firmware: arm_scmi: Add SCMI v3.0 sensors descriptors extensions

Add support for new SCMI v3.0 Sensors extensions related to new sensors'
features, like multiple axis and update intervals, while keeping
compatibility with SCMI v2.0 features.

While at that, refactor and simplify all the internal helpers macros and
move struct scmi_sensor_info to use only non-fixed-size typing.

Link: https://lore.kernel.org/r/20201119174906.43862-3-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 369 insertions, 21 deletions

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 6aaff478d032..a85827f60a02 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -7,16 +7,22 @@
 
 #define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt
 
+#include <linux/bitfield.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
 #include "notify.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,
 };
 
 struct scmi_msg_resp_sensor_attributes {
@@ -28,23 +34,100 @@ struct scmi_msg_resp_sensor_attributes {
 	__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_resp_sensor_description {
 	__le16 num_returned;
 	__le16 num_remaining;
-	struct {
+	struct scmi_sensor_descriptor {
+		__le32 id;
+		__le32 attributes_low;
+/* Common attributes_low macros */
+#define SUPPORTS_ASYNC_READ(x)		FIELD_GET(BIT(31), (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_MAX_STR_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_ASYNC_READ(x)	((x) & BIT(31))
-#define NUM_TRIP_POINTS(x)	((x) & 0xff)
 		__le32 attributes_high;
-#define SENSOR_TYPE(x)		((x) & 0xff)
-#define SENSOR_SCALE(x)		(((x) >> 11) & 0x1f)
-#define SENSOR_SCALE_SIGN	BIT(4)
-#define SENSOR_SCALE_EXTEND	GENMASK(7, 5)
-#define SENSOR_UPDATE_SCALE(x)	(((x) >> 22) & 0x1f)
-#define SENSOR_UPDATE_BASE(x)	(((x) >> 27) & 0x1f)
-		    u8 name[SCMI_MAX_STR_SIZE];
-	} desc[0];
+		u8 name[SCMI_MAX_STR_SIZE];
+		__le32 resolution;
+		struct scmi_msg_resp_attrs attrs;
+	} 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_trip_point_notify {
@@ -114,6 +197,194 @@ static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
 	return ret;
 }
 
