1 files changed, 936 insertions, 0 deletions

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
new file mode 100644
index 0000000000..6e94ef2e6b
--- /dev/null
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -0,0 +1,936 @@
+// 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 <module.h>
+#include <linux/scmi_protocol.h>
+
+#include "protocols.h"
+
+#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_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 sensors_info {
+	u32 version;
+	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);
+	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,
+					u32 version)
+{
+	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(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->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 !
+	 */
+	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 (si->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(si->version) >= 0x3 &&
+	    SUPPORTS_EXTENDED_NAMES(attrl))
+		ph->hops->extended_name_get(ph, SENSOR_NAME_GET, s->id,
+					    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, si->version);
+
+	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 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;
+
+	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);
+
+	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 int scmi_sensors_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	u32 version;
+	int ret;
+	struct sensors_info *sinfo;
+
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
+
+	dev_dbg(ph->dev, "Sensor Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	sinfo = devm_kzalloc(ph->dev, sizeof(*sinfo), GFP_KERNEL);
+	if (!sinfo)
+		return -ENOMEM;
+	sinfo->version = version;
+
+	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,
+	.instance_init = &scmi_sensors_protocol_init,
+	.ops = &sensor_proto_ops,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER(sensors, scmi_sensors)