x) FIELD_GET(BIT(9), (x))
                __le32 attributes_high;
                u8 name[SCMI_SHORT_NAME_MAX_SIZE];
                __le32 resolution;
                struct scmi_msg_resp_attrs attrs;
        } desc[];
};

struct scmi_msg_resp_sensor_axis_names_description {
        __le32 num_axis_flags;
        struct scmi_sensor_axis_name_descriptor {
                __le32 axis_id;
                u8 name[SCMI_MAX_STR_SIZE];
        } desc[];
};

/* Base scmi_axis_descriptor size excluding extended attrs after name */
#define SCMI_MSG_RESP_AXIS_DESCR_BASE_SZ        28

struct scmi_msg_sensor_list_update_intervals {
        __le32 id;
        __le32 index;
};

struct scmi_msg_resp_sensor_list_update_intervals {
        __le32 num_intervals_flags;
#define NUM_INTERVALS_RETURNED(x)       FIELD_GET(GENMASK(11, 0), (x))
#define SEGMENTED_INTVL_FORMAT(x)       FIELD_GET(BIT(12), (x))
#define NUM_INTERVALS_REMAINING(x)      FIELD_GET(GENMASK(31, 16), (x))
        __le32 intervals[];
};

struct scmi_msg_sensor_request_notify {
        __le32 id;
        __le32 event_control;
#define SENSOR_NOTIFY_ALL       BIT(0)
};

struct scmi_msg_set_sensor_trip_point {
        __le32 id;
        __le32 event_control;
#define SENSOR_TP_EVENT_MASK    (0x3)
#define SENSOR_TP_DISABLED      0x0
#define SENSOR_TP_POSITIVE      0x1
#define SENSOR_TP_NEGATIVE      0x2
#define SENSOR_TP_BOTH          0x3
#define SENSOR_TP_ID(x)         (((x) & 0xff) << 4)
        __le32 value_low;
        __le32 value_high;
};

struct scmi_msg_sensor_config_set {
        __le32 id;
        __le32 sensor_config;
};

struct scmi_msg_sensor_reading_get {
        __le32 id;
        __le32 flags;
#define SENSOR_READ_ASYNC       BIT(0)
};

struct scmi_resp_sensor_reading_complete {
        __le32 id;
        __le32 readings_low;
        __le32 readings_high;
};

struct scmi_sensor_reading_resp {
        __le32 sensor_value_low;
        __le32 sensor_value_high;
        __le32 timestamp_low;
        __le32 timestamp_high;
};

struct scmi_resp_sensor_reading_complete_v3 {
        __le32 id;
        struct scmi_sensor_reading_resp readings[];
};

struct scmi_sensor_trip_notify_payld {
        __le32 agent_id;
        __le32 sensor_id;
        __le32 trip_point_desc;
};

struct scmi_sensor_update_notify_payld {
        __le32 agent_id;
        __le32 sensor_id;
        struct scmi_sensor_reading_resp readings[];
};

struct sensors_info {
        bool notify_trip_point_cmd;
        bool notify_continuos_update_cmd;
        int num_sensors;
        int max_requests;
        u64 reg_addr;
        u32 reg_size;
        struct scmi_sensor_info *sensors;
};

static int scmi_sensor_attributes_get(const struct scmi_protocol_handle *ph,
                                      struct sensors_info *si)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_msg_resp_sensor_attributes *attr;

        ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
                                      0, sizeof(*attr), &t);
        if (ret)
                return ret;

        attr = t->rx.buf;

        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
                si->num_sensors = le16_to_cpu(attr->num_sensors);
                si->max_requests = attr->max_requests;
                si->reg_addr = le32_to_cpu(attr->reg_addr_low) |
                                (u64)le32_to_cpu(attr->reg_addr_high) << 32;
                si->reg_size = le32_to_cpu(attr->reg_size);
        }

        ph->xops->xfer_put(ph, t);

        if (!ret) {
                if (!ph->hops->protocol_msg_check(ph,
                                                  SENSOR_TRIP_POINT_NOTIFY, NULL))
                        si->notify_trip_point_cmd = true;

                if (!ph->hops->protocol_msg_check(ph,
                                                  SENSOR_CONTINUOUS_UPDATE_NOTIFY,
                                                  NULL))
                        si->notify_continuos_update_cmd = true;
        }

        return ret;
}

static inline void scmi_parse_range_attrs(struct scmi_range_attrs *out,
                                          const struct scmi_msg_resp_attrs *in)
{
        out->min_range = get_unaligned_le64((void *)&in->min_range_low);
        out->max_range = get_unaligned_le64((void *)&in->max_range_low);
}