+static inline void scmi_parse_range_attrs(struct scmi_range_attrs *out,
+					  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);
+}
+
+static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
+					struct scmi_sensor_info *s)
+{
+	int ret, cnt;
+	u32 desc_index = 0;
+	u16 num_returned, num_remaining;
+	struct scmi_xfer *ti;
+	struct scmi_msg_resp_sensor_list_update_intervals *buf;
+	struct scmi_msg_sensor_list_update_intervals *msg;
+
+	ret = scmi_xfer_get_init(handle, SENSOR_LIST_UPDATE_INTERVALS,
+				 SCMI_PROTOCOL_SENSOR, sizeof(*msg), 0, &ti);
+	if (ret)
+		return ret;
+
+	buf = ti->rx.buf;
+	do {
+		u32 flags;
+
+		msg = ti->tx.buf;
+		/* Set the number of sensors to be skipped/already read */
+		msg->id = cpu_to_le32(s->id);
+		msg->index = cpu_to_le32(desc_index);
+
+		ret = scmi_do_xfer(handle, ti);
+		if (ret)
+			break;
+
+		flags = le32_to_cpu(buf->num_intervals_flags);
+		num_returned = NUM_INTERVALS_RETURNED(flags);
+		num_remaining = NUM_INTERVALS_REMAINING(flags);
+
+		/*
+		 * Max intervals is not declared previously anywhere so we
+		 * assume it's returned+remaining.
+		 */
+		if (!s->intervals.count) {
+			s->intervals.segmented = SEGMENTED_INTVL_FORMAT(flags);
+			s->intervals.count = num_returned + num_remaining;
+			/* segmented intervals are reported in one triplet */
+			if (s->intervals.segmented &&
+			    (num_remaining || num_returned != 3)) {
+				dev_err(handle->dev,
+					"Sensor ID:%d advertises an invalid segmented interval (%d)\n",
+					s->id, s->intervals.count);
+				s->intervals.segmented = false;
+				s->intervals.count = 0;
+				ret = -EINVAL;
+				break;
+			}
+			/* Direct allocation when exceeding pre-allocated */
+			if (s->intervals.count >= SCMI_MAX_PREALLOC_POOL) {
+				s->intervals.desc =
+					devm_kcalloc(handle->dev,
+						     s->intervals.count,
+						     sizeof(*s->intervals.desc),
+						     GFP_KERNEL);
+				if (!s->intervals.desc) {
+					s->intervals.segmented = false;
+					s->intervals.count = 0;
+					ret = -ENOMEM;
+					break;
+				}
+			}
+		} else if (desc_index + num_returned > s->intervals.count) {
+			dev_err(handle->dev,
+				"No. of update intervals can't exceed %d\n",
+				s->intervals.count);
+			ret = -EINVAL;
+			break;
+		}
+
+		for (cnt = 0; cnt < num_returned; cnt++)
+			s->intervals.desc[desc_index + cnt] =
+					le32_to_cpu(buf->intervals[cnt]);
+
+		desc_index += num_returned;
+
+		scmi_reset_rx_to_maxsz(handle, ti);
+		/*
+		 * check for both returned and remaining to avoid infinite
+		 * loop due to buggy firmware
+		 */
+	} while (num_returned && num_remaining);
+
+	scmi_xfer_put(handle, ti);
+	return ret;
+}
+
+static int scmi_sensor_axis_description(const struct scmi_handle *handle,
+					struct scmi_sensor_info *s)
+{
+	int ret, cnt;
+	u32 desc_index = 0;
+	u16 num_returned, num_remaining;
+	struct scmi_xfer *te;
+	struct scmi_msg_resp_sensor_axis_description *buf;
+	struct scmi_msg_sensor_axis_description_get *msg;
+
+	s->axis = devm_kcalloc(handle->dev, s->num_axis,
+			       sizeof(*s->axis), GFP_KERNEL);
+	if (!s->axis)
+		return -ENOMEM;
+
+	ret = scmi_xfer_get_init(handle, SENSOR_AXIS_DESCRIPTION_GET,
+				 SCMI_PROTOCOL_SENSOR, sizeof(*msg), 0, &te);
+	if (ret)
+		return ret;
+
+	buf = te->rx.buf;
+	do {
+		u32 flags;
+		struct scmi_axis_descriptor *adesc;
+
+		msg = te->tx.buf;
+		/* Set the number of sensors to be skipped/already read */
+		msg->id = cpu_to_le32(s->id);
+		msg->axis_desc_index = cpu_to_le32(desc_index);
+
+		ret = scmi_do_xfer(handle, te);
+		if (ret)
+			break;
+
+		flags = le32_to_cpu(buf->num_axis_flags);
+		num_returned = NUM_AXIS_RETURNED(flags);
+		num_remaining = NUM_AXIS_REMAINING(flags);
+
+		if (desc_index + num_returned > s->num_axis) {
+			dev_err(handle->dev, "No. of axis can't exceed %d\n",
+				s->num_axis);
+			break;
+		}
+
+		adesc = &buf->desc[0];
+		for (cnt = 0; cnt < num_returned; cnt++) {
+			u32 attrh, attrl;
+			struct scmi_sensor_axis_info *a;
+			size_t dsize = SCMI_MSG_RESP_AXIS_DESCR_BASE_SZ;
+
+			attrl = le32_to_cpu(adesc->attributes_low);
+
+			a = &s->axis[desc_index + cnt];
+
+			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);
+			strlcpy(a->name, adesc->name, SCMI_MAX_STR_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);
+			}
+
+			adesc = (typeof(adesc))((u8 *)adesc + dsize);
+		}
+
+		desc_index += num_returned;
+
+		scmi_reset_rx_to_maxsz(handle, te);
+		/*
+		 * check for both returned and remaining to avoid infinite
+		 * loop due to buggy firmware
+		 */
+	} while (num_returned && num_remaining);
+
+	scmi_xfer_put(handle, te);
+	return ret;
+}
+
 static int scmi_sensor_description_get(const struct scmi_handle *handle,
 				       struct sensors_info *si)
 {
@@ -131,9 +402,10 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 	buf = t->rx.buf;
 
 	do {
+		struct scmi_sensor_descriptor *sdesc;
+
 		/* Set the number of sensors to be skipped/already read */
 		put_unaligned_le32(desc_index, t->tx.buf);
-
 		ret = scmi_do_xfer(handle, t);
 		if (ret)
 			break;
@@ -147,22 +419,97 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 			break;
 		}
 
+		sdesc = &buf->desc[0];
 		for (cnt = 0; cnt < num_returned; cnt++) {
 			u32 attrh, attrl;
 			struct scmi_sensor_info *s;
+			size_t dsize = SCMI_MSG_RESP_SENS_DESCR_BASE_SZ;
 
-			attrl = le32_to_cpu(buf->desc[cnt].attributes_low);
-			attrh = le32_to_cpu(buf->desc[cnt].attributes_high);
 			s = &si->sensors[desc_index + cnt];
-			s->id = le32_to_cpu(buf->desc[cnt].id);
-			s->type = SENSOR_TYPE(attrh);
-			s->scale = SENSOR_SCALE(attrh);
-			/* Sign extend to a full s8 */
-			if (s->scale & SENSOR_SCALE_SIGN)
-				s->scale |= SENSOR_SCALE_EXTEND;
+			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);
-			strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
+			/**
+			 * 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(handle, s))
+					dev_dbg(handle->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);
+			strlcpy(s->name, sdesc->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(handle, s);
+				if (ret)
+					goto out;
+			}
+
+			sdesc = (typeof(sdesc))((u8 *)sdesc + dsize);
 		}
 
 		desc_index += num_returned;
@@ -174,6 +521,7 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 		 */
 	} while (num_returned && num_remaining);
 
+out:
 	scmi_xfer_put(handle, t);
 	return ret;
 }