struct scmi_sens_ipriv {
        void *priv;
        struct device *dev;
};

static void iter_intervals_prepare_message(void *message,
                                           unsigned int desc_index,
                                           const void *p)
{
        struct scmi_msg_sensor_list_update_intervals *msg = message;
        const struct scmi_sensor_info *s;

        s = ((const struct scmi_sens_ipriv *)p)->priv;
        /* Set the number of sensors to be skipped/already read */
        msg->id = cpu_to_le32(s->id);
        msg->index = cpu_to_le32(desc_index);
}

static int iter_intervals_update_state(struct scmi_iterator_state *st,
                                       const void *response, void *p)
{
        u32 flags;
        struct scmi_sensor_info *s = ((struct scmi_sens_ipriv *)p)->priv;
        struct device *dev = ((struct scmi_sens_ipriv *)p)->dev;
        const struct scmi_msg_resp_sensor_list_update_intervals *r = response;

        flags = le32_to_cpu(r->num_intervals_flags);
        st->num_returned = NUM_INTERVALS_RETURNED(flags);
        st->num_remaining = NUM_INTERVALS_REMAINING(flags);

        /*
         * Max intervals is not declared previously anywhere so we
         * assume it's returned+remaining on first call.
         */
        if (!st->max_resources) {
                s->intervals.segmented = SEGMENTED_INTVL_FORMAT(flags);
                s->intervals.count = st->num_returned + st->num_remaining;
                /* segmented intervals are reported in one triplet */
                if (s->intervals.segmented &&
                    (st->num_remaining || st->num_returned != 3)) {
                        dev_err(dev,
                                "Sensor ID:%d advertises an invalid segmented interval (%d)\n",
                                s->id, s->intervals.count);
                        s->intervals.segmented = false;
                        s->intervals.count = 0;
                        return -EINVAL;
                }
                /* Direct allocation when exceeding pre-allocated */
                if (s->intervals.count >= SCMI_MAX_PREALLOC_POOL) {
                        s->intervals.desc =
                                devm_kcalloc(dev,
                                             s->intervals.count,
                                             sizeof(*s->intervals.desc),
                                             GFP_KERNEL);
                        if (!s->intervals.desc) {
                                s->intervals.segmented = false;
                                s->intervals.count = 0;
                                return -ENOMEM;
                        }
                }

                st->max_resources = s->intervals.count;
        }

        return 0;
}

static int
iter_intervals_process_response(const struct scmi_protocol_handle *ph,
                                const void *response,
                                struct scmi_iterator_state *st, void *p)
{
        const struct scmi_msg_resp_sensor_list_update_intervals *r = response;
        struct scmi_sensor_info *s = ((struct scmi_sens_ipriv *)p)->priv;

        s->intervals.desc[st->desc_index + st->loop_idx] =
                le32_to_cpu(r->intervals[st->loop_idx]);

        return 0;
}

static int scmi_sensor_update_intervals(const struct scmi_protocol_handle *ph,
                                        struct scmi_sensor_info *s)
{
        void *iter;
        struct scmi_iterator_ops ops = {
                .prepare_message = iter_intervals_prepare_message,
                .update_state = iter_intervals_update_state,
                .process_response = iter_intervals_process_response,
        };
        struct scmi_sens_ipriv upriv = {
                .priv = s,
                .dev = ph->dev,
        };

        iter = ph->hops->iter_response_init(ph, &ops, s->intervals.count,
                                            SENSOR_LIST_UPDATE_INTERVALS,
                                            sizeof(struct scmi_msg_sensor_list_update_intervals),
                                            &upriv);
        if (IS_ERR(iter))
                return PTR_ERR(iter);

        return ph->hops->iter_response_run(iter);
}

struct scmi_apriv {
        bool any_axes_support_extended_names;
        struct scmi_sensor_info *s;
};

static void iter_axes_desc_prepare_message(void *message,
                                           const unsigned int desc_index,
                                           const void *priv)
{
        struct scmi_msg_sensor_axis_description_get *msg = message;
        const struct scmi_apriv *apriv = priv;

        /* Set the number of sensors to be skipped/already read */
        msg->id = cpu_to_le32(apriv->s->id);
        msg->axis_desc_index = cpu_to_le32(desc_index);
}

static int
iter_axes_desc_update_state(struct scmi_iterator_state *st,
                            const void *response, void *priv)
{
        u32 flags;
        const struct scmi_msg_resp_sensor_axis_description *r = response;

        flags = le32_to_cpu(r->num_axis_flags);
        st->num_returned = NUM_AXIS_RETURNED(flags);
        st->num_remaining = NUM_AXIS_REMAINING(flags);
        st->priv = (void *)&r->desc[0];

        return 0;
}

static int
iter_axes_desc_process_response(const struct scmi_protocol_handle *ph,
                                const void *response,
                                struct scmi_iterator_state *st, void *priv)
{
        u32 attrh, attrl;
        struct scmi_sensor_axis_info *a;
        size_t dsize = SCMI_MSG_RESP_AXIS_DESCR_BASE_SZ;
        struct scmi_apriv *apriv = priv;
        const struct scmi_axis_descriptor *adesc = st->priv;

        attrl = le32_to_cpu(adesc->attributes_low);
        if (SUPPORTS_EXTENDED_AXIS_NAMES(attrl))
                apriv->any_axes_support_extended_names = true;

        a = &apriv->s->axis[st->desc_index + st->loop_idx];
        a->id = le32_to_cpu(adesc->id);
        a->extended_attrs = SUPPORTS_EXTEND_ATTRS(attrl);

        attrh = le32_to_cpu(adesc->attributes_high);
        a->scale = S32_EXT(SENSOR_SCALE(attrh));
        a->type = SENSOR_TYPE(attrh);
        strscpy(a->name, adesc->name, SCMI_SHORT_NAME_MAX_SIZE);

        if (a->extended_attrs) {
                unsigned int ares = le32_to_cpu(adesc->resolution);

                a->resolution = SENSOR_RES(ares);
                a->exponent = S32_EXT(SENSOR_RES_EXP(ares));
                dsize += sizeof(adesc->resolution);

                scmi_parse_range_attrs(&a->attrs, &adesc->attrs);
                dsize += sizeof(adesc->attrs);
        }
        st->priv = ((u8 *)adesc + dsize);

        return 0;
}

static int
iter_axes_extended_name_update_state(struct scmi_iterator_state *st,
                                     const void *response, void *priv)
{
        u32 flags;
        const struct scmi_msg_resp_sensor_axis_names_description *r = response;

        flags = le32_to_cpu(r->num_axis_flags);
        st->num_returned = NUM_AXIS_RETURNED(flags);
        st->num_remaining = NUM_AXIS_REMAINING(flags);
        st->priv = (void *)&r->desc[0];

        return 0;
}

static int
iter_axes_extended_name_process_response(const struct scmi_protocol_handle *ph,
                                         const void *response,
                                         struct scmi_iterator_state *st,
                                         void *priv)
{
        struct scmi_sensor_axis_info *a;
        const struct scmi_apriv *apriv = priv;
        struct scmi_sensor_axis_name_descriptor *adesc = st->priv;
        u32 axis_id = le32_to_cpu(adesc->axis_id);

        if (axis_id >= st->max_resources)
                return -EPROTO;

        /*
         * Pick the corresponding descriptor based on the axis_id embedded
         * in the reply since the list of axes supporting extended names
         * can be a subset of all the axes.
         */
        a = &apriv->s->axis[axis_id];
        strscpy(a->name, adesc->name, SCMI_MAX_STR_SIZE);
        st->priv = ++adesc;

        return 0;
}

static int
scmi_sensor_axis_extended_names_get(const struct scmi_protocol_handle *ph,
                                    struct scmi_sensor_info *s)
{
        int ret;
        void *iter;
        struct scmi_iterator_ops ops = {
                .prepare_message = iter_axes_desc_prepare_message,
                .update_state = iter_axes_extended_name_update_state,
                .process_response = iter_axes_extended_name_process_response,
        };
        struct scmi_apriv apriv = {
                .any_axes_support_extended_names = false,
                .s = s,
        };

        iter = ph->hops->iter_response_init(ph, &ops, s->num_axis,
                                            SENSOR_AXIS_NAME_GET,
                                            sizeof(struct scmi_msg_sensor_axis_description_get),
                                            &apriv);
        if (IS_ERR(iter))
                return PTR_ERR(iter);

        /*
         * Do not cause whole protocol initialization failure when failing to
         * get extended names for axes.
         */
        ret = ph->hops->iter_response_run(iter);
        if (ret)
                dev_warn(ph->dev,
                         "Failed to get axes extended names for %s (ret:%d).\n",
                         s->name, ret);

        return 0;
}

static int scmi_sensor_axis_description(const struct scmi_protocol_handle *ph,
                                        struct scmi_sensor_info *s)
{
        int ret;
        void *iter;
        struct scmi_iterator_ops ops = {
                .prepare_message = iter_axes_desc_prepare_message,
                .update_state = iter_axes_desc_update_state,
                .process_response = iter_axes_desc_process_response,
        };
        struct scmi_apriv apriv = {
                .any_axes_support_extended_names = false,
                .s = s,
        };

        s->axis = devm_kcalloc(ph->dev, s->num_axis,
                               sizeof(*s->axis), GFP_KERNEL);
        if (!s->axis)
                return -ENOMEM;

        iter = ph->hops->iter_response_init(ph, &ops, s->num_axis,
                                            SENSOR_AXIS_DESCRIPTION_GET,
                                            sizeof(struct scmi_msg_sensor_axis_description_get),
                                            &apriv);
        if (IS_ERR(iter))
                return PTR_ERR(iter);

        ret = ph->hops->iter_response_run(iter);
        if (ret)
                return ret;

        if (PROTOCOL_REV_MAJOR(ph->version) >= 0x3 &&
            apriv.any_axes_support_extended_names)
                ret = scmi_sensor_axis_extended_names_get(ph, s);

        return ret;
}

static void iter_sens_descr_prepare_message(void *message,
                                            unsigned int desc_index,
                                            const void *priv)
{
        struct scmi_msg_sensor_description *msg = message;

        msg->desc_index = cpu_to_le32(desc_index);
}

static int iter_sens_descr_update_state(struct scmi_iterator_state *st,
                                        const void *response, void *priv)
{
        const struct scmi_msg_resp_sensor_description *r = response;

        st->num_returned = le16_to_cpu(r->num_returned);
        st->num_remaining = le16_to_cpu(r->num_remaining);
        st->priv = (void *)&r->desc[0];

        return 0;
}

static int
iter_sens_descr_process_response(const struct scmi_protocol_handle *ph,
                                 const void *response,
                                 struct scmi_iterator_state *st, void *priv)

{
        int ret = 0;
        u32 attrh, attrl;
        size_t dsize = SCMI_MSG_RESP_SENS_DESCR_BASE_SZ;
        struct scmi_sensor_info *s;
        struct sensors_info *si = priv;
        const struct scmi_sensor_descriptor *sdesc = st->priv;

        s = &si->sensors[st->desc_index + st->loop_idx];
        s->id = le32_to_cpu(sdesc->id);

        attrl = le32_to_cpu(sdesc->attributes_low);
        /* common bitfields parsing */
        s->async = SUPPORTS_ASYNC_READ(attrl);
        s->num_trip_points = NUM_TRIP_POINTS(attrl);
        /**
         * only SCMIv3.0 specific bitfield below.
         * Such bitfields are assumed to be zeroed on non
         * relevant fw versions...assuming fw not buggy !
         */
        if (si->notify_continuos_update_cmd)
                s->update = SUPPORTS_UPDATE_NOTIFY(attrl);
        s->timestamped = SUPPORTS_TIMESTAMP(attrl);
        if (s->timestamped)
                s->tstamp_scale = S32_EXT(SENSOR_TSTAMP_EXP(attrl));
        s->extended_scalar_attrs = SUPPORTS_EXTEND_ATTRS(attrl);

        attrh = le32_to_cpu(sdesc->attributes_high);
        /* common bitfields parsing */
        s->scale = S32_EXT(SENSOR_SCALE(attrh));
        s->type = SENSOR_TYPE(attrh);
        /* Use pre-allocated pool wherever possible */
        s->intervals.desc = s->intervals.prealloc_pool;
        if (ph->version == SCMIv2_SENSOR_PROTOCOL) {
                s->intervals.segmented = false;
                s->intervals.count = 1;
                /*
                 * Convert SCMIv2.0 update interval format to
                 * SCMIv3.0 to be used as the common exposed
                 * descriptor, accessible via common macros.
                 */
                s->intervals.desc[0] = (SENSOR_UPDATE_BASE(attrh) << 5) |
                                        SENSOR_UPDATE_SCALE(attrh);
        } else {
                /*
                 * From SCMIv3.0 update intervals are retrieved
                 * via a dedicated (optional) command.
                 * Since the command is optional, on error carry
                 * on without any update interval.
                 */
                if (scmi_sensor_update_intervals(ph, s))
                        dev_dbg(ph->dev,
                                "Update Intervals not available for sensor ID:%d\n",
                                s->id);
        }
        /**
         * only > SCMIv2.0 specific bitfield below.
         * Such bitfields are assumed to be zeroed on non
         * relevant fw versions...assuming fw not buggy !
         */
        s->num_axis = min_t(unsigned int,
                            SUPPORTS_AXIS(attrh) ?
                            SENSOR_AXIS_NUMBER(attrh) : 0,
                            SCMI_MAX_NUM_SENSOR_AXIS);
        strscpy(s->name, sdesc->name, SCMI_SHORT_NAME_MAX_SIZE);

        /*
         * If supported overwrite short name with the extended
         * one; on error just carry on and use already provided
         * short name.
         */
        if (PROTOCOL_REV_MAJOR(ph->version) >= 0x3 &&
            SUPPORTS_EXTENDED_NAMES(attrl))
                ph->hops->extended_name_get(ph, SENSOR_NAME_GET, s->id,
                                            NULL, s->name, SCMI_MAX_STR_SIZE);

        if (s->extended_scalar_attrs) {
                s->sensor_power = le32_to_cpu(sdesc->power);
                dsize += sizeof(sdesc->power);

                /* Only for sensors reporting scalar values */
                if (s->num_axis == 0) {
                        unsigned int sres = le32_to_cpu(sdesc->resolution);

                        s->resolution = SENSOR_RES(sres);
                        s->exponent = S32_EXT(SENSOR_RES_EXP(sres));
                        dsize += sizeof(sdesc->resolution);

                        scmi_parse_range_attrs(&s->scalar_attrs,
                                               &sdesc->scalar_attrs);
                        dsize += sizeof(sdesc->scalar_attrs);
                }
        }

        if (s->num_axis > 0)
                ret = scmi_sensor_axis_description(ph, s);

        st->priv = ((u8 *)sdesc + dsize);

        return ret;
}

static int scmi_sensor_description_get(const struct scmi_protocol_handle *ph,
                                       struct sensors_info *si)
{
        void *iter;
        struct scmi_iterator_ops ops = {
                .prepare_message = iter_sens_descr_prepare_message,
                .update_state = iter_sens_descr_update_state,
                .process_response = iter_sens_descr_process_response,
        };

        iter = ph->hops->iter_response_init(ph, &ops, si->num_sensors,
                                            SENSOR_DESCRIPTION_GET,
                                            sizeof(__le32), si);
        if (IS_ERR(iter))
                return PTR_ERR(iter);

        return ph->hops->iter_response_run(iter);
}

static inline int
scmi_sensor_request_notify(const struct scmi_protocol_handle *ph, u32 sensor_id,
                           u8 message_id, bool enable)
{
        int ret;
        u32 evt_cntl = enable ? SENSOR_NOTIFY_ALL : 0;
        struct scmi_xfer *t;
        struct scmi_msg_sensor_request_notify *cfg;

        ret = ph->xops->xfer_get_init(ph, message_id, sizeof(*cfg), 0, &t);
        if (ret)
                return ret;

        cfg = t->tx.buf;
        cfg->id = cpu_to_le32(sensor_id);
        cfg->event_control = cpu_to_le32(evt_cntl);

        ret = ph->xops->do_xfer(ph, t);

        ph->xops->xfer_put(ph, t);
        return ret;
}

static int scmi_sensor_trip_point_notify(const struct scmi_protocol_handle *ph,
                                         u32 sensor_id, bool enable)
{
        return scmi_sensor_request_notify(ph, sensor_id,
                                          SENSOR_TRIP_POINT_NOTIFY,
                                          enable);
}

static int
scmi_sensor_continuous_update_notify(const struct scmi_protocol_handle *ph,
                                     u32 sensor_id, bool enable)
{
        return scmi_sensor_request_notify(ph, sensor_id,
                                          SENSOR_CONTINUOUS_UPDATE_NOTIFY,
                                          enable);
}

static int
scmi_sensor_trip_point_config(const struct scmi_protocol_handle *ph,
                              u32 sensor_id, u8 trip_id, u64 trip_value)
{
        int ret;
        u32 evt_cntl = SENSOR_TP_BOTH;
        struct scmi_xfer *t;
        struct scmi_msg_set_sensor_trip_point *trip;

        ret = ph->xops->xfer_get_init(ph, SENSOR_TRIP_POINT_CONFIG,
                                      sizeof(*trip), 0, &t);
        if (ret)
                return ret;

        trip = t->tx.buf;
        trip->id = cpu_to_le32(sensor_id);
        trip->event_control = cpu_to_le32(evt_cntl | SENSOR_TP_ID(trip_id));
        trip->value_low = cpu_to_le32(trip_value & 0xffffffff);
        trip->value_high = cpu_to_le32(trip_value >> 32);

        ret = ph->xops->do_xfer(ph, t);

        ph->xops->xfer_put(ph, t);
        return ret;
}

static int scmi_sensor_config_get(const struct scmi_protocol_handle *ph,
                                  u32 sensor_id, u32 *sensor_config)
{
        int ret;
        struct scmi_xfer *t;
        struct sensors_info *si = ph->get_priv(ph);

        if (sensor_id >= si->num_sensors)
                return -EINVAL;

        ret = ph->xops->xfer_get_init(ph, SENSOR_CONFIG_GET,
                                      sizeof(__le32), sizeof(__le32), &t);
        if (ret)
                return ret;

        put_unaligned_le32(sensor_id, t->tx.buf);
        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
                struct scmi_sensor_info *s = si->sensors + sensor_id;

                *sensor_config = get_unaligned_le64(t->rx.buf);
                s->sensor_config = *sensor_config;
        }

        ph->xops->xfer_put(ph, t);
        return ret;
}

static int scmi_sensor_config_set(const struct scmi_protocol_handle *ph,
                                  u32 sensor_id, u32 sensor_config)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_msg_sensor_config_set *msg;
        struct sensors_info *si = ph->get_priv(ph);

        if (sensor_id >= si->num_sensors)
                return -EINVAL;

        ret = ph->xops->xfer_get_init(ph, SENSOR_CONFIG_SET,
                                      sizeof(*msg), 0, &t);
        if (ret)
                return ret;

        msg = t->tx.buf;
        msg->id = cpu_to_le32(sensor_id);
        msg->sensor_config = cpu_to_le32(sensor_config);

        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
                struct scmi_sensor_info *s = si->sensors + sensor_id;

                s->sensor_config = sensor_config;
        }

        ph->xops->xfer_put(ph, t);
        return ret;
}

/**
 * scmi_sensor_reading_get  - Read scalar sensor value
 * @ph: Protocol handle
 * @sensor_id: Sensor ID
 * @value: The 64bit value sensor reading
 *
 * This function returns a single 64 bit reading value representing the sensor
 * value; if the platform SCMI Protocol implementation and the sensor support
 * multiple axis and timestamped-reads, this just returns the first axis while
 * dropping the timestamp value.
 * Use instead the @scmi_sensor_reading_get_timestamped to retrieve the array of
 * timestamped multi-axis values.
 *
 * Return: 0 on Success
 */
static int scmi_sensor_reading_get(const struct scmi_protocol_handle *ph,
                                   u32 sensor_id, u64 *value)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_msg_sensor_reading_get *sensor;
        struct scmi_sensor_info *s;
        struct sensors_info *si = ph->get_priv(ph);

        if (sensor_id >= si->num_sensors)
                return -EINVAL;

        ret = ph->xops->xfer_get_init(ph, SENSOR_READING_GET,
                                      sizeof(*sensor), 0, &t);
        if (ret)
                return ret;

        sensor = t->tx.buf;
        sensor->id = cpu_to_le32(sensor_id);
        s = si->sensors + sensor_id;
        if (s->async) {
                sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
                ret = ph->xops->do_xfer_with_response(ph, t);
                if (!ret) {
                        struct scmi_resp_sensor_reading_complete *resp;

                        resp = t->rx.buf;
                        if (le32_to_cpu(resp->id) == sensor_id)
                                *value =
                                        get_unaligned_le64(&resp->readings_low);
                        else
                                ret = -EPROTO;
                }
        } else {
                sensor->flags = cpu_to_le32(0);
                ret = ph->xops->do_xfer(ph, t);
                if (!ret)
                        *value = get_unaligned_le64(t->rx.buf);
        }

        ph->xops->xfer_put(ph, t);
        return ret;
}

static inline void
scmi_parse_sensor_readings(struct scmi_sensor_reading *out,
                           const struct scmi_sensor_reading_resp *in)
{
        out->value = get_unaligned_le64((void *)&in->sensor_value_low);
        out->timestamp = get_unaligned_le64((void *)&in->timestamp_low);
}

/**
 * scmi_sensor_reading_get_timestamped  - Read multiple-axis timestamped values
 * @ph: Protocol handle
 * @sensor_id: Sensor ID
 * @count: The length of the provided @readings array
 * @readings: An array of elements each representing a timestamped per-axis
 *            reading of type @struct scmi_sensor_reading.
 *            Returned readings are ordered as the @axis descriptors array
 *            included in @struct scmi_sensor_info and the max number of
 *            returned elements is min(@count, @num_axis); ideally the provided
 *            array should be of length @count equal to @num_axis.
 *
 * Return: 0 on Success
 */
static int
scmi_sensor_reading_get_timestamped(const struct scmi_protocol_handle *ph,
                                    u32 sensor_id, u8 count,
                                    struct scmi_sensor_reading *readings)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_msg_sensor_reading_get *sensor;
        struct scmi_sensor_info *s;
        struct sensors_info *si = ph->get_priv(ph);

        if (sensor_id >= si->num_sensors)
                return -EINVAL;

        s = si->sensors + sensor_id;
        if (!count || !readings ||
            (!s->num_axis && count > 1) || (s->num_axis && count > s->num_axis))
                return -EINVAL;

        ret = ph->xops->xfer_get_init(ph, SENSOR_READING_GET,
                                      sizeof(*sensor), 0, &t);
        if (ret)
                return ret;

        sensor = t->tx.buf;
        sensor->id = cpu_to_le32(sensor_id);
        if (s->async) {
                sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
                ret = ph->xops->do_xfer_with_response(ph, t);
                if (!ret) {
                        int i;
                        struct scmi_resp_sensor_reading_complete_v3 *resp;

                        resp = t->rx.buf;
                        /* Retrieve only the number of requested axis anyway */
                        if (le32_to_cpu(resp->id) == sensor_id)
                                for (i = 0; i < count; i++)
                                        scmi_parse_sensor_readings(&readings[i],
                                                                   &resp->readings[i]);
                        else
                                ret = -EPROTO;
                }
        } else {
                sensor->flags = cpu_to_le32(0);
                ret = ph->xops->do_xfer(ph, t);
                if (!ret) {
                        int i;
                        struct scmi_sensor_reading_resp *resp_readings;

                        resp_readings = t->rx.buf;
                        for (i = 0; i < count; i++)
                                scmi_parse_sensor_readings(&readings[i],
                                                           &resp_readings[i]);
                }
        }

        ph->xops->xfer_put(ph, t);
        return ret;
}

static const struct scmi_sensor_info *
scmi_sensor_info_get(const struct scmi_protocol_handle *ph, u32 sensor_id)
{
        struct sensors_info *si = ph->get_priv(ph);

        if (sensor_id >= si->num_sensors)
                return NULL;

        return si->sensors + sensor_id;
}

static int scmi_sensor_count_get(const struct scmi_protocol_handle *ph)
{
        struct sensors_info *si = ph->get_priv(ph);

        return si->num_sensors;
}

static const struct scmi_sensor_proto_ops sensor_proto_ops = {
        .count_get = scmi_sensor_count_get,
        .info_get = scmi_sensor_info_get,
        .trip_point_config = scmi_sensor_trip_point_config,
        .reading_get = scmi_sensor_reading_get,
        .reading_get_timestamped = scmi_sensor_reading_get_timestamped,
        .config_get = scmi_sensor_config_get,
        .config_set = scmi_sensor_config_set,
};

static bool scmi_sensor_notify_supported(const struct scmi_protocol_handle *ph,
                                         u8 evt_id, u32 src_id)
{
        bool supported = false;
        const struct scmi_sensor_info *s;
        struct sensors_info *sinfo = ph->get_priv(ph);

        s = scmi_sensor_info_get(ph, src_id);
        if (!s)
                return false;

        if (evt_id == SCMI_EVENT_SENSOR_TRIP_POINT_EVENT)
                supported = sinfo->notify_trip_point_cmd;
        else if (evt_id == SCMI_EVENT_SENSOR_UPDATE)
                supported = s->update;

        return supported;
}

static int scmi_sensor_set_notify_enabled(const struct scmi_protocol_handle *ph,
                                          u8 evt_id, u32 src_id, bool enable)
{
        int ret;

        switch (evt_id) {
        case SCMI_EVENT_SENSOR_TRIP_POINT_EVENT:
                ret = scmi_sensor_trip_point_notify(ph, src_id, enable);
                break;
        case SCMI_EVENT_SENSOR_UPDATE:
                ret = scmi_sensor_continuous_update_notify(ph, src_id, enable);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        if (ret)
                pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
                         evt_id, src_id, ret);

        return ret;
}

static void *
scmi_sensor_fill_custom_report(const struct scmi_protocol_handle *ph,
                               u8 evt_id, ktime_t timestamp,
                               const void *payld, size_t payld_sz,
                               void *report, u32 *src_id)
{
        void *rep = NULL;

        switch (evt_id) {
        case SCMI_EVENT_SENSOR_TRIP_POINT_EVENT:
        {
                const struct scmi_sensor_trip_notify_payld *p = payld;
                struct scmi_sensor_trip_point_report *r = report;

                if (sizeof(*p) != payld_sz)
                        break;

                r->timestamp = timestamp;
                r->agent_id = le32_to_cpu(p->agent_id);
                r->sensor_id = le32_to_cpu(p->sensor_id);
                r->trip_point_desc = le32_to_cpu(p->trip_point_desc);
                *src_id = r->sensor_id;
                rep = r;
                break;
        }
        case SCMI_EVENT_SENSOR_UPDATE:
        {
                int i;
                struct scmi_sensor_info *s;
                const struct scmi_sensor_update_notify_payld *p = payld;
                struct scmi_sensor_update_report *r = report;
                struct sensors_info *sinfo = ph->get_priv(ph);

                /* payld_sz is variable for this event */
                r->sensor_id = le32_to_cpu(p->sensor_id);
                if (r->sensor_id >= sinfo->num_sensors)
                        break;
                r->timestamp = timestamp;
                r->agent_id = le32_to_cpu(p->agent_id);
                s = &sinfo->sensors[r->sensor_id];
                /*
                 * The generated report r (@struct scmi_sensor_update_report)
                 * was pre-allocated to contain up to SCMI_MAX_NUM_SENSOR_AXIS
                 * readings: here it is filled with the effective @num_axis
                 * readings defined for this sensor or 1 for scalar sensors.
                 */
                r->readings_count = s->num_axis ?: 1;
                for (i = 0; i < r->readings_count; i++)
                        scmi_parse_sensor_readings(&r->readings[i],
                                                   &p->readings[i]);
                *src_id = r->sensor_id;
                rep = r;
                break;
        }
        default:
                break;
        }

        return rep;
}

static int scmi_sensor_get_num_sources(const struct scmi_protocol_handle *ph)
{
        struct sensors_info *si = ph->get_priv(ph);

        return si->num_sensors;
}

static const struct scmi_event sensor_events[] = {
        {
                .id = SCMI_EVENT_SENSOR_TRIP_POINT_EVENT,
                .max_payld_sz = sizeof(struct scmi_sensor_trip_notify_payld),
                .max_report_sz = sizeof(struct scmi_sensor_trip_point_report),
        },
        {
                .id = SCMI_EVENT_SENSOR_UPDATE,
                .max_payld_sz =
                        sizeof(struct scmi_sensor_update_notify_payld) +
                         SCMI_MAX_NUM_SENSOR_AXIS *
                         sizeof(struct scmi_sensor_reading_resp),
                .max_report_sz = sizeof(struct scmi_sensor_update_report) +
                                  SCMI_MAX_NUM_SENSOR_AXIS *
                                  sizeof(struct scmi_sensor_reading),
        },
};

static const struct scmi_event_ops sensor_event_ops = {
        .is_notify_supported = scmi_sensor_notify_supported,
        .get_num_sources = scmi_sensor_get_num_sources,
        .set_notify_enabled = scmi_sensor_set_notify_enabled,
        .fill_custom_report = scmi_sensor_fill_custom_report,
};

static const struct scmi_protocol_events sensor_protocol_events = {
        .queue_sz = SCMI_PROTO_QUEUE_SZ,
        .ops = &sensor_event_ops,
        .evts = sensor_events,
        .num_events = ARRAY_SIZE(sensor_events),
};

static int scmi_sensors_protocol_init(const struct scmi_protocol_handle *ph)
{
        int ret;
        struct sensors_info *sinfo;

        dev_dbg(ph->dev, "Sensor Version %d.%d\n",
                PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));

        sinfo = devm_kzalloc(ph->dev, sizeof(*sinfo), GFP_KERNEL);
        if (!sinfo)
                return -ENOMEM;

        ret = scmi_sensor_attributes_get(ph, sinfo);
        if (ret)
                return ret;
        sinfo->sensors = devm_kcalloc(ph->dev, sinfo->num_sensors,
                                      sizeof(*sinfo->sensors), GFP_KERNEL);
        if (!sinfo->sensors)
                return -ENOMEM;

        ret = scmi_sensor_description_get(ph, sinfo);
        if (ret)
                return ret;

        return ph->set_priv(ph, sinfo);
}

static const struct scmi_protocol scmi_sensors = {
        .id = SCMI_PROTOCOL_SENSOR,
        .owner = THIS_MODULE,
        .instance_init = &scmi_sensors_protocol_init,
        .ops = &sensor_proto_ops,
        .events = &sensor_protocol_events,
        .supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
};

DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(sensors, scmi_sensors